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poieniial it high (> 10) the positive ion ap propriates one or more oxygen ion. freeing Department ofSoil and I the hydrogen and forming an oxyanion, Hebrew University ofJei which it generally soluble; this it charac Rehovot, Israel teristic of the nonmetals in the upper right comer of the periodic table. IrfimniiN If life began in the primitive terrestrial oceans, elements whose abundances in the aqueous phase are high should have a high representation in living material. In Fig. I, the enrichment factor for a number of ele ments--that is. the ratio of the concentra LOO IONIC POTENTIAL tion of the element in an organism to its Fig. 2. Elemental enrichment factors in seawa concentration in the earth's crust (7)--is ter. related to the ionic potential of the elements. plotted against ionic potential. A similar curve is seen for all major groups of orga- nistju, at we proceed up the evolutionary may be taken as a clue to a more exact lo scale from bacteria to fungi to plants to cation for the origin of life, it can be specu land animals, and for the ocean (Fig. 2). lated that life began at the interface of the A general pattern is observed for all primitive atmosphere and the ocean, in the living organisms: (i) For elements of low thin microlayers at the surface of the ocean ionic potential values (IP < 3) the log of where large enrichments of the atmo the enrichment factor (EF) is in the range spheric constituents (mainly nitrogen and of-I to +1 indicating small enrichment or carbon at that stage) may occur. Various small depletion relative to the crust, (ii) other elements may also be concentrated in For intermediate IP values (3 < IP < 10) these microlayers because of the effects of log EF is -3 to -4 indicating large de surface-active materials, surface tension, pletion in living organisms, (iii) For large and the transfer processes between the liq IP values (IP > 10) log EF increases as the uid and the gaseous phase. In any event, it ionic potential increases and varies from is evident that a chemical environment -4 to +4. It should be noted that the ele similar to the earth's ocean is sufficient to ments mentioned by Crick and Orgel as explain the elemental abundance relation showing anomalous distribution patterns-- ships in living materials. A nonterrestrial 1. S. Arrhenius, Worlds In the Unking (Hirpcr A Row. New York. 1901). *^ 2. F. H. C. Crick end L E Orgel. leans I*. Ml (1973). J. W. R. Chappell R. R. Meglca, D. D. RunnelU. Ibid. 21, 313(1974). 4. T. H. Juke*/Aid, p. 516. J. L. E OrgeUbid., p. 511. 6. K. B. Krsuskopf, Introduction to Geochemistry (McGraw-Hill. New York, 1965k 7. Om oo concentration ringer and mean values of elemental abundances were compiled from the fol lowing sources (Earth's crust) S. R. Taylor. Geochim. Cosmochim Meta 23. 1260 (1964). (Seawa ter) J. P. Riley and G. Skirrow, Eds, Chemical Oceanography (Academic Press. New York, 1965k vol. I, pp. 164-165. (Bacteria and fungi) J. R. Porter. Bacterial Chemistry and Physiology (Wiley. New York. 1946), p. 365: W. S. Spector. Ed, Handbook of Biological Data (Saunders, Philadelphia, 1956), pp. 68-89, C. Long. Ed, Bio chemists' Handbook (Spon. London. 1961). on 1050-1052. (Plants) H. D. Chapman. Ed, Diag nostic Criteria for Plants and Soils (Umv. of Cali fornia Press. Berkeley. 1966). p. 793. (Land ani mals) H. J. M. Bowen, Trace Elements in Bio chemistry (Academic Press, London. 1966). pp. 174--210t A. Banin and J. Navrot, Common. Soil Sei. Plant Anal. 3, IT! (1972). Where available, data for a range of concentrations were used to calculate a range of enrichment factors for a group of organisms. When only the mean concentration was available, only one enrichment factor value was given. The ionic potential was calculated using crystal radius values given by L. H. Ahrens (Geochim. Cosmochim. Meta 2. 155 (1952)). For ele ments appearing in various ondation states the most abundant form was chosen. 8. A. I. Oparin, in Exobiology, C. Ponnamperuma. Ed. (North-HolLtnd. Amsterdam. 1972). p. II. 9. For constructive criticism of this manuscript we extend our thanks to J. Kronfcld and I. Cohen. Mo, Ni, and Cr--also follow this general explanation, especially one that has in- II March 1975 -attem. Specifically, Mo does not show any significant enrichment in living organ isms as compared to the earth's crust. Obviously, taking each element and each group of organisms separately, we may ex Exposure to Asbestos in the Use of Consumer Spackling, pect many exceptions to the rules; still, Patching, and Taping Compounds the general pattern is strikingly similar for " all the groups of organisms investigated. Abstract. Analysis of representative samples of spackling, patching, and jointing com According to Oparin (S), some com pounds. purchased at retail stores in the New York City area, has shown that some con binations of biochemical reactions are tain asbestos minerals as well as other biologically active substances. Measurements sug characteristic of all contemporary orga gest that home repair work involving the use of such materials may result in exposure to nisms. These are combinations of patterns dust at concentrations sufficient to produce disease. acquired by the emerging living matter in its very early stages of development, before Spackling and drywall taping com Fifteen samples of consumer spackling further specialization and differentiation pounds consist of extremely fine-grained and patching compounds were purchased took place. Thus the basic similarity of the white powders or premixed pastes. Plaster at hardware stores in the New York City elemental composition pattern of all of Paris is supposedly the major constitu area, four in 1972 or earlier and the re groups of living organisms (Fig. 1) in ent, but other light-colored materials in mainder in January 1974. We analyzed the dicates that the pattern was determined cluding clays, micas, quartz, talc, and samples for mineral phases by polarized at the initial steps of the development of ground limestone, supplement or replace light microscopy, x-ray powder diffraction, life. the plaster in many formulations. Chryso- and transmission electron microscopy, It should be noted that in the range of tile is added to some products, apparently with particular attention to quantitative ionic potentials higher than 10, where the because these minute fibers act as rein determination of asbestos minerals. The major biochemical elements sulfur, car forcing agents. The presence of amphibole spackling and taping compounds consist bon, and nitrogen are found, organisms asbestos in some products results from its mainly of particles smaller than 3 ^m in have a very significant enrichment of 10 to natural occurrence in talc, carbonates, and average diameter or length (Fig. 1). Par Trost 10,000 relative to the ocean. This other rocks used as raw materials (/). ticles of this size are generally too small to hUGUST 1975 551 Ttble 1. Minerml content orconsumer speckling and catching compounds and industrial drywall upmg compounds. Frequency of occurrence of mineral phase* weight basis. Diagnostic reflections for each of the asbestos minerals were select ed. These reflections were step-scanned by x-ray diffraction at increments of 0.02* 2t, where * is the dispersion angle, over a Mineral phase Chrysotile T remotile Anthopthyllilc Talc Quartz Feldspar Pyrophylliic Mica Kaolinite Caldlc Dolomite Plaster of Paris la 15 consumer In 10 spackling industrial and patching drywall taping compounds compounds 3 (5-10%) 1 (4- 6%) 1 (10-12%) 2 9 (5-70%) 1 2 8 5 II 3 7 9(5-12%) 1 (5- 7%) 2 6(10-30%) 9 7 4 4 6 goniometric interval sufficient to define a peak-to-background ratio for the diagnos tic reflections. A digital printout of elapsed time in a fixed-count determination was used to prepare precise positions and pro files of the diagnostic reflections. The area above background, determined with a compensating polar planimetcr. was taken to be proportional to the concentration. Details of the method have been presented elsewhere (2). Samples of spackling and taping compounds were prepared, ana lyzed, and measured under the same condi tions as the dilution standards. Com parison of the results of known dilution * Fig. I Electron photomicrograph of a < spackling product Large numbers of c fibers and fiber bundles are present. 1 particulates ate clay, mica, and carbor eraIs. standards with the samples permitted the amounts of asbestos to be estimated with stituent in two samples and pyroph be individually studied by polarized light approximately 20 percent reproducibility. two. The crystal structure and ; microscopy, and identification is further The presence of certain minerals may in properties of pryrophyllite are confounded because these compounds , terfere with the detection or quantitation identical to those of talc; pyrophyll commonly are mixtures of four or more of chrysotile in spackling and taping com be considered the aluminum analog different materials. The analytical use of pounds. For example, chrysotile and Its biological activity is presen the optical microscope with its limited res kaolinite have similar crystal structures known. Quartz was a major consti olution allows large numbers of fibers to and consequently similar x-ray diffraction seven of the samples, and it was pr go undetected. The asbestos minerals, in patterns (3). However, electron micros two others in lesser concentrations, particular, are usually too fine-grained to copy can be used to corroborate the re basis of the x-ray intensities of sevc identify. In such circumstances, x-ray pow sults of x-ray diffraction and to directly jor quartz reflections, including t der diffraction may be used to identify and estimate the asbestos content of materials, 4.26, 3.34, and 1.817 A, the am quantify the individual crystalline phases since each mineral type has a characteristic quartz present is estimated to be present in the mixtures. morphology and electron diffraction pat than 10 percent in the seven sample In this investigation the amounts of as tern. cal and transmission electron mic bestos present in spackling compounds was The results of the analyses of IS con have shown essentially all the quar determined by comparison with dilution sumer spackling and patching compounds of respirable size (< 5 >im). Both standards (2). Binary systems of chrysotile, are given in Table I. Three of the samples and talc can produce pulmonary tremolite, and anthophyllite asbestos in were found to contain chrysolite asbestos, (silicosis, talcosis) (4). One samp plaster of Paris (CaS04 '/jHjO) were pre and two others contained tremolite and an sisted largely of quartz wfth lesser a pared at varying dilutions on a weight-to- thophyllite asbestos. Talc was a major con- of feldspar and anthophyllite. This dicate that the source material product was an anthophyllite sch Table 2. Asbestos fiber concentrations during use of taping compounds containing asbestos miner als. M duplication of the number of fibers per milliliter by 10* gives the number of fibers per cubic meter of air, an amount which may be inhaled during I hour. An unstudied proportion of these fibers is retained and others are exhaled Current (interim) regulations of the OSHA prohibit concentra tions of 5 fibers per milliliter or more, longer than 5 inn, as a time-weighted average for workers. Concentrations above 2 fibers per milliliter win be iflegal-after 1976. Current regulations set a ceil ing concentration of 10 fibers, longer than 5 Mm, per milliliter of air. combination of talc with some t and quartz in another sample repr common mineral association ty commercial talc ore bodies. Both optical and electron mic analyses showed that the asbestc Operations Number of samples Peak fiber concentration (fibers per milliliter) Mean Range present in the samples ranged it from 0.25 to 8.0 |im. Most were than 5 Mtn in length, which is rc size, yet they were not generally Pole-sanding (l to 1.5 m) Background {IS m), same room Backgi ound (7.5 m), adjacent room Hand-sanding (1 to 1.5 m) Background (2.5 m). same room Background (4.5 m), adjacent room Dry mixing (1 to 1.5 m) Background (3 to 6 m), same room Background (5 to 10 m), adjacent room 10 3 2 11 2 2 2 3 .' 2 10.0 1.2 to 19.3 by optical microscopy. 8.6 3.5to 19.8 The possibility of asbestos expo: 4.8 0.7to 8.8 ing home construction and repa 5.3 2.3 1.3 to 16.9 2.1 to 2.5 dicated by the fact that drywall c 4.3 1.5 to 7.1 tion workers are exposed to si 47.2 - 35.4 to 59.0 concentrations of asbestos a 5.8 0.5 to 13.1 lamination. Mineralogical analyst 2.6 2.1 to 3.1 industrial drywall taping compvour Sweeping floor (3 to 15 m) 15 Minutes after sweeping 35 Minutes after sweeping 1 "1 41.4 26.4 that nine contain chrysotile, in co lions ranging from 5 to 12 per weight) (Table 1). 552 SCIENCE. We made measurements of peak as* ing had ceased. Personal air samples were fore, recommended that potentially toxic bcstos air concentrations in the breathing taken after sanding was completed. The or hazardous materials be eliminated from zone of drywall construction workers, uti floors of the rooms and halls were swept consumer spackling, taping, and wall lizing the standard technique of the Na with a hand broom, which raised a cloud of patching compounds as soon as feasible. tional Institute for Occupational Safety dust Fiber counts could not be made on As an interim measure, labels should be re and Health (NIOSH) for asbestos sam floor sweeping samples because the fillers quired on such products stating their con pling and analysis (phase-contrast optical were too heavily laden to count. Samples tent and providing instructions for the use microscopy at x 430) (3). These air sam were taken after 15 minutes had elapsed, of appropriate respirator protection and ples were also analyzed by transmission and, in one case, 15 m away in another for safe cleanup procedures, including the electron microscopy. Air samples were room. Measurements showed that signifi disposal of waste materials. taken at various building jobs and job sites cant concentrations of asbestos remained and included such operations as hand- suspended and could pervade living quar A. N. Rohl A. M. Lange* sanding. pole-sanding, mixing of dry ters for a considerable duration of time af I. J. OfcLIKOFF spackle with water, and sweeping after ter sweeping had ceased. W. J. Nicholson completion of such operations. Personal In summary, our analysis of 15 repre Environmental Sciences Laboratory, air samples were also taken in adjacent sentative samples of consumer spackling, Mount Sinai School ofMedicine, City areas; such air samples, taken in the patching, and taping compounds has University of New York. New York 10029 'breathing zones of the operators, consti shown that five contained appreciable tute measurements of their exposure to amounts of chrysolite or other asbestos Rtftnucn 1*4 Nwo dust. Table 2 shows that airborne concentra tions of 5 fibers per milliliter of air or more, longer than 5 #/m, are common dur ing the use of drywall taping compounds containing asbestos. This exceeds the inter im legal standard excursion set by the Oc cupational Safety and Health Administra tion (OSHA) of the U.S. Department of Labor. The OSHA standard calls for an 8hour time-weighted average. The discon tinuous nature of these operations suggests that the 8-hour sampling is inappropriate in that peak exposures in the present in stance, under a range-of application and cleanup operations, greatly exceed the maximum allowable excursions of 10 fi bers per milliliter for a 15-minute interval. minerals. Many contained substantial amounts of quartz, talc, and other miner als with disease potential. Optical micro scopic analysis of personal air samples ob tained during the use of asbestos-contain ing compounds showed concentrations frequently in excess of the current oc cupational standard of 5 fibers per mil liliter, longer than 5 *im. Use of these ma terials in home repair work (for example, mixing, sanding, and cleanup) may expose the user (and other members of the house hold) to significant concentrations of as bestos. Even more important, none of the_25 in dustrial and consumer spackling and tap ing compounds examined had warning la bels or indication that they might contain 1. M. Rost. W. L. Smith. W. Athlon. Am. Mineral. S3. 751 (1968): W. A. Dter. R. A. Howie, J. Zuts- mn. Rock Forming Mintrab (Wiley. New York. 1962). voL 2, pp- 223-262; H. S. Yoder. Am.J.Sci.. Bowen volume(1952). p. 569. 2. A. N. Rohl -and A. M. Linger, Environ. Health Perjpecl 9.95 (Dec. 1974). 3. G. W. Brindley, in X-ray Identification and Crystal Structures of Clay Minerals, G. W. Brindley, Ed. (Mineralogical Society. London. 1951), pp. 32-75. 4. For example, tee: M. Klemfcld. J. Meuile. A. M. Langer. Environ. Res. t, 132(1973): M. Kleinfeld, J Mcssiie. O. Kooyman. M. Ziki. Arch. Environ. Health 14. 663 (1967): W. G. B. Graham and E. A. Gacnskr. Med. Thorac. 22, 590(1965). 5. S. G. Bayer. T. A. Brown. R. D Zumwalde (Door men! TR-84, U S. Department of Health, Educa tion. and Welfare, Public Health Service. National Institute for Occupational Safety and Health. Cin cinnati. Ohio. 1975). 6. Supported by National Institute of Environmental Health Sciences (NIEHS) Center grant ES 00928 and by New York City Health Research Council grant U-2331. One of us (A.M.L.) withes to ac knowledge support under a Career Scientist Award from the NIEHS (grant ES 44812). We thank K. Martin. R. Klimentidis. and P. Formby for technical assistance. These concentrations, determined by the toxic or hazardous materials. It is, there- 7 March 1975 NIOSH method, are only suggestive of the total asbestos exposure. Comparison of optical microscopic and electron micro scopic analyses of asbestos fiber counts of Water Wells as Possible Indicators of Tectonic Strain identical samples showed that, for every fi ber visible by light microscopy (x400 mag Abstract. Coseismic water level changes associated with the lzu-Hanto-oki earthquake nification), there were from 200 to almost of 9 May 1974 were recorded in 59 among 95 observation wells located in the districts of 1000 that could be seen only at electron Tokai and Kamo. Japan. The spatial distribution of wells in which the groundwater level microscopic magnifications of x25,000. rose or fell is rather systematic. The areas in which these wells are located closely coin The background measurements in Table cide with the areas of contraction and dilatation expected by the faulting. This strongly 2 suggest that in home repair work in suggests a possible correlation between the observed changes in groundwater level and volving sanding of spackling compounds, the tectonic strain. The results may indicate that the water level of wells is able to monitor members of the entire household or other at least acute coseismic strain changes. occupants of a building may inhale as bestos fibers. This could occur during mix A destructive earthquake occurred on Coscismic changes in groundwater level ing. sanding, or cleaning up of debris. Dur the southern tip of the Izu Peninsula, Ja caused by the earthquake were examined ing mixing of drywall taping compounds, pan, at 08:33 hours on 9 May 1974. The in 95 observation wells (J), located 50 to spackle is gradually poured from a bag seismological data (/) are: epicenter, 34* 210 km from the epicenter. These wells into a bucket of water and the mixture is 34'N, 138'48'E; depth of focus, 10 km; were drilled originally for the protection of stirred until the desired consistency is at and magnitude. 6.9. The focal mechanism groundwater resources and measurement tained. Fiber counts measured during mix of the earthquake was a quadrant type of land subsidence. Most of the wells range ing were found to be from 7 to 12 times with the maximum pressure axis in a near in depth from 100 to 300 m, the shallowest greater than the current occupational ly north-south and horizontal direction. and the deepest being 35 and 2150 m deep, standard. Detectable fiber concentrations Distinct earthquake faults appeared along respectively. Groundwater level changes were found in adjacent rooms during the preexisting, dextral strike-slip faults were continuously monitored, in most mixing, and fibers were still suspended in trending in a northwest-southeast direction cases, with recorders manufactured by the the room air at least 15 minutes after mix- (2). Nakaasa Sokki Co. The practical sensitiv- 15 AUGUST 1975 553 .jlJSt t <ge PZ: a--J & v^. h.~> ' -- --T, ."""J r--* a -- tixw DWfWtWft ScA<ei letoretonr uA \ 01 Jh0 C*t UMTWy f New Tort INSULATION HYGIENE PROGRESS REPORTS FROM THE INSULATION INDUSTRY HYGIENE RESEARCH PROGRAM Irvin* J. SaMfcoff. M.D., Program Director Vot. 6 No. 1 Spring 1*75 r r i t t t i i The Asbestos Exposure of Insulation Workmen Extensive information has been de veloped on the mortality experience of insulation workers. It would, thus, be of considerable value to have quantita tive information on the asbestos dust ievels to which these workers were ex posed. Because of the long lapse period between exposure and clinical appear ance of disease, the dust estimates of greatest concern are those of 20, 30, 40 or more years ago. While historical data are scant and fragmentary, insulation work practices have changed relatively little, prior to 1970. either in the U.S. or abroad. Thus, measurements taken prior to .1970 w ill also, provide data of use in assessing earlier exposure. United Sunes Data The only early work of note is the 1945 study of Fleischer and his col leagues' who reported asbestos dust levels during insulation application in four U.S. shipyards. In this study, dust levels were assessed using a konimeter (an instrument widely used at the time but no longer employed), and both total ASBESTOS STANDARD TO BE REVIEWED On December 7, 1971 an Asbestos Standard was promulgated that prohibited workmen's eight-hour average asbestos exposures to exceed 5 fibers per milliliter (f/ml) of air. A milliliter is about a thimbleful of air and only fibers longer than five microns (about 1/25.000 of an inch) are to be counted. This level is mandated to go to 2 f/ml during June. 1976. Last year, the U S. Court of Appeals ordered portions of the current U S standard to be reviewed by the Department of Labor. Of interest to insulators, the court specifically stated that in those industries where a dust level of 2 f/ml was feasible, it should be implemented before 1976. Because of this pending review of the standard, a summary of all research on the asbestos exposure of insulation workers has been prepared for submission to the Dept, of Labor by the Insulation Industry Hygiene Research Program. Because of ihe importance of achieving a safe U.S. Asbestos Standard and the interest of asbestos workers in this goal, we are publishing the full report in this issue. dust levels and fiber levels were re corded. This study gains importance in that one of the yards studied by Fleischer was resurveyed during 1965 and 1966 by personnel of the Depart ment of Industrial Hygiene, Harvard School of Public Health13 and a com parison of levels is possible. During 1964, additional data were published by Marr1 on exposure levels at the Long Beach Naval Shipyard (Local 20. IAHFIAW) However, de tailed numerical data on dust concentra tions are only given for panicles. If fibers were present, bui the count re vealed less than I million panicles per cubic foot (mppcf). they were reported only as a trace. Thus, no average fiber concentrations can be derived from this study. tCottumtcd on i*i%e 7/ TABLE I Vat* Shipyard asbestos fiber concentrations by Konimeter count--1945, 1965-66 A fiber coac. MPPCF tJmd i fiber com. MPPCF tfmt C 11*45l fiber com. MPPCF f/ml c fiber com. MPPCF Urn1 D fiber com. MPPCF f/ml Shop Activity No. of men exposed (1945) Layout and cutting Sewing and fabrication General room air 84 0.35 12.4 0.03 l.l 0.08 2.8 50 0.23 0.1 0.01 8.1 35 0.4 51 22 6 62 0.8 78 22 28 1 76 62 0.27 9.5 0.3 10.6 8 0.63 22 0 03 l.l 0.02 0.7 The following shop activities were done at infrequent intervals and involved only one or. at most. two men: Band saw cutting Mixing cement Scrap gnnding 0.12 0.2 0.47 4.2 7.0 16.6 3.0 106 1.7 60 ---- 6.19 3.1 -- 218 109 -- 0.7 0.23 -- 24.7 8.1 -- -- 0.01 -- -- 0.4 -- Aboard Ship No. of men exposed (1945) Avg exposure, all activities 467 0.02 0.7 700 2.8 98 123 l.l 39 0.17 6 0 1 60 0.03 l.l u--u a CO f^f1 0.5 . Average Exposures Low 1945 Results Available Table I lists the fiber exposure data obtained from over 200 dust counts by Fleischer in 1945 and also those ob tained by Murphy1 during 1965 and 1966. Using data supplied on the number of individuals engaged in the various work activities, a timeweighted (actually man-weighted) av erage asbestos exposure is calculated. A detailed analysis of the results, however, presents difficulties. In each yard, a worker's average exposure was dominated by insulation activities aboard ship. For such activities, the average asbestos dust levels reported in Insulation Hygiene Progress Reports Vol. 6 No. 1 Spring 1975 from the Insulation Industry Hygiene Research Program Editor: VV. J. Nicholson, Ph.O., Pub lished at the Environmental Sciences Laboratory (Irving J. Selikoff. M D . Director). Mount Sinai School of Medicine of the City University of New York. N Y. 10029 - Advisory Council of IIHRP Irving J Selikoff. M D Program Director and Chairman E. Cuyler Hammond. Sc.D . Vice Presi dent. American Cancer Society. New York. N Y. Andrew Haas. General President. Interna tional Association of Heat and Frost Insulators and Asbestos Workers. Washington. D C. Fred L Pundsack. Ph D Vice President. Research and Development. JohnsManville Corporation. Denver. Colo. PURPOSES OF THE INSULATION INDUSTRY HYGIENE RESEARCH PROGRAM 1. To develop improved methods for minimizing exposure of insu lation workers to dusts and fumes encountered in their work. the different shipyards varied by nearly one hundred times. It should be recognized that these fiber counts represent all fibers enu merated in the field of view of a konimeter. These would include fibers perhaps as short as 1.5 microns. Supplementary data1 on the size dis tribution of amosite aerosols in ship yards suggest that this overestimates the number of fibers longer than five microns by a factor of two. Taking this factor into account, the average of the eight-hour concentra tions of fibers longer than five microns in the four U.S. shipyards studied by Fleischer in 1945 would be from 15 to 20 fibers per milliliter (f/ml). It must be emphasized, however, that such aver ages are highly subjective and depend strongly upon the vagaries of the par ticular work practices selected for sam pling and conditions present at that time. Similar considerations would yield a value of 4 f/ml for the shipyard survey by Murphy in 1965-66. New Techniques Used The first research that quantified as bestos insulation exposures using membrane filter techniques was that of Balzer and Cooper published in 1968s and extended in a report at the Dresden Conference on the Biological Effects of Asbestos in 1969.7 Their initial publication, however, enumerated fiber concentrations in marine and commercial insulation work in terms of all visible fibers, in cluding those shorter than five microns. The later subsequent publication also provided data on fiber concentrations longer than five microns. Table 2 summarizes these results. Using the information provided on dust concentrations and the percentage of time a worker is engaged in a particu lar practice, a time-weighted average of 2.7 f/ml was obtained for exposures during asbestos insulation work in light and heavy construction, and 6 6 f/ml in marine construction and repair. Cooper and Balzer noted that at the time of their study, approximately 55% of the work time of insulation workers was spent using materials other than asbestos. Thus, eight-hour timeweighted average exposures for asbes tos workers during 1968 in the western United States would have averaged less than 1.5 f/ml in light and heavy con struction. Moreover, it is noteworthy that Cooper and Balzer state their sam ples were "deliberately taken under conditions where the highest dust con centrations representative of a particu lar job were being developed. " Union Cooperation Obtained The environmental evaluation of in sulation work that was undertaken by the Mount Sinai School of Medicine under the auspices of the Insulation In dustry Hygiene Research Program5 re vealed asbestos air concentrations somewhat higher than those measured by Balzer and Cooper. Again using in formation supplied by union members and from observation of work prac tices. estimates were made of the per centage of time workmen were engaged in various activities in commercial and industrial construction. The information on measured asbes tos air concentrations obtained during these work activities is shown in Table 3. They were used as indicated to arrive at the estimated time-weighted average exposure of about 6 f/ml for insulators when working with asbestos. On the average, in the eastern United TABLE 11 Asbestos fiber concentrations by membrane filter techniques CtnuftcMJoa Pcrcrvtftft f wert wtli fttbestai U*ht tad Hor>; FlWn/ec AM Infill Ln|ltt >Su Marine Construction end Repair Flben/cc mean All Lrtkfth > Su 2. To disseminate knowledge of these improved methods of dust control wherever they may be applied advantageously and to offer cooperation, advice and assistance toward their universal adoption. Prefabrication Application Mixing Finishing Tearing Out General 10% 40% 5* 30*510% 5% Time-Weighied Average Exposure 10. 1 12.4 2.4 2.7 12.8 0.8 6.6 8.0 1.6 1.8 8.4 .5 30.4 24.8 10 6 1.8 31.5 .2 20.0 16.8 71 12 20 2 01 4 | 27 99 66 C3tllSG H U BB-0005748 '/^rs' *v=3 L/--J E* IH1 SI IIHRP Results Reported States during the 1960's, over half of the work activities of these men were with materials other than asbestos. Thus, the over eight-hour timeweighted average asbestos exposure was approximately 3 f/ml. In the research that led to these data, it was reported that peak exposures could be extremely high. It was not uncommon, for example, for two to five-minute concentrations of asbestos to range between SO f/ml and 100 f/ml during the mixing of cement. This mix ing. however, would consume only a few minutes time and be done perhaps once an hour. Thus, exposures meas ured over that hour, including the mix ing. would seldom average over 5 f/ml. Peak High. Average Low Similar experiences were subse quently reported by Cooper* at Lyon who stated that. `' Peak concentrations may be high for brief periods, while time-weighted averages are often de ceptively low." In a continuation of the work of the Department of Industrial Hygiene of Harvard University in assessing asbes tos exposure in Naval Shipyards, Ferris ei at* reported on the results obtained by J. Lynch and W. Burgess from 81 shipyard asbestos air samples taken during 1969. Using fiber counting techniques they determined a mean as bestos concentration of 0.3 f/ml inland fabrication shops and 2.9 f/ml in ship board installation work. 3 fiml Exposure Three research programs in the United States point to the conclusion that the time-weighted average expo sure of insulators between 1965 and 1969 was less than.? fibers longer than five microns per milliliter. We have direct information on asbes tos fiber concentrations, measured using the currently prescribed analysis procedures, during recent years only. Insulation materials have changed from earlier years. Fibrous glass has found extensive use while work with cork is seldom seen today. Moreover, changes in the asbestos composition of insula tion products have taken place. Pipe covering and insulation block may have had twice the asbestos content in past years as exists today. During this period, however, work practices were virtually identical io those of past years and during the period of those measurements, lew controls of significance were in use. TABLE III Asbestos concentrations during various work practices Type of Herb McMttrtd Fiber Cnocentrafl-- (f/ml) (jrt*ur thaa S nkraaal PtrccoUfe Tint Practice Occur* Wbea Attest** b Ute4 Catena One dmm Caluma T* Mixing and Applying Cement and Cloth Covering to Insulation Material Good Ventilation Poor Ventilation Cutting and Applying Insulation Block or Sections of Pipe Covering Good Ventilation Poor Ventilation Pre-Fabrication work including Cutting Materials for later use 2.5 4.6 5.2 11.5 7.6 Time-weighted average 535/85 * 6.3 f/ml 17.5 44 17.5 81 20 104 20 230 10 76 535 The above pwttcev which occupy 85^ of the wort ume in asbestos insulation work, five nse to a ume-weifhted average eipoture of 6 J f/ml As the majority of the other activities of insulation work (supervision, collection of materials, movement art installation of equipment, etc.) are relatively clean, the overall exposure tiu> be lower (In the L S.. vwcepinf art dusty cleanup are done by members of the Laborers Union > In a review of wort activities in commercial art irtustnai construct ton. it was found that little removal of insulation was cortucted art asbestos sprav applications were very rarely undertaken by insulators I Asbestos worker* app(*\J sprav insulations oni\ ir> powerhouse turbines ) li is estimated ihai less ihan two or three percent of nonmarine tnsulauon work b> memocrv o( ihe Asbestos Workers Union is m ihese continuously duvty operations Even ,f average exposures here were SO fmi art the men wort no respmion. their overall average exposure wtuk) he fvrea>ed only to 7 i.ml when working with asbestos Insulators Still Exposed to Asbestos While much of new insulation material contains no asbestos, pipe-coverers may still be exposed to high asbestos concentrations dur ing removal and demolition. In such work, safe procedures and personal protective equipment must be used. Thus, obtaining an effective and safe Asbestos Standard remains of paramount importance. Thus, dust concentrations measured under these conditions have relevance for the estimate of levels of past years. Considering the possible doubling of asbestos content of insulation materials and considering that workers may have used asbestos materials more often in the past than now. the data from these three studies would suggest that the upper limit on insulators exposures in the United States during past years would be about 10 f/ml. British Data At the Devonport Naval Dockyard in Plymouth. England, extensive mea surements of asbestos dust concentra tions during the application and re moval of insulation aboard ship have been reported by Harries.10 These are listed in Table 4 During the applica tion of insulation material, fiber con centrations from 2 I to 22.4 f/ml were found, not unlike those found in U.S. studies. However, during the removal of pipe and machinery insulation, mean dust concentration in various compartments ranged from 88 to 257 f/ml. and in the removal of sprayed crocidolite asbes tos. fiber concentrations ranged from 20 to 500 f/ml, with short-term breath ing zone samples showing concentra tions exceeding 1000 f/ml. Moreover, the spread of asbestos from the site of removal can be extensive. Concentra tions of 30 f/ml were found at hatchway openings to decks from the area of crocidolite stripping. High Dust During Rtpout Additionally, short-term fiber con centrations measured during the variety of specific application and removal techniques are reported. High levels, exceeding 200 f/ml. occurred while mixing asbestos cemeni. The cleaning of debris (155 f/mli and the sawing (55 f/ml). fitting 14.X (Inil). or removing (52 f/ml) of calcium silicate sections also produced high dust concentrations. A subsequent publication bv Har ries" of lone-term area sampling in var ' C3tlloOS u iiD D .a o iK iiia ft v<T\ \\./ u e_fcC ^\C I Tw-- Adequacy of Standard Questioned ious circumstances indicated a mean concentration.of 226 f/ml during the removal of spray, of 152 f/ml during the removal of pipe insulation; and of 8.9 f/ml during the application of pipe lag ging As with the Mount Sinai research and the Balzer-Cooper study, short term dust concentrations during spe cific insulation practices can be ex tremely high, while samples taken over long periods of time yield concentra tions that are relatively low when com pared with current and past asbestos standards. Summary Studies on asbestos concentrations from 1965 through 1971 by five differ ent research groups in two countries are summarized in Table 5. along with es timates made of earlier insulation as bestos exposures. They indicate that recent average exposures of insulation workers to asbestos are from 3 to 9 f/ml when working with asbestos. As asbestos workers in the United States in the period these measurements were taken used asbestos materials in their work less than 50% of the time, their eight-hour average exposure to asbestos was less than 3 f/ml. ft is noteworthy that these exposures existed prior to the implementation of the current 5 f/ml standards in the U.S. As extensive substitution of non asbestos materials has subsequently taken place in insulation work, current exposures are now considerably lower. The estimate of from 10 to 15 f/ml obtained for past exposures in non marine insulations work does not offer much confidence that 5 f/ml, or even 2 f/ml, is sufficient to protect asbestos workmen. Forty percent of insulators' deaths can be attributed to their pasTM occupational exposure to asbestos a^ such levels. A standard set at two, oifcg even five limes lower, is unlikely id offer significant protection to asbesto^ workmen. cq -------------------------------------------------------------------- --C Asbestos Workers Have High J Peak but Low Average Asbestos Exposures The high peak exposures of asbes tos workers measured by different groups can be deceptive These often are of short term and may in volve few men. Average exposures have universally been found to be low, usually less than current stand ards. This result leads to two con clusions: I) Current standards may be inadequate to protect workers, and 2) Easily accomplished control of peak exposures can significantly reduce the long-term average expo sures. TABLE IV Asbestos dust concentrations during the fabrication, application and removal of insulation materials General Almneptwre Breadline Zone Lacaoau No. of sampfc* Mom AbcrWca* tup No. of aunptes M*a flben/cm* Rant* Application of pipe and machinery insulation: Boiler rooms Engine rooms Accumulator room Mattress fabrication: Old shop New shop Removal of pipe and machineryinsulation: Boiler room Engine room Brick stowage space Removal of asbestos acoustic panels: 17 22.4 1-61 28 2.1 0.1-14 5 16.5 2.5-46 12 12.7 0-126 11 16.3 2-83 153 171 0.04-1062 45 88 0.16-3021 13 257 9-592 6 413.5 30-684 14 16.8 0 1-68 16 7.3 0 04-40 17 9 6 ! -47 15 1 5 0- 7 25 3.7 0-17 20 97 25-220 25 91 2-490 ------ 6 131 48-271 TABLE V Summary of astrife asbestos air concentrations durinf insulation work ftMOCN* 4*** (nut MMra l^i Hm VbnM Mount Sinai (IIHRP) 6.3 Balzer-Cooper 2.7 6.6 Murphy. Harvard 8 0- Burgess-Lynch 29 Hames 88 Estimates of earl\ eapovure Fleischer 15*20 Mount Sinai 10-15 TV-a* roMct<WH*WM were thaw* wcrus'rsJ .u eziww*\J itr aur> wfuk aaiftf nArstos tf*u Ikui a>mge r'pewfvt < twnaerinf iV u*e n'.ncr mairr-ats hr as )>nk as half >fw Nr * F<ki >w AMt> Ali 'v.f'k i ihrr\ REFERENCES 1 Reiscfer.W E . V,|.F J Jr.. Cade. R L and Drifeet. P A Health Survey of Pipe Covering Opcraitona in Conwucimg Naval VnieH Journal of Industrial Hygiene and Toxicology 28, 9-16(1946) 2 Mutphy, R L H . Jr . Ferns. B G . Jr . Burgess. W A cl al . Effecu of Low Concentrations of Asbestos Clinical. Environmental. Radiologic and Epidemiologic Ofecn atiotu m Shipyard Pipe Covcren and Controls New England Journal of Modicmc 2AS. (27|.|2Tgn9Th 3 Murphy. R L H . Jr Asbesxosis in Pipe Coverers Engaged in New Ship Construction Thesis. Har vard School of Public Health. (1968) a Marr. W T Asbestos Etposure During Naval Vessel Overhaul American Industrial Hygiene Atsocijtion Journal 25 26J-268 (1964) 5 NkMwui J.Hotaday.D A and Heimann. H Direct and Indtrcci Occupational Exposure to inwlaiion Du><> in Lnited States Shipyards Proceeding oi the IniernjiiA'nal SsmfVMum on Safely and Health m Shipbuilding 4n<J Ship Repairing, Helsinki. JO *ugu\i u> l September. 19* i ILO Occupaitonal Satciv and Health Series No. 27. 27-7. Geneva (1972. 6 BaUer. J L and Cooper, W C TfeWWknx. ronmeni of Insulating Workers American Industrial Hygiene Association Journal 29 222-227 < I96di 7 Cooper. W C and Baleer. J L E' aluanon and control of asbestos eipotures m the irv.ulai.nfr trade International Konfercru liber die biologi-w/fen ^ir kungen de> Asbestos. Dresden. 22-2J April 1964 Deuucfe* Zencaiinsnrute fur Arbettsmedmn pp 151 160. Holstein and Anspach, eds . Berlin K Cooper. W. C Asbestos in.the Manutacture of Insulation MatcnaJs Biological Effects ot Asbewov IARC Lyon. France, pp 175-178 9 Ferns. B G . Jr . Ranadive. M S' . Peters I M et al Prevalence of Chronic Respirators -- Asbestosts in Ship Repair Worten Archive* oi En vironmental Health^. 220-225 (I97| i 10 Hames. P G . Asbestos Dust Concentrations In Ship Repairing' A Practical Approach in Improving Avfe\<(fy Hygiene m Naval Dtvkvardx AnruU of Oc cupjiutnal Hygiene N 241-254 (I97i t I 1 H4/ries. P G . A Comparisons Mas- uix' F.nre C.kkcntrjih>n\ ol Avbesios Du si m Shipv arc ir.'uiji.in Pf'.c-"<s. Anruls til Occupation^ Hvciene 2'- 2-U) i 1971 i ` C3TlloO-1