Document NGQ875km2ygp5k2Dmazy8VDd8

FILE NAME: RT Vanderbilt (RTV) DATE: 2007 Apr DOC#: RTV083 DOCUMENT DESCRIPTION: White Paper Prepared by RT Vanderbilt Co. Asbestos, Health Risk and Tremolitic Talc WHITE PAPER ASBESTOS, HEALTH RISK AND TREMOLITIC TALC Prepared By: John W. Kelse, Corporate Industrial Hygienist Manager, Corporate Risk Management Department R. T. Vanderbilt Company, Inc. 30 Winfield Street Norwalk, Connecticut 06855 Telephone: 203-853-1400 Fax: 203-831-0648 Email: jkelse@rtvanderbilt.com Most Recent Update: April 2007 (Prior update: January 200S) Introduction One o f our country's oldest and most interesting mineral risk issues involves an industrial grade talc commonly known as tremolitic talc. Tremolitic talc is a unique and complex blend of minerals most often used in the manufacture o f paints and ceramics. Today this talc is mined exclusively in upstate New York by R. T. Vanderbilt Company, Inc. Vanderbilt has mined and milled this ore since 1948. Vanderbilt tremolitic talc was the focus o f an asbestos-linked rulemaking by the Occupational Safety and Health Administration (OSHA) in 1992 (l), the cause o f an internal National Institute o f Occupational Safety and Health (NIOSH) controversy in the 1980's (2), and the center o f a media scare involving children's crayons in 2000 (3). In December o f 2000 it also perplexed a subcommittee of the National Toxicology Program (NTP) for the better part o f a day . For three decades the complex mineralogy o f Vanderbilt's tremolitic talc has confused analytical laboratories and regulatory agencies. The issues associated with Vanderbilt talc are multi-layered involving no less than the definition o f asbestos, fiber risk theory and what constitutes meaningful health research. The original controversy involved an OSHA proposal to regulate nonasbestiform amphibole cleavage fragments as asbestos. That proposal led to extensive research into the health effects associated with exposure to tremolitic talc and other materials containing nonasbestiform amphiboles. Vanderbilt talc is also a focal point o f study concerning the nature o f talc fiber and talc/amphibole mixed fiber (a minor but observable component in this talc as well). This paper reviews the origins and current status o f each o f these issues. 2 CONTENTS ASBESTIFORM AND NONASBESTIFORM AMPHIBOLES: MINERALOGY Early Confusion The Definition of Asbestos The Impact of Imprecision Early Regulatory Response ASBESTIFORM AND NONASBESTIFORM AMPHIBOLES: HEALTH Vanderbilt Lung Cancer Experience A Comparison o f New York vs. Vermont Talc Mining Animal Studies Mesothelioma Non-Talc Cancer Mortality Studies: Nonasbestiform Amphiboles Non-Malignant Respiratory Disease Chest X-Rays Pleural Plaques Pulmonary Function Summary OSHA MAKES A FINAL DECISION ON NONASBESTIFORM AMPHIBOLES TALC AND MIXED TALC/AMPHIBOLE FIBER CONCLUSION: LESSONS LEARNED 3 ASBESTIFORM AND NONASBESTIFORM AMPHIBOLES: MINERALOGY EARLY CONFUSION The tremolitic talc saga begins in 1972. This was the year OSH A promulgated its first asbestos standard^. At that time, OSHA listed the following six minerals under the commercial, generic term "asbestos": The serpentine chrysotile and five amphibole minerals; crocidolite, amosite, tremolite, anthophyUite and actinolite. Having identified the minerals subject to its new standard, OSHA then provided a means of quantifying airborne exposure to these minerals utilizing the 3 to 1 aspect ratio or greater, 5 micrometers or longer, fiber counting scheme. Under this scheme, airborne particles from one o f these six listed minerals can be collected on an air filter, measured and counted according to this dimensional criteria. It is very easy to understand and not terribly complicated to do. However, as so often happens with simple schemes, OSHA had overlooked one critical factor. Besides its chemical composition, the crystal growth o f a mineral has a dramatic impact on its characteristics and properties. The same mineral with the same chemical composition can be strikingly different if formed differently in nature. OSHA, as it turns out, was completely unaware o f this crystal growth distinction. Asbestiform and Nonasbestiform Varieties of Selected Silicate Minerals and Their Chemical Abstract Service Numbers (CAS) Asbestiform Variety (CAS #) Chemical Composition Nonasbcstiform Variety (CAS #) Serpentine Group; Chrysotile (12001-29-5) Mg(Si20,K 0H )4 antigorite. lizardite (12135-86-3) Amphibole Group: Crocidolite (12001-28-4) Gruente asbestos (amosite) (12l72-73-5*)A AnthophyUite asbestos (77536-67-5*) Na2FciFe2(Si022)0 H .F )2 (M g,F e)H S i022K 0H >F h (Mg,Fe)v(Si022XOFI.F)2 Riebeckite (17787-87-0) cummingtonite-grunente (14567-61-4) AnthophyUite (17068-78-9) Tremolile asbestos (77536-68-6*) Ca2Mgs(Si*022X0H,F2) Tremolile (14567-73-8) Actinolite asbestos (77536-66-4*) Ca2(Mg,Fe)5(Si*O2>X0H,F)2 Actinolite (13768-00-8) A The presence o f an asterisk following a CAS Registry Number indicates that the registration is for a substance which CAS does not treat in its regular CA index processing as a unique chemical entity. Typically, this occurs when the material is one of variable composition' a biological organism, a botanical entity, an oil or extract of plant or animal origin, or a material that includes some description of physical spet ificily, such as morphology. 4 This table lists the six asbestos minerals OSHA listed under the heading "asbestiform." All other US regulatory agencies list these minerals as asbestos as well. Minerals listed under this column are formed in what is known as the "asbestiform" crystal growth habit. For every one o f these six minerals, however, there is a corresponding mineral listed under the heading "nonasbestiform". Nonasbestiform minerals share the same chemical composition as their asbestiform analogs but they are formed differently in nature and exhibit a different crystal growth pattern. Some are called by different names - some are not. This table conforms to the nomenclature set forth by the U.S. Dept, o f Interior<6)' Alarmingly, many health professionals, analytical laboratories and industrial hygienists are not aware o f this distinction. The following graphic simply illustrates the difference between asbestiform and nonasbestiform crystal growth. These drawings are not precise but will hopefully assist in the understanding o f this key crystal growth difference. ASBESTIFORM NONASBESTIFORM In the asbestiform habit, mineral crystals grow in a single dimension, in a straight line until they form long, thread-like fibers with aspect ratios of 20:1 to 1000:1 and higher. When pressure is applied, the fibers do not shatter but simply bend much like a wire. Fibrils of a smaller diameter are produced as bundles of fibers are pulled apad. This bundling effect is referred to as polyfilamentous. Sr <3 In the nonasbestiform variety, crystal growth is random, forming multidimensional prismatic patterns. When pressure is applied, the crystal fractures easily, fragmenting into prismatic particles. Some of the particles or cleavage fragments are acicular or needle-shaped as a result of the tendency of amphibole minerals to cleave along two dimensions but not along the third. Stair-step cleavage along the edges of some particles is common and oblique extinction is exhibited under the microscope. Cleavage fragments never show curvature. Although asbestiform crystal growth is very rare in nature, under the right geologic conditions upwards o f 100 minerals may be formed in this manner - not just the six minerals we refer to as asbestos (7'8). This is an important point which will be addressed at greater length later in this paper. Bearing in mind this crystal growth distinction, and recalling the OSHA asbestos fiber counting scheme, an obvious problem emerges: many nonasbestiform fragments or "cleavage fragments" will satisfy the minimal dimensional fiber counting criteria. For example, we could find a 3 to 1 aspect ratio, longer than 5 micrometer nonasbestiform cleavage fragment o f actinolite or tremolite, but this would not be an actinolite or tremolite asbestos fiber. In fact, no matter what the dimension o f a cleavage fragment, it is not asbestos and no mechanical manipulation or weathering will turn it into asbestos. 5 However, for those with no understanding o f this very basic growth distinction and inclined to use the counting criteria as part o f the definition o f asbestos, elongated cleavage fragments will mistakenly be counted as asbestos fibers. This counting rule is not, o f course, part o f the definition of asbestos(810). The rule is merely an arbitrary elongated particle counting scheme imported from the United Kingdom to improve consistency in asbestos fiber counting in a known asbestos exposure. With the exception o f the 5 micrometer minimum length, there is no biologic relevance to this dimension. Photographs of the actual minerals are appended to this paper (last two pages)(6). These photographs clearly reflect this important crystal growth distinction for each o f the six minerals in both habits. Note that even in hand specimens an obvious fiber crystal growth pattern can be observed for asbestos. In the asbestiform habit fiber separation is also evident. The fibers are very long and thin, curvature can be observed, and most importantly, fiber bundling is apparent. Under the light microscope at relatively low magnification, these characteristics become even more obvious. It might be noted that under light microscopy, very few (if any) asbestos fibers will be seen that are not a bundle. Since individual fibrils are extremely thin (typically <0.25 but almost always <0.5 micrometers), most fall below the resolution limit o f the microscope01 l4). When laboratories "jump over" the use o f light microscopy, they do run the risk o f overlooking this bundling characteristic - the hallmark o f asbestiform crystal growth. This is an especially important distinguishing characteristic in rare instances when asbestiform fibers and elongated cleavage fragments are o f the same size. In stark contrast to the asbestiform growth pattern, nonasbestiform growth is just as obvious in hand specimens as under the light microscope. In hand specimens, random prismatic crystal growth and the absence o f obvious fibers is evident. When this structure is crushed or broken, prismatic cleavage fragments are formed which again show no fiber bundles, splayed ends, or marked curvature (6,8,10" l6)' Cleavage fragments tend to be blocky, with a few elongated or acicular fragments that may satisfy the OSHA asbestos fiber counting criterion. These are low aspect ratio particles typically wider than l micrometer and shorter than 20 micrometers l,l719>. Optical continuity can be seen that suggests the absence of fiber bundles. The nonasbestiform tremolite pictured is from the Vanderbilt mine, and appears in the talc product at a weight percent o f 40 to 60%, depending on the grade. When this rock is examined by health professionals and regulators, they often ask where the fibers are. For many, it's hard to believe that the word "tremolite" could possibly mean anything other than asbestos. More often then not, however, it does. THE DEFINITION OF ASBESTOS: In order to clarify the mineralogical characteristics o f asbestos and the meaning o f the term "asbestiform", a group o f mineral scientists agreed upon the following definitions. Many of those who contributed to these definitions have published extensively on asbestos nomenclature issues (20). While all mineral scientists may not agree with every entry in this definition, it does present a more.mineralogically accurate description than does the early OSHA definition. This definition is now accepted in whole or in part by most regulatory and standards setting groups. 6 A. ASBESTOS -- A collective mineralogie term that describes a variety o f certain silicates belonging to the serpentine and amphibole mineral groups, which have crystallized in the asbestiform habit causing them to be easily separated into long, thin, flexible, strong fibers when crushed or processed. Included in the definition are: chrysotile, crocidolite, asbestiform granente (amosite), anthophyllite asbestos, tremolite asbestos and actinolite asbestos. B, ASBESTOS FIBERS -- Asbestiform mineral fiber populations generally have the following characteristics when viewed by light microscopy: 1. Many particles with aspect ratios ranging from 20:1 to 100:1 or higher for particles >5 pm in length. 2. Very thin fibrils generally <0.5 micrometers in width. 3. In addition to the mandatory fibrillar crystal growth, two or more o f the following attributes: (a) Parallel fibers occurring in bundles (b) Fibers displaying splayed ends (c) Matted masses o f individual fibers (d) Fibers showing curvature THE IMPACT OF IMPRECISION It might be asked what would be the harm if we simply considered cleavage fragments the same as asbestos and did not concern ourselves with this crystal growth distinction? The following map shows the areas o f the continental US where these minerals are commonly found in bedrock and soil. The shaded areas do not mean that every rock or soil mass in that area contains these minerals but rather that they are often present in these areas(21). 7 According to the US Bureau o f Mines, if the nonasbestiform analogs o f asbestos were regulated as asbestos, it would significantly impact the mining o f such important mineral commodities as gold, copper, iron, crushed stone, sand, gravel and talc. Downstream users of these commodities, such as construction, smelters, ceramics and paint manufacturers would be impacted as well. The Bureau o f Mines determined that such a lack o f mineral discrimination would result in a very significant economic impact(22). EARLY REGULATORY RESPONSE Vanderbilt did bring the asbestiform/nonasbestiform amphibole mineral distinction issue to the attention o f OSHA. At that time, OSHA gave every indication that this was an oversight that they would correct in their final asbestos standard. They stated this intention in the Federal Register in 1984(23). When OSHA formally revised its asbestos standard in 1986(24), it did point out the mineral distinction just discussed. However, while recognizing this distinction, it stated that they would regulate amphibole cleavage fragments in the same way as asbestos anyway. Mysteriously, however, OSHA intended to include only the amphiboles with the same name for both habits (tremolite, anthophyllite and actinolite). Fortunately, the Secretary of Labor and the Office o f the Solicitor intervened and an administrative stay was ordered pending further review(25). But why, after recognizing this mineral nomenclature problem, did OSHA opt to ignore this distinction? Simply put, OSHA felt that elongated cleavage fragments posed the same health risk as asbestos fibers. OSHA reasoned that because the cleavage fragments at issue had the same chemical composition as their asbestiform analogs, were durable, could be elongated and o f respirable size, it would be reasonable to expect a "same as" asbestos health effect 24). The health effects most closely associated with excess exposure to asbestos include lung cancer, mesothelioma and nonmalignant respiratory disease (asbestosis). To support this presumption, OSHA cited two mortality studies of upstate New York talc workers as evidence o f a "same as" health effect for nonasbestiform am phiboles(24). Upstate New York talc does contain a high concentration o f nonasbestiform amphiboles (tremolite in particular). A review o f these studies appears next. 8 ASBESTIFORM AND NONASBESTIFORM AMPHIBOLES: HEALTH VANDERBILT LUNG CANCER EXPERIENCE The two mortality studies OSHA cited include early work by the New York State Health Department (Kleinfeld)(26) and most significantly, a 1980 NIOSH study o f Vanderbilt miners and m illers(27). These were the only health studies OSHA cited in support o f the regulation o f nonasbestiform amphiboles as asbestos. The Kleinfeld studies did record excess lung cancer among upstate NY miners with exposures dating back to the 1930's and 40's. These studies did not, however, include many Vanderbilt miners and millers given the requirements for entry into the study (15 years or more o f exposure between 1940 and 1969 - the Vanderbilt mine did not open until 1948). Further, there were no lung cancer cases recorded for Vanderbilt mine and mill workers (earliest lung cancer death recorded in Vanderbilt only mortality studies that met Kleinfeld's study requirements was in 1973. Thus, the Kleinfeld studies involved ore bodies never mined by Vanderbilt and dust exposure levels many times greater than any ever encountered by Vanderbilt miners and millers (5 to 10 fold greater reflected in Kleinfeld exposure tables). Accordingly, there is uncertainty regarding exposure and relevance to Vanderbilt talc. Further still, only 260 miners were included in these studies, and the characteristics of the lung cancer mortality observed did not parallel those observed in asbestos exposed cohorts. The excess lung cancer observed may have been associated with lung cancer risks such as smoking or particle overload (early talc dust exposures were very high). These studies have been used to argue for and against nonasbestiform amphiboles as a "same as" asbestos risk. Kleinfeld himself urged caution in interpreting their results. In regard to the NIOSH study, OSHA felt it had something more up-to-date and pertinent since after 1974 the only talc mining operation in upstate New York was Vanderbilt's. In the NIOSH study, approximately 3 times the expected rate o f lung cancer mortality was observed. This is considered a moderate but statistically significant excess. The NIOSH study included anyone who had ever worked in the talc mine or mill for any period o f time between 1948 through 1977. The total cohort size was 398 (also a comparatively small study group). NIOSH attributed the lung cancer excess to a 40 - 60% amphibole asbestos exposure it believed existed at the Vanderbilt mine. Since nonasbestiform tremolite makes up 40 - 60% o f this talc, it was clear that NIOSH was confusing nonasbestiform tremolite with tremolite asbestos. NIOSH has a policy (that stands to this day) which considers elongated amphibole cleavage fragments no differently than asbestos. Looking at this overall excess lung cancer it did appear that nonasbestiform amphiboles might indeed pose an asbestos risk. However, after this internally reviewed study was formally released as a Technical R eport, a number o f weaknesses in the study were noted. The most significant of these included the following: , 9  The report stated that the relevant exposure was 40 - 60% amphibole asbestos when clearly it wasn't. The presumption o f such an elevated asbestos exposure may have caused an "expectation bias" . Interestingly, most actual asbestos mines contain less than 5% asbestos in the raw ore <28,29). The lung cancer cases appeared highest among those least exposed to the dust. This is inconsistent with a dust dose-response connection and inconsistent with what is seen in asbestos exposed cohort studies. Although a critical consideration in any study involving lung cancer, there was no smoking data presented in the NIOSH work. No prior or post employment exposure information was provided. In effect, Vanderbilt did not question the excess lung cancer. Vanderbilt and many health researchers question whether it was actually linked to the dust exposure (2'30"35,~ In order to address these questions, an additional 6 mortality studies were undertaken. It wasn't long before Vanderbilt talc miners and millers were among the most studied miners in the world. The six studies included the following (in chronological order): 1. Stille, W. Tabershaw (36) 2. Lamm S., et a l (37) 3. Lamm S., et a l (33) 4. NIOSH HHE U pdate<38) 5. Gamble, J . (39) 6. Honda, Y., et al (40) Pub. Yr. 1982 1986 1988 1990 1993 1995 L u n e C ancer SM R C ohort Size 157 708 220 741 same cohort, but focus on short term workers. 207 710 same NIOSH cohort - case control study 252 818 A detailed review o f each o f these studies is beyond the scope o f this paper but the following table reflects the most up-to-date breakdown o f lung cancer among Vanderbilt talc miners and millers. 10 LUNG CANCER CASES Honda. Y. et al: 1995: Cohort 818 SMR: 254 Covers all talc workers 1948 to the end o f 1989 who worked for any period o f time Tenure Time at GTC Work Area Year DOD Smoker* Cigarctte/Per Day 1 day 4 days 7 days MINER Mll no exposure 80 yes 20 87 ? - 86 ? - 7 days no exposure 70 ' yes 20 18 days Mill 70 yes 40 18 days MINER 88 ? - 1Vt months MINER 70 yes 40 1Vi months Mill 88 ? - 2 months MINER 71 yes 20 2 months MINER 84 yes 40 2'A months MINER 75 yes 20 T h months Mill 84 yes 40 41/a months MINER 81 yes 20 6 months Mill 89 ? - 7 months no or min. exposure 85 ? - 10 months IOV2 months MINER MINER 73 yes 20 85 ? - 2.1 years MINER 82 yes 20 2.5 years MINER 74 yes 20 2.6 years MINER 61 yes 20 2.9 years 3.6 years 9.9 years MINER MINER min. exposure 64 yes 10 89 ? - 86 ? - 12 years MINER 75 yes 30 17 years Mill 76 yes 20 17 years MINER 73 yes 20 17 years MINER 84 yes 50 17 years MINER 85 yes 20 23 years Mill 82 yes 20 23 years 23 years MINER no exposure 79 yes 40 88 ? - *Smoking data obtained to 1985 (Gamble-Case Control). To that date, all cases smoked, 73% o f controls smoked (includes a small proportion in both groups o f ex-smokers). Each study did find that the overall lung cancer excess recorded by NIOSH remained essentially unchanged. It was further observed that the basic characteristics of the cases (tenure, latency information, work area, etc.) did not change substantially either. When reviewing the above table one sees a much higher number of cases among miners than among millers. This is important because dust exposure data over the years show similar overall dust levels (all categories - total dust, respirable dust, 3:1 aspect ratio fiber counts) in the mine and the m ill<4I). Some reports suggest the mill has historically had the higher dust levels <26,27). Accordingly, there should be more cases among millers if a dust etiology is to be supported. Summary dust exposure data appears below: Dust Exposures Mill Mine Cases 7 19 Resp. Mg/m3 Dust Avg. 0.46 0.73 (1970-85) . . . m An M ppcf Averages for Select Activities (27-41) Mill: Packers 16; wheeler mill operator 10, dryer 8 Mine; Crusher 17; slusher 15, trammer 7 M ppcf Avg. 14 11 (1954-75) Fibers/cc 1.5-8.0 1.7-9.8 The lung cancer mortality table also shows a very high percentage of cases with very minimal exposure time (tenure) on the job. In fact, 55% o f all the cases worked less than a year, and 45% worked less than 6 months. There are cases with 1 day o f exposure, 4 days o f exposure in an individual's entire work life. O f all the cases, 22 or 71% had less than 5 years o f exposure. If the dust were so potent as to cause lung cancer with such minimal exposure, one would certainly expect to see those exposed longer to show even higher lung cancer rates. This does not, however, occur. This is not suggestive o f a dust etiology and is not what is seen when lung cancer rates are elevated among cohorts exposed to asbestos(2'30,35'37,40). A case control study published by Gamble obtained smoking data up to 1985 (39). From this study it was learned that all the lung cancer cases up to that time had been smokers. It was also learned that the controls (workers o f similar age and exposure as the lung cancer cases) had also been heavy smokers with a smoking prevalence o f 73%. The following graph shows the historical prevalence o f smoking among Vanderbilt talc miners and millers contrasted to national norms for US males. Smoking records for Vanderbilt workers are not reliably recorded prior to 1980 but the smoking rate was likely just as elevated - about twice the national average (based upon trend). Cigarette Sm oking (Current) U .S. M ales vs. Vanderbilt Talc W orkers co M ales 3Q. V a n d e rb iU OQ_ '9 6 S 1974 1979 1983 1985 1987 1988 1990 1991 1992 *9 93 1994 1998 ' 997 1998 U S Rates- Source U M W R Voi 49 No 39 12 NIOSH concluded that smoking, although a factor, could not account for all the excess(38). Other researchers, however, feel that it does, and that it is the most plausible explanation for the lung cancer excess (2`39). These researchers point out that the latency period between first smoked and death versus first exposed to tremolitic talc and death, fits a smoking latency better than an asbestos latency. In addition, the expected number of deaths linked to smoking falls within the confidence interval for expected lung cancer deaths. In other words, it is statistically possible that the excess was entirely due to smoking. This point, however, remains the source o f debate and largely depends on which statistical model one chooses to use. Nevertheless, whether smoking - in whole or in part - accounts for the excess, it was confirmed through a dust exposure assessment study that an inverse dose-response exposure existed. This had been strongly suggested in the earlier tenure data. Actual cumulative respirable dust exposure for the lung cancer cases was 31% below that o f all the decedents (4 ' 4I). Such a finding is referred to as an "inverse dose-response". Regarding current Vanderbilt tremolitic talc exposures, it might be mentioned that "even i f ' the excess lung cancer recorded was linked to dust exposure, the excess existed only among underground miners - not millers. In 1995 Vanderbilt closed the underground mine. Therefore, that exposure no longer exists. With regard to downstream users o f Vanderbilt talc, the talc millers are exposed to dusts that most closely matches that o f the finished product. Health studies o f tremolitic talc users are limited but the few that do exist show no excess lung cancer (i.e., paint manufacturers and sanitary ware ceramic workers) (42,43). Uses of tremolitic talc involve the blending or encapsulation of this talc into product matrix systems such as paint and wall tile. This significantly limits product linked airborne exposures to this talc, or any mineral component, similarly encapsulated(44,45)' A COMPARISON OF NEW YORK VERSUS VERMONT TALC MINING: In addition to studies directly involving Vanderbilt talc workers, other studies lend insight into whether exposure to Vanderbilt talc is or is not likely responsible for the excess lung cancer observed (whatever its' mineral content). At about the same time NIOSH was studying tremolitic talc and issuing a report they titled "Talc containing Asbestos", it was also working on a study involving talc miners and millers in Vermont, who mined pure, platy, cosmetic grade talc. Vermont talc was said not to contain amphibole cleavage fragments and other components that appear in Vanderbilt talc (i.e. minor talc fiber). NIOSH would later issue the Vermont report under the title "Talc not containing Asbestos" (46). It is difficult to compare one epidemiology study with another, but the comparison shown below is reasonable for a variety o f reasons. When miners and millers with more than one year o f exposure are compared in both study groups, the number o f talc workers in both studies was similar. Both mining populations had similar exposure years and similar overall dust exposure levels as w ell(47). 13 Mortality Comparison: Vermont & New York For Workers With >1 Year Exposure S M R 'S 600 500 400 300 200 100 0 VT NY LUNG CANCER VT NMRD This comparison shows that the overall lung cancer mortality is no different. Also, mortality linked to nonmalignant respiratory disease (which would include pneumoconiosis) is actually higher in Vermont. The idea that amphibole cleavage fragments (or anything else present in New York talc, but not in Vermont talc) causes lung cancer is clearly not supported by this comparison. Interestingly, NIOSH concluded that the small lung cancer excess observed in Vermont was not linked to the dust because dust levels were about the same or higher in the mill, and most o f the lung cancer cases were found among the miners. Hence, no exposure/response relationship could be seen. That same work area observation is no different than in NY. In NY, however, NIOSH incorrectly reported a massive "asbestos" exposure which became the explanation for the NY lung cancer experience. In Vermont, the excess was said to be likely due to smoking or some other "undetermined" cause. ANIMAL STUDIES: Besides the epidemiology work, there are also two published animal studies that directly test Vanderbilt talc against asbestos. One study was undertaken by Merle Stanton o f the National Cancer Institute(48) and the second by William Smith o f Fairleigh Dickinson U niversity(49>. Dr. Stanton was testing the theory that morphology (particle dimension) is most key to fiber toxicity. He tested 72 samples measuring the lengths and widths of particles in each sample. Dr. Stanton concluded that samples containing the most fibers with a width less than 0.25 micrometers and a length greater than 8 micrometers produced the most tumors. Dr. Stanton called this minimum length and width his "critical dimension". This work is frequently cited by those who believe that only fiber morphology influences biological response. Critics o f Stanton's work argue that it is statistically flawed and that it does not show that morphology alone is involved (5 `52). There is no doubt that fiber dimension does play an important ro le -ju s t not the only role. Dr. Stanton's critical dimension, o f course, would be 14 inclusive o f most any asbestos fiber (unless found in a thick bundle), and would not include cleavage fragment (dimensions. Most o f his samples were asbestos-containing samples. Among all the samples Dr. Stanton tested was an off-the-shelf sample o f Vanderbilt talc, as well as several platy talc sam ples(53). As the following table reflects, the Vanderbilt talc sample produced no tumors, and the platy talc an insignificant background level. NCI ANIMAL STUDY M. Stanton - Correlation of Fiber Dimension to Carcinogenicity M aterial Critical Dimension (log fibers/ug) <0,25 um W & >8 um L Animals % tumors Amosite 3.5 T remolite Asbestos 3.1 Platy Talc 0 Vanderbilt Talc 3.3 93% 100% 3% 0% Study involved pleurae implant in rats for periods of one year or more. 72 samples were used in the study. 7 talc samples were used, two of which were Vanderbilt talc (off the shelf). The middle column reflects the presence of "critical dimension" fibers. This column indicates there are fibers in the Vanderbilt tremolitic talc sample that meet Stanton's critical dimension. The fibers recorded here are talc fibers and mixed talc/amphibole fibers. With these dimensions, they are clearly not cleavage fragments. These fibers do appear in Vanderbilt talc at minor, but observable levels. These interesting fibers will be discussed more fully later in this paper. It should be noted, however, that the Vanderbilt talc sample flies in the face o f Stanton's hypothesis. According to Stanton's own calculations, we should have seen upwards o f 60% tumors in the Vanderbilt sample, but no tumors were observed. The following table reflects the results o f the second animal study by William Smith, who also tested Vanderbilt talc against asbestos. At the highest dose level, Vanderbilt talc as well as a concentrate of tremolite (nonasbestiform) taken from Vanderbilt talc, produced no tumors while tremolite asbestos tested under the same experimental conditions, did. BIOLOGIC TESTS OF TREMOLITE IN HAMSTERS William Smith Material Tumors/Survivors After 350 500 600 Days Tremolite Asbestos (sample 72) 3/20 5/6 5/1 Vanderbilt Talc (sample FD-14) 0/35 0/27 0/20 Tremolite Nonasbestiform (275) 0/31 0/15 0/3 Study involved intrapleural injection in hamsters. 25 mg Dose 15 The next table reflects the results o f a series of animal studies by Addison & Davis, who also studied animal response to tremolite asbestos as,opposed to nonasbestiform tremolite. Tremolite from Vanderbilt's talc was not tested in this work, but once again, the results show a striking difference between tremolite asbestos and nonasbestiform tremolite. ADDISON/DAVIS Peritoneal Injection Study (rats - lOmg) 18 MONTHS AFTER INJECTION (54>* Sample: # Deaths # Survivors Tremolite Asbestos (California) 33 3 Tremolite Asbestos (Korea) 29 4 Tremolite Asbestos (Swansea) 31 1 Nonasbest. Tremolite (Italy) 0 36 Nonasbest. Tremolite (Scotland) 1 32 Nonasbest. Tremolite (Scotland) 0 36 * The final completed study covering 24 months<55) showed a significant number of deaths late in the study for the Italian sample. These late deaths were reported by the authors as likely attributable to a small asbestos fiber sub-population later identified in this sample. MESOTHELIOMA: There are currently no known mesothelioma cases reasonably linked to Vanderbilt talc or any of the mineral components in this talc (e.g., amphibole cleavage fragments). The qualifying term "reasonably linked" must be used because two reported cases are recorded in the mortality studies. However, neither case was linked to exposure to Vanderbilt talc by the authors(27,40). In one case the worker was exposed to Vanderbilt talc for no more than 15 years before the malignancy was diagnosed. A 20 to 40 year latency is typically expected as one indicator o f a possible causal connection. In a second case a minimal exposure was reported (6 months in 1948), followed by decades o f furnace and boiler repair and removal. Since the last mortality study vital status cut-off (end o f 1989), several mesothelioma deaths where also reported through the worker's compensation system. These claims were investigated in respect to work histories and diagnosis reliability by physicians experienced in this field *56,57). Investigation (including tissue analysis when available) suggests that these cases fell into one o f two categories: those more likely than not to have been diagnosed incorrectly or those diagnosed correctly but showing clear evidence o f exposure to actual asbestos including exposures within the Vanderbilt mine itself from machine brake pads and insulation m aterials<58). 16 In 2002 a case review study was published as a supplement paper that addressed mesothelioma among upstate New York talc miners(59). Although this study is not specifically linked to Vanderbilt talc, it does suggest a link between talc mined in the region and mesothelioma. The study involved a comparison o f minerals found in the lungs o f area miners (lung burden) with and without mesothelioma and suggests that elevated rates in one New York State county in the 1970's might be linked to regional talc mining. In 2006 the above referenced study underwent critical review by a panel composed o f pathologists, epidemiologists, mineral scientists and a risk specialist who found the document seriously flawed on several levels (60,61). Concerns included (but not limited to): the absence of work histories beyond regional mining, limited lung content analysis with inadequate sensitivity (e.g. analytical tools used), likely case/control selection bias, dissimilar lung burden content described as similar, small numbers, questions on proper mineral identification and linkage to a county in which talc mining does not occur. Mesothelipma is difficult to accurately diagnose given the morphological variability o f the tumor. For example, malignant mesothelioma cells are difficult to distinguish from benign reactive mesothelial cellsi62). There is considerable debate over the degree o f association between asbestos exposure and mesothelioma. Association estimates range anywhere from 100% to as little as 13% (63) with most researchers reporting an 80 to 70% link (64' 65), There is also debate regarding the under reporting o f mesothelioma when asbestos exposures are not anticipated and over reporting when they a re <66). Until most recently mesothelioma has not had a unique code in the International Classification o f Disease and Causes o f Death, further complicating epidemiological analysis (67). Although the exact number of confirmed mesothelioma cases not linked to asbestos exposure will likely never be known (asbestos being as pervasive as it is), it is generally recognized that there are causes other than asbestos. Though rare, the occurrence of mesothelioma in children is an example o f this. Though some nonasbestos causes remain controversial, exposures to radiation, pleural tuberculosis, wood lignon constituents, the SV40 monkey virus that is said to have contaminated polio vaccines between 1954 & 1963, some herbicides, heredity links, heavy metals such as nickel and general chronic irritation from inflammatory processes like peritonitis have been reported (among others)(65). Given such uncertainties, responsible medical groups such as the American Thoracic Society repeatedly urge caution with regard to the interpretation o f reported mesothelioma. Certainly, before such a risk was unequivocally linked to Vanderbilt talc, one would want the diagnosis positively confirmed, actual exposure to the talc confirmed and a complete accounting of all lifetime exposures other than Vanderbilt talc. Such confirmatory expectations are not generally viewed as unreasonable. Finally, with regard to tremolitic talc and mesothelioma, it should be noted that the animal studies discussed above are pleural injection and implantation studies. Tumor promotion in pleural tissue speaks more to mesothelioma induction than it does to lung cancer. Under the same test conditions, New York State talc (whatever its mineral make-up) did not produce tumors in pleural tissue while asbestos did. 17 NON-TALC CANCER MORTALITY STUDIES - NONASBESTIFORM AMPHIBOLES It was noted earlier that nonasbestiform amphiboles are common rock and soil producing minerals, found throughout the earth's crust. Human studies involving nonasbestiform amphiboles other then those found in Vanderbilt talc therefore exist. Two such studies are o f particular significance. The first o f these studies is the famous Reserve Mining case involving taconite (iron ore) mining in Minnesota. Reserve Mining became a major media and legal event in the early 1970s. It is a very interesting and very disturbing case. Years after Reserve Mining was forced into Chapter 11 bankruptcy, a book entitled "Judgment Reserved" was written about this sad episode. Reserve Mining was taken to court by the EPA because their waste piles (tailings) were placed along Lake Superior and were washing into the lake. The public was outraged - especially people who used Lake Superior as their drinking water. To make matters worse, Dr. Irving Selikoff from Mount Sinai Hospital visited the area, and told the press that anyone driving past the waste piles should roll up their windows because these waste piles were riddled with asbestos. With that pronouncement, the level o f public indignation and fear rose to new heights. Emotional court battles followed, piles o f papers were written, lawyers became wealthy and Reserve Mining (with several other mining companies) did seek bankruptcy protection. At the time it was felt that this hardship was justified as the EPA was saving people from asbestos. Later, it was learned, the asbestos reported was actually the nonasbestiform variety o f cummingtonite-grunerite (the nonasbestiform analog o f am osite)(69>. While polluting Lake Superior with mining waste was not a wise idea, later health studies o f iron ore miners, as well as studies o f those who drank water from Lake Superior, showed no cancer excess <69 72\ The second study involved NIOSH and nonasbestiform cummingtonite-grunerite once again. This time, Homestake Mining, one o f the countries largest gold mining operations located in Lead, South Dakota, was studied. Like Reserve Mining, a very large mining cohort was involved. The following statement appeared in a preliminary study report by NIOSH (73): " Environmental samples clearly showed airborne fibers to be characterized as cummingtonite-grunerite with composition identical to the commercial amosite fiber." It is clear that NIOSH recognized it was dealing with nonasbestiform cummingtonite-grunerite and that it was different than amosite (despite the same chemical composition). But, one paragraph below, NIOSH simply turned nonasbestiform cummingtonite-grunerite into asbestos and that, they argued, was the reason for a moderate elevation in lung cancer that they initially felt they saw. "Thus, the amosite variety of asbestos which is the asbestiform minerals found at the subject mine, must be considered the naturally occurring suspect agent in the excess malignant neoplasms of the respiratory system found in this cohort." 18 Homestake objected to technical lapses they felt existed in the NIOSH work. Many o f these problems (absence of smoking data, error in exposure characterization, etc.) were very similar to those encountered in the Vanderbilt NIOSH study. Homestake petitioned NIOSH to return and perform a more thorough evaluation. Upon closer review, the excess lung cancer originally reported did not, in fact exist(74). Other studies o f Homestake miners and millers further confirmed the absence of dust linked excess lung cancer in this cohort exposed to nonasbestiform amphiboles (as well as to crystalline silica) ^75,76). NONMALIGNANT RESPIRATORY DISEASE: While cancer is typically the principle concern whenever asbestos (real or imagined) is addressed, excess exposure to asbestos is also associated with asbestosis. Asbestosis is a dust linked nonmalignant respiratory disease that falls under the broad term pneumoconiosis (or dusty lung). The clinical signs of asbestos are largely indistinguishable from those observed as a result of overexposure to most any durable, respirable mineral dust. These signs involve lung scarring in the lower air exchange region o f the lung (interstitial fibrosis). A profusion of scarring in this lung region results in restrictive ventilatory patterns, reduced blood oxygenation and cardio vascular stress. Some dusts are capable o f producing these signs and effects at lower exposure levels and/or at a more rapid rate and are therefore viewed as posing an elevated risk. Respirable crystalline silica (silicosis) and asbestos (asbestosis) are examples of such elevated nonmalignant respiratory risks. Lower risk dusts such as kaolin (kaolinosis) or talc (talcosis) produce similar signs and effects but require extended exposure to much higher exposure levels. Smoking compromises pulmonary dust clearance defenses and thus enhances the onset and severity o f all pulmonary dust disease(77). Antidotal, sensationalized news reports regarding nonmalignant dust linked respiratory disease (pneumoconiosis) among Vanderbilt talc miners and millers do ex ist(78). However, a great deal is known about the actual onset and progression o f pneumoconiosis among these talc workers. Chest radiographs are routinely obtained and date back to the opening o f the mine in 1948. Over the years these chest x-rays have been reviewed by many pulmonary specialists (?9). Pulmonary function testing is also routinely conducted and reviewed 21\ Such an unusually complete pulmonary record has been used to address whether or not elevated dust linked disease exists among these miners and millers. Such reviews provide further insight into whether asbestos, or something just as harmful, is present in this talc. The historical prevalence o f non malignant pulmonary disease (NMRD) among living miners (morbidity) and deaths caused or linked to nonmalignant respiratory disease was investigated and discussed in several o f the health studies previously cited <27'36' 39-4 N?) Unlike the lung cancer experience, a positive exposure/response relationship is seen in respect to NMRD and therefore supports a link between exposure to this talc and NMRD. This observation, however, does not confirm or reject an asbestos or asbestos like risk since excessive exposure to any talc dust can cause dust linked NMRD. This association has never been contested. Even here, however, some interesting observations regarding NMRD and exposure to Vanderbilt talc can be made. 19 Studies that have addressed NMRD among Vanderbilt talc workers do show that the NMRD observed is almost always associated with talc exposures prior to Vanderbilt talc employment(36, 37, 3x,40) j n jjjg m o s t recent mortality study, for example, 80% of the NMRD cases (up to 1990) had prior mining dust exposures(40). The significance o f prior dust exposure can be seen in the following table. Million Particles Per Cubic Foot Talc Operation Averages Vanderbilt Talc vs. Earlier Area Talc Operations Vanderbilt Talc Mppcf Range: 0.2 -14 0 S o u rce s: M SH A, N Y Health Dept . Ep i Studies O th er Area Talc O p eratio n s M ppcf R a n g e: 0.2 - 2000 It is not surprising to find elevated dust linked NMRD (especially when smoking prevalence is high) in many upstate New York talc miners exposed to extremely elevated dust levels (as much as 50 times higher than those experienced at the Vanderbilt mine and mill). In 1974, the last talc mine in this region closed (except for the Vanderbilt operation) and these exceptionally high dust exposures came to an end. Vanderbilt, wishing to hire experienced talc miners, did, however, hire many talc workers from these other companies. The importance o f this hiring practice is made even clearer when the health status o f Vanderbilt talc workers in more recent years is addressed. Chest X-Rays: Since 1985, Brian Boehlecke, a highly regarded occupational pulmonary specialist from the University of North Carolina, has reviewed the chest x-rays and pulmonary function tests results o f all Vanderbilt talc workers every two years. The following statements by Dr. Boehlecke summarize his impressions well (as o f the end o f 2000)(80). 20 Pulmonary findings (to Jan. 2001): Brian Bochlecke, MD, MSPH "The medical surveillance results at this time continue to support the conclusion submitted to the OSHA docket in 1990, i.e., the data do not indicate that the workers exposed to the talc at this facility are at risk for developing asbestos related pneumoconiosis." "...essentially, no progression of pneumoconiosis related to cumulative exposure appears to have occurred in men in this workforce for whom 1 have had serial radiographs to review." Current status - "Only one man had any evidence of increased interstitial marking which could be consistent with a pneumoconiosis. These markings have not increased in profusion in the past 6 years despite continued exposure." It is important to note that Dr. Boehlecke does not feel he is dealing with an asbestos-like dust risk. Note that he finds very, very little in the way o f pneumoconiosis among Vanderbilt talc workers in more recent years. The experience Dr. Boehlecke is reporting upon involves a workforce where 60% have worked more than 20 years at the Vanderbilt mine and 90% more than 15 years. This excellent record, likely among the best in the mining industry, is not confounded by short term workers. Also, the number o f talc workers with talc exposures other than at the Vanderbilt mine is dramatically less (5% today versus over 40% ten years ago). The significant role earlier, non Vanderbilt talc exposures played in dust linked NMRD is very apparent today. Pleural Plaques: One x-ray finding that is often a source o f confusion is the fact that prolonged exposure to all talc (platy as well as industrial grade) and perhaps a host o f other mineral dusts as well, can result in pleural plaques and thickening (though pleural thickening is less commonly seen among Vanderbilt talc workers). Plaques are commonly observed after 10 to 15 years of exposure. As the following table shows, about 4 to 6% o f Vanderbilt talc workers currently show plaques. This is a typical finding among platy talc workers as w e llt8l). 2002 Medic a Surveillance Work Area Mine Mill P leural P la q u e s Y ears W orked Dust Linked P a r e n c h y m al O pacities 27 None 30 None M ill 27 None M ill 17 None Mi l l 13 None R e p r e s e n ts 4 .5 % of T otal W o rk G ro u p P u Im o n a ry Function W NL W NL Moderate Obstructive W NL W NL 21 It is important to understand that these pleural effects are not just limited to asbestos exposures and that they are not premalignant lesions. Clinically, they have no confirmed relationship to the evolution of mesothelioma or lung cancer - these are different biologic processes involving different pathology (82'84). As the table shows, plaques observed in Vanderbilt talc workers are not associated with pneumoconiosis or pulmonary restriction. Plaques are generally considered an abnonnality but not an impairment. Pronounced pleural thickening can, however, reduce lung function, but pleural thickening is not common among Vanderbilt talc workers today. Pulmonary Function: With regard to pulmonary function, Vanderbilt talc workers do show a fairly high prevalence o f mild to moderate obstructive pulmonary disease but with little or no radiographic evidence o f dust involvement. Obstructive impairment (as opposed to restrictive impairment) is most commonly associated with various forms o f airway obstruction. Such effects are often linked to smoking and would be expected given the smoking patterns among these miners (see discussion above). 2002 M edical Surveillance P U L M O N A R Y F U N C T I O N S N O T W IT HIN N O R M A L LIMITS (NWNL) % of Total Group NWNL: % of NW NL that are "X " or Current S m o k e r s : 25% 70% % Si gn s ol Ob st r ucl i ve % S i g n s of Rest ri c t i ve # With Dust Linked ________ I m p a i r m e n t ___________________I m p a i r m e n t ___________ P a r g n h y m a l O p a c i t i e s 8 2 % 2 8 % 1 lm p a irm e n t L e v e Is B o r d e rlin e 1 6 % E a rlv 2 6 % M Id 3 2 % M o d e ra te 2 6 % Severe 0 % Conclusion: The actual health experience o f Vanderbilt talc miners and millers stands in sharp contrast to antidotal media reports o f widespread dust linked respiratory disease. Confusion is somewhat understandable given elevated dust linked pulmonary disease among regional talc workers exposed to extremely high talc dust levels. Such levels, however, no longer exist and more recent health surveillance data does show a marked improvement in the avoidance of parenchymal opacities. The observation of pleural abnormalities commonly used as a marker of asbestos exposure and the prevalence o f respiratory problems thought linked to dust rather than smoking have contributed to the false impression that Vanderbilt talc miners are exposed to asbestos or a dust "just as bad" when in fact they are not. 22 The diagnosis o f any dust linked pulmonary disease does require radiographic evidence of dust involvement. Often that evidence (interstitial markings) is not as easy to identify or interpret as many believe - especially during the early stages o f a dust disease. There are many confusing images seen in chest x-rays (vascular lines, pleural fat, rib cage shadows, poorly contrasted film, etc.)(82), The "expectation" of dust disease contributes to false negative interpretations. The control of bias and the use o f pulmonary specialists trained and experienced in occupational dust disease are o f critical importance for this reason. It is also common to assume that a "positive" chest x-ray interpretation for pneumoconiosis is always correct while "negative" interpretations o f the same chest radiograph are not correct. This is not always the case. There is no question that New York State talc miners and millers exposed to extremely elevated dusts decades ago have suffered from dust linked disease. However, it is important to understand present day experience as it pertains to talc miners and millers exposed only to the significantly reduced dust exposures found at the Vanderbilt mine. If this is not understood, inappropriate risk perception is inevitable (linking an earlier exposure risk that no longer exist to current day exposures). Difficulties and bias factors long associated with chest radiographic interpretation must be understood as well. OSHA MAKES A FINAL DECISION ON NONASBESTIFORM AMPHIBOLES In 1992, 20 years after its first asbestos standard and after a week o f hearings, OSHA formally adopted a mineralogically correct definition of asbestos. OSHA would not treat nonasbestiform amphiboles as asbestos (l). The following statement appeared in the Federal Register. "OSHA has made a determination that substantial evidence is lacking to conclude that nonasbestiform tremolite, anthophyllite and actinolite present the same type or magnitude of health effect as asbestos." "OSHA hereby lifts the Administrative Stay, removes and reserves 29 CFR 1910.1101, and amends the revised asbestos standard to remove nonasbestiform tremolite, anthophyllite and actinolite from their scope." Simply put, OSHA could find no evidence that would support their original regulatory plan. Since OSHA could not rely upon Vanderbilt talc studies to provide the justification, there was essentially "no" supporting evidence. 23 TALC AND MIXED TALC/AMPHIBOLE FIBER With the above mineral and biological background in mind (especially the understanding that Vanderbilt talc cancer health studies do not support a "same as" asbestos health risk), a minor component in Vanderbilt talc that is far more complicated than amphibole cleavage fragments can be addressed. This component is the minor talc fiber and mixed fiber mentioned earlier. The following reflects the actual composition (by weight %) o f Vanderbilt tremolitic talc. These ranges are inclusive o f all grades. VANDERBILT TALC COM POSITION(85) (Weight %) T alc: (Talc & Talc/amphibole fiber = 0.5 to 5.6% in whole product)* 20 to40% Tremolite (nonasbestiform): 40 to60% Serpentine (antigorite-lizardite): 15 to30% Anthophyllite (nonasbestiform): 1 to 5% Quartz: <1% (when detected at all) * Of combined fiber (<0.05 to 1.8 in the whole product is asbestiform (Avg. all grades <0.50) The nonasbestiform amphibole component in this talc is obvious. Note also that there is a minor but measurable amount o f talc fiber and mixed fiber in this talc. The mixed or "transitional" fiber is part talc and part amphibole (most probably anthophyllite), intimately mixed at the lattice level (86"98). These are true fibers which are very long and thin. Some, but not all o f these fibers do exhibit an asbestiform growth habit. These fibers have been described as academic curiosities and are relatively unrecognized outside the mineral science community. The combined weight % for those fibers that do exhibit an asbestiform growth habit typically falls around 0.5%. These fibers are not cleavage fragments, nor are they asbestos. There are analytical laboratories that would contradict this statement. A few laboratories believe that some of these fibers are anthophyllite asbestos (though typically at an extremely trace level) (99, ioo) y h e r e j s debate over whether some or all o f the mixed fiber is asbestiform, and whether it should be called anthophyllite asbestos when amphibole is the dominant phase (assuming it can be determined which phase is dominant) (94). Mineral scientists argue against this last proposition because the physical properties o f these mixed fibers differ from those o f either constituent, while impurities in asbestos fibers do not, in contrast, reflect significant alteration in their physical properties(101' l02). Beyond some o f these more detailed issues, it is admittedly confusing to most to hear that a fiber may be "asbestiform" but not "asbestos" . It does sound like a contradiction. However, it must be remembered that asbestos is a commercial term that is applied to the six minerals earlier discussed. The term "asbestiform" merely means "like asbestos". Asbestiform fibers grow like 24 asbestos, they look like asbestos, they exhibit parallel crystal growth, they are flexible, they appear as fiber bundles with splayed terminations, they are very long and thin. However, these characteristics do not make them asbestos merely because they exhibit morphological similarities (8). As mentioned earlier, it has been reported that upwards o f 100 minerals may grow in an asbestiform habit, and the mineral talc is one o f them. The following photomicrographs reflect the minor fiber content of Vanderbilt talc. The reader may wish to compare these photomicrographs with those earlier presented o f asbestos fibers (last two pages). The large fiber in the center o f the photomicrograph labeled "TF" is an asbestiform talc fiber. There is evidence o f bundling, some curvature suggesting flexibility and it's very long and thin. The particle at the lower left labeled "A" is a prismatic anthophyllite cleavage fragment. The particles labeled "T" are elongated tremolite cleavage fragm ents(93). Some laboratories fail to recognize that there are anthophyllite cleavage fragments in this talc and may misinterpret SAED patterns o f these fragments as anthophyllite asbestos. 25 The above photomicrograph shows a more typical talc fiber found in Vanderbilt ta lc (H). This fiber tends to be ribbon-like, and some feel it would not properly be called asbestiform. This is pure talc - not an amphibole or a mixed fiber. The above photomicrograph is a typical mixed fiber found in Vanderbilt talc. It is part talc and part amphibole (92). These fibers tend to be rod-like and are also subject to controversy as to whether they are or are not truly "asbestiform". 26 This photomicrograph shows the termination o f one o f these ro d s<94). Some o f the mixed fiber rods exhibit flat terminations while others (pictured) suggest the pulling apart of fibrils - though this is less pronounced then that typically seen in asbestos fibers. The above photomicrograph shows light and dark areas on a transitional fiber(94). These areas are said to be different mineral domains - areas of talc, areas o f amphibole (likely anthophyllite). If one directs an electron diffraction beam against different portions o f this fiber, a different mineral fingerprint or pattern will emerge depending on where the beam strikes the fiber. This is another common area o f analytical confusion. 27 The above diffraction pattern is common for talc/anthophyllite intergrowth (94). Note the "triplet" spots. The center spot is linked to a talc pattern - a forbidden reflection for pure anthophyllite. Other ways exist to distinguished the mixed fibers. For example, Polarized Light Microscopy and index oils can be used to identify the mineral with a refractive index (85>. Mixed fibers will give an index above pure talc but below the lower limit o f an amphibole. Commonly applied index criteria appear below. M in e ra l Talc Transitional A m p h ib o le a, Rl < 1.598 < 1.598 > 1 .5 9 8 y, r i < 1.598 > 1.598 > 1.598 28 Given the level o f attention these fibers receive, it is easy to lose sight o f the fact that they make up a very small component o f this talc, especially on a weight basis. It is common, however, to find widely divergent percent content data for these fibers. Percentages must be interpreted with caution. Often, percents refer to particle counts and not weight. To further complicate matters, many of these fiber prevalence percents relate only to subsets and not the whole product. Widely divergent fiber content levels have also been reported based upon broad "approximations" or extrapolation from very small fractions o f the material (such as those seen by TEM). Improper mineral identification and sample preparation can play a role in quantification error as well. Mineral scientists often refer to these fibers as "mineral curiosities " General public exposure to these fibers is extremely limited to nonexistent. Still, as interesting as these fibers may be mineralogically, the key concern is always risk. It is known that the six regulated asbestos minerals (particularly amphibole asbestos) are associated with significant health risks. However, it appears that other minerals that form in an asbestiform habit show various levels o f risk. Some mineral fibers like fibrous erionite (a zeolite), richterite and winchite (amphiboles) suggest a risk every bit as strong as that o f asbestos. On the other end o f the spectrum are talc fibers and water-soluble fibers (i.e. xonotilite) that do not pose an asbestos risk (7). Besides morphology, different minerals have different biodurability, surface chemistry, friability once in the lung, harshness scores, etc. These differences do appear to influence their biological activity in whole or in p a rt(7,8'50,103). This is one o f the reasons it is important to recognize the physical properties o f minerals and call them by their proper names. Further, the critical role of dose should not be ignored. Risk is not simply a matter o f good and bad but rather a matter of degree. The common saying in toxicology that "the dose makes the poison" is no less true for asbestos than any other material. Despite the minor fibers present in Vanderbilt tremolitic talc, it clearly does not act like an asbestos-containing material in people or in test animals. Proponents o f "morphology is everything" thinking, or those who incorrectly believe the term "asbestiform" is or should be a synonym for "asbestos", argue that the reason Vanderbilt talc does not act like an asbestoscontaining material is because these fibers are too few. "Well, if there were more o f them, then the talc would act like asbestos", is a common refrain. The correct response to this is "Well, there aren't" . This is important to note because Vanderbilt talc may well contain more o f these fibers than any other talc. Although there is no known higher exposure to these rare fibers, it would be o f interest to test this dose-linked assertion because it would speak to the "morphology is everything" proposition. Accordingly, a test was undertaken to test this hypothesis. In this test a concentrate o f talc (predominantly) and mixed fiber from Vanderbilt talc was tested against an equal weight of asbestos fiber in a rodent tracheal epithelial and mesothelial cell study. The findings o f this study are reflected below. 29 Wylie, A. G., Mossman, B. T., et a] - 1997 (50) Mineralogical Features Associated with Cytotoxic and Proliferative Effects o f Fibrous Talc and Asbestos on Rodent Tracheal Epithelial and Pleural Mesothelial Cells "fibrous talc does not cause proliferation of HTE cells or cytotoxicity equivalent to asbestos in either cell type despite the fact that talc samples contain durable mineral fibers with dimensions similar to asbestos. These results are consistent with the findings of Stanton, et al (1981) who found no significant increases in pleural sarcomas in rats after implantation of minerals containing fibrous talc." The talc fiber concentrate acted differently than the asbestos fibers, again suggesting that more than simple fiber morphology is involved in asbestos pathogenicity. This study also suggests that the demonstrated absence o f an asbestos risk in Vanderbilt tremolitic talc is not simply dose related. As desirable as it would be to find one simple, easy to recognize characteristic that predicts "fiber" risk, studies like this, as well as the entire nonasbestiform amphibole experience, suggest that we need to proceed with caution. Finding one variable linked to fiber risk (i.e. morphology) does not automatically mean that other variables can or should be ignored. At least not until scientifically discounted. CONCLUSION - LESSONS LEARNED It is important that we call substances by their proper names and that we control them based on demonstrated risk. When health studies characterize exposures in broad brush terms and ignore proper nomenclature, researchers are less likely to understand risk. Less discrimination in the name o f prudence is a "slippery slope," one more likely to lead to the presumption o f risks that do not exist rather than the avoidance o f those that do. This is certainly one o f the lessons of the tremolitic talc saga. There are many reasons why Vanderbilt talc has been the source of debate and confusion for decades. Imprecise asbestos definitions(5, l5' 86-1031 over zealous federal agencies inclined to champion excessive prudence over good science<2,24,27,31,32,35,104) imprecise asbestos analytical protocols (7, l0, n ' l3,1 ' l9'84'98' 105"I08)>bias/experience factors leading to possible error in difficult medical evaluations (i.e., chest x-ray interpretations, mesothelioma diagnosis and attribution), the relationship of past exposure risk to current exposure risk and irresponsible media involvement(3) are key among these reasons. The tremolitic talc story may well be one o f the very best examples of a confluence o f serious ongoing lapses. Certainly there are serious risks in this world, we must be cautious and act prudently. But even prudence can be excessively stretched. While we must not ignore adverse health effects when 30 we see them, we must not invent them either. When a risk is observed, we must control it commensurately with the threat. It does matter what we call things, especially when improper nomenclature leads to improper conclusions and the presumption of risk. Asbestos, or something just a bad, is not a constituent o f New York tremolitic talc. The health experience of New York State miners and millers does not show an "asbestos-like" risk. The health status o f active tremolitic talc workers today is likely among the best in the mining industry. Such health experience (supported by animal and cell studies) argues against any risk to product users and the public. While excessive exposure to this talc is capable o f producing pulmonary harm (and has), current dust exposure levels appear adequately protective. 31 asbesiiorm non-asbestiform f osbestform Some Names A. non-asbestiform 32 RFFi Hi. \ < i E X H U i l l i l i G H l MICROSCOPIC COMPARISONS. . ( 2 . 7 5 urn M lv isio n s) A-SBESTIFOKM -NONAS BESTIFORM i i \ 'ft jkJO te. <L rtelKddtc 33 C on tin u ed ASBESTFORM NONASBESTIFOKM g. anthophyllitc asbestos - tre m o lltc asbestos j- t remonte I- actinoHtc 34 REFERENCES: 1. Occupational Safety and Health Administration, 1992, 29 CFR Parts 1910 and 1926 (Docket No. H-033-d), Occupational Exposure to Asbestos, Tremolite, Anthophyllite and Actinolite: Federal Register, v. 57, no. 110, Monday, June 8, 1992, p. 24310-24331. 2. Reger, R., W.K. Morgan: On Talc, Tremolite and Tergiversation (editorial). Br. J. Ind. Med. 47:505-507(1990). 3. Schneider, A., C. Smith: 2000d - Old Dispute Rekindled Over Content o f Mine's Talc'. The Seattle Post-Intelligencer, (May 30, 2000). 4. Olden, K.: Correspondence to George Salem (Akin, Gump, Strauss, Hauer and F'eld) regarding confusion over the nomination o f talc in the 10th ROC, June 14, 2001. 5. Occupational Safety and Health Administration, 1972,29 CFR Part 1910-93a, Asbestos Dust Standard: Federal Register, v. 37 no. 202, Wed. Oct. 18, 1972, p. 22142-22144. 6. United States Department of the Interior: Selected Silicate Minerals and Their Asbestiform Varieties by W. J. Campbell, et al (Bureau o f Mines Information Circular, I. C. 8751). Washington, D.C.: Dept, o f the Interior, Bureau o f Mines. (1977). 7. Wylie, A.G The Habit o fAsbestiform Amphiboles: Implications fo r the Analysis o fBulk Samples, (paper) Advances in Environmental Measurement Methods for Asbestos, American Society for Testing and Materials - STP 1342, Michael Beard, Plarry Rook, editors p. 62 (Jan. 2000). 8. Steel, E., A. G. Wylie: Mineralogical Characteristics o fAsbestos, (article) in Geology of Asbestos Deposits, P. H. Riodon, ed., Society of Mining Engineers o f AIME p. 93-100, (1981). 9. National Institute for Occupational Safety and Health: NIOSH Manual o fAnalytical Methods (DHHS/NIOSH Pub. No. 84-100). Washington, D.C. Government Printing Office, Method #7400 (1984). 10. Wylie, A.G., R. J. Virta, and E. Russek: Characterizing and Discriminating Airborne Amphibole Cleavage Fragments and Amosite Fibers - Implications fo r the NIOSH Method. Am. Ind. Hyg. Assoc. J. 46(4): 197-201 (1985). 11. Snyder, J. G., R. L. Virta, and J.M. Segret: Evaluation o f the Phase Contrast Microscopy Methodfo r the Detection o f Fibrous and Other Elongated Mineral Particulates by Comparison with an STEM Technique. Am. Ind. Hyg. Assoc. J. 48:471-477 (1987). 12. Wylie, A. G.: Optical Properties o f the Fibrous Amphiboles. Health Hazards o f Asbestos Exposure. Ann. N.Y. Acad. Sci. 330:611-620 (1979). 13. Langer, A. M., R. P. Nolan, J. Addison: Distinguishing Between Amphibole Asbestos Fibers and Elongate Cleavage Fragments o f Their Non-Asbestos Analogues. Mechanisms in Fibre Carcinogenisis, R. C. Brown et al., editors, Plenum Press, New York. P 253 -267 (1991). 14. Zoltai, T.: Asbestiform and Acicular Mineral Fragments: Health Hazards o f Asbestos Exposure. Ann. N. Y. Acad. Sci. 330:621-643 (1979). 15. Wylie, A. G.: Mineralogical definitionsfor Asbestos Fibers and Cleavage Fragments. Report of the Committee on Geology and Public Policy GPP012. Geology Society of America, p. 2-4, (1989). 16. Ross, M.: The Asbestos Minerals: Definitions, Description, Modes o f Formation, Physical and Chemical Properties and Health Risk to the Mining Community. Proceedings of the Workshop on Asbestos: Definitions and Measurement Methods. National Bureau o f Standards Special Publication 506. Washington, D.C. Government Printing Office, pp. 4964(1978). 17. Wylie, A. G.: Membrane Filter Methodfo r Estimating Asbestos Fiber Exposure. Definitions for Asbestos and Other Health-Related Silicates (ASTEM STTP 834), Benjamin Levadie, Ed. Philadelphia, PA: American Society for Testing and Materials, pp. 105-117(1984). 18. Kelse, J. W., C. Sheldon Thompson: The Regulatory and Mineralogical Definitions o f Asbestos and Their Impact on Amphibole Dust Analysis. Am. Ind. Hyg. Assoc. J. 50(11) pp. 613-622(1989). 19. Wylie, A. G., K. F. Bailey, J. W. Kelse, R. J. Lee: The Importance o f Width in Asbestos Fiber Carcinogenicity and Its Implications for Public Policy. Am. Ind. Hyg. Assoc. J. 54(5) pp. 239-252 (1993). 20. Occupational Safety and Health Administration: Post-Hearing Comments in the Matter o f Proposed Revisions to the Asbestos Standard, Code o f Federal Regulations Title 29, 1910.1001,(1984). 21. Kuryvial, R. J., R. A. Wood, R. E. Barrett: Identification and Assessment o fAsbestos Emissionsfrom Incident Sources o fAsbestos, Environmental Protection Agency Report. EPA-650/2-74-087 (1974). 22. United States Department of the Interior: Analysis o f the Cost Effectiveness o f the OSHA Regulation o f Nonasbestiform Amphiboles with Respect to Selected Sectors o f the Domestic Minerals Industry. Richard Gillette & R. Virta, Washington, DC: US Dept, of the Interior, Bureau of Mines, pp 1-55 (1989). 23. Occupational Safety and Health Administration: Proposed Revisions to the Asbestos Standard, 29 CFR 1910.1001 49 Fed. Reg. 14116-14145 (April 10, 1984). 24. Occupational Safety and Health Administration: Final Rule Exposure to Asbestos, Tremolite, Anthophyllite and Actinolite for Construction and General Industry, Federal Register v. 51. no. 119 Friday, June 20, 1986. 25. United States Department of Labor: Letter from John Pendergrass, Assist Sec. of Labor (OSHA) to Dennis Race (R. T. Vanderbilt Co. Inc. Counsel) granting a Labor Dept. Administrative Stay regarding the regulation of non-asbestiform tremolite, anthophyllite and actinolite under the revised June 20, 1986 Asbestos Standard. (July 18, 1986). 26. Kleinfeld, M., J. Messite, M. H. Zaki: Mortality Experiences among Talc Workers: A Follow-up Study, J. Occup. Med. 16:345349/ (1974). 27. National Institute for Occupational Safety and Health: Occupational Exposure to Talc Containing Asbestos, Brown, D. P., J. Wagoner, J.M. Dement, R. D. Zumwalde, J. Gamble, W Fellner, M. DeMeo, NIOSH Publ. No. 80-115 (1980). 28. Asbestos: Properties, Applications, and Hazards, L. Michaels, S. S. Chissick Ed., Pub. By John Wiley & Sons, Chapter 2, p. 57 (1972). 29. Society of Mining Engineers: Geology o f Asbestos Deposits. P. H. Riodon Ed., American Institute of Mining, Metallurgical and Petroleum Engineers, Inc. (1981). 30. National Institute for Occupational Safety and Health: Critique o f NIOSH position o f Vanderbilt Talc as an Asbestiform Mineral Increasing the Risk o fLung Cancer in Exposed Workers. J. Gamble, Memo to director, DRDS, Nov. 22, 1985. (In OSHA Docket H-33d). 31. Cooper, W. C.: Critique o f NIOSH Study o fNew York Tremolitic Talc, letter to the R. T. Vanderbilt Company, Inc. Oct. 4, 1982. (In OSHA Docket H-33-d). 32. Morgan, R.W.: A review o f the Literature on the Carcinogenicity o f Asbestiform and Nonasbestiform Actinolite, Tremolite and Anthophyllite, for the National Stone Association. Feb. 4, 1988. (In OSHA Docket H-33-d). 33. Lamm, S. H., M. Levine, J. Starr, J. Tirey: Analysis o f Excess Lung Cancer Risk in Short-Term Employees, Am. J. of Epid. v. 127 #6pp. 1202-1209. (1988). 34. Boehlecke, B. A: Review and Comments on the Evidencefo r Human Health EJfectsfrom Exposure to Nonasbestiform Tremolite, Actinolite and Anthophyllite and the Regulation o f Occupational Exposures, for the American Mining Congress - 1988 (In OSHA Docket H33-d). 35. Gibbs, G. W.: An Evaluation o f the Epidemiological Evidence Concerning "Talc" and Respiratory Cancer in Humans with Specific Attention to "Talc" as produced by the Gouverneur Talc Company - A subsidiary o f the R. T. Vanderbilt Company, Inc. - At Its Mines and New York State. Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)". (Nov. 27, 2000). 36. Stille, W. T., I. R. Tabershaw: The Mortality Experience o f Upstate New York Talc Workers, J. Occ. Med. v. 24 #6 pp. 480-484. (1982). 48. Stanton, M. F., M. Layard, A. Tegeris, E. Miller, M. May. E. Morgan, A Smith: Relation o f Particle Dimension to Carcinogenicity in Amphibole Asbestosis and Other Fibrous Minerals, JNCI 67, pp. 965-975. (1981). 49. Smith, W. E., D. Hubert, H. Sobel, E. Marquet: Biologic Tests ofTremolite 1Hamsters, Dusts and Disease, R. Lemen & J. Dement Editors, Proceedings o f the Conference on Occupational Exposures to Fibrous and Particulate Dust and Their Extension into the Environment. Pathotox Pub. Park Forest S. IL. pp 335-339. (1979). 50. Wylie, A.G., H.C. Skinner, J. Marsh, H. Snyder, C. Garzione, D. Hodkinson. R. Winters & B. Mossman: Mineralogical Features Associated with Cytotoxic and Proliferative Effects o fFibrous Talc and Asbestos on Rodent Tracheal Epithelial and Pleural Mesothelial Cells. Tox. & Applied Pharmacology 147, pp.143-150. (1997). 51. Oehlert, G. W.: A reanalysis o f the Stanton, et al. Pleural Sarcoma Data. Environ. Res. 54, pp. 194-205.(1991). 52. Wylie, A.G., et al: Characterization o f Mineral Population by Index Particle: Implication fo r the Stanton Hypothesis. Env. Res. 43 pp. 427-439. (1985). 53. Wylie, A. G.: Analysis o f Stanton Talc Samples. Affidavit submitted into OSHA Docket H-33-d, 1988. 54. Addison, J., J.M.G. Davis: A Comparison o f the Carcinogenicity o f Six Tremolites Using the Intraperitoneal Injection Assay in Rats: Interim report. VIIth International Pneumoconiosis Conference, Pittsburgh, PA. Aug. 1988. (In OSHA Docket H-33-d). 55. Davis, J.M.G., J. Addison, C. McIntosh, M. Miller, K, Niven: Variations in the Carcinogenicity ofTremolite Dust Samples o f Differing Morphology; Annals o f the New York Academy of Sciences, v. 643 pp. 473-490. (1991). 56. Garcie, B: Correspondence to W.K.C. Morgan, MD from Dept, o f Pathology, University Hospital, London, Ontario. July 6, 1995. 57. Rubin, E.: Correspondence to John Kelse, R. T. Vanderbilt Company from Emanual Rubin, MD, Gladwyne, PA Nov. 8, 2006 58. Van Orden, D.: RJLee Group Analytical Report to John Kelse, R. T. Vanderbilt Company. Bulk samples submitted for analysis for asbestos content. Nov. 5, 2002 59. Hull, M., J. Abraham, B. Case: Mesothelioma among Workers in Asbestiform Fiber bearing Talc Mines in New York State. Annals o f Occupational Hygiene, Vol. 46, Supplement l , pp 182-185. 2002 60. Nolan, R., A. Langer, B. Price, A.Gibbs, E. Rubin: Comments on - Mesothelioma among Workers in Asbestiform Fiber-bearing Talc Miners in New York State - Is there an Associaton between Mesothelioma and Tremolitic Talcfrom New York State? Document review submitted to the R. T. Vanderbilt Company Inc. March 12, 2006 61. Addison, J.: Mesothelioma among Workers in Asbestiform Fiber-bearing Talc Mines in New York State. A Critical Review. Document review submitted to the R. T. Vanderbilt Company Inc. 2005. 62. Churg, A.: Diseases o f the Pleura-Malignant Mesothelioma-in-Pathology o f the Lung. W.M. Thurlbeck Thieme Med. Publishers Inc., NY, pp. 783-802. (1988). 63. Brenner, J., et al: Malignant Mesothelioma o f the Pleural-Review oj 123 Patients. Cancer, 49:2431-2435. June (1982). 64. Browne, K.: The Epidemiology o fMesothelioma. J. Soc. of Occ. Med. Vol 33, No. 4, 190-194.(1983). 65. Hunchare, K, M.: The Epidemiology o f Pleural Mesothelioma: Current Concepts and Controversies - Cancer Investigation. 7(1), 93-99. (1989) 66. Wright, W. E., et all Malignant Mesothelioma-Incidence, Asbestos Exposure, and Reclassification of Histopathology. Br. J. of Ind. Med. Vol. 41 pages 39-45. (1984). 67. Spirtas, R. et al: Recent Tremnds o f Mesothelioma Incidence in the United States. Am. J. Ind. Med. 9:397-407. (1986). 68. Schaumburg, F. D. : Judgement Reserved: A Landmark Environmental Case: Reston Publishing Company, Inc. Reston, Virginia (1976), 69. Cooper, W. C., O. Wong, R. Graebner: Mortality o f Workers in Two Minnesota Taconite Mining and Milling Operations; J. Occ. Med. 30 pp. 507-511. (1988). 70. Levy, B.S., E. Signurdson, J. Mandel, E. Laudon, J. Pearson: Investigating Possible Effects o fAsbestos in City Water: Surveillance o f Gastrointestinal Cancer Incidence in Duluth, Minnesota: Amer. J. o f Epid. v. 103 no. 4 pp. 362-372. (1976). 71. Higgins, I. T., J. H. Glassman, M. S. Oh, R. Cornell: Mortality o f Reserve Mining Company Employees in Relation to Taconite Dust Exposure: Amer. J. o f Epid., v. 118. no. 5, pp. 710-719(1983). 72. Cooper, W. C., O. Wong, L. Trent, F. Harris: Mortality of Workers in Two Minnesota Taconite Mining and Milling Operations - An Update: J. Occup. Med. 34, pp. 1173-1180. (1992). 73. Gillam, J. D., J. Dement, R. Lernen, J. Wagoner, V. Archer, H. Blejer (NIOSH): Mortality Patters Among Hard Rock Gold Miners Exposed to an Asbestiform Mineral: Paper (Pre-Publication Copy) - Conference on Occupational Carcinogenesis. The New York Academy o f Sciences, New York, N.Y. March 24, 1975. 74. Brown, D. P., S Kaplan, R. Zumwalde, R. Kaplowitz, V. Archer (NIOSH): Retrospective Cohort Morality Study o f Underground Gold Mine Workers: In Controversy in Occupational Medicine, Cancer Research Monograph, v. 2, Praeger, NY, NY, pp. 335 350. (1986). 75. McDonald, J. C., G. Gibbs, F. D. K. Liddell, A. D. McDonald: Mortality After Long Exposure to Cummingtonite-Grunerite: Amer. Rev. Resp. Disease 118, pp. 271-277. (1978). 76. Steenland, K., Brown, D. (NIOSH): Mortality Study o f Gold Miners Exposed to Silica and Nonasbestiform Amphibole M inerals-An Update With 14 More Years o fFollow-up. Amer. J. Ind. Med. v. 27 pp. 217-229. (1995). 77. Preger, L. et al: Clinical Problems in Asbestos-Related Diseases in Asbestos-Related Disease. Grue & Stratton, NY, NY, pp. 16-19. (1978). 78. Schneider, A.: It Didn 7 Matter What They Called It ...It's Killing Us: The Seattle Post Intelligencer. (June 22, 2000). 79. Boehlecke, B. : Report on Interpretation o f Radiographs o f Workers At Gouverneur Talc A Consensus Reading. Report to R. T. Vanderbilt Company, Inc. Includes review of independent "B" reader reviews by A. Wiot and Felson. (May 9, 1985). 80. Boehlecke, B.: Results o f Medical Surveillance Examinations Performed Every 2 Years on Workers at the Gouverneur Talc Company (985 -2000): Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)''. (Nov. 19,2000). (Partial in OSHA Docket H-33-d, 1988). 81. Gamble, J., et al: An Epidemiological - Industrial Hygiene Study o f Talc Workers. Ann. Occup. Hyg. 26:841-859. 82. Rubin, AE: Common Problems in Asbestos-Related Pulmonary Diseases. Am. J. Ind. Med. 10:5555-562(1986). 83. Edelman, D. A.:: Asbestos Exposure, Pleural Plaques and the Risk o f Lung Cancer. Int. Arch. Occup. Environ. Health. 60:3899-393 (1988). 84. Weil, H.: Asbestos-Associated Diseases. Science Public Policy and Litigation. Chest 84(5):601-608 (1983). 85. Van Orden, D., R. J. Lee: Weight Percent Compositional Analysis of Seven RTV Talc Samples. Analytical Report to R. T. Vanderbilt Company, Inc. Nov. 22, 2000. Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)". Dec. 4, 2000. 86. Veblen, D. R.: Anthophyllite Asbestos - Microstructures, Intergrown Sheet Silicates, and Mechanisms o f Fiber Formation. Am. Mineral, v. 65 pp. 1075-1086. (1980). 87. Veblen, D. R. and P. B. Buseck: Microstructures and Reaction Mechanisms in Biopyriboles. Am. Mineral, v. 65 pp. 599-623. (1980). 88. Virta, R.: The Phase Relationship o f Talc and Amphiboles in a Fibrous Talc Sample. US Dept, of Interior, Bureau of Mines Report oflnvestigations #8923. (1985). 89. C rane, D.: Letter to Greg Piacitelli (NIOSH) describing the analytical findings o f the Occupational Safety and Health Administration regarding R. T. Vanderbilt Talc. Nov. 26, 1986 (In OSHA Docket H-33-d and In Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations - June 2, 2000). 90. C rane, D.: Background Information Regarding the Analysis o fIndustrial Talcs. Letter to the Consumer Product Safety Commission from the Occupational Safety and Health Administration. June 12, 2000 (Appended to CPSC Staff Report on "Asbestos in Children's Crayons" Aug. 2000). 91. M cCrone Associates - A tlanta Lab.: Report on the Analysis o f Paint CLS-5067-1 and Mineral Filler CLS-N-439-1. To Unspecified Paint Company Sept. 23, 1992. (Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10lh ROC Nominations "Talc (containing asbestiform fibers)". June 2, 2000. 92. RJ Lee G roup - M onroeville Lab.: Magnesium Silicate Fiber Found in - Paint. Analysis report to Unspecified Paint Company April 2, 1993. (Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)". June 2, 2000. 93. Wylie, A.G.: Report o f Investigation. Analytical Report on RTV talc submitted to R. T. Vanderbilt Company, Inc. Feb. 13, 1987 (Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)". June 2, 2000. 94. N ord, G, L, S. W. Axen, R. P. Nolan: Mineralogy and Experimental Animal Studies o f Tremolitic Talc. Environmental Sciences Laboratory, Brooklyn College, The City University of New York. Submitted to Public Comments Record - C. W. Jameson, National Toxicology Program, 10th ROC Nominations "Talc (containing asbestiform fibers)". December 1,2000. 95. Greenwood, W.: A Mineralogical Analysis o f Fibrous Talc. MS Thesis, University o f Maryland, 162 pages, (1998). 96. W atson, M.: The Effects o f Intergrowths on the Physical Characteristics o f Fibrous Anthophyllite. MS Thesis, University o f Maryland, 129 pages, (1999). 97. Stemple, I.S. and G. W . Brindley: A Structural Study o f Talc and Talc-Tremolite Relations. Journal of the American Ceramic Society. # 43, pp. 34-42 (1960). 98. W right, H. D.: An Optical Study o f Talc-Tremolite Relations. Journal o f the American Ceramic Society, # 43, pp. 42-43 (1960). 99. Beard, M.E., O. Crankshaw, J. Ennis & C.E. Moore: Analysis of Crayonsfor Asbestos and Other Fibrous Materials, and Recommendationsfor Improved Analytical Definitions: Research Triangle Park, North Carolina. Feb. 28, 2001. Withdrawn from distribution August 9, 2001. 100. DataChem Laboratories: Report o fAnalysis - Fibrous Materials in Crayons. Submitted to the US Consumer Product Safety Commission, Washington, DC; June 29, 2000. 101. Lee, R. J., D. Van Orden: Preliminaiy Review o f the RTI Report on the "Analysis o f Crayonsfor Asbestos Submitted to the R. T. Vanderbilt Company, Inc. March 13, 2001. (Provided to the US Consumer Product Safety Commission - March 2001). 102. Wylie, A.G.: Communication regarding review o f the RTI Report on the "Analysis of Crayons for Asbestos" to the R. T. Vanderbilt Company, Inc., March 2001. 103. Nolan, R. P., A.M. Langer, G. Oechsle, J. Addison & D.E. Colflesh: Association o f Tremolite Habit with Biological Potential - Preliminary Report: Mechanisms in Fibre Carcinogenisis, R. C. Brown et al,, editors, Plenum Press, New York, pp. 231-252 (1991). 104. Gall, Mary Sheila: Statement - On Commission Action Concerning Reformulation o f Crayons: Public Record - CPSC 4330 E. West Highway, Bethesda, MD. (June 13, 2000). 105. U.S. Environmental Protection Agency: Letter to J. Kelse, R. T. Vanderbilt Company Inc. from Diane Sheridan, Chief Abatement-Programs Section Office of Prevention, Pesticides and Toxic Substances. (Aug. 28, 1992). 106. U.S. Environmental Protection Agency: Interim Methodfo r Asbestos in Bulk Materials: EPA-600/MA -82-020. (1982). 107. Perkins, R. L., B. W. Harvey: Test Method - Methodfo r the Determination o fAsbestos in Bulk Building Materials: EPA contract nos. 68024550 and 68D10009. Research Triangle Institute, Research Triangle Park, NC. (June 1993). 108. Beard, M.: Internal correspondence to Sally Sasnett USEA EN-342; 401 "M" Street SW; Washington, DC; from USEPA, Atmospheric Research and Exposure Assessment Laboratory Research Triangle Park, NC. (Nov. 3, 1992). RJ LeeGroup, Inc. 350 Hochberg Road Monroeville, PA 15146 Tel: (7 2 4 )3 2 5 -1 7 7 6 Fax: (724) 733-1799 The Materials Characterization Specialists November 22, 2000 Mr. John W . Kelse R. T . Vanderbilt Com pany, Inc. 30 Winfield Street Norwalk, C T 06856-5150 RE: T E M Asbestos Analysis RJ Lee Group Job No.: LS H 006444-3 D ear Mr. Kelse: Enclosed are the results from the transmission electron microscopy (TE M ) asbestos analysis of the above referenced samples using the counting rules established by the N IO S H M ethod 7 4 0 2 , issue 2, 8/15 /9 4. The sam ple and volum e information w ere provided by R. T. Vanderbilt Com pany, Inc. personnel. T h e analysis for asbestos fibers consisted of fiber m orphology, visual selected a re a electron diffraction (S A E D ) and elem ental chemical analysis by energy dispersive spectroscopy (E D S ), supplemented by the m easurem ent and interpretation of micrographs of several selected S A E D patterns. The samples were analyzed at a m agnification of 1 ,0 0 0 X . Particles m eeting the definition of a fiber > 5 pm in length, > 0 .2 5 pm in width, and having a length to width aspect ratio > 3:1 w e re classified as chrysotile, am phibole asbestos, amphibole cleavage, or transitional fiber. T h e attached table lists each sam p le identification num ber, filter area, volum e, a re a analyzed, asbestos fiber counts (f5), analytical sensitivity, concentration of asbestos (f/cc), total fibers counted (F s), and asbestos fiber ratio (fs/Fs). Copies of the count sheets a re presented in Appendix A. E ach sheet contains sam ple information pertaining to structure identification, dimensions, magnification, filter size, and type. RJ L ee G roup, Inc. is accredited by the N ational Voluntary Laboratory Accreditation Program (N V L A P ), New York Departm ent of Health Environmental Laboratory Approval Program (ELAP), and by the Am erican Industrial H ygiene Association (A IH A ). This report relates only to the item s tested and shall not be reproduced except in full. N V L A P accreditation d oes not imply endorsem ent b y N V L A P or a ny a gen cy of the U S governm ent. T h e s e resuits a re subm itted pursuant to RJ Lee G ro u p 's current term s and conditions of sale, including the com pan y's standard w arranty and limitation of liability provisions. No responsibility or liability is assum ed for the m an ner in which the results a re used or interpreted. Unless notified in writing to return the sam ples covered in this report, RJ Lee G roup will store the sam ples for a period of 3 0 days before discarding. A shipping and handling fe e will be assessed for the return of any sam p les. If you have any questions, please feel free to call m e. Sincerely, Drew R. Van Orden, PE Senior Scientist -- Page 1 on 2 ---- Monroeville, PA San Leandro, CA Washington, DC Richland, WA TEST REPORT Asbestos Concentrations and Fiber Ratios N IO S H 7402 Analysis Project LSH 006444-3 RJLG Sam ple Number 0 1 14780HT 0114781 HT 0 1 14782HT Client Sam ple Number F-11 F-12 F-13 Filter Area (m m 2) 385 385 385 Volum e (Liter) 190.0 300.0 120.0 Area A n a ly ze d (m m 2) 0 .1 1 5 5 0 .0 9 0 8 0 .1 4 8 5 Asbestos Fibers (V 1 0 0 Analytical Sensitivity (f/cc) 0 .0 1 7 5 0.0141 0 .0 2 1 6 Asbestos Concentration (f/cc) 0.0175 < 0 .0 1 4 1 < 0 .0 2 1 6 Total Fibers (Fs) 1 0 3 .5 9 8 .0 1 0 1 .5 Fiber Ratio (VF.) 0.01 0 0 A n aly sis D ate 1 1 /1 6 /0 0 1 1 /1 6 /0 0 1 1 /2 0 /0 0 F-11 F-12 F -1 3 Below mill crusher C enter mills 1, 2, 3 Over packer - NYTAL 300 V olum es provided by R. T. Vanderbilt C o m p an y, Inc. w e re u se d to calculate analytical results and sensitivities. A nalytical sensitivity is c alcu lated b ased on one structure in the a re a analyzed . Page 2 of 12 RJ Lee Group, Inc. Count Sheet Client Nam e Project Number RJLG Sample # Client Sam ple # M icrosco p e Accelerating Voltage M a g n ifica tio n Analyst E D S Disk R. T. Vanderbilt Com pany, Inc. L S H 0 0 6 4 4 4 -3 0114780HT F -1 1 / B elow mill crusher 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings T otal Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ 18755 14 1 102.5 CE 385 mm2 190.0 Liters 0.0083 mm2 1 Field Fiber 1 0.5 1 1 1 1 1 1 1 1 1 1 1 1 2 1 2 0.5 2 1 2 1 2 1 2 0.5 2 0.5 2 1 2 1 2 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 3 1 4 0.5 4 0.5 4 1 4 1 4 1 4 1 4 1 4 1 4 1 5 1 5 1 Length |im 11.00 20.00 17.00 40.00 9.00 11.00 12.50 8.20 17.00 11.25 7.00 8.00 12.50 7.50 5.50 6.50 17.00 8.25 11.00 10.25 10.50 11.00 8.50 5.20 10.00 6.75 13.50 9.50 6.50 12.00 7.25 6.00 11.00 25.00 6.00 5.75 10.50 8.50 5.20 8.50 Width urn Structure Type Morph EDS 2.00 Amphibole X 3.00 Nonasbestos X 2.00 Nonasbestos X 1.10 Nonasbestos X 0.40 Nonasbestos X 1.00 Amphibole 291 0.50 Nonasbestos 290 0.30 Nonasbestos 0.60 Nonasbestos 0.70 Nonasbestos 0.80 Nonasbestos 1.50 Amphibole X 2.50 Nonasbestos X 0.30 Nonasbestos X 1.20 Amphibole X 1.10 Amphibole X 0.30 Nonasbestos X 0.80 Amphibole X 0.35 Nonasbestos X 1.10 Amphibole X 0.90 Amphibole X 1.50 Amphibole X 0.50 Nonasbestos 0.90 Nonasbestos 2.50 Nonasbestos 0.80 Nonasbestos 0.35 Nonasbestos 0.30 Nonasbestos 1.00 Nonasbestos X 1.10 Nonasbestos X 1.00 Amphibole X 0.90 Amphibole X 1.10 Amphibole X 1.10 Nonasbestos 0.40 Nonasbestos X 0.50 Nonasbestos 1.75 Amphibole X 2.00 Amphibole X 0.40 Amphibole X 0.60 Nonasbestos Photo SAED Amphibole Type Comment X X X X X 29817 29815 X X X X X X X X X X X X X X X X X X X X X X X X X X X X Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite T remolite Tremolite T remolite Tremolite Tremolite Tremolite Tremolite Tremolite Cleavage TF TF TF TF Cleavage TF TF TF TF TF Cleavage TF TF Cleavage Cleavage TF Cleavage TF Cleavage Cleavage Cleavage TF TF TF TF TF TF TF TF Cleavage Cleavage Cleavage TF TF TF Cleavage Cleavage Cleavage TF Page 4 of 12 RJ Lee Group, Inc. Count Sheet Client N am e Project Number RJLG Sample # Client Sample # M icrosco p e Accelerating Voltage M ag n ificatio n Analyst ED S Disk R. T. Vanderbilt Com pany, Inc. L S H 0 06 44 4-3 0 1 14780HT F -1 1 / Below mill crusher 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter Volum e Grid Opening Area Dilution Factor HQ 18755 14 1 102.5 CE 385 mm5 1 90 .0 Liters 0.0083 mm2 1 Field Fiber 5 0.5 5 0.5 5 1 5 1 5 1 5 1 5 0.5 5 1 5 1 5 1 6 1 6 1 6 1 6 1 6 1 7 1 7 1 7 1 7 1 7 1 7 1 7 1 7 1 7 1 8 1 8 1 8 1 8 1 8 1 8 1 8 1 8 1 8 1 9 0.5 9 0.5 9 1 10 0.5 10 1 10 1 10 1 Length pm 22.00 23.00 10.00 6.00 9.50 12.50 12.50 10.00 8.30 5.40 10.00 7.00 10.00 7.25 5.40 22.00 6.00 7.00 5.50 12.50 7.50 17.50 7.00 10.00 6.50 7.50 10.00 16.00 6.00 10.00 5.50 12.50 5.50 6.50 7.00 7.50 24.00 6.50 26.00 6.00 Width run Structure Type Morph EDS 0.50 Nonasbestos 0.65 Nonasbestos 0.40 Chrysotile 0.60 Nonasbestos X 1.40 Amphibole X 1.50 Nonasbeslos 0.50 Nonasbestos X 2.00 Nonasbestos 0.60 Nonasbestos 1.25 Amphibole X 3.00 Amphibole X 0.80 Amphibole X 2.50 Amphibole X 0.40 Nonasbestos 0.90 Nonasbestos 1.50 Nonasbestos X 1.50 Amphibole X 1.00 Amphibole X 0.35 Amphibole X 0.50 Nonasbestos B 0.40 Nonasbestos 0.30 Nonasbestos 0.20 Nonasbestos 1.00 Nonasbestos X 1.40 Amphibole X 0.70 Amphibole X 0.30 Nonasbestos 2.00 Amphibole X 2.00 Amphibole X 0.50 Nonasbestos 0.80 Nonasbestos 0.50 Nonasbeslos 1.00 Amphibole X 0.70 Amphibole X 2.00 Nonasbestos X 0.50 Nonasbestos X 1.00 Nonasbestos X 1.00 Amphibole X 0.50 Nonasbestos 1.20 Amphibole X Photo SAED Amphibole Type Comment X X 29822 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite T remolite Tremolite T remolite Tremolite Tremolite Tremolite Tremolite TF TF TF Cleavage TF TF TF TF Cleavage Cleavage Cleavage Cleavage TF TF TF Cleavage Cleavage Cleavage TF TF TF TF TF Cleavage Cleavage TF Cleavage Cleavage TF TF TF Cleavage Cleavage TF TF TF Cleavage TF Cleavage Page 5 of 12 RJ Lee Group, Inc Count Sheet Client N am e Project Number RJLG Sample # Client Sam ple # M icrosco p e Accelerating Voltage Magnification Analyst EDS Disk R. T. Vanderbilt Company, Inc. LSH006444-3 0 1 14780HT F -1 1 / Below mill crusher 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 14 1 102.5 CE 385 mm' 190.0 Liters 0.0083 mm2 1 Field Fiber 10 1 10 1 10 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 12 0.5 12 1 12 1 12 1 12 1 12 1 12 1 13 0.5 13 0.5 13 1 13 1 13 1 13 1 13 1 13 1 13 1 14 0.5 14 0.5 14 1 14 1 14 1 14 1 Length pm 8.00 5.50 17.00 6.50 7.00 5.50 7.00 6.00 6.00 7.00 15.00 12.00 7.00 18.00 16.00 17.00 19.00 6.00 5.50 8.00 5.50 6.00 7.00 8.00 5.50 10.00 15.50 8.00 8.00 13.00 18.50 9.00 Width pm Structure Type Morph EDS 1.00 Amphibole X 0.30 Nonasbestos 2.00 Nonasbestos X 0.30 Nonasbestos 0.60 Amphibole X 1.00 Nonasbestos 0.50 Nonasbestos 0.90 Nonasbestos 0.70 Amphibole X 0.80 Nonasbestos 1.50 Nonasbestos X 2.50 Amphibole X 0.50 Nonasbestos 2.50 Amphibole X 3.00 Nonasbestos 1.00 Nonasbestos 0.40 Nonasbestos 0.60 Nonasbestos X 0.60 Nonasbestos 0.50 Nonasbestos X 1.00 Nonasbestos X 1.00 Amphibole X 1.30 Amphibole X 1.75 Amphibole X 1.25 Amphibole X 2.50 Amphibole X 1.10 Nonasbestos X 0.45 Amphibole M X 0.60 Nonasbestos X 3.20 Nonasbestos X 2.50 Amphibole X 1.75 Amphibole X Photo SAED Amphibole Type Comment X Tremolile Cleavage X TF TF X TF X T remolite Cleavage X TF X TF X TF X Tremolite Cleavage X TF X TF X Tremolite Cleavage X TF X Tremolile Cleavage X TF X TF X TF TF X TF X TF X TF X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X Tremolile Cleavage X Tremolite Cleavage X TF X Tremolile Cleavage X TF X TF X Tremolite Cleavage X Tremolite Cleavage Page 6 of 12 RJ Lee Group, Inc. Count Sheet Client Nam e Project Number RJLG Sample # Client Sample # M icrosco p e Accelerating Voltage Magnification Analyst ED S Disk R. T. Vanderbilt Com pany, Inc. L S H 0 06 44 4-3 0114781HT F -1 2 /C e n t e r mills 1 , 2 , 3 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening A rea Dilution Factor HQ 18755 11 0 98 CE 385 mm2 3 0 0 .0 Liters 0.0083 mm2 1 Field Fiber 1 0.5 1 1 1 1 1 1 1 0.5 1 0.5 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 0.5 3 1 3 0.5 3 1 3 1 3 1 3 0.5 3 0.5 3 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 5 1 5 1 5 1 Length urn 5.75 6.50 8.25 17.00 13.00 24.00 13.00 8.25 7.50 20.00 8.50 12.00 7.00 6.00 10.00 6.75 6.00 6.50 8.50 6.25 9.00 5.25 19.00 13.50 8.50 11.50 37.00 7.00 7.00 6.00 6.00 8.00 8.00 8.50 7.50 23.00 6.50 10.00 10.00 22.00 Width pm Structure Type Morph EDS 0.50 Nonasbestos X 1.00 Nonasbestos X 0.60 Nonasbestos 296 1.50 Nonasbestos 295 1.20 Nonasbestos X 5.25 Amphibole X 2.00 Nonasbestos X 2.00 Amphibole X 1.90 Amphibole X 3.50 Amphibole X 2.00 Nonasbestos X 0.50 Amphibole X 1.50 Amphibole X 0.70 Amphibole X 1.75 Amphibole 297 0.50 Nonasbestos M 0.50 Nonasbestos 0.45 Nonasbestos 1.50 Amphibole X 1.20 Amphibole X 1.00 Nonasbestos 0.40 Nonasbestos M 0.50 Nonasbestos M 1.00 Nonasbestos X 2.00 Nonasbestos X 2.00 Nonasbestos X 2.00 Nonasbestos X 0.50 Nonasbestos X 1.00 Nonasbestos X 1.00 Amphibole X 1.00 Nonasbestos X 1.00 Nonasbestos X 2.00 Amphibole X 1.50 Nonasbestos X 0.40 Nonasbestos X 3.00 Nonasbestos X 1.20 Nonasbestos X 0.30 Nonasbestos X 2.00 Amphibole X 0.90 Nonasbestos X Photo SAED Amphibole Type Comment 29830 29828 X X 29832 X X X X X X X X X X X X X X X X X X X X X Tremolile T remolite Tremolite Tremolile Tremolite Tremolite Tremolite T remolite Tremolite Tremolite Tremolite Tremolite Tremolite TF TF TF TF TF Cleavage TF Cleavage Cleavage Cleavage TF Cleavage Cleavage Cleavage Cleavage TF TF TF Cleavage Cleavage TF TF TF TF TF TF TF TF TF Cleavage TF TF Cleavage TF TF TF TF TF Cleavage TF Page 7 of 12 RJ Lee Group, Inc. Count Sheet Client N am e Project Number RJLG Sample # Client Sam ple # Microscope Accelerating Voltage M ag n ifica tio n Analyst ED S Disk R. T . Vanderbilt C om pany, Inc. L S H 0 0 6 4 4 4 -3 0114781HT F-12 / C enter mills 1 , 2 , 3 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 11 0 98 CE 385 mm2 300.0 Liters 0.0083 mm2 1 Field Fiber 5 1 5 1 5 1 5 1 5 1 5 1 6 1 6 1 6 1 6 1 6 1 6 1 6 1 6 1 7 1 7 1 7 1 7 1 7 1 7 1 7 1 8 0.5 8 1 8 1 8 1 8 1 8 1 8 1 8 1 9 0.5 9 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 9 1 Length pm 9.00 17.00 9.00 15.00 5.40 47.00 16.00 8.50 15.00 14.00 5.50 21.50 7.00 5.20 11.00 5.50 5.10 9.00 9.00 6.00 15.00 15.50 9.50 5.50 8.50 7.50 10.00 8.00 15.00 6.00 10.50 5.20 23.50 23.00 6.50 6.00 8.00 7.50 8.00 6.00 Width pm Structure Type Morph EDS 0.50 Amphibole X 5.00 Nonasbestos X 0.50 Nonasbestos X 2.00 Amphibole X 0.30 Nonasbestos X 2.50 Nonasbestos X 0.30 Nonasbestos X 0.50 Nonasbestos X 2.00 Amphibole X 1.00 Nonasbestos X 1.00 Amphibole X 1.00 Nonasbestos X 0.50 Amphibole X 0.30 Nonasbestos X 1.50 Amphibole X 0.60 Nonasbestos X 0.80 Amphibole X 1.00 Amphibole X 1.50 Amphibole X 0.40 Nonasbestos X 1.30 Nonasbestos X 0.50 Nonasbestos X 1.00 Nonasbestos X 0.60 Nonasbestos X 2.00 Nonasbestos X 1.00 Nonasbestos X 1.50 Nonasbestos X 2.50 Nonasbestos X 3.00 Nonasbestos X 0.50 Nonasbestos X 1.00 Nonasbestos X 0.60 Nonasbestos X 0.50 Nonasbestos X 3.20 Amphibole X 1.50 Nonasbestos X 0.40 Amphibole X 0.50 Nonasbestos X 1.00 Nonasbestos X 0.90 Nonasbestos X 1.90 Amphibole X Photo SAED Amphibole Type Comment X Tremolite Cleavage X TF X TF X Tremolite Cleavage X TF X TF X TF X TF X Tremolite Cleavage X TF X Tremolite Cleavage X TF X Tremolite Cleavage X TF X Tremolite Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X TF X TF X TF X TF X TF X TF X TF X TF X TF X TF X TF X TF X TF X TF X Tremolite Cleavage X TF X Tremolite Cleavage X TF X TF X TF X Tremolite Cleavage Page 8 of 12 RJ Lee Group, Inc Count Sheet Client N am e Project Number RJLG Sam ple # Client Sam ple # M icros co p e Accelerating Voltage Magnification Analyst E D S Disk R. T . Vanderbilt C om pany, Inc. L S H 0 06 44 4-3 0114781HT F -12 / C enter mills 1 ,2 , 3 2000 FX 120 Kv 1,000 X TW S/LH RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 11 0 98 CE 385 mm2 3 0 0 .0 Liters 0.0083 mm2 1 Field Fiber 9 1 10 0.5 10 1 10 1 10 1 10 1 10 1 10 1 10 1 10 1 10 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 11 1 Length pm 7.50 15.50 8.00 5.20 9.00 16.00 21.00 6.00 7.00 18.00 7.50 6.00 20.00 7.50 5.50 9.00 8.00 6.00 6.50 6.00 8.20 28.50 5.50 Width pm 1.50 1.50 0.30 0.80 0.40 2.00 1.00 0.70 0.60 2.50 1.00 0.80 6.00 0.60 1.00 2.00 2.00 0.50 2.00 1.50 0.30 0.70 0.70 Structure Type Amphibole Nonasbestos Nonasbestos Nonasbestos Nonasbestos Nonasbestos Nonasbestos Nonasbestos Amphibole Nonasbestos Nonasbestos Non asbestos Nonasbestos Amphibole Nonasbestos Amphibole Amphibole Nonasbestos Amphibole Amphibole Nonasbestos Nonasbestos Nonasbestos Morph EDS X X X X X X X X X X X X X X X X X X X X X X X Photo SAED Amphibole Type Comment X Tremolite Cleavage X TF X TF X TF X TF X TF X TF X TF X Tremolite Cleavage X TF X TF X TF X TF X Tremolite Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X TF X TF X TF Page 9 of 12 RJ Lee Group, Inc. Count Sheet Client Nam e Project Number RJLG Sample # Client Sample # M icrosco p e Accelerating Voltage Magnification Analyst EDS Disk R. T. Vanderbilt Com pany, Inc. L S H 0 06 44 4-3 0 1 14782HT F-13 / Over packer - NYTAL 300 2000 FX 120 Kv 1,000 X TW S/BF RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 18 0 101.5 CE 385 mm2 120 .0 Liters 0.0083 mm2 1 Field Fiber 1 0.5 1 0.5 1 1 1 0.5 1 1 1 1 1 1 1 0.5 1 1 1 1 2 0.5 2 1 2 1 2 0.5 2 1 2 1 2 0.5 2 1 2 1 2 1 3 1 3 1 3 1 3 1 3 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 5 0.5 5 1 5 1 5 1 5 0.5 5 1 6 1 6 1 Length pm 6.00 9.50 10.25 9.00 7.50 8.00 7.25 6.25 9.00 12.00 7.00 10.00 7.25 5.25 5.50 6.75 11.00 14.50 6.00 16.00 8.50 8.00 8.25 11.50 7.00 10.50 8.00 7.50 5.25 35.00 21.00 8.00 7.00 7.00 6.50 11.50 20.00 11.50 11.00 12.50 Width Structure Type Morph EDS 1.30 Amphibole X 2.00 Nonasbestos X 2.20 Amphibole X 1.50 Nonasbestos X 0.70 Nonasbestos 299 2.00 Amphibole X 1.75 Amphibole 298 1.10 Amphibole X 0.80 Nonasbestos X 2.50 Nonasbestos X 0.50 Amphibole X 2.40 Nonasbestos X 1.10 Amphibole 0.30 Nonasbestos M 0.60 Nonasbestos X 1.30 Amphibole X 0.50 Nonasbestos X 3.00 Nonasbestos X 1.10 Amphibole X 1.80 Nonasbestos X 1.50 Amphibole 2.00 Amphibole 1.10 Amphibole 0.35 Nonasbestos 0.50 Nonasbestos 1.30 Amphibole 0.80 Nonasbestos X 0.80 Amphibole 0.60 Amphibole 5.00 Amphibole X 2.20 Nonasbestos X 0.90 Amphibole 0.90 Amphibole X 0.80 Nonasbestos 1.00 Nonasbestos 0.50 Nonasbestos 5.00 Amphibole X 0.40 Nonasbestos 1.00 Amphibole 3.00 Amphibole X Photo SAED Amphibole Type Comment X X X X 29836 X 29834 X X X X X X X X X X X X X X X X X X X X X X X X X Tremolile Tremolile Trem olite Tremolile Tremolile Tremolile Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Tremolite Cleavage TF Cleavage TF TF Cleavage Cleavage Cleavage TF TF Cleavage TF Cleavage TF TF Cleavage TF TF Cleavage 1F Cleavage Cleavage Cleavage TF TF Cleavage TF Cleavage Cleavage Cleavage TF Cleavage Cleavage TF TF TF Cleavage TF Cleavage Cleavage Page 10 of 12 RJ Lee Group, Inc Count Sheet Client N am e Project Number RJLG Sam ple # Client Sam ple # M icros co p e Accelerating Voltage M ag n ificatio n Analyst EDS Disk R. T . Vanderbilt Com pany, Inc. L S H 0 0 6 4 4 4 -3 0114782HT F-13 / Over packer - NYTAL 300 2000 FX 120 Kv 1,000 X TW S/BF RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 18 0 101.5 CE 385 mm' 120.0 Liters 0.0083 mm2 1 Field Fiber 6 0.5 6 1 6 1 6 1 6 0.5 6 1 7 1 7 1 7 1 7 1 8 1 8 1 8 1 9 0.5 9 0.5 9 0.5 9 1 9 1 9 1 9 1 10 0.5 10 1 10 1 11 1 11 1 12 1 12 1 12 1 12 1 12 1 13 0.5 13 1 13 1 13 1 13 1 14 1 14 1 14 1 14 1 14 1 Length um 10.25 5.50 7.00 18.00 5.75 7.00 8.50 7.75 5.75 9.75 7.50 8.00 8.50 10.50 6.50 9.00 18.00 5.75 5.50 6.50 6.00 5.50 9.50 6.50 12.50 6.50 5.20 6.80 7.00 20.00 19.00 5.20 5.50 16.00 6.10 7.00 7.30 9.30 7.00 6.00 Width tim Structure Type Morph EDS 0.40 Nonasbestos 1.00 Nonasbestos 1.50 Nonasbestos X 1.50 Amphibole 0.90 Nonasbestos 0.50 Nonasbestos 1.75 Amphibole 0.40 Nonasbestos 0.50 Nonasbestos 0.75 Nonasbestos 0.60 Nonasbestos 0.75 Nonasbestos 0.40 Nonasbestos 0.80 Amphibole 1.50 Amphibole 0.45 Nonasbestos 1.00 Amphibole 0.90 Amphibole O.90 Amphibole X 0.80 Nonasbestos 1.00 Nonasbestos 1.00 Amphibole 1.00 Nonasbestos 1.80 Amphibole X 0.50 Nonasbestos 0.80 Nonasbestos 0.60 Amphibole X 1.00 Amphibole X O.40 Nonasbestos X 3.00 Amphibole X 2.50 Amphibole X 0.50 Amphibole 0.80 Amphibole 1.50 Nonasbestos B 0.60 Amphibole X 1.00 Nonasbestos 0.70 Nonasbestos X 1.00 Amphibole 1.00 Nonasbestos X O.80 Amphibole X Photo SAED Amphibole Type Comment X TF X TF TF X Tremolile Cleavage X TF X TF X Tremolite Cleavage X TF X TF X TF X TF X TF X TF X Tremolile Cleavage X Tremolite Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X TF X TF X Tremolite Cleavage X TF X Tremolite Cleavage X TF X TF X Tremolite Cleavage X Tremolite Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X TF X Tremolite Cleavage X TF X TF X Tremolite Cleavage X TF X Tremolite Cleavage Page 11 of 12 RJ Lee Group, Inc. Count Sheet Client N am e Project Number RJLG Sample # Client Sam ple # M icro sco p e Accelerating Voltage Magnification Analyst ED S Disk R. T. Vanderbilt C om pany, Inc. L S H 0 06 44 4-3 0 1 14782HT F-13 / Over packer - NYTAL 300 2000 FX 120 Kv 1 .0 0 0 X TW S/BF RJLG QA Number Grid Openings Total Asbestos Total Non-Asbestos Filter V o lu m e Grid Opening Area Dilution Factor HQ18755 18 0 101.5 CE 385 mm2 120 .0 Liters 0.0083 mm2 1 Field Fiber 14 1 14 1 15 1 15 1 15 1 15 1 15 1 15 1 15 1 15 1 16 0.5 16 0.5 16 0.5 16 0.5 16 0.5 16 1 16 1 16 1 16 1 17 0.5 17 1 17 1 17 1 17 1 17 1 17 1 17 1 17 1 18 0.5 18 1 18 1 18 1 18 1 Length jim 6.50 9.90 15.00 9.50 16.00 6.00 14.00 5.20 6.50 8.50 10.40 7.30 18.50 7.00 9.00 5.20 6.30 6.50 8.00 15.00 6.00 5.50 7.00 7.50 9.50 7.00 6.00 9.00 6.00 14.00 6.50 7.0 14.00 Width pm Structure Type Morph EDS 1.00 Amphibole X 2.20 Amphibole X 2.00 Amphibole 2.30 Amphibole 2.00 Amphibole X 0.60 Amphibole X 1.60 Amphibole X 1.00 Nonasbestos 1.50 Nonasbestos X 1.60 Nonasbestos X 0.60 Nonasbestos 1.20 Amphibole 3.50 Amphibole X 0.40 Amphibole X 1.40 Amphibole 0.50 Nonasbestos 1.20 Amphibole 0.50 Amphibole 2.00 Nonasbestos 2.00 Nonasbestos X 0.40 Amphibole 0.60 Nonasbestos X 0.50 Nonasbestos 1.00 Amphibole 0.60 Nonasbestos X 1.00 Amphibole 0.26 Amphibole 0.60 Amphibole 0.60 Nonasbestos B 0.90 Amphibole 0.60 Amphibole 0.40 Nonasbestos 1.10 Nonasbestos X Photo SAED Amphibole Type Comment X Tremolile Cleavage X Tremolite Cleavage X Tremolile Cleavage X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X TF X TF X TF X TF X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X Tremolite Cleavage X TF X Tremolile Cleavage X Tremolite Cleavage X TF X TF X Tremolite Cleavage X TF X TF X Tremolite Cleavage TF X Tremolite Cleavage X Tremolite Cleavage X Tremolile Cleavage X TF X Tremolite Cleavage X Tremolite Cleavage X TF X TF Page 12 of 12 OCCUPATIONAL EXPOSURE TO TALC CONTAINING ASBESTOS M orbidity, M o rta lity , and Environmental Studies o f Miners and M ille rs I . Environmental Study 11. Cross Sectional Morbidity Study I I I . Retrospective Cohort Study of Mortality John M. Dement^ Ralph D. Zumwaldel John F. Gambie^ William Fellner^ Michael J . DeMeo^ David P. Brownl Joseph K. Wagoner^ U .S . Department of Health, Education, and Welfare Public Health Service Center for Disease Control National I n s t i t u t e fo r Occupational Safety and Health D ivision o f S u r v e illa n c e , Hazard Evaluations and F ie ld Studies C in c in n a t i, Ohio 45226 2Di v i s ion o f Respiratory Disease Studies Morgantown, West V irg in ia 26505 ^Occupational S a fe ty and Health Administration, DOL Washington, D.C. 20210 February, 1980 F o r tale b y t h e S u p e r i n t e n d e n t o f D o c u m e n ts , U .S . G o v e rn m e n t P rin tin g O ffice, W ashington, D .C . 20402 Appendix. Summary Statistics for NIOSH 1975 Industrial Hygiene Study (Tables A - 1 through A-10). Table A - 1 Summary of Fiber Exposures in Mine Operations as Determined by Optical Microscopy Operation or Job Fiber >5 pm in Length per cc Range of Individual S a m p les Mean (+ SE) of Individual Samples Median of Individual Samples TimeWe igh ted Average Crusher Operator (4) 7.7 - 14.7 10.3 + 1 .5 9.3 9.8 Trammer (25) 2.3 - 14.6 6.4 + 0.7 5 .1 5.6 Driller (5) 0.9 - 6.8 3.9 + 1 .0 4.6 3 .0 Cageman (5) 6.0 - 18.2 10.3 + 2.1 8.4 9.5 Blacksmith (3) 1 .2 - 4 .4 3.1 + 1 .0 3.7 2.6 Mechanic (12) 0.2 - 3.9 1.9 + 0.3 1 .9 1 .7 ( ) Number of samples SE Standard error 97 TABLE A - 2 Summary of Fiber Exposures in Mill Operations as Determined by Optical Microscopy Operation or Job Mill Foreman (9) General Laborer (5) Crusher Operator (16) Hardinge Operator (14) wheeler Operator (14) Packer (48) Packer Serviceman (11) pa'ckhouse Foreman (5) Fork Lift Operator (15) Rail Car Liner (3) Bulk Car Loader (3) Millwright (3) Instrument Repairman (6) Machinist (3) Millwright Helper (2) Sheet Metal Worker (3) Oiler (4) Welder (3) ( ) Number of samples SE Standard error Range of Individual Samples 2.4 - 16.0 1.5 - 13.2 1.7 - 11.6 1.7 - 26.8 2.6 - 29.1 0.2 - 21.0 1.6 - 8.3 1 . 0 - 1.9 1 . 1 - 8.3 1 . 3 - 5.6 1 . 6 - 2.4 0.9 - 2.6 1 . 2 - 4.0 0.3 - 3.6 0.7 - 8.9 1 . 2 - 2.2 1 . 7 - 4.5 0.8 - 3.1 Fiber >5 urn in Length per cc Mean (+ SE) of Individual Sample s Median of Ind ividua1 Samples 5.8 + 1.4 5.8 + 2.0 5.5 +_ 0.9 8.7 + 1.8 9.9 + 2.1 6.9 + 0.6 4.9 + 0.7 1.5 + 0.2 4.5 + 0.5 3.8 + 1.0 1.9 + 0.2 1.9 + 0.5 2.8 + 0.4 1.5 + 1.1 4.8 + 4.1 1.8 + 0.3 3.6 + 0.7 1.8 + 0.7 4.7 5.5 4.7 6.4 6.5 6.1 5.5 1.6 4.6 4.1 1.8 2.3 3 .0 0.5 4.8 1.9 4. 1 1.6 TimeWeighted Average 5 .3 5.6 5.1 7.9 8.4 5.1 3.6 1.5 4.0 3.4 2.0 1.9 2.8 1.8 4 .0 1.7 4.0 1.9 RJ LeeGroup, Inc. 350 Hochberg Road Monroeville, PA 15146 Tel: (724) 325-1776 Fax: (724) 733-1 799 The Materials Characterization Specialists November 22, 2000 Mr. John W . Kelse R. T. Vanderbilt Com pany, Inc. 30 Winfield Street Norwalk, C T 06856-5150 RE: PLM Evaluation of Talc Sam ples RJ Lee Group Job No.: LS H 006444 D ear Mr. Kelse: RJ Lee Group has com pleted the analysis of several samples of talc. The procedure used for these analyses is b as ed on a procedure developed by Dr. Ann W ylie. Basically, a known m ass of sam ple is placed on a clean glass slide to which is added several drops of 1 .5 9 8 refractive index oil. Tw en ty percent of the slide is exam ined in a polarizing light m icroscope; the dim ensions of every particle with an aspect ratio of at least 3:1 (length to width) are recorded. T h e m inerals w ere identified as talc, tremolite, anthophyllite, or "transitional" according to the following system: M in e ra l Talc a, Rl jl L < 1.598 < 1.598 T ransitional < 1.598 > 1.598 Amphibole > 1.598 > 1.598 In addition, the particles w e re classified as "fiber" or "cleavage" using a consensus definition. Particles classified as "fiber" are asbestiform and show evidence of high aspect ratio, bundles, splayed ends, and curvature. Splayed ends are generally indicative of bundles of asbestiform fibers. T h e re w ere several high aspect ratio transitional particles which did not m eet the consensus definition of asbestiform (generally not displaying evidence of curvature or splayed ends). Seven samples were submitted for analysis (N Y TA L 100, NYTAL 200, NYTAL 300, NYTAL 400, N Y TA L 330 0, N Y TA L 7700, and IT-3X ). This preliminary report discusses the data generated on the N Y T A L 100 and N Y T A L 3 0 0 sam ples, with partial analyses of the other sam ples. A nalyses of the rem aining sam ples are progressing and will be reported as they become available. _--_ -- - -- page TDT8 ~ ' Monroeville, PA San Leandro, CA Washington, DC Richland, WA www.rjlg.com Table 1 shows the concentration of the particles with aspect ratios of at least 3:1. The table shows two m easures of concentrations, particles/mg of sam ple and weight percent. In the sam ples, the particle type with the largest concentration is tremolite. V ery few anthophyllite particles w ere observed in any sam ple. T a b le 2 shows the concentration of all asbestiform fibers observed in these sam ples. In the samples, only talc fibers w ere observed to be asbestiform; all other particles are cleavage fragm ents. V ery few asbestiform fibers w ere observed with an aspect ratios less than 5:1. Figure 1 com pares the average lengths for the principal mineral components of the Nytal products. Figures 2 and 3 show the average width and aspect ratios for the sam ple products. Figure 4 shows the particle num ber concentration and particle weight percent for each analyzed product. RJ Lee Group, Inc. is accredited by the National Voluntary Laboratory Accreditation Program (NVLAP), New York Departm ent of Health Environmental Laboratory Approval Program (ELAP), and by the American Industrial Hygiene Association (AIHA). This report relates only to the items tested and shall not be reproduced except in full. N V LA P accreditation does not imply endorsem ent by N VLA P or any agency of the US government. These results are submitted pursuant to RJ Lee Group's current terms and conditions of sale, including the company's standard warranty and limitation of liability provisions. N o responsibility or liability is assum ed for the m anner in which the results are used or interpreted. Unless notified in writing to return the sam ples covered in this report, RJ Lee G roup will store the sam ples for a period of 3 0 days before discarding. A shipping and handling fee will be assessed for the return of any sam ples. If you have any questions, please feel free to call m e. Sincerely, Drew R. Van Orden, PE Senior Scientist Page 2 of 8 Table 1. Concentration of All Mineral Particles With An Aspect Ratio of At Least 3:1 Product Nytal 100 Nytal 300 Slide M in era l p artic le /m g 3:1 -5 :1 >5:1 >3:1 1 Tremolite 353 Anthophyllite Transitional 16 Talc 16 839 1,193 12 12 265 281 189 205 2 Tremolite 289 Anthophyllite T ransitional Talc 15 1,042 6 66 114 1,331 6 66 129 3 Tremolite 375 Anthophyllite Transitional 6 Talc 2 1,288 4 101 230 1,663 4 107 233 1 Tremolite 843 Anthophyllite Transitional 12 Talc 3.638 12 341 1,056 4,481 12 353 1,056 2 Tremolite 18 Anthophyllite Transitional Talc 3,395 3,412 272 272 727 727 3 Tremolite 361 Anthophyllite Transitional 8 Talc 16 3,453 4 261 1,044 3 ,8 1 4 4 269 1,060 Particle W t, % 3:1 -5:1 >5:1 >3:1 4.39 0.19 0.21 2.02 < 0 .0 1 3.09 0.31 6.41 < 0 .0 1 3.28 0.52 4.09 0.03 2.69 0.01 0.37 0.08 6.77 0.01 0.37 0.11 6.78 0.06 < 0 .0 1 1.04 0.07 3.58 < 0 .0 1 1.03 0.14 1.29 0.01 0.57 0.37 10.35 < 0 .0 1 1.09 0.15 2.33 0.01 0.64 0.37 < 0 .0 1 0.63 0.64 0.44 0.01 0.03 0.31 0.08 1.24 < 0 .0 1 0.35 0.17 0.31 0.08 1.68 < 0 .0 1 0.36 0.20 Page 3 of 8 T a b le 1. C oncentration of All M ineral Particles W ith An A spect Ratio of At Least 3:1 (continued) p artic le /m g Product Slide M in era l 3:1 -5 :1 >5:1 >3:1 Nytal 3300 1 Tremolite 337 Anthophyllite Transitional 18 Talc 4,376 18 285 1,318 4,713 18 302 1,318 Nytal 7700 Nytal 200 Nytal IT-3X 1 Tremolite Anthophyllite T ransitional Talc 1 T remolite Anthophyllite T ransitional Talc 1 Tremolite AnthODhvllite Transitional Talc 123 5 166 13 26 206 4 110 35 4,486 11 277 2 ,0 5 0 1,748 4,609 11 277 2,050 1,914 145 950 1,310 101 1,117 4,844 158 977 1,516 105 1,226 4,880 Particle W t, % 3:1 - 5:1 >5:1 >3:1 0.28 0.24 0.89 0.01 0.55 0.35 1.17 0.01 0.79 0.35 0.04 < 0 .0 1 0.49 0.27 < 0 .0 1 0.33 0.15 1.80 0.31 < 0 .0 1 0.33 0.15 2.30 0.08 0.11 1.20 0.06 0.84 0.48 0.72 0.63 1.52 0.02 3.45 2.20 0.79 0.74 2.73 0.09 4.29 2.68 Table 2. Concentration of All Asbestiform Mineral Fibors With An Aspect Ratio of At Least 3:1 Product Slide Mineral Nytal 100 Nytal 300 Nytal 3300 Nytal 7700 Nytal 200 Nytal IT-3X 1 Tale 2 Tale 3 Tale 1 Tale 2 Tale 3 Tale 1 Tale 1 Tale 1 Tale 1 Tale F ib er/m g 3:1 - 5:1 >5:1 104 60 128 707 477 879 1,099 1,895 4 381 13 2,961 >3:1 104 60 128 707 477 879 1.099 1,895 385 2,974 Fiber W t.% 3:1 -5 :1 >5:1 >3:1 0.02 0.05 0.06 0.02 0.05 0.06 0.29 0.05 0.11 0.29 0.05 0.11 0.32 0.32 < 0 .0 1 0.02 0.13 0.30 1.76 0.13 0.31 1.78 P a n n nf ft I Figure 1. Comparison of particle length (pm ) for Nytal products; all particles > 3:1. 14 Nytal 100 Nytal 200 Nytal 300 Nytal 3300 Nytal 7700 NylallT-3X Figure 2. Com parison of particle width (p m ) for Nytal products; all particles > 3:1. D'inrt O ryf O Cefi Me an fo r A s p e c t Ratio 60 Intergrow th Talc T re m o lile Nytal 100 Ny tal 200 Nytal 300 Ny tal 3300 Nytal 7700 Nytal IT-3X Figure 3. Com parison of Aspect Ratio for all particles > 3:1 for Nytal products. Pane 7 of 8 14 12 10 o a a m 0 u r<o 01 5? 6 1000 2000 3000 4000 5000 Particles > 3:1/mg 6000 7000 NYTAL 100 NYTAL 200 NYTAL 300 NYTAL 3300 A NYTAL 7700 NYTAL IT-3X 8000 9000 Figure 4. Comparison of particle num ber concentration and particle weight percent for N Y TA L products. Page 8 of 8 A m .ind. H)g, Assoc. J 50(11) 613-622 (1989) 00015 The Regulatory and Mineralogical Definitions of Asbestos and Their Impact on Amphibole Dust Analysis JO H N W. KELSE and C. S H E L D O N T H O M P S O N R.T. Vandcrbill Company, Inc., JO Winfield Street. Norwalk, C T 06855 Although a familiar occupational health topic, the term asbestos generally is not well understood. Significant differences between mineralog ical and regulatory definitions sustain the confusion. Definitional ambiguity is addressed and its effect upon the characterization of New York State tremolitic talc are investigated. Analysis of asbestiform and nonasbestiform airborne dust populations clearly demonstrates the nonspecificity of the regulatory definition and the 3:1 aspect ratio "fiber*'counting scheme. Shifting to a higher aspect ratio would reduce false positives radically without a loss in sensitivity for true asbestos. Any change in aspect ratio, however, must be accompanied by a mineralogically correct definition of asbestos if proper mineral characterization is to be assured. Introduction Few environmental health hazards have been as widely pub licized or viewed with as much dread as asbestos. Despite this attention, considerable confusion exists as to what the generic term a s b e s to s actually means. American regulatory definitions arc incomplete and, in some instances, at odds with the mineralogical view of this substance. The purpose o f this paper is to review this definitional problem and demonstrate its effect on one controversial dust environment. Definitions Regulatory The National Institute for Occupational Safety and Health (N 10S H) has established the definitions and analysis methods for asbestos used by almost all regulatory bodies in the United States. Under this scheme, asbestos is defined as any fiber of chrysotile, crocidolite, amosite, anth ophyllite, tremolite or actinolile. A f i b e r is defined as a particle with a length to width ratio (aspect ratio) of at least 3:1 and a length o f 5 tm or more as determined by the phase-contrast optical microscope (PCM ) at a magnification of 450X to 500X.U) While N iO SH acknowledges that this dimensional criteria and fiber counting method is not specific to asbestos,t2) regulatory definitions offer no furtherdcscription Of what is or is not asbestos. Mineralogical In the G lo s s a r y o f G e o lo g y , asbestos is defined simply as A commercial term applied to a group of highly fibrous silicate minerals that readily separate into long, thin, strong fibers of sufficient flexibil ity to be woven, are heat resistant and chemically inert, and possess a high electrical insulation and therefore arc suitable for uses where incombusti ble, nonconductive orchemically resistant mate rial is required.131 While chemicai and electrical it tness are proper s shared by almost all silicates, asbestos is unique because of its long, thin, strong, flexible fibers. Accordingly, to a min eral scientist the term a s b e s to s always includes some refer ence to the fibrous crystal growth pattern often described as the "asbestiform habit." Mineralogically, asbestos is a mat ter of how a mineral grows, not simply a matter o f one mineral versus another or an arbitrary dimensional concept. Several minerals, including those designated in United States' regulations, do grow in nature in an asbestiform habit. These would include the most commonly exploited forms of asbestos: chrysotile, crocidolite, and amosite. The regulated asbestiform minerals, however, also occur in nature in a nonasbestiform habit. In all cases, the nonasbes tiform habit is by far the more common. Table J lists the asbestiform and nonasbestiform habits of the six regulated minerals and their separate Chemical Abstract Service numbers. The list conforms to the nomenclature set forth by the United States Department of the lnterior.M) It should be noted that the chemical composition is the same for each mineral in either growth habit. In all cases ex cept chrysotile, the internal crystal structure is identical as well. Also, the first three minerals have been assigned separate names todistinguish thedifferent growth patterns, while the last three--anthophyllite, tremolite, and actinolite-- have not. For these three the nonasbestiform analogs are com mon rock-forming minerals found throughout the earth's crust and, therefore, routinely encountered in many indus tries. Figure I graphically depicts lhe basic difference in the two mineral growth patterns while Figure 2 contrasts the two macroscopically and microscopically. While nonasbestiform particles clearly differ from asbesti form particles, many would be counted as asbestos under the current regulatory J: I dimensional criterion for a fiber w-hen an ore is crushed, milled or otherwise reduced. Thus, while all asbestos is fibrous, not all fibers are asbestos. It is also important to note that asbestiform fibers cannot be created from nonasbestiform materials by crushing, milling, or grind ing. Mineralogically, a particle with an aspect ratio of 3:1 would not be considered a fiber. Because the termf i b e r is in terpreted in different ways, its use in this paper will be restricted C o p y **g h t 1999 A m e ric a n o d u s ir-a l H y g ie n e A s s o c ia tio n Am Ind Hyg A Sc J (50) NOvembct 1989 6(3 TABLE I . Asbestilorm and Nonasbestilorm Varieties ol Selected Silicate Minerals and Their Chemical Abstract Service Numbers (CAS) Asbestilorm Variety (CAS U) Nonasbestilorm Chemical Variety Composition . ' (CAS It) Serpentine Group. Chrysotile (12001-29-5) M g jfS fiO jH O H ), antigorile, lizardile (12135-86-3) Amphibole Group: Crocidolite (12001-28-4) Grunerite asbestos (amosile) (12172-73-5' )'' Anthophyllite asbestos (77536-67-5' ) Tremolite asbestos (77536-68-6-) Actinolite asbestos (77536-66-4-) NasFeaFeaiSijOvjKOH.F)* (M g .F eM S isO aH O H .F fi (M g .F e )7 (S iiO a )(O H .F )2 Ca2Mgs{SUOz2)(OH,F2) Ca2(Mg.Fe)s(S i,0 )(O H ,F )7 nebeckile (17787-87-0) cummingtonite-grunerite (14667-61-4) anthophyllite (17068-78-9) tremolite (14567-73-8) actinolite ` (13768-00-8) ''The presence of an asterisk following a CAS Registry N um ber indicates that the registra tion is for a substance which CAS does not treat in its regular CA index processing as a unique chemical entity. Typically, this occurs when the m aterial ison eof variable com po sition: a biological organism, a botanical entity, an oil or extract ol plant o r animal origin, ora material that includes some description ol physical specificity, such as morphology. in the interest of clarity to specific definitions only. To reflect ' the mineralogical characteristics of asbestos in a definition, a group o f mineral scientists agreed to the following.'5' A. Asbestos-- A collective mineralogical term that de scribes certain silicates belonging to the serpentine and amphibole mineral groups, which'have crystal lized in the asbestiform habit causing them to be easily separated into long, thin, flexible, strong fibers when crushed or processed. Included in the definition are chrysotile; crocidolite, asbestiform grunerite (amosite); anthophylliteasbestos; tremoliteasbestos;and aclinolite asbestos. B. Asbestos Fibers--Asbestiform mineral fiber popula tions generally have the following characteristics when viewed by light microscopy: 1. Many particles with aspect ratios ranging from 20:1 to 100:1 or higher (> 5 jum length) 2. Very thin fibrils gene rally less than 0.5 pm in width, and 3. In addition to the mandatory fibrillar crystal growth, two or more of the following attributes: (a) Parallel fibers occurring in bundles; (b) Fibers displaying splayed ends: (c) Matted masses of individual fibers; and (d) Fibers showing cur\ature'5' Mar>\ of those who contributed to this definition and support the listed criteria have published extensively on the problems associated with the NIOSH definitions and the 514 membrane filter method."'6"1" This definition has been incorporated in a proposed American Society for Testing and Materials (ASTM ) method submitted to committee D-22.05 (January 14. 1988). The criteria have long been endorsed by the U.S. Department of the Interior."'11'13' While all mineral scientists may not agree with every entry in this definition, it does present a more mineralogically accurate description of asbestos and asbestos fibers than does the regulatory definition. This is especially true when it is applied to a dust population rather than on a particle by particle basis. The definition, therefore, will be used in the remainder o f this paper as the "mineralogical" definition of asbestos. It might be noted that the width criterion (0.5 p m ) represents a dimension below svhich all individual "fibrils" and clumps or masses of fibrils would be encountered in processed asbestos. Unprocessed clumps or masses may exceed this width, but such particles would not be represen tative of common airborne asbestos fibers. The Study Environment One of the most controversial uorkplace exposures asso ciated with this definitional issue involves the mining and milling of New York State tremolitic talc. Accordingly, a study was undertaken to contrast dust data obtained in this environment with both the regulatory and mineralogical definitions discussed above. New York State tremolitic talc is an industrial grade talc used extensively in the ceramics, tile, and paint industries. Since (974 the R..T. Vanderbilt Company. Inc., has owned and operated the only New York State tremolitic talc mine. 7i ln<3 H, ~ i> :. ; (SO) November 19B9 Talc mined from this operation varies somewhat in mineral content but an assay of the ore generally reflects 40%-60% tremolite. I%-I0% anthophyllite, 20%-40% talc, 20%-30% serpentine (antigorite-lizardite), and 0 % -2 % quartz."8' The R.T. Vanderbilt Company states that all of the tremo lite and anthophyllite in its talc products appear only in the nonasbestiform habit."9^' in 1980. however. NIOSH pub lished a technical report entitled O c c u p a tio n a l E x p o su re to T a lc C o n ta in in g A sb e sio sm ) specifically addressing this mineral dust exposure. In the report, NIOSH applied its regulatory asbestos definition to bulk and airborne dust samples collected at this mine and reported over 70% asbes tos for airborne fibers satisfying the 3:1 or greater aspect ratio and greater than 5-pm length limit (NIOSH PCM method). Particles were identified as tremolite and antho phyllite by standard X-ray diffraction technique. Method o f Study Samples for particulate analysis were collected on open faced. 37-mm diameter Millipore type AA filters (0,8-pm pore size. Millipore Corp., Bedford, Mass.). Precalibrated Mine Safety Appliances'Model G pumps were used to draw air through these filters at a rate of 1.7 L/min- Although fiber sampling technique has changed since, this technique was used in order to compare results with data previously collected. Filters were changed throughout a full work shift A SB ESTIFO R M In the asbestilorm habit, mineral crystals grow in a single dimension, in a straight line until they form long, thread-like fibers with aspect ratios of 20:1 to 1000:1 and higher. When pressure is applied, the fibers do not shatter but simply bend much like a wire. Fibrils of a smaller diameter are produced as bundles of fibers are pulled apart. This bundling effect is referred to as polyfilamentous. N O N A SB ESTIFO R M \ In the nonasbestiform variety, crystal growth is random, forming multidimensional prismatic patterns. When pressure is applied, the crystal fractures easily, fragmenting into prismatic particles. Some of the par ticles or cleavage fragments are acicular or needle shaped as a result of the tendency of amphibole minerals to c le a v e a lo n g tw o d im e n s io n s but not a lo n g the third. Stair-step cleavage along the edges of some particles is common, and oblique extinction is exhibited under the microscope. Cleavage fragments never show curvature. F ig u re 1---A sbestiform and nonasbestiform graphics Am inti Hyg -SJCC i (50/ November 1383 as needed to prevent overloading. In all, 22 air samples were obtained representing nine work activities in the R.T Vanderbilt Co., Go'uverneur, New York, mine and mill. Work activities sampled included milling (Hardinge and Wheeler mills), drying, packing, bag stacking, crushing, mine drilling, scraping, and tramming. Analyses were performed by The R.J. Lee Group, Inc., of Monroeville. Pennsylvania (Project N o.86-12318). Analytical techniques employed included phase contrast microscopy (PCM), polarized lightmicroscopy(PLM),scanningelectron microscopy (SEM), computer-controlled scanning electron microscopy(CCSEM).and transmission electron microscopy (TEM). In accordance with NIOSH method 7400. all sam ples received PCM particle counts at 400X magnification in Walton-Bcckctt graticule measuring at least 5-jim long with a 3:1 or greater aspect ratio. Beyond these specified parame ters. exact particle widths and lengths were not measured. For each sample, 100 fields or 100 particles, whichever came first, were counted (with a minimum of20 fields). In all, 2295 particles were counted and sized by PCM. A separate wedge was cut from each filter for PLM a nalysis. Particles were tapped, then gently scraped from the wedge to a glass slide. Any remaining particles were cap tured by rolling a needle moistened with 1.592 refractive index (R l) liquid over the surface of the filter wedge (R! selected for low-iron talc). Additional 1.592 RI liquid was added to the slide and used to wash particles from the needle onto theslide. It should be noted that this transfer technique could bias the PCM analysis if very fine particles were lost in the transfer. Additional analysis of particles not removed from the filter (another filter section) suggests such bias is unlikely for tremolite (see SEM partible width discussion below). PLM counts were made in a 1.592 Rl oil to differen tiate talc from all amphiboles on all 22 air samples. Follow ing this basic cut, tremolite was differentiated from antho phyllite by angle of extinction (tremolite has an inclined extinction o f 14 to 17, whilcanthophylliieexhibits parallel extinction). Since all asbestos exhibits parallel extinction, mineral habit (asbestiform or nonasbestiform) then was decided on the basis of criteria noted in the mineralogical definition. Depending on particle concentration for each of the 22 samples, 100 to 200 points were counted and charac terized at I00X magnification, yielding a minimum of 2200 particles subjected to PLM analysis. If positive particle iden tification could not be made at 100X total magnification, higher magnifications (up to 400X) were applied on a parti cle by particle basis. As in the PCM analysis, only particles with an aspect ratio of 3:1 or greater and a length of 5 p m or more were so characterized. Although exact length and width measurements were not obtained, particles were sized by basicaspcct ratio categories (i.e.. those3:l orgreatcr, 10.1 or greater, e tc .). One additional step was taken in the PLM analysis in which particles presumed to be anthophyllite (> 1.592 Rt) were tested for"transitionarphases(meaning talc intertwined withorevolvingfromanthophylliteand/or biopyriboles). This svas accomplished by finding particles which most closely appro.' mated the same sir ind morphological characteristics of these suspect panicles on another portion 615 EXAMPLES A m p h ib o les w ith S eparate Names: RAW ORE A m p h ib o les w ith the Sam e Name: EXAMPLES A m p h ib o les w ith S eparate Names: MICROSCOPIC 2 6 5 X M agnification, 2 .7 5 ju.m /Division A m p h ib o les w ith th e Sam e Name: 616 tremolile A S B E S TIFO R M S ' amosite tremolite N O N A S B E S T IF O R M 1 ' % S ' " ' - ' " - 'v : I.?-"-. *-r r' , - -t* / V s *-y X l S : : -& cummingtonite-grunerite tremolile Am fnd Hf i - j: jC 150) of the filter and testing them at 1.608 Rl (the low gamma index lor anthophyllite). Because of problems inherent in this technique, testing the Same parti'cle with different Rl liquids was not possible. Particles withan index of refraction between 1.592 and 1.608 were classed as "transitional." In all, 6 samples underwent this additional analysis. To test further the differences and similarities between asbestiform dust populations and the tremolitic talc dust environment, electron microscopy was employed on 5 sam ples most representative of common mine and mill expo sures (e .g ., product packaging). S EM with energy dispersive X-ray (E D X ) first required the mounting of another 1/8 filter wedge from each sample on a carbon-coated stub. Fifty fields at 2000X magnification then were analyzed for count, size, and identity of all particles in every field with an aspect ratio greater than 3:1and a length greater than 5 jum. For the five filters, a total of J83 particles were characterized in this way. Particles below and above a width o f 0.25 jum were noted as well. This width was selected primarily because it is used in references against which the findings of this study shall be compared.'6 ''227'3'These references generally refer to this width as the approximate lower resolution limit of the light microscope.'24' While other references report lower width sensitivity,t2i'261 it generally is agreed this lower limit varies with the quality of the microscope, use of dispersion staining and background contrast, magnification, and the microscopistinvolved. CCSEM with EDX was used on the same carbon-coated filter wedges to scan a total of 2500 particles (500 per sample) at magnifications of 35X, I00X, and 500X . Particles were sized by the preselected parame- ters.and the chemical composition of all particles was noted. Particle distribution was expressed in volume percent and all tremolile particles were counted. TEM with selected area electron diffraction (S A ED) alsp was employed on new carbon-coated filter wedges from the same five filters. Chem ical composition by EDX analysis and SAED patterns of individual fibers which measured 10 pm or greater on four grid squares per wedge were obtained after the filter matrix wasdissolved from the carbon film. Whileconsiderabledata were thus generated from this multiple analytical approach, only data summaries which directly address the definitional comparison are included in this paper. It should be noted that the EDX chemistries obtained through the CCSEM analysis and the SAED patterns obtained through TEM analysis were not adequate to distin guish talcand anthophyllite. While an in-depth discussion of this problem is beyond thescope of this paper, in summary it should be said that talc may present the same X-ray spectrumasanthophyllite because talcdisplaysa similar 2:1 Si/ Mg ratio and overlapping range. RegardingS AED patterns, talc in the fibrous form often reflects the same 5.3 A spacing as anthophyllite. Talc/anthophyllite in an intermediate or transitional phase poses further identification problems when electron diffraction analysis is restricted to one point per particle. This is more fully described in other papers.'27 Study Results and Definitional Comparison ' Table II contrasts bulk tremolite asbestos particles described in the li terature"2' to tremolite particles reflected on five New Samples Trem olile asbestos" TABLE II Ratio Com parison o f Bulk Tremolite A sb esto sAto N.Y. S tate Tremolite in Five Air S am ples8 by O ptical an d E lectro n M icroscopy ' Ratio of Trem olile Particles 3:1 aspect ratio (a.r.) or Greater to Total Tremolite (> 5 pm length) SEMC 10:1 a.r. or Greater to Total Tremolite (> 5 jim L) SEM 20:1 a.r. or Greater to Total Tremolile (> 5 pm L) SEM 1 in 1.6 1 in 2.6 1 in 4.6 Tremolite asbestos" # total tremolile particles per sample (all sizes): 200 1 in 1.8 (approx. 55%) 1 in 2.3 (approx. 4t% ) 1 in 2.5 (approx. 31%) 10:1 a.r. or Greater to 3:1 a.r. or Grealer Opt" SEM 1 in 1,6- 1 in 1.6 1 in 1.6 1 in 12 N ^ 1 in 1.5 (66%) Tremolite in 5 N .Y . air samples" total tremolite particles (all sizes) 949 1 in 6.2 (16%) CCSEM 1 in 949 or greater (0.1%) CCSEM 0 in 949 (0%) CCSEM OpI 1 in 141 or greater CCSEM 1 in 152 or greater 1 in 146 or greater ( 0.6% ) AData from U S. Dept of Interior, Bureau of Mines Report of Investigation 8367, page 13, Table 2 (1979)."'1 "Present study: CCSEM analysis of 5 air samples at35X. lOOX.and 500X magnifications. (2500 total p a rtic le count (ail s.zes)) O p tic a l (P C M and PCM) analysis of Ihe same 5 samples up to 400X magnifications (534 total particles with a 3:1 a.r. o r g re a te r > 5 ^m le n g th ) ` Particles counted using SEM with magnification up to 50 OOOX. "Particles counted using optical-light microscopy at 1250X magnification (200 tremolite particles counted per tiller' ``Obtained from California (no other description of literature). Wiley milled ` Obtained from museum sample from Rajasthan, India. Wiley milled. Am ln(i Hyg ~iS0C J (50) November 1989 61? TABLE III Average of 22 Mine and Mill Air S am ples {2295 Particles) by Com position, A spect Ratio 3:1 or G reater (> 5 pm length), and Mineral Habit by Light Microscopy* Aspect Ratio: 3:1-10:1 % of Total >10:1-20:1 >20:1 Particles per C C (TW A) 3:1-10:1 > 10:1-20:1 >20:1 Total Particles (8-hr TWA) `/.A s b e s tifo rm Mineralogical Del. Tremolite 35.8 .33 0 .45 .009 0 0.459 0 Transitional" 0.0 .76 0 0.00 .015 0 0.015 0 Talc 58.2 4.60 0 .67 .058 0 0.728 0 All particles 93.0 7.00 0 1.12 0 082 0 1.210 0 'M in eral type and % by aspect ratio were obtained by PLM analysis at 100X to 400X magnification. Total particles per cc were obtained by PCM at 400X magnification. "% Talc/anthophyllite transitional particles were extrapolated from 6 of 22 a ir samples based ona refractive index between 1.592 and 1.608 lor the gamma index. No pure anthophyllite particles were noted in the fields analyzed. York state tremolitic talc air samples by both optical and electron microscopy. In this comparison, the ratio o f tremo- lite pa rticles which satisfy the regulatory definition of a fiber {3:1 or greater aspect ratio, > 5 p m length) and those that exceed a 10:1 and 20:1 aspect ratio ( > 5 p m length) are addressed. O f the 2500 total particles scanned by CCSEM on 5 air sam ples, 38% or 949 were tremolite. Of these tremolite parti cles. 16% or 152 satisfied the regulatory size criteria.for a fiber. This represents a ratio of I tremolite regulatory fiber in every 6.2 tremolite particles. In contrast, tremolite asbestos reflected an average of I regulatory size fiber in every 1.7,, particles (55%). Most striking, however, is the difference reflected at 10:1 and 20:1 aspect ratios. For the New York state tremolite, only 1 tremolite particle in 949 (total counted) exceeded a 10:1 aspect ratio (0.1%). For tremolite asbestos this ratio was approximately 1 inevery2.5 particles or 40%. At a 20:1 aspect ratio or greater, no New York tremolite particles were counted, while I in every 3 (approx imately) were found for tremolite asbestos. Significant vari ation in these ratios was not noted under optical microscopy for the same samples at the magnifications applied. While a bulk to airborne particle comparison is not ideal, the dimensional differences likely would be even greater if two airborne particle distributions were compared, since wider width, lower aspect ratio particles are more common in bulk particle distributions. Published particle distribu tions for airborne asbestos dust populations support this contention and support the basic dimensional similarity of tremolite asbestos to other asbestiform minerals (see the extended discussion on airborne particle aspect ratio distri butions below). Accordingly, on a tremolite to tremolite basis, an entirely different particle-size distribution would be expected in the New York state tremolitic talc samples if this tremolite were asbestiform. Table 111 reflects the average of all 22 air samples by p ercent m in e ra l com po sitio n* a s p e c t ra tio {3:1 o r greater) and crystal growth habit (asbestiform or nonasbestiform). Results in this table reflect the combined application of the PCM and PLM methods outlined above. In the fields analyzed by PLM. no particles exceeded a 20:1 aspect ratio or showed splated ends, curvature, 01 parallel fibers occurring in bundles. Using the mineralogical definiti on, therefore, no asbestos was found; however, 0.459 particles/ cc would be noted if the regulatory definition were used (talc and transitional particles excluded). A total of 1.21 particles/cc would be reported if talc and transitional particles were counted. Proper characterization of talc, anthophyllite and transitional particles is extremely difficult in this ore body except by PLM. While PLM air sample data reflect no asbestiform fibers, boih talc and transitional par ticles can appear in a fibrous, asbestiform and/ or nonasbes. .liform habit in this ore body.(S1) If misclassifted as anthophyilite, these asbestiform fibers would be characterized as asbestos under both the regulatory and mineralogical defini tions. TEM. SAED analysis with multiple electron diffrac tion patterns (each indexed) confirmed the presence of both nonasbestiform and asbestiform transitional and fibrous talc particles in a random scan of fields not included in the PLM analysis. No effort to quantify these fibers was made. Because of the rarity of these fibers and their marginal significance to the definitional distinctions being addressed here, further detail in this area is beyond the scope and intent of this paper. Table IV reflects acomparison of fiber counts obtained in this study with data previously obtained in the same mine and mill (same or similar work activities). These data con firm a marked difference in what is reported as asbestos, depending upon the definition used. Note that theaverage of all regulatory fibers counted by PCM (Column 2) shows far less variance between investigators than the percent of parti cles considered asbestiform (Column 5). Mineralogical dis tinctions made reflect consideration of the characteristics described in the mineralgica! definition. Although none of the particles in the study dust population exceeded a 20.1 aspect ratio by light microscopy, this factor alone did not dictate habit characterization for the 22 samples analyzed. Although the lack of 20:1 aspect ratio particles in a dust population certainly suggests a nonasbestiform dust envi ronment. aspect ratios alone a re not pivotal in a mineralogi cal sound definition of asbestos. To test definitional specified), further, a comparison nf basic dimensional characteristics common to asbestiform dust populations, nonasbestiform (cleat age fragment) amphi- sis i i r rd H ,e ! (:-0> November 1989 Source and Year R. Lee (1988) MSHA (1984-85)c Insurance (I9 8 4 )t NIOSH (1975)` Dunn (1982)" TABLE IV Historical Air Sam ples* by Definitional Approach Average of All Parlfcles/CC Mill and Mine Range Partlcles/CC Mill and Mine1"' " Definitional Approach V.Partlcles/CC Classed as Asbestos 1.21 2.39 1.8 4.6 0.65 0 14-3.56,ia` 0.14-18.40*" ' 1.38-2.15`5' 1.5-8.41" " 0.03-1.38."" mineralogical mineralogical not classed regulatory mineralogical but classifica tion completed on bulk sam ples only 0.00 0.40 72.00 Particies/CC Considered Asbestos 0.000 0.009 3.312 AAII parlicles 3:1 or greater in aspect ratio, > 5 pm in length and resolvable under the light microscope. "(n) = number ol air samples. `'Mine Safety and Health Administration Survey Reports dated: 7/17/85, 7/30/85,5/22/85.6/12/84.1/9/84. MSHA performs analysis lor fiber type onl y on filters with elevated total fiber counts. Of the 38 filters. 22 were so analyzed. O f these. 2 filters were reported as containing 2% asbestiform fibers. All other filters were found or assumed to contain 0%. `"Hartford Insurance Company Report dated November 1984 to R.T. Vanderbilt Company, Inc. KNlOSH Technical Report. O ccupational a n d Exposure to Talc C on tain ing Asbestos. Table 7 (i960).r,m "Dunn Geoscience Corp. report to R.T. Vanderbilt Company (1985). bole dust populations, and the study dust population -was undertaken. Figure 3 compares airborne asbestiform and nonasbestiform particles which fall aboveand below a width of 0.25 pm , described in the literature,'22* with study dust population particle widths obtained by SEM. With regard to the tremolite found in the talc air samples (the only amphi'bole noted), all tremolite particles(88 out of 183 total parti cles) were wider than 0.25 p m . Particle widths noted in % % 100 m i CHRYSOTILE* 100 80 t u n AMPHIBOLE ASBESTOS* 80 100% : % 100% 100 1 -1------ r t : 80 60 I 40 35% 34% T I 20 pm <0.25 >0.25 W id th 60 ACLMEPAHVIBAGOELE FRAGMENTS* 40 20 0% < 0 .2 5 width >0.25 60 N.Y. STATE TREMOLITIC TALC 40 TREMOLITE 20 0% <0.25 width >0.25 'From- J.G. Snyder, R.L. Vlrta, and J.M. Segret: "Evaluation ol me Phase Contrast Microscopy Method for the Detection of Fibrous and O t h e r Elongation M i n e r a l P a r t i c u l a t e s by Comparison'with a STEM Technique." A m . I n d . H y g . A s s o c . J. 48(5,1:471-477 (1987) Table IV. Average of 17air samples. From: Average of 5 air samples analyzed by SEM (represents 88 particles out of 183 total particles), F ig u re 3 -- A v e ra g e a irb o rn e p article width c o m p a riso n by e le c tro n m ic ro s c o p y (ail particles 3:1 o rg re a te r aspect ra tio , 5 p m or m ore length). Am tm j Hyg -s jo c J (50) November 1989 619 TABLE V A spect Ratio C om parison Airborne Asbestos Particles* (Mining and Bagging) > 0.25 /im Widlh, > 5 pm Length Airborne Cleavage Fragments11 (Approx. 4500 Total Particles) > 0.25 pm Width, > 5 pm Length % ot Particles Seen at: . ' % ot Particles Seen al: Aspect Ratio: 3:1 10:1 15:1 > 20: Aspect Ratio: 3:1 10:1 15:1 > 20:1 Crocidolite 100 100 91.5 Amosite 100 100 89.5 Chrysolite 100 100 86.0 Average: 100 100 89 64.5 58.0 37.0 53 cu m m in g to n ite 100 24 10 6 cum m in gton ite 100 32 7 3 aclinolile 100 15 4 3 grunerite/actinolite 100 8 0 0 tremolitic talc<; 100 7 NDU 0 Average: 100 17 5 2.4 ATaken trom G.W. Gibbs and C.Y. Hwung, D im ensions o l A irb o rn e Asbestos Fibers. IARC Scientific Pub. #30 Lyon, France, pp. 79-86.UJ1 "Taken trom A.G. Wylie, Ft.L. Virta, and E. Russek, "Characterizing and Discriminating Airborne Fibers: Im plications tor the NIO SH Method," A m erican In dus trial H yg ie n e Association Journal, Vol. 46. pp. 197-201 ,lT' ` Data taken from the R.J. Lee G roup Dust Analysis Project prepared tor the R.T. Vanderbilt Co., In c , 1988. Reflects PCM /PLM analysis of 22 tillers: % represents 2295 total particles. UND = not determined. asbestiform dust populations by STEM differ markedly, with an average of 35% (ranging from 9% to 81%) reported to fall below a 0.25-tm width.122* The similarity between amphibole cleavage fragment particle width and tremolite widths noted in the study dust population, therefore, suggests a nonasbestiform habit. It also might be noted that, since all tremolite particles exceeded a 0.25-Ttm width, they should all be resolvable at the lower magnifications used for both PCM and PLM analysis. Further, it is unlikely that particles of this width would be lost in the transfer of parti cles from the filter to the glass slide in preparation for the PLM analysis. In terms of aspect ratio, major differences between nonas bestiform amphibole cleavage fragments and asbestiform particles also exist. Table V makes such a comparison for airborne particles which meet or exceed a 3:1 aspect ratio and a greater than 5 - p m length. Variances shown in this table typically are found in the literature/6,1231 Figure 4 graphically depicts thesedataand furtherclarifies thedifference. In terms of the study dust population, particle aspect ratio distribution Is included in Table V under the cleavage fragment colOmn where it best fits. Interestingly, total par ticulate aspect ratios noted in this study (based on 2295 particles) would represent the low end of the cleavage frag ment line in Figure4. Unfortunately, an airborne dust size characterization for asbestiform tremolite could not be found for inclusion in this comparison. Although asbesti form tremolite is rare and is not exploited for commercial use, localized occurrences do exist in the United States(/.e.. California, Montana). At least one industrial hygiene study exists of a mining operation containing asbestiform tremo lile, but detailed airborne size characterization is not available.'`!a, An aspect ratio distribution, however, was obtained on bulk asbestiform tremolite from this mine.'30*For parti cles longer than 5 /uni, 88% fell above 10:1,70% above 15:1. and 52% above 20:1. These ratios correlate most closely to the average airborne asbestos ratios reflected in Table V and Figure 4 of 100%, 89%, and 53%. respectively. In summary, when the study dust population is contrasted with the mineralogical definition--as well as the dimen . sional characteristics of asbestiform and nonasbestiform particles reflected in the literature--the nonasbestiform nature o f New York state tremolitic talc is quite apparent. The authors believe this reaffirms the nonspecificity o f the NIOSH PCM method and the regulatory definitions it underpins when applied to mineralllust environments con taining common nonasbestiform cleavage fragments. Corrective Measures Given the differences between asbestiform and nonasbesti form particulates, the least dramatic change necessary to improve specificity would involve an upward adjustment in the aspect ratio. As seen in Figure 4, airborne asbestiform particles exceed a 10:1 aspect ratio with very few less than 15:1. Cleavage fragments, in contrast, rarely exceed a 10:1 aspect ratio with fewer still exceeding 15:1. Any aspect ratio adjustment, however, should be applied as a screening tool only because there is some aspect ratio overlap between asbestiform and nonasbestiform particles. It, therefore, is considered essential that a mineraloeically correct definition of asbestos and criteria specific to asbestos should be reflected in regulations. Discussion Although it is not the intent of tilts paper to address health issues, the subject cannot be ignored in any discussion regarding the definition of asbestos. It can be argued, for example, that regulator) definitions are designed to address human health concerns and not the realities of physical science. This argument suffers, however, when it is under- 620 Ani Ind Hy A w e i (S0) Novcmbei 1S89 NOTE: The majority ot cleavage fragments do not fall in this range (most reflect lengths of < 5 ^ m ). The 100%, therelore. represents . the starting point for 3:1 aspect ratio particle counting and not the total % of airborne cleavage fragments. Figure 4--Airborne asbestos versus cleavage fragment aspect ratio comparison (particules with an aspect ratio of 3:1 or greater, > 5 gm length, > 0 25 pm width). From Table V. stood that health effects attributable to asbestos are not reasonablydemonstrated for nonasbestiform exposures *31'381 Moreover, it can beargued thatanyenvironmental exposure ought to be studied and regulated for what it is. To do otherwise presents needless bias. It also has been argued that any change in the regulatory definition of asbestos would confuse the extensive data base developed for commercially used asbestos. Nonasbestiform amphiboles, however, cannot and are not used for applica tions typically reserved for asbestos ( e .g .,.insulation, struc tural binding, fire proofing, brake linings, e tc ). Accord ingly, this asbestos data base would not be affected signifi cantly if a mi ncralogtcally correct definition o f asbestos were adopted. The definitional ambiguity discussed here relates to dust populations which do contain nonasbestiform min eral cleavage fragments. Such environments commonly involve hard rock and aggregate mining operations and industries who use their mineral products (e .g .. ceramics, construction, paint, etc.). Whatever asbestos data exist for theseenvironmcnts may be misleadingand, therefore, ought to be corrected. Conclusion Major differences in crystal growth patterns, lengths, and widths exist between asbestiform particles and common, hard rock-forming mineral cleavage fragments. Current regulators' asbestos definitions and fiber quantification methods do not address these distinct ions adequately. Thus, nonasbestiform dust p op i'iiion s can and ha*e been mis taken as asbestiform. Confusion is likely to persist until a regulatory definition and analytical approach specific to ' asbestos is adopted. References 1. 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Chatfield: C o lle c tio n , A n a ly s is a n d C h a r a c t e r iz a t io n o f V e rm ic u lite S am p les fo r F ib e r C o n ten t a n d A sb esto s C o n ta m in a tio n . Washington, D.C.: United States Environmental Protection Agency. 1982. 31. Marsh, J.P. and B.T. Mossman: Mechanisms of Induction of Orithine Decarboxylase Activity InTracheal Epithelial Cells by Asbestiform Minerals. C a n c e l R e s . 4 8 :709-714 (1988). 32. Smith, W.E., D.D. Hubert, H.J. Sobel, and E. Marquet: Bio logic Tests of Tremolite in Hamsters. In D u s t a n d D is e a s e edited by R.J. Lemen. J.M. Dement. Park Forest South, III.: Pathotox Publishers, 1979. pp. 335-339. 33. Stanton, M.P., M. Layard, A. Tegerls, E. Mllies, M. May, E. Morgan, and A, Smith: Relation ol Particle Dimension to Carcinogenicity in Amphibole Asbestosis and Other Fibrous Minerals. J. N a tl. C a n c e r In s t. 6 7 :965-975 (1981). 34. Lamm,S.H., M.S. Levine,J.A.Starr,and S.L.Tirey:Analysis . ot Excess Lung Cancer Risk inShort-Term Employees. A m . ' J . E p id e m io l. 1 2 7 (6 ): 1202-1209 (1988). 35. Tabershaw, I.R.and W.T. Stiile: The Mortality Experience of Upstate New York Taic Workers. J. O c c u p . M e d . 24:480-484 (1982). 36. McDonald, J.C., G.W. Gibbs, F.D.K. Liddell, and A.D. McDonald: MortalityAfterLong Exposure toCummingtoniteGrunerite. A m . R e v . R e s p ir. D is . 178:271-277 <1978). 37. Cooper, W.C., Otto Wong, and R. Graebner: Mortality of Workers in Two Minnesota Taconile Mining and Milling Operations. J . O c c u p . M e d . 30:506-511 (1988). 38. McConnell, E.E., H.A. Rutler, B.M. Uliand, and J.A. Moore: Chronic Effects ol Dietary Exposure to Amosite Asbestos and Tremolite in F344 Rats. E n v iro n . H e a lth P e r s p e c t. 53:27-44 (1983). 6 M a y 1988. Revised 19 June 1989 672 Am nd. Hyg -Ajsoc ) (SO) November '.t39 RJ LeeGroup, Inc 350 Hochberg Road Monroeville, PA 15146 412/325-1776 FAX 412/733-1799 February 5, 1992 Mr. John W. Kelse Corporate Industrial Hygienist Manager, Occupational Health & Safety R. T. Vanderbilt Company, Inc. ' < ' 30 Winfield Street Norwalk, CT 06856-5150 RE: Project No. A OH 110601 Dear John: Enclosed is the Asbestos Analysis Report for the 24 air samples received October 7,1991. The sample and volume information were supplied by you and accompanied the cassettes. These results are submitted pursuant to RJ Lee Group's current terms and conditions of sale, including the company's standard warranty and limitation of liability provisions, and no responsibility or liability is assumed for the manner in which the results are used or interpreted. If you have any questions, please do not hesitate to call us. Sincerely yours, W. H. Powers, Manager Bulk Materials Analysis oc: R. J. Lee B. A. Smith Monroeville, PA * Berkeley. CA Washington, D.C. Raleigh, NC Houston, TX Chopra-Lee, Inc., Grand Island, NY RJ Lee Group, Inc 350 Hochberg Road Monroeville, PA 15146 412/325-1776 Asbestos Analysis Report 412/733-1799 Project No. AOH110601 February 5, 1992 On October 7, 1991, 24 air samples were received from Mr. John Kelse of the R. T. Vanderbilt Company, Inc. It was requested that these air samples be analyzed for asbestos content through the application of mineralogically correct criteria specific to asbestos and to compare this analysis with the nonspecific NIOSH 7400 method for fiber counting. In following the NIOSH 7400 method, a portion of the filter (1/4 circumference wedge) was removed and mounted on a glass slide using acetone vapor and triacetin. The preparation was then covered with a No. 1-1/2 glass coverslip and allowed to sit until the filter wedge became transparent. The method requires that 100 fields be counted, or at least a minimum of 20 fields, depending upon fiber concentration. All fibers or fiberlike particles measuring 5 micrometers (pm) in length and having a length-to-width aspect ratio equal to or greater than 3:1 were counted. This count considers panicles typically referred to as "federal fibers" and does not distinguish asbestos fibers from elongated nonasbestos particles. These results are presented in Table I. During the fiber count, the particles counted were "defined" based on the guidelines set forth in the testimony presented before OSHA by Dr. R. J. Lee, March 9, 1990. Dr. Lee proposed that PCM be used as a screening technique to overcome the intrinsic limitations of the current PCM method (i.e., nonspecificity). The advantage of the proposed method is that it retains and builds on historical federal fiber data (fibers >5 pm length, >3:1 aspect ratio) which has been developed under the P&CAM 239 and NIOSH 7400 methods. Basically, the proposed method categorizes federal fibers by width. If the <1 pm diameter plus bundles >1 pm in width federal fiber count is statistically below the permissible limit, the analysis is terminated; otherwise additional analysis can be performed by scanning electron microscopy (SEM) or transmission electron microscopy (TEM) to determine the portion of the count that is asbestos. A copy of this approach with supporting data is enclosed. Table II gives the fiber diameter breakdown for each sample. The column identities are shown on page 2 of Table II. Columns B and E were identified as possibly asbestos based on the morphological characteristics of asbestos. The fibers in column C were considered "fibrous" (long and thin), but not asbestiform, and those in column D were clearly cleavage fragments. Table III presents a comparison of the PCM counts as determined by the NIOSH 7400 method and the proposed method. The NIOSH 7400 method column is the calculation of all the fibers counted during the PCM analysis. The proposed method column is the calculation using only those fibers <1 pm in diameter and fiber bundles > 1 pm in diameter (columns B, C, and E of Table II). In following this protocol, SEM analysis should have been the next method of analysis, due to the concentration of fibers in columns B, C and E of Table II. SEM, though, has not been a good analytical tool in differentiating between fibrous talc, anthophyllite, and talc-anthophyllite intergrowth because of the confusion that stems from similarity of their elemental chemistries (i.e., similar silicon to magnesium ratio). Therefore, in an attempt to identify the various species on the filters, we undertook the polarizing light microscopy (PLM) analysis using the following approach. Monroeville, PA Berkeley. CA Washington, D.C. Raleigh. NC Houston, TX Chopra-Lee, Inc., Grand Island, NY Page 2 Each slide which had been prepared for PCM was scanned by PLM at approximately 200X m agnification, during which time 100 fibers were counted and characterization attempted However, severe lim itations were placed on the analysis by using a medium much lower than one would use in identifying the particles by normal PLM. The PCM preparation has a refractive index o f 1.46; and to the best o f his ability, our analyst categorized the fibers he counted as talc, anthophyllire, tremolite, and m iscellaneous. The m iscellaneous particles included all 5 p.m, 3:1 particles that did not fit into any o f the previous categories, and the majority o f these were cellulose, glass, and quartz. Unfortunately, w e did not feel confident with the results o f this analysis, and those results are not included in this report. H owever, the analysis did give us information on the morphology o f the fibers. It was felt that by starting ''fresh" with a sample that could be analyzed by PLM using the proper refractive index liquid, an accurate identification o f the mineral species present could be made. The final step performed in this analysis was correlating the data accumulated from the fiber count by PCM and that obtained by the PLM morphological interpretation. Based on the PLM observation, we identified the fibers in columns B and E o f Table H as talc fibers and talc fiber bundles. The "federal fibers" in column C were elongated (betw een 0 .5 and 1.0 pm in width) but not asbestiform and were identified as anthophyllite. The fibers in column D were cleavage fragments and included a portion o f the anthophyllite and all o f the tremolite. Results Based upon this analysis, pone o f the "federal fibers" observed should be considered asbestos. Although the particle size distribution and mineral mix varies somewhat from that observed in previously examined R. T. Vanderbilt tremolitic talc, the cleavage fragment and talc fiber observations are consistent with prior observations relative to the absence o f chrysotile and amphibole asbestos. D ifferences from prior analysis may, in part, be attributable to a m ixed dust environment (i.e., not a pure talc sam ple) and to some methodological differences in sample handling dictated by sample loading. Sample Number 0402365 BHPC 0402366BHPC 0402367B HPC 0 4 0 2 3 6 8 B HPC 0402369BHPC 0402370BHPC 040237 IB HPC 0402372BHPC 0402373BHPC 04023 74 BHPC 0402375BHPC 0402376BHPC 04023 77BHPC 0402378 BHPC 0402379BHPC 0402380B HPC 3402381 BHPC 3402382BHPC Client Sample Number 1491 -F 1478-F 1485-F 1479-F 1383-F 1393-F 1475-F 1487-F 1481-F 1490-F 1462-F 1456-F I457-F I398-F I452-F 1348-F 1381 -F 1378-F Table I Total Fiber Concentrations PCM Air Analysis Project AOH11060I Analyzed Area (sq. mm) 0.6123 0.5495 0.6123 0.5495 0.4239 0.4318 0.785 0.4632 0.4632 0.785 0.2905 0.4318 0.314 0.785 0.4475 0.4239 0.4946 0.5495 Volume (Liters) 24.48 21.42 32.13 15.3 38.25 39.78 Blank 19.89 29.51 26.82 14.9 35.76 14.9 0 165.39 27.55 27.55 17.4 Fibers 100 100.5 100.5 100 100.5 103 1 102.5 102 21 100.5 100 101 0 102 100 100.5 101.5 Fields 78 70 78 70 54 55 100 59 59 100 37 55 40 100 57 54 63 70 Concentration (fibers/sq. mm) 163.3186 182.8935 164.1352 181.9836 237.0842 238.5640 1.2739* 221.3106 220.2310 26.7516 346.0148 231.6155 321.6561 <7.0064* 227.9584 235.9047 203.2150 184.7134 Concentration! (fibers/cc) 2.5685 3.2873 1.9668 4.5793 2.3863 2.3089 4.2838 2.8732 0.3840 8.9407 2.4936 8.3112 0.5306 3.2967 2.8398 4.0870 90% Confidence Limit! Lower Upper 1.6237 2.0787 1.2437 3.5133 4.4959 2.6898 2.8949 6.2638 1.5090 3.2637 1.4621 3.1557 2.7119 5.8557 1.8184 3.9280 0.1970 5.6536 0.5710 12.2277 1.5764 5.2571 3.4109 11.3654 0.3358 0.7255 2.0840 4.5093 1.7958 3.8839 2.5859 5.5882 Limit of Quantification 0.1102 0.1259 0.0840 0.1763 0.0705 0.0678 0.1356 0.0914 0.1006 0.1810 0.0754 0.1810 0.0163 0.0979 0.0979 0.1550 t Analytical results based upon the volumes provided by R.T. Vanderbilt Company. Sample is a Blank, or no volume was supplied. Calculation could not be done. * Results Below Analytical Sensitivity Prepared, Counted, and Calculated in accordance with NIOSH 7400 RJ Lee Group, Inc. Headquarters Authorized Signature Date 350 Hochberg Road Monroeville, PA 15146 Page: 1 of 2 tO V . ( 'C o ^ Tuesday, F e b r u a r y 92 Phone Fax (412)325-1776 (412)733-1799 Sample Number 0402383BHPC 0402384 BHPC 0402385BHPC 0402386BHPC 0402387BHPC 0402388BHPC 0402389BHPC 0402390BHPC 0402391 BHPC 0402392BHPC Table I Total Fiber Concentrations PCM Air Analysis Project A O H 110601 Client Sample Number 1377-F I375-F 1344-F 1386-F 1384-F 1387-F 1389-F 1394-F 1396-F 1372-F Analyzed Area (sq. mm) 0.5888 0.4632 0.785 0.5338 0.6673 0.4161 0.369 0.4004 0.2277 0.785 Volume (Liters) 14.5 18.85 Blank 24.65 13.05 23.2 23.2 20.3 8.7 Blank Fibers 101.5 101 0 102.5 102 101 100 101.5 103 0 Fields 75 59 100 68 85 53 47 51 29 100 Concentration (fibers/sq. mm) 172.3992 218.0719 <7.0064* 192.0195 152.8662 242.7593 271.0394 253.5282 452.4489 <7.0064* Concentration! (fibcrs/cc) 4.5775 4.4540 2.9991 4.5098 4.0285 4.4979 4.8083 20.0222 90% Confidence Limili Lower Upper 2.8962 6.2588 2.8173 6.0907 1.8986 4.0996 2,8542 6.1655 2.5482 2.8434 5.5089 6.1523 3.0423 6.5743 12.6788 27.3655 Limit of Quantificati on! 0.1860 0.1431 0.1094 0.2067 0.1163 0.1163 0.1329 0.3101 t Analytical results based upon the volumes provided by R.T. Vanderbilt Company. Sample is a Blank, or no volume was supplied. Calculation could not be done. * Results Below Analytical Sensitivity Prepared, Counted, and Calculated in accordance with NIOSH 7400 Authorized Signature i t Date RJ Lee G roup, Inc. Headquarters 350 Hochberg Road Monroeville, PA 15146 Page: 2 of 2 o/ Tuesday, February^ ,,j92 Phone Fax (412)325-1776 (412)733-1799 T a b le II Project No. AOH110601 Fiber Diameter Breakdown - Based on PCM Analysis Number of Fibers* Sample No. A B C D E 1348-F 1375-F 1377-F 1378-F 1381 -F 1383-F 1384-F 1386-F 1387-F 1389-F 1393-F 1394-F 1396-F 1452-F 1456-F 1457-F 1462-F 1478-F 1479-F 1481-F 1485-F 100.0 16.0 9.0 60.0 15.0 101.0 8.5 8.0 78.5 6.0 101.5 6.5 16.0 73.0 6.0 101.5 9.5 19.5 69.0 3.5 100.5 9.5 14.0 69.5 7.5 100.5 17.5 17.5 59.5 6.0 102.0 16.0 5.0 75.0 6.0 102.5 8.0 4.5 84.0 6.0 101.0 15.0 10.0 71.0 5.0 100.0 11.0 8.5 76.5 4.0 103.0 19.5 9.5 69.0 5.0 101.5 7.5 9.5 78.0 6.5 103.0 18.5 7.0 68.5 9.0 102.0 17.5 19.0 58.0 7.5 100.0 7.5 16.5 65.0 11.0 101.0 16.0 12.0 67.0 6.0 100.5 18.0 8.5 67.0 7.0 100.5 8.5 19.5 67.5 5.0 100.0 9.5 22.5 59.0 9.0 102.0 14.0 5.5 73.0 9.5 100.5 12.0 20.0 59.0 9.5 T a b le II (C o r n 'd ) Project No. AO H 110601 Fiber Diameter Breakdown - Based on PCM Analysis Number of Fibers* Sample No. A B C D E 1487-F 1490-F 1491-F 102.5 20.0 10.5 62.5 9.5 21.0 6.0 1.5 10.5 3.0 100.0 15.0 12.5 59.5 13.0 *Column Identities A-Particles >5pm long; >3:1 aspect ratio; all diameters B-Particles >5pm long; >3:1 aspect ratio; <0.5pm diameter C-Particles >5pm long; >3:1 aspect ratio; >0.5/<I .0pm diameter D-Particles >5pm long; >3:1 aspect ratio; >1.0pm diameter E-Particles >5pm long; 3:1 aspect ratio; >1.0pm diameter-bundles T a b le III Project No. AOH 110601 Fiber Count ComDarison Between NIOSH 7400 and ProDosed Method Based on PCM Analysis SamDle No. NIOSH 7400 Fibers Der cc Proposed Method Fibers per cc 1348-F 1375-F 1377-F 1378-F 1381-F 1383-F 1384-F 1386-F 1387-F 1389-F 1393-F 1394-F 1396-F 1452-F 1456-F 1457-F 1462-F 1478-F I479-F 1481-F 1485-F 3.2967 4.4540 4.5775 4.0870 2.8398 2.3863 4.5098 2.9991 4.0285 4.4979 2.3089 4.8083 20.0222 0.5306 2.4936 8.3112 8.8407 3.2873 4.5793 2.8732 1.9668 1.3187 0.9922 1.2853 1.3087 0.8760 0.9735 1.1938 0.5413 1.1966 1.0570 0.7621 1.1132 6.7064 0.2289 0.8728 2.7978 2.9802 1.0794 1.8775 0.8169 0.8121 T able m (Corn'd) Project No. A OHI 10601 Fiber Count Comparison Between NIOSH 7400 and Proposed Method Based on PCM Analysis Sample No. NIOSH 7400 Fibers per cc Proposed Method Fibers per cc 1487-F 1490-F 1491 -F 4.2838 0.3840 2 .5 6 8 5 1.6717 0.1920 1 .0 4 0 2 Million Particles Per Cubic Foot Talc Operation Averages Vanderbilt Talc vs. Earlier Area Talc Operations 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0 1951 -8 5 Vanderbilt Talc Mppcf Range: 0.2-140 Sources: M SH A , N Y Health Dept., Epi Studies 246 Pre 1 9 4 5 -6 0 Other Area Talc Operations Mppcf Range: 0.2 - 2000 Mppcf r . M O i r r A U T Y AMOXC TAf.C M i X i X - h LKi X E li U ) ET Ai, Tab 2 .-- D e . i t i i s .inn E x p e c t e d M o r i . i t i ' v F r o m C a n c e r o l t.'ir? L u n g a n d P i e i;;.i o - : 0 G e Z l r o i n i c - - l . n n l t r a c t . a n d P e r i t o n e u m . c i n t e t i t y f i e ? i n T r J c '.'/ c C I S AGO Grou> <40 60-79 504- T o to l W. *1 o**.'.;). 3 C/ 1J C 'il S. r r o;- f''lu'njnl Cru'`'S I u n r . -"nd Pic tira CI i*iKl V' InD^um ' 0* 0 lo L u i" OOsryM 0 S~3 17 0 Tf l i o n . 5M ' . i t i U ) ' > 'i * u f . n.cv 3 9; 3 .2 : G I ; n d P e n lo n n iu r : OPrsc 0 _S 3 e 5 25 _ 7.7 fli O'rhcul G.Oj <3 f..3* G astro in te stina l ir^ c t. 4 D iffe re n c r. b e tw e e n o b s e rv e d nr<J th e o r e tic a l v a lu e s is n o t s t c t is t i'a l ly s j n ilic > n l. * D iffe re n ce betw e e n o bserved .m d tn e o rc t c *l values is s ta tis tic a lly sic n ih c a n t { P -- < O .0 I). lo bronchopneumonia. The lapsed lim e from and pleura shows jin^qw r^lljnorU lityJrom first talc exposure to tlc a lh from pngpmo- caTcTribrba- of the lung and pleura to be ap- coniosis or com plications, of both, averaged pn^imaTglyTonrJtuncs that expected. H ow 25.9 y earifw ith a range.f rpnyl5_i o_39_yea ever, tire significant increase appears to oc 'TnThis group there were 31 tale millers, sev cur in the age group of 60 in 79 years en talc miners, and nine who had been both rather than in the 40 to 59 year age millers and miners. All 2S had their initial group. This is at variance to what we exposure befora-1 94J3 f v.'hen jrnore effective have observed among workers exposc-rl engineer ing_co ntrols^in clu cling _wef__dril.ljng to asbestos dust where the observed `values jn the J.ok minesL were introduced. in the 40 to 59 as well as 60 to 79 year age r * K \ \ Other Causes.-- Of the 11 deaths in groups were significantly different from the .nis category. Jour were due to cerebrovascu expected values (Table 4 ). The asbestos lar accidents, two to lobar pneumonia, and group consisted of 152 asbestos insulators the remaining five, to one of the. following: who had 15 or more years of exposure in bleeding duodenal ulcer, strangulated ingui 1945 or achieved 1G years between the period nal hernia, perforated diverticulum with of 1945 to 1965. T h e overall mortality was peritonitis, acute glomerulonephritis, and 46 or 30.3%. The reason for the earlier o c mesenteric arterial occlusion. currence of an increased incidence of lung or Environm ental Exposure.-- Of Ihe 91 pleural-cancers in the asbestos workers.corn- death cases, data on envi ronm ental exposure were available in 50. T he mean Table 3.-- C om parative D ust Counts in Tate M ines and M ilts. N o rth e rn Wei*/ Y o r k ' duration of exposure for this Before 1945 1946-1965 group was 24.7 years with a ' range of 15 to 47 years. The _dusLexposure consisted pre' dominantly of tnlc-arlmixed Work Type M ines OfiMing Low 83 Me dium High 413 2300 Aver M e A ver age low dium High ag e 8)8 0 3 10 5 Avith other silicates such as serpentine and trcm olite, "carSonales, a nd . a srnal 1. afnbliht of free,silica. .The comparative dust counts in the talc mines and mills prior to 1915 and between Mwckin,* Scraoing Mills ` C ru sh in g Screening M illing G arners and separators 2 30 475 120 No Oust Counts M ade ( u d l o 1 9 -1 3 ) 22 69 690 180 43 61 136 69 32 75 271 92 58 70 728 278 3 5 9 5 5 e 13 9 ( 1949-1965) 3 13 3 6 0 42 8 37 G8 37 5 20 70 2d 5 27 60 27 1946 and 1965 arc shown in P u l v e n r c r s No Oust Counts M ade 25 28 31 ?8 Table 3. UaK.vnr 26 129 520 151 b 23 69 27 R R car and Comment truck lo id tto.v Room No Counts Made 115 1196 24SO 1227 10 03 109 73 Disconl inuetf Malignancies.--T h ed a tn , Open chutes 21 03 440 123 O fsconhnu'vl on carcinoma of "the lung C o n c e n tra tio n in mllons o t p a rtic le s p er c u b ic fo o t o f a ir. A rch E nrirnn H e a lth -- Voi 1-1, M a y I0G7 CTc - ! : d.`* l i . :. :1 IIf.*!* - - . . ;i / -' ' *i: :: .;! `r fi - r d < |, it ; * if: i* ' liiN l! t ^ JV: i!i *. r . * ;:. I w ; ' i *" k ` ;ii *. . * , . d* i:lMl * : '= ! '* T * ' ' : . V!i !I !I : ; : d 1t : :!'