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14256997033 2002-02-26 19:09:21 (GMT), page 2 URGENT Exposing flie "Mystery" ofABC: A Critique ofthe Canadian Asbestos Mining IndustryMcGill Chrysotile Studies David Egilman MD, MPH Clinical Associate Professor, Brown University Department of Community Health Providence, Rhode Island Never Again Consulting 8 North Main St Suite 404; Attleboro, MA; 02703 tel 617-438-7676 fax 781-394-0381 Shannon Connolly, Brown University Providence, Rhode Island CoreyFehnel, Never Again Consulting Attleboro, Massachusetts SCF-FA-0005 SC-ALL-00074 1 14256997033 2002-02-26 19:09:21 (GMT)* page 3 2 Abstract Background: There is along history ofcorporate corruption ofliterature about the health risks of Canadian asbestos mining. Beginning in the 1930s, the Canadian asbestos industry created and advanced that idea that chrysotile asbestos is safer than asbestos of other fiber types. This was noted by Lanza in 1937: "Their argument was motivated by self-interest ratherthanto make a scientific contribution." Methods: We critically evaluate unpublished and published studies funded by QAMA and performed by researchers at McGill University. Results: The findings indicated that much of the academic literature on the health effects of asbestos mining was based upon unsound science and false claims. Conclusions: In addition to promoting the marketing and sales of asbestos, these spurious studies have had a substantial effect on policy and occupational health litigation from the 1960s onward. Until the misinformation promulgated by the industry is identified and corrected, injured workers will have no means of recompense and unsafe mining practices will continue. ' Key Words: asbestos, chrysotile, corruption, crocidolite, QAMA, McGill, tremolite 2 14256997033 2002-02-26 19:09:21 (GMT), page 4 3 Introduction The history ofthe corruption of literature on the health effects of asbestos is well documented.(Egilman et al. 1998;Egilman and Reinert 2000a;Hardy and Egilman 1991) In corporate-sponsored studies, scientists have manipulated data to falsely claim that there is no significant increase in the risk of lung cancer associated with asbestos work.(Egilman and Reinert 2000a) For example, a letter to file editor previously published in this journal cited a 1957 study funded by the Quebec Asbestos Mining Association (QAMA) in which the researchers deleted all references to lung cancer before presenting their results.(Egilman and Reinert 2000b) ' In 1964, Irving Selikoffj who recognized the unsound nature of many asbestos studies, organized a large conference devoted to understanding the physiological effects of the mineral.(Selikoff 1965) This conference irrefutably established the carcinogenic consequences and other health hazards ofexposure to asbestos, and undermined over sixty years of corporate cover-up by the Canadian asbestos mining industry, and American and British asbestos product manufacturing companies. It threatened to irrevocably damage the industry's position domestically and in the global market In response, Canadian mining companies, acting through its association the Quebec Asbestos Mining Association (QAMA), renewed its association with McGill University to develop contrary scientific evidence, hoping to sew doubt about file toxicity of various asbestos fiber types. While the fact that asbestos caused cancerwas no longer contestable, QAMA promulgated the Anything But Chrysotile (ABC) arguments in the hope that they could maintain or expand market share for their form of this poison and avoid liability. The ABC argument implicates various substances other than Canadian chrysotile for asbestos' toxicity. In the past three decades, QAMA sponsored research at McGill University and 3 14256997033 2002-02-26 19:09:21 (GMT), page 5 4 elsewhere have promulgated several different ABC theories and some have gained widespread acceptance ami influence within the scientific community. This influence stems from a vast body of academic literature, published primarily from McGill University, which supports the claims of the industry. Beyond promoting the marketing and sales of asbestos, these studies have had a tremendous effect on litigation from the 1960s onwards. Lawyers for asbestos-manufacturing corporations have used the corrupted studies to assert that the causal link between asbestos exposure and cancer was unclear ami hypothetical, thus effectively denying injured workers and ' their dependents compensation for their illness. In this paper, we analyze and discuss four fallacies that underlie the most recent wave of ABC arguments. The first is that organic and synthetic oil contamination--and not the chrysolile itself, is the cause of lung cancer and primary malignant mesothelial tumors in miners and other people who work with asbestos. The second is that the crocidolite allegedly imported from Australia and found at a nearby factory during World War II was what caused an increase in mesothelioma in the workers. A third myth put forth by the industry is that tremolite, and not chrysotile was the culpril, and that current commercial chrysotile is "innocuous" because contemporary mining practices either avoid it entirely or remove it during processing. Finally we review the flawed methodology that the QAMA epidemiologists and scientists used to support the various industry claims. 4 14256997033 2002-02-26 19:09:21 (GMT), page 6 5 Organic and Synthetic Oil Contamination Beginning in 1962, Harington and Roe published a series of articles purporting that naturally occurring as well as contaminating organic compounds may play a key role in the carcinogenic nature of asbestos. From die industry's perspective, this was an ideal way to obfuscate the notion that its product, chrysotile, was deadly. If this "mystery" contaminant could be determined and die chrysotile "cleaned," the product and profits could be saved. Therefore QAMA supported further studies, both by providing Rinding and in helping with the collection of samples and other data.(Gibbs 1969) ' Further investigating Harington and Roe's claims, Graham Gibbs and others at McGill University wrote a succession of papers examining organic contaminants of chrysotile. H Gibbs raised the question of whether the compounds may*. 1. Themselves act as carcinogens; 2. Enhance the carcinogenic activity of other substances such as trace metals, asbestos itself or associated oils; 3. Inhibit the action of carcinogens present in the fiber, or 4. Have no influence on the biological action whatsoever. (Gibbs 1969) Through their studies, the researchers found that the organic contaminants were implicated in die "biological action" of chrysotile asbestos products, suggesting that these contaminants, and not the chrysotile itself were the cause ofcancer in workers. (Gibbs and Hui 1971) They determined that the long chained alkanes found in asbestos products resulted from three possible sources: hydrocarbons occurring naturally in the ore body, contamination from the mining and milling process, and contamination from shipping, manufacturing, and utilization processes. (Gibbs and Hui 1971) 5 14256997033 2002-02-26 19:09:21 (GMT), page 7 6 Polyethylene bags and asbestos dryers were allegedly the primary culprits in this oil contamination.(Gibbs 1969) However, even Gibbs, recognized the lack of mesotheliomas occurring in animals exposed to organic compounds, and stressed the need for further investigation into the alleged link to lung cancer. Emphasis was placed on the importance of assessing the differences in organic content ofasbestos to which workers were exposed, but in toe end there was no evidence that organic contaminants accounted for increased cancer rates. In 1969, Wagner and Berry published a report in the British Journal ofCancer demonstrating that removal of organic contaminants from asbestos did not decrease, and in fact possibly increased *' toe ability of the fiber to cause mesotheliomas in rats.(Wagner and Berry 1969) Therefore toe argument that oil contaminants were toe chief cause oftoe carcinogenic effects of chrysotile exposure was no longer plausible, and had to be scrapped in exchange for more other explanations as to why chrysotile was safe. 6 14256997033 2002-02-26 19:09:21 <GMT), page 8 7 Crocidolite Studies published in the late 1970s by J.C. McDonald et al. offered yet another explanation for the non-carcinogenicity of chrysotile. (McDonald and McDonald 1978) They claimed that most of the mesothelioma cases from the Asbestos, Quebec mines occurred as a result of exposure to amphibole crocidolite (also known as film)us reibeekite), which was allegedly imported from Australia for use in gas mask manufacture at the factory located "adjacent to" the Johns Manville Jeffrey mine during World War II. The QAMA-McGill researchers postulated that this use of crocidolite in filter pad manufacture from 1939-1941 accounted for increased ft ' mesothelioma and lung cancer rates among miners and millers at the Jeffrey mine even though none ofthem had ever worked in the factory. It is interesting to note that there are no citations to interviews with workers or correspondences that prove imported crocidolite was ever used for this purpose at the mine location. British regulations specified the used ofeither chrysotile or crocidolite for WWII gas mask filters. Why would QAMA members producing gas masks import crocidolite from Australia, past Japanese submarines and battleships, past other filter factories in Ontario that used crocidolite, to fill gas mask filters at a factory adjacent to the largest chrysotile mine in the world? Furthermore, Begin (1992) reported that mesothelioma rates were not as elevated as one would expect if crocidolite was used at Asbestos in gas-mask manufacture. (Begin et al. 1992) He revealed his own doubts about the presence of amphiboles at the factory by stating that amphiboles "may have" been used there and noted that there were no cases ofmesothelioma in other departments that were nearby such as quality control. Because the QAMA-McGill longitudinal cohort mortality was a follow-up of a birth cohort, most members of the cohort had worked at the mine or mill during this two-year period that gas masks were produced. However at the time the McDonalds initially suggested that this 7 14256997033 2002-02-26 19:09:21 (GMT), page 9 8 bystander crocidolite exposure was the cause for mesothelioma at the Jeffrey mine, only 3 of the 20 workers who contracted the disease were employed tiiere. However, Begin (1992) and Dufresne (1995) reviewed the detailedjob histories ofall 20 workers who contracted mesothelioma, and confirmed that none ofthem had worked during World War II in die preparation ofmaterials for the fabrication of gas masks as previously noted by McDonald, nor had any of them been exposed to crocidolite in the factory or mill during the two-year period.(Begin et al. 1992;Dufresne et al. 1995) In October 2000, at a presentation to a group of asbestos defense lawyers. Case reported %' that the factory was located "immediately adjacent" to the mine and mill. He stated, "not only had some ofthe men worked there, but most has [sic] to pass through the building as it contains common areas."(Case 20000) However at a deposition a year later Case stated that he did not know where the Jeffrey factory was located.(2001c) From 1928-1972 the factory at Jeffrey was located across an open pit mine about a mile from the entrance to the mine and the mill.(Tourist Bureau 2002) It is inconceivable that miners would ever walk through the old factory as a part of their daily routine. There were no common areas and two separate roads led from town to the factory and mine entrances. To walk through the mine, workers would be forced to descend a mile down into the mine pit, walk one to two miles across the bottom ofthe mine and up the other side of the mine, a vertical one and a half miles. Alternatively they would have had to circumnavigate about two miles along the upper ridge ofthe mine. It is highly improbable that any of the workers ever did this.(2001b) Regardless of its source, the QAMA - McGill scientists found crocidolite in the lungs of a high proportion of miners from Asbestos. (Case 1998a;Case 1998b) Initially this finding was only reported for miners at the Jeffrey mine but later the researchers found lower concentrations 8 14256997033 2002-02-26 19:09:21 (GMT), page 10 9 of crocidolite in a smaller percentage of miners from Thetford (13 vs. 71 percent). (Nayebzadeh et al. 2001) Nayebzadeh et al repeat the assertion that the crocidolite in the lungs ofAsbestos miners came from exposures to imported crocidolite used in the gas mask manufacture. However, they overtook the fact that if crocidolite was used, it was only during the time from 1939-1941, and about half of the workers in their study began working after 1941. They offer no explanation for the crocidolite in the Thetford miner's lungs. The most likely source ofthis crocidolite was the local mine ore, not imported fibers. Two geological surveys found that mines from both areas contained blue fibrous reibeckite otherwise known as crocidolite. (De 1961;Rejean Hebert 2002;Hebert and R 1980;Hebert R 1980) ` How did the QAMA-McGill researchers miss this information on crocidolite contamination of ore? The QAMA was given the De PhD thesis in 1960 and the McGill research team cited the thesis in 1972.(Gibbs and LaChance 1972) However while noting that De found actinolite in the Canadian mines, they omitted any mention of his twelve-page discussion ofthe crocidolite contamination ofthe mine ore body. Over two decades later in 1995, Dufresne and others extracted and published considerable information from the De thesis: "There are very few data studies on concentration oftremolite in the ore body except that from the PhD thesis entitled ` Petrology of dikes emplaced in the ultramafic rocks of south eastern Quebec' of Dr. De deposited in 1961 at Princeton University. The objective of the thesis was to study the dike rocks and their relation to the ultramafic rock in the Eastern Townships. It appears that the concentration ofamphiboles in the rocks are variable and can be substantially high in some dikes of granitic and dioritic composition. For instance, he reported the 9 14256997033 2002-02-26 19:09:21 (GMT), page 11 10 presence offibrous actinolite in concentrations as high as 14% in granitic dikes and suggested that the granitic pegmatite from the Jeffrey mines in the town ofAsbestos would even contain anthophyllite. Thus as suggested by lung burden analyses and mineralogical data, the concentrations of amphibole fibers (especially tremolite and actinolite) contaminating the chrysotile mineral ore from Asbestos or Thetford-Mines are at about the same level, although this may not be reflected in sporadic air samples. These mineral matters were likely constituents in the final product. There is a need to clarify how high were the concentrations of amphibole fibers in the host dunite rock especially tremolite and actinolite." (Dufresne et al. 1995) The authors failed to mention that De had written extensively on the location as well as a mineralogic and chemical analysis of the crocidolite he found in the Eastern township asbestos deposits. We find it hard to believe this was an error, especially since the De study was cited in 1972, 1986, and 2001 in papers that dealt with the issue of crocidolite in the miners' lungs. (Gibbs 1972) (Dufresne etal. 1995) (Nayebzadeh etal. 2001) Moreover, in 2001, some ofthe same authors who had cited De's thesis six years earlier actually make a completely contradictory claim, citing an as yet unpublished paper: "Furthermore, Jones et al. confirmed amosite and crocidolite are not present in the rocks mined in Asbestos regron."(Nayehzadeh et al. 2001) While it may be true that Jones et al failed to find any crocidolite it is also true that they never seriously looked for it, that the mine geologist had told them crocidolite had been seen in the ore and that they were aware ofa masters thesis that had reported that crocidolite was present in the ore.(Charles Normand 2001) (Rejean Hebert 1987) 10 14256997033 2002-02-26 19:09:21 (GMT), page 12 11 Why did the QAMA researchers omit the information on crocidolite contamination of the care bodies from all the published work? Had they published on the presence of crocidolite in the ore, it would have cast a pall over any argument that Canadian asbestos was "innocuous." Although the presence of crocidolite contamination would have supported the scientific argument that chrysotile did not cause mesothelioma, crocidolite could not be removed from the ore or final product and thus would have completely undermined the argument that the Canadian asbestos was "innocuous." While using crocidolite, as a scapegoat would have drawn attention away from chrysotile, the point was to maintain the illusion that Canadian asbestos was safe. If t' crocidolite periodically contaminated the mine ore, then the ore could not be considered safe. Tremolite Contamination Most recently, however, the QAMA researchers have blamed ore contamination for mesothelioma risk. The QAMA researchers argue that tremolite contamination of chrysotile, and not exposure to chrysotile per se is the cause of asbestos-related cancers in miners and millers. In 1985, Peto and Doll reviewed this argument and deemed it to be ofacademic interest only because tremolite was found to contaminate commercial chrysotile fibers, which could be found in the end product.(Doll and Peto 1995) In response the QAMA sponsored researchers fabricated two new conjectures. First, there are "high" and "low" concentrations of tremolite depending on the mine location, with current chrysotile coming from "low tremolite" mines.(McDonald and McDonald 1995) Second, current commercial chrysotile contains "minimal" concentrations oftremolite because the tremolite is mined from "tremolite-free" mines and any remaining tremolite is avoided in mining and removed through the milling processes. (2001a) 11 14256997033 2002-02-26 19:09:21 (GMT), page 13 12 In 1995, Science published a letter to the editor submitted by McDonald and McDonald which indicated that exposure to tremolite, and not chrysotile was the likely cause of mesothelioma cases present in miners and millers who worked in Thetford Mines, Quebec. (1) This was the first in a series of articles in which the McDonalds and other QAMA-funded researchers set forth the argument that there were central (high tremolite) and peripheral (low tremolite) mines in Thetford. (2-10) In subsequent publications they have presented data informing readers that all but one of the mesothelioma cases occurred in miners who had worked in "central (high tremolite) mines." (2-10) * McDonald and McDonald cited a 1989 article by Sebastien et al. as the source of data ' indicating a wide disparity in tremolite contamination levels between central and peripheral mines in the town of Thetford Mines. (11) In their letter to Science, the McDonalds summarized the information as follows: "The possibility that this distribution (fewer mesothelioma cases in peripheral mines) might be related to the concentration of fibrous tremolite in the two areas was then tested with data on asbestos fiber concentrations in lung tissue from 83 cohort members from Thetford mines who had died from causes other than mesothelioma and had been examined by electron microscopy in 1988. The number of lungs examined was 58 from area A (Central -- high tremolite mines) and 25 from area B (peripheral -- low tremolite mines); the groups were similar in duration of employment (36 and 37 years) and time from termination to death (8 years in both), but estimated accumulative dust exposure was about 30 % higher in group B. The geometric mean concentrations of fibers equal to or greater than five 12 14256997033 2002-02-26 19:09:21 (GMT), page 14 13 micrometers in length per microgram of dried lung were as follows: chrysotile, area A, 7; area B, 13 (not significant); tremolite, area A. 32; area B. 7 (P = 0.0002)." (/) This information is not in the cited study, and the researchers do not specify the exact location or names of the area A and B mines in any published or unpublished study. Dr. Sebastien has confirmed that his report did not examine this issue, and he was unaware of any other studies (including his own), published or unpublished, that recorded any lung fiber measurements by mine location. {12} The authors provided no comparative data on age, work years, date of first exposure, job, underlying disease or time spent working in other mines, (i) Any of these variables could explain the comparative data, and in their 1997 publication they noted that most of the peripheral mines "had started so recently that there were inadequate periods oflatency" for mesothelioma to occur in workers at "peripteral" mines. (2) Since chrysotile is cleared from the lung over time, this fact alone could explain the higher chrysotile/tremolite ratios in workers from "peripheral" mines. {13} If the findings are not confounded by any of these factors, then the accuracy of the dose estimates used in the entire series of epidemiologic studies published on the Canadian miners must be questioned. The study by Sebastien et al. used comparative chrysotile/tremolite ratios between mine workers and textile workers to justify their dose estimates. {11} Ifthe mine tremolite/chrysotile ratios used for this comparison came from two different miner exposure categories, then the analysis is fatally flawed. In 1997, McDonald et al. published a detailed explanation of the "tremolite hypothesis," and claimed they had "re-analyzed" the data found in Sebastien (1989X but they did not present any data or analysis of lung tremolite levels. {2} Instead the 1997 "re-analysis" appears to be an 13 14256997033 2002-02-26 19:09:21 (GMT), page 15 14 example of "Texas sharp shooting," where the shooter paints the bulls-eye around pre-existing bullet holes. The authors present mesothelioma rates in terms of "central and peripheral" locations, but they again fail to provide any specific information on the exact mine locations. (2) Gibbs categorized at most nine mines at Thetford Mines, and he did not classify diem as central and peripheral, but McDonald et al. refer to 15 mines in another paper and 21 mines in still another. (14,2,9) Ten studies have based their conclusions on the central vs. peripheral distinction, but the 1995 letter to Science is the only publication which provides any foundation for this proposition. (1-10) Four other papers, all of which are co-authored by the McDonalds, * ` erroneously cite Sebastien et al. (1989) and not the Science letter, as the source for the data on different tremolite levels, while five other papers failed to provide any basis for this conclusion. (1-5,6-10) The assertion that the Thetford mines have varying tremolite contamination conflicts with other published data on this topic. McDonald et ctL (1997) cite Sebastian (1989) and Gibbs (1979) as support for the central-peripheral theory. (2) However Gibbs, a McGill co-worker and co-author with McDonald of otter papers concerning this inter-mine difference, published contrary and confusing information on this issue. (14) The number and locations of mines in question are anything but clear. None ofthe publications illustrate locations on a map, nor do they name the mines. Gibbs concluded that intra-mine non-malignant asbestos disease rates were larger than inter-mine differences and therefore differences in tremolite concentration, if they existed, could not explain differing disease rates. (14,15) He also noted that the mines were all part ofthe "same ore body" and there was no geological evidence showing any difference between mines in Thetford Mines. (14) 14 14256997033 2002-02-26 19:09:21 (GMT), page 16 15 In pursuit of the missing data, we conducted a Medline search and contacted J.C. McDonald and Janet Hughes (co-author of a post-1995 study). Dr. Hughes did not know which mines were central and which were peripheral, and McDonald has not responded to our inquiries. (76) Case, a co-author of another paper with the McDonalds that relied on the high and low tremolite mines distinction, also stated that he did not know which mines were central and which were peripheral. (77) We hope only the citation needs to be rectified. However this incorrect citation, which was overlooked by the reviewers often separate articles in five differentjournals, is further ' evidence of shortcomings and the importance of the peer review process. (18) The repetition of this error has given the tremolite hypothesis the guise of sound science, but it is the replication of data, not assertions, that confers validity to scientific evidence. In 1997, McDonald et al. contended that, based on the low disease rates in peripheral mines, "the explanation [for high rate of mesothelioma] is mineralogical." (2) Liddell implied that the medical community had "generally accepted" this high-low distinction when he asserted without citation that, "...contamination of the chrysotile by fibrous tremolite was known to be much greater in the central than in the peripheral area" and went on to conclude that, "...it is now clear for all practical purposes that it [excess incidence of mesothelioma] was confined to the central area there." (5) [Emphasis added] The Canadian researchers have used this evidence before the World Trade Organization and in U.S. tort litigation to buttress the proposition that chrysotile is not a cause of mesothelioma. (20,17) Medical literature relying on the central-peripheral tremolite distinction continues to be used as an argument to promote the sale of Canadian chrysotile in the developing world. (27) 15 14256997033 2002-02-26 19:09:21 (GMT), page 17 16 The second theory put forth by the QAMA-McGill researchers is that there are minimal traces of tremolite in the asbestos mined today because it is avoided during mining or removed during the milling process. Kevin Browne presented these arguments to a conference held in Havana, Cuba and they are prominently displayed on the Asbestos Institute web site.(2001a) He stated: ... all [Canadian mine related] cases of mesothelioma were, "related to tremolite contamination. The main tremolite-contaminated mines are now closed... But in the past, the percentage of tremolite in the fibre could be as -i high as 1%, whereas the high tremolite-contaminated mines in the central ' Thetford area have closed, and in any case the high geological research has shown that tremolite is not uniformly mixed with the chrysotile, but occurs in separate seams which can be identified and avoided. And lastly, there is evidence that much ofthe tremolite is lost in die milling, so that what is delivered to the manufacturer will have an even lower content So present and future supplies from these sources have and will have minimal tremolite.(Browne 200b) However, when asked in 2001, Browne did not know whether or not Black Lake, the only operating mine at the time, was a central or peripheral mine.(Browne 2001) After "checking," a few days later he reported that it was a peripheral Thetford mine and therefore had low tremolite contamination.(Browne 2001) Unfortunately the Black Lake mine is not even in Thetford; it is in Black Lake. The McGill-QAMA researchers base their argument on the absence oftremolite in current commercial asbestos on four pieces of evidence. To explain these arguments and 16 14256997033 2002-02-26 19:09:21 (GMT), page 18 17 demonstrate why they are wrong, we will briefly describe the mining process and the route tremolite travels to get into the final product. In fact the mining and milling process adds tremoUte to the chrysotile. The process is as follows: 1. Chrysotile is about 5% of the deposit. It forms in layers or sheets between serpentine rocks. Tremolite (or crocidolite, see below) is present in the serpentine rock alongside the 100% pure chrysotile veins. The serpentine rock containing both tremolite and chrysotile is crushed in rock crushers. This is repeated 3 times. The rock is left to dry for 48 hours ' after the first crushing. This releases the tremolite from the serpentine and it is mixed in with the chrysotile. 2. All fibers on the belt, including the released tremolite and crocidolite, are vacuumed and carried into the mill. The system is closed to fiber from this point forward. Once a fiber enters the system it leaves in a bag labeled "chrysotile." So the end product is contaminated with tremolite and crocidolite. 3. The fiber is transported to the sorting mill. The sorting mill then separates the fiber by size. This is a two-part process. The fiber is shaken and rocked from side to side on a "sifter." It moves down the sifter at an angle. A 5 foot long by 2 inch wide cyclone at the end ofthe sifter vacuums the fiber into a tube and it is air carried to the bagging area. This is how sizing is achieved. The suction is set to pull short fibers, of all chemical compositions, off first The remaining longer fibers are dropped onto another conveyer and the process is repeated until the longest fibers are cyclone vacuumed off. It is clear that the tremolite is sized along with the chrysotile. 17 14256997033 2002-02-26 19:09:21 (GMT), page 19 18 4. The fiber is blown from the sifting area (all closed system) and transported to the bagging area where it is blown into bags. While it is clear from this process that most ofthe tremolite is bagged with the short fibers, the Canadian asbestos industry present several pieces of evidence in an attempt to show that current chrysotile product is tremolite free. Frank et al. were unable to find tremolite in any UICC sample chrysotile, which were prepared in the late 1960s. (Frank et al. 1998) However at the time it is undisputed that the chrysotile product contained tremolite, which has been found in foe mines as well as in the lungs of miners, and textile workers who used Canadian chrysotile. ft _ ` (Dufresne et al. 1995) Ifthe UICC samples prepared in foe late 1960's are tremolite free, and this is an actual reflection offoe historical commercial chrysotile product, then the tremolite argument fails. After all, the argument that current Canadian chrysotile is safe (tremolite-free)is based on the premise that it no longer contains tremolite, which was a problem of the past The most likely explanation for this apparent incongruity is the likelihood that foe UICC samples were made from crude 1 and 2 ore. Historically, foe highest-grade chrysotile, crude 1 and 2, did not go through the usual milling process. Miners hand picked this from veins of pure chrysotile and it was not milled at the mine. Another myth perpetuated by foe Canadian mining industry is that tremolite is removed from foe chrysotile in a "water process." Bruce Case has claimed that this process takes place at Canada's last and largest operating mine. Black Lake. (2001d) As anyone who has visited Black Lake would know, foe most compelling tourist information provided about the mine is the feet that it is located at foe bottom ofa waterless lake. It took four years to drain the lake and at the time, it was viewed as an engineering marvel. There is no water in the milling process either. No one who ever visited or reviewed the mine or milling process would ever make this mistake. 18 14256997033 2002-02-26 19:09:21 (GMT), page 20 19 While it is clear that tremolite is not removed from the chiysotile through any of the ways that are mentioned above, the Canadian asbestos industry has continued to insist in the literature that there is no tremolite in today's chrysotile. For example, Kevin Browne writes: "You may say, as many have done, that unless you can separate out the tremolite, which you can't, it doesn't matter to the unfortunate person concerned what fibre the mesothelioma is due to. That is certainly true, but there are two reasons why it is no longer such a concern. It has been shown that for a miner to collect enough tremolite in his lungs to cause a '* mesothelioma he had to have very heavy exposure in the high tremolite areas, ' enough to cause asbestosis11. But in the past, the percentage of tremolite in the fibre could be as high as 1%, whereas die high tremolite-contaminated mines in the central Thetford area have closed, and in any case the high geological research has shown that tremolite is not uniformly mixed with the chrysotile, but occurs in separate seams which can be identified and avoided. And lastly, there is evidence that much of the tremolite is lost in the milling, so that what is delivered to the manufacturer will have an even lower content. So present and future supplies from these sources have and will have minimal tremolite" (Browne 200a) Williams-Jones et al claim that "Amphibole-free chrysotile can be produced from the Jeffrey mine, and other chrysotile mines, provided that appropriate measures are taken to avoid contamination of the ores."(Williams-Jones et al. 2001) While this maybe true, the inference that current or past production has utilized this method is incorrect and misleading. For despite the 19 14256997033 2002-02-26 19:09:21 (GMT), page 21 20 results of this study, the newest shaft at the Jeffrey mine is located in one of the most heavily tremolite contaminated parts ofthe mine. (Charles Normand 2001) Tremolite and other fibers that are released during the mining process end up in the bags ofend product Therefore it is likely that current and past shipments from this mine and all other Quebec mines were contaminated with tremolite, crocidolite and amosite.(De 1961;Gibbs 1972) This conflicts with information dispensed to the public by The Asbestos Institute (AI).(2001a) The AI doesn't mention the fact that crocidolite and amosite are also present in the mine ore, and claims that tremolite is removed through various mining and milling processes. (De 1961) This is t '- simply untrue; in feet other McGill researchers have shown that some ofthe mined tremolite ends up in the lungs of US woikers.(Sebastien et al. 1989b;Gibbs 1972) Clearly the idea that current shipments of asbestos are amphibole-free is a myth, and one that continues to pose a grave threat to worker health. It remains to be seen whether or not the mine operators will implement the authors' suggested survey techniques in the future. The Textile Mystery: Another ABC 14256997033 2002-02-26 19:09:21 (GMT), page 22 21 The QAMA McGill researchers have also claimed that even if fiber mined from Canada causes mesothelioma and lung cancer, studies show that the dose required to induce these diseases is so high that there is no practical risk to current workers. Unfortunately, studies of textile workers exposed to the same fiber have revealed a dose response curve that indicates that the Canadian fiber is fifty fold more potent then the QAMA studies show. Dr. McDonald described this inconsistency, the "slope of file exposure response lines for lung cancer in the textile industry was some fitly times steeper than that observed in Quebec chrysotile miners and millers..." (McDonald 1998a) The QAMA-McGill researchers have dubbed this variation the "textile mystery and have failed to provide any kind of explanation for it" (McDonald 1998b) Ignoring the textile dose response data, they have vociferously opposed the French chrysotile ban before the WTO and in testimony for chrysotile asbestos product manufacturers have claimed that their chrysotile products did not in ary way contribute to worker's asbestos caused mesotheliomas and lung cancers. Incredibly, JC McDonald served as co-counsel forthe Canadian legal team and presented partofCanada's opening argument at the appeal ofthe WTO ruling on the French ban.(Barry Castleman 2000) McDonald summarily dismissed miscalculations in dose measurement and errors that occurred Mien the Canadian researchers converted particle to fiber counts as possible explanations for this apparent disparity. He asserted, "There is nothing to suggest thatthe estimates of cumulative exposures in the relevant cohorts were seriously in error although questions of peak exposures and fibre size distributions in ambient air have not been examined." [Emphasis added] m However, the QAMA-McGill researchers evaluated the quality of the dose estimates quite differently when they first reported them. (Gibbs and LaChance 1972;Gibbs and LaChance 1974) While McDonald flatly stated that errors in measurement or actual 21 14256997033 2002-02-26 19:09:21 (GMT), page 23 22 differences between these populations could not explain more than a tenfold difference in the dose-response slope, the QAMA-McGill dose estimates alone differ by more than a hundredfold for the same job, both within the same mine and between mines.(Gibbs 1972) Other members of the QAMA-McGill team noted, "If membrane filter and midget impinger counts were considered by work area, it was clear fiat the ratios of the two in some mines were of a different order [of magnitude] from those in otters where the same process was employed.[Emphasis added] (Gibbs and LaChance 1974) Conversion from particle to fiber counts compounded the dose estimate problem: "Though only 87 pairs of samples were collected in this plot investigation, these were sufficient to demonstrate that no single conversion factor could be applied to all mines or to all work areas within a mine."[Emphasis added] (Gibbs and LaChance 1974) In low fiber specimens, which accounted for nearly one-third of the samples, the QAMA-McGill researchers found that particle counts were inversely correlated with fiber counts. That is, the higher the particle counts the lower thefiber exposure.(Gibbs and LaChance 1974) The QAMAMcGill researchers concluded, "Thus, the conversion of dust disease relationships for the Quebec mining and milling industry to fiber-disease relationships does not seem possible at the present time "(Gibbs and LaChance 1974) However, later ignoring their own data and recommendations, the QAMA-McGill researchers moved recklessly to convert from particle to fiber dose estimates. (McDonald et al. 1980b) The researchers have conveniently institutionalized the idea of the textile mystery as a means of cloaking bad science. We believe incorrect dose estimates and a systematic bias against diagnosing asbestos-related disease in the Canadian asbestos mining region explain the textile mystery. Misestimating the Dose: Particles are Not fibers 22 14256997033 2002-02-26 19:09:21 (GMT), page 24 23 The QAMA McGill researchers used available dose measurements from 1949-1966, which were measures of"total" particles collected by midget impinger.fGibbs and Hui 1971) This method cannot distinguish fibers from other dust particles (silica, other "non-toxic" dusts, etcetera).(Egilman and Reinert 1996) Unfortunately only the fibers, which may or may not be captured in the total particle measurements, cause disease. The dose estimates from the QAMA- McGill mine studies are wrong and systematically overestimate the actual exposures. To the extent that accurate estimates of exposures of the Canadian miners and millers can be made, they indicate that the miners were, in all likelihood, exposed to fewer fibers than were the South % Carolina textile workers, rather than the other way around, as the QAMA-McGill researchers ` suggest. However, much like the man who refused to replace his broken watch because it was correct twice a day, the researchers failed to give up their flawed measurement technique. As early as 1931, QAMA researchers realized that the calculation of dose estimates for Quebec miners was impossible. As Vorwald, a consultant to the QAMA, wrote to Cartier, the director ofthe QAMA industrial disease clinic in Thetford Mines, "Last week, while in Washington, I had the opportunity to discuss our program concerning the epidemiology of pulmonary cancer in subjects exposed to asbestos dust and to present the problem which you posed regardingjob classification. I agree with your views. Certainly it is an impossible task to tabulate the various jobs on comparable scientific data, since such data does not exist Therefore the code suggested by both you and Ken [Smith medical director ofJohns-Manville] should be used." [Emphasis added] (2001c;Vorwald 1951) Cartier later served as a consultant to the QAMA-McGill researchers. What was impossible in 1951 became the dose reconstruction of 1971.(Gibbs and Hui 1971) Dr. McDonald was aware ofthis problem no later than April 23, 1969. During the discussion period following his chairing of a session on asbestos measurement 23 14256997033 2002-02-26 19:09:21 (GMT), page 25 24 techniques, which was highly critical of the midget impinger method, he asked, "Can an Inaccurate instrument like the midget impinger, give an accurate result?"(1969) Rendall responded, "I have not had enough experience with the MI but it is the wrong instrument on which to base standards." Incredibly, four years later, Mr. Gibbs who was the next speaker after Rendall, suggested that the MI be used for this purpose. Dose response relationships based on a completely inaccurate, but apparently large set of exposure data provide a false sense of statistical security to these results. Measuring Visible Fibers: The Iceberg Effect 24 14256997033 2002-02-26 19:09:21 (GMT), page 26 25 The measurement of fibers by light microscopy and any conversion from particle to fiber count rests on the assumption that each fiber measured is representative of the total number of fibers present in the air. This is so because most fibers present in the air are not visible under light microscopy. In addition, by convention the QAMA-McGill researchers did not measure fibers < 5 microns in length. HjjjB Therefore, for QAMA-McGill exposure estimates to be valid, two requirements must be met First, there must have been a consistent relationship between visible fibers and total fibers and a consistent relationship between visible fibers and fibers < 5 microns in length in various processes (mining, milling, maintenance etc.) over a 60 year time period during which many processes changed dramatically. Second, in order to compare exposures between two completely different processes like mining ami textiles, the ratio of visible to invisible and uncounted fibers must be similar. There are more invisible fibers per visible fiber in textile manufacturing than in mining. Therefore, each textile fiber counted representsmore invisible fibers than each mine fiber counted. An examination ofthe mining, milling and textile processes and the history offiber measurement techniques indicates that neither of the two requirements is met. Nicholson summarized the main technical problems in establishing asbestos exposuredisease relationships.(Nicolson 1986b) All of these issues are relevant to the "Textile Mystery." "Even with the advances in fiber counting techniques, significant errors may be introduced into attempts to formulate general fiber exposure-response relationships. The convention now in use, that only fibers longer than 5 um be counted, was chosen solely for the convenience of optical microscopic evaluation (since surveillance agencies are generally limited to such instrumentation). It does not necessarily correspond to any sharp demarcation of effect for asbestosis, lung cancer, or mesothelioma. While it is 25 14256997033 2002-02-26 19:09:21 (GMT), page 27 26 readily conceded that counting only fibers longer than 5 uni enumerates just a fraction of the total number of fibers present, there is incomplete awareness that the fraction counted is highly variable, depending upon the fiber type, the process or products used, and even file past history of the asbestos material (e.g., old versus new insulation material), among otter factors. For example, the fraction of chrysotile fibers longer than 5 um in an aerosol can vary by a factor of 10 (from as little as 0.5 percent ofthe total number to more than 5 percent). When amosite aerosols are counted, the fraction longer than 5 um may be 30 percent, extending the variability of the fraction counted to two orders of magnitude Even if consideration is restricted to fibers longer than 5 um, many are missed by optical microscopy. Using electron microscopy, Rendall and Skikne (1980) measured the percentage of fibers with a diameter less than 1-4 um (the approximate limit of resolution ofan optical microscope) in various asbestos dust samples.(Skikne et al. 1971;Rendall and Skikne 1980) In general, they found that more than 50 percent of the 5 um or longer fibers are less than 0.4 um in diameter and thus, are not visible using a standard phase contrast optical microscope." (Nicolson 1986a) Asbestos fiber counting is a "tip of the iceberg" phenomenon because fibers are counted by light microscopy. Since chrysotile fibers split longitudinally, some ofthe fibers are too narrow to be seen and are not counted. The first steps of the textile process are specifically designed to split fiber bundles; therefore textile exposures involve a higher percentage of thin (invisible fibers) than mill or mine exposures|m|H As a result of increased fiber splitting in tiie textile process each counted fiber represents many more uncounted fibers then is so in the mining and milling process. (Nicholson 1991) 26 14256997033 2002-02-26 19:09:21 (GMT), page 28 27 "Moreover, as with length distribution, diameter distribution varies with activity and fiber types. As a result, the fraction of fibers longer than 5 urn visible by light microscopy varies from about 22 percent in chiysotile and crocidolite mining and amosite/chrysotile insulation manufacturing to 53 percent in amosite mining. Intermediate values of40 percent are measured in chrysotile bake lining manufacturing and 33 percent in amosite mill operations. Thus, even perfect measurement of workplace air, with accurate enumeration of fibers according to currently accepted methods, would be expected to lead to different exposure-response relationships for any specific asbestos disease when different work environments are studied." Fiber width is clinically important to carcinogenic potency. Thinner fibers (generally < . 1 umX which are invisible under light microscopy and therefore uncounted, are farmore mesothliogenic than wider fibers. BHHHHIi (Stanton et al. 1981) (Pott et al. 1972) Lippmann first noted this explanation for the "textile mystery" in 1987: "The origin of this lower risk [for miners] is not fully understood, but part of the difference may lie in the different fiber size distributions between the mining and milling of chrysotile and its use in a textile plant or other production facility. Animal experiments.... indicate that the fibers most likely to produce cancer are too thin to be observed by a light microscope. In the mine and mill the chrysotile fiber bundles have only been partially broken apart. Many of the fibers are large and easily counted: some of those counted are curly and non-respirable. When shipped to a chrysotile textile mill the fibers are further broken apart during carding. In the high-speed spinning and weaving processes. Thin fibers may split off from the threads most of which are not visible in a light microscope. Thus in the air of a textile plant the percentage of thin, uncounted, but 27 14256997033 2002-02-26 19:09:21 (GMT), page 29 highly carcinogenic fibers can be greater than in the mine and mill air and cancer risk observed for the same measured cumulative fiber exposure." Critique of QAMA-McGill Dose Estimates 14256997033 2002-02-26 19:09:21 (GMT), page 30 29 The QAMA-McGill researchers based their dose estimates on midget impinger measurements taken between 1948 and 1966.1 However, cohort workers were most heavily exposed before 1946. In fact, the QAMA began the exposure measurement program to help control dust levels. The QAMA-McGill researchers claim that the exposure sampling, because it relied on 4,152 individual samples, reflected real exposure levels and was of high quality: ". ..this is far more data than you're ever going to get in the average epidemiological study, this was a monumental task" and "Thus this environmental data base was of a quality better than most"(2001c) Gibbs stated, "Measurements from other sources such as government reports, % insurance companies, mining companies and others were consulted and data gathered when ' necessary using surveys by the research team. The distribution of measurements was such that it was possible to obtain a reasonable estimate ofthe concentrations associated with most jobs and work areas on an annual basis." (Gibbs 1994) However the QAMA-McGill researchers admitted the poor quality of sampling from the factory at Asbestos, "A total of 3,096 dust measurements, made periodically since 1944, was used as a guide to the exposure in the factory. Since they were made by several different persons using various methods, including the Greenberg Smith impinger, midget-impinger, and Owens jet sampler, these measurements were less satisfactory than those for the mills." (Gibbs and LaChance 1972) Nonetheless the QAMA-McGill researchers based several publications on these data. (McDonald et al. 2001;Liddell et al. 1998a;McDonald et al. 1980tr,Liddell and McDonald 1980;McDonald and McDonald 1980;McDonald 1980;McDonald et al. 1993;Liddell et al. 1997h,McDonald et al. 1997;Liddell et al. 1998b) 1 Some ofthe studies say the dose estimates began in 1948 and others report 1949. 29 14256997033 2002-02-26 19:09:21 (GMT), page 31 30 Unfortunately, the quantity of samples is no substitute for quality and the QAMA-McGill researchers acknowledged the poor quality ofthe measurements in other published assessments the exposure data: "We cannot claim precision or certainty for our estimates, only that the available data-more plentiful in this industry than most others were used to the best of our ability "(Liddell et al. 1984) Despite the fact that the QAMA-McGill researchers recognized that the MI samples were of no practical value they stated that "No attempt was made to extend work histories beyond 1966 because exposure levels in the period 1967-75 were much lower than in the past, and exposure in a short period before death could not be expected to contribute to risk." (Liddell et al. 1984) However, the QAMA-McGill researchers followed the cohort until 1992 and about one quarter ofthe cohort had significant post-1966 exposures long before they died.(Liddell et al. 1998a) Incredibly, although they had access to the cohort and could have prospectively determined exposure levels form 1966 forward, the QAMA-McGill researchers merely projected the previous 18 years of exposure data measurements forward. (Liddell et al. 1998a) The QAMA-McGill researchers try to equate the "quantity" of measurements with "quality." Unfortunately, the quantity of samples is also misleading. In fact, hardly any samples were taken, given the number of mines and mills, job classifications, variability of exposures in the same process within and between mines and the eighty-year follow-up period. The QAMA (the mine owners performed the sampling) sampled forty-four mines and each mill and mine had at least eight major processes, each of which resulted in variable particle counts and particle/fiber ratios taken over an eighteen-year period. (2001c) (Gibbs and LaChance 1972) Therefore, on average, the QAMA sampled each of the major mine processes less than once every three years for between 5 and thirty minutes. Furthermore, QAMA never monitored two large cohorts of 30 14256997033 2002-02-26 19:09:21 (GMT), page 32 31 workers, miners, and maintenance workers who comprised 20-30% ofthe entire study population.(Gibbs 1972) Gibbs based his dose estimates for these groups on an historical assessment of "visibility" reported in interviews with workers. In his PhD. thesis he noted, "Visibility, which was affected by fog and lighting, as well as dust, probably played a part in the workers' assessment in underground mines and mills and may have led to an overestimation of dust levels." [Emphasis added](Gibbs and LaChance 1972) We would add that lighting and distance variables per se, could result in particle estimate differences of one hundred fold.(Hemeon WCL 1963) This problem is compounded by the fact that visibility is a function of % total particles and not fiber counts. The researchers stated that their "historical analysis" based on interviews indicated that the maintenance workers had high exposures compared to the miners. (Gibbs and LaChance 1972) This may be true, but Gibbs later reported that miners had twice as much pleural disease as the millers or rock crushers in the same mines and the maintenance workers generally worked in the mill or other process buildings.(Gibbs 1979) In 1971, Gibbs noted that there "was general agreement among" the workers questioned. (Gibbs and LaChance 1972) However, in another paper published 12 years later, the QAMA-McGill researchers noted that the occupational histories often conflicted with written records.(Liddell et al. 1984) (See below) The QAMA McGill researchers applied these dose estimates to particular workerjobs, which included 13,346 differentjob descriptions. (McDonald et al. 1971) Gibbs "reduced" these to 5,500 different jobs. He further reduced these jobs to thirteen general exposure categories. He then applied these individual exposure categories to individual work histories based on written records ton average each worker had ten different jobs). (Gibbs and LaChance 1972) 31 14256997033 2002-02-26 19:09:21 (GMT), page 33 32 Gibbs claimed the QAMA samples were taken to assess both industrial dust control effectiveness and individual exposures. However, in the same paper he also noted that die midget impinger is, "a relatively short term instrument, is difficult to use for personal monitoring and is not specific for fibers."(Gibbs 1994) Gibbs reported that QAMA knew which samples were recorded for control purposes and which were collected to be "representative" of actual exposures. However, no breakdown ofthe relative proportion of samples in each category is provided and there is no indication that any personal sampling was ever done.(Gibbs 1994) Interestingly, in the same paper, Gibbs criticized Dement's textile exposure estimates for failing *' to provide "information on whether or not samples were personal samples" or information on "the distribution of locations at which side by side samples were taken." (Gibbs 1994) Each midget impinger sampling lasted between five and thirty minutes and thus could not possibly reflect average daily, let alone yearly, exposures. QAMA did not record counts below the "exposure limit" and the QAMA-McGil1 researchers never indicate what the "exposure limit or limits were during the relevant time period or how they dealt with these "unrecorded" measurements in their dose estimates. (Gibbs 1994) 32 14256997033 2002-02-26 19:09:21 (GMT), page 34 33 Missing Data Points In 1972, Gibbs and Lachance hint at the inadequacy of the sampling locations when they report the results of new samples taken "to obtain information in areas where no dust measurements had previously been made" during the previous 60 years.(Gibbs and LaChance 1972) These areas included most of the job categories involving exposures. (See Table 1) While they report that this data was missing for only three mines, these actually represented ten mines, which had either previously merged or whose exposures the authors felt were comparable. Another five mines were closed at the time of the study and no data of any sort appears to be available for the workers at these mines.(Gibbs 1972) Gibbs collected some samples for each of the jobs listed in Table 1, but he created and used a new method for measurement, which is incompletely described (Gibbs 1972) He made no effort to compare these results to the MI total particle counts that were available for the rest ofthe workers. (Gibbs 1972) Although "mean" values are reported in the published paper many of these represent a single sample result(Gibbs 1972) Gibbs and Lachance based much of the dose reconstruction on these results. For example, they reported that maintenance workers had higher exposures than millers but the range of exposures for maintenance workers was 1.1-61.8 and the mean (based on 2 samples) was 25. The range for mill workers was .3-159 and the mean was 31. Moreover the exposure measurements varied widely. Gibbs published the data on between mine variance but omitted data on the variation of dose at the same mine for the same job. In fact Gibbs found that exposures at the same mine for the same job had a range of as much as 200 fold.(Gibbs 1972) 33 14256997033 2002-02-26 19:09:21 (GMT), page 35 Table 1. Missing data for at least ten mines, perhaps fifteen MINING Driller Shovel operator or pay loader operator Truck driver CRUSHING & DRYING Crusher oiler Dryer helper operator Dry rock storage Conveyor attendant MILLING Mill general Bagging Laboratory Filter floor attendant WASTE DISPOSAL Rock dump Tailings dump MILL MAINTENANCE 34 34 14256997033 2002-02-26 19:09:21 (GMT), page 36 Table 2. Wide range of exposures for die same jobs Overall Mill floor . 2.1-159.4 Mill bagging .3-23.5 Mine Drilling .4-82.5 Shovel operator .4-3.2 Truck driver ND-10.1 Crusher 1-18.5 Milling general .5-155.6 14256997033 2002-02-26 19:09:21 (GMT), page 37 36 Particle-fiber Conversion Issues The impossibility of estimating asbestos fiber exposures and the irrelevance of particle counts to toxicity has long been known to QAMA. In 1953,the QAMA minutes noted, "The industrial hygiene surveys that have been made in the past, and in which only dust particles were measured, are practically without value." (1953) QAMA waited 20 years to change to membrane filter measurement after obtaining this information. The QAMA-McGill researchers were left with particle counts, but ifthe particle counts could not be correlated with fiber counts or were inversely related to fiber levels, then the particle counts were useless as indices of exposure to determine asbestos toxicity. Gibbs and Lachance tested this hypothesis by performing eighty-seven matched pairs oftests utilizing light microscopy and membrane filters to count fibers and comparing these with midget impinger particle countsYGibbs and LaChance 1974) They found that overall the relationship between particle counts and fiber counts were 13% better than random number generation. Incredibly, for low fiber count exposures, the particle counts were inversely related to fiber exposures. This inverse relationship occurred in more than one third of the samples (31 out of 87). Therefore, for at least one third ofthe particle counts, the worker fiber exposures correlated as follows: the higher the count, the lower the worker's exposure to asbestos. "For thirty-one samples with less than one fiber per field, the linear correlation was very close to zero, - 0.03, and the correlation of log rhythmically transformed data was 025. However, these correlations suggest that for all mines the regression lines are unsatisfactory for the prediction of fiber counts from impinger counts, as the improvement and prediction for the best correlation, 0.45, is only 13% better than a 36 14256997033 2002-02-26 19:09:21 (GMT), page 38 37 conversion obtained at random. Thus the conversion of dust disease relationships to fiber disease relationships does not seem possible.''(Gibbs and LaChance 1974) Gibbs and Lachance summarized their results as follows: "...eighty-seven side by side midget impinger membrane filter samples were taken at five mines and mills showed that the correlation was poor and no single conversion effect was justified. Until more detailed information on the relationships between midget impinger and membrane filter counts can be obtained, it is recommended that safety standards, at least in this industry, should continue to be based on dust counts for which there is considerable epidemiologic support rather on fiber counts, for which there is no direct ' evidence." (Gibbs and LaChance 1974) They concluded, "The conversion ofdust disease relationships for the Quebec Mining and Milling Industry to fiber disease relationships does not seem possible at the presenttime. Further information on the relationship ofthese two methods at each site within each plant is required. Without this, there is no way ofestimating with any accuracy the total fiber exposure of persons in the Quebec Asbestos Mining and Milling Industry or indeed of deciding whether the dose response relationships would be better or worse than those obtained from particle counts." [Emphasis added] (Gibbs and LaChance 1974) The lack of scientific validity ofthese dose estimates did not stop the QAMA-McGill research team. They selected a single conversion factor for all processes and all subsequent publications relied on this single value. (They made minor adjustments to the value from time to time.) McDonald states in a 1973 IARC conference publication that dust-sampling methods, in addition to unreliable particle-fiber conversions, produced data too variable to be considered a reliable basis for estimating exposure. HHj 37 14256997033 2002-02-26 19:09:21 (GMT), page 39 38 The lack of scientific merit did not mean that the studies were valueless in promoting the idea that chrysotile was innocuous. As Dr. Anthony Lanza, medical director of Met Life and QAMA consultant noted in 1937, "Of course, the asbestos people in Canada have advanced that idea for some time as an explanation of why asbestos seems to be more clinically severe in England than in this country but I have always hadthe feeline that their argument was motivated by self-interest rather than to make a scientific contribution. " [Emphasis added] (Lanza 1937) Indeed the QAMA-McGill researchers have successfully used this data to maintain chrysotile sales, avoid payments of liability claims to workers and influence regulatory standards. 38 14256997033 2002-02-26 19:09:21 <GMT), page 40 39 Attempted Corrections By 1989 tiie QAMA-McGill researchers realized that they needed to do something else to justify their high dose estimates. Since the chrysotile came from the same mine, the most obvious and simple explanation for this "mystery" was the inadequacy or non-comparability of the dose estimates from these two operations. After all, the QAMA-McGill researchers had already shown that there was at best no correlation between particle and fiber counts in the QAMA sampling. At worst, there was an inverse relationship between particle and fiber counts. (Gibbs and LaChance 1974) On the other hand, the textile particle counts correlated with fiber counts because each textile process produces a narrow range of particle/fiber ratios. The QAMAMcGill researchers tried to "fix" this irreparable problem with QAMA dose estimates by comparing particle counts to retained fiber levels in the lung.(Sebastien et al. 1989a) This could only add another level of error since as they noted, lung fiber counts depend on retention, clearance, and dissolution. "In the absence of an accepted model for lung retention of asbestos fibres comparison between the two groups was restricted to cases having similar time characteristics of exposure (duration and cessation). In these circumstances it was assumed that retention would be proportional to mean intensity of exposure. This assumption, impossible to test without good environmental data may be questioned, especially for chrysotile .''(Sebastien etal. 1989a) Sebastien even re-proved the inadequacy of the original QAMA-McGill exposure data, "Initially we thought it might be appropriate to use regression analysis to relate exposure, intensity (mpcf) to lung fibre concentrations in the two series and to compere observed values in one with those expected by application of the regression equations from the 39 14256997033 2002-02-26 19:09:21 (GMT), page 41 40 other. Although the results obtained by this approach were similar to those from the matched pair and stratification analyses, we have not quoted them here because the underlying assumptions as to linearity did not seem justified.''(Sebastien et al. 1989a) They compared the ratio of chrysotile exposure in millions of particles per cubic foot in miners and millers with the exposure data from textile workers in South Carolina who used Canadian fiber, with the ratio of chrysotile to tremolite in the lungs.(Sebastien et al. 1989b) They claimed that if the "mean" of these data were similar, this would support the idea that the dose estimates were correct This is not true since a systematic error in the Canadian dose estimate would also ' ' result in similar ratios of tremolite/chrysotile. In addition the QAMA-McGill researchers selected lung cancer cases for 8% of the Charleston workers but 25% of the Quebec miners, thus introducing another systematic bias since it is likely that workers with lung cancer had higher exposures to asbestos. The selected cases freon Thetford were not even representative of the Thetford cohort as the QAMA-McGill researchers noted, "high [exposure] values were over represented in necropsied cases." (Sebastien et al. 1989a) The QAMA-McGill researchers did not count fibers less than 5 um and they only analyzed "the first five fibers seen." Unsurprisingly, the mean diameters and fiber lengths were similar. Unfortunately the comparison of mean ratios did not comport with their theory because the mean ratio ofthe particle counts between Thetford and Charleston was 11.8 and the mean chrysotile/tremolite lung fiber count ratio was 18. QAMA-McGill researchers did not report this comparison ofmeans; instead without explanation orjustification, the researchers calculated geometric means and compared these "means." Geometric means are utilized to minimize the impact of outlier data points. However this is precisely the type of information the QAMA-McGill researchers claimed 40 14256997033 2002-02-26 19:09:21 {GMT), page 42 41 to be evaluating in the first place. 2 Clearly comparing the averages of ratios to determine if exposure measurements are accurate does not call for an evaluation of geometric means. If any statistical test is appropriate it is the comparison of arithmetic means. This comparison again showed that the QAMA-McGill exposure measurements were wrong. Ofcourse this was obvious from Gibbs' original analysis anvwavs.(Gibbs and LaChance 1974)1 1 Geometric means are utilized to calculate power function averages. For example, to determine what an average interest rate would have to be if you invested $100,000 in the bank in 1990 and had variable interest rates each year 41 14256997033 2002-02-26 19:09:21 (GMT), page 43 42 Worker Interviews Since the QAMA exposure data did not measure exposures for most of the workers in the cohort, the QAMA-McGill researchers relied on company records to reconstruct exposures. Their reports on this "check" of the validity ofthe work records are contradictory. In 1971, Gibbs first reported. "Men were asked to relate dust conditions they remembered to those in areas where measurements had been made recently. In general, there was agreement among those we questioned." [Emphasis added] (Gibbs and LaChance 1974) However in 1984 Liddell reported, t' "Over the years, we had come across several inconsistencies and other evidence of errors in work histories. We took this opportunity to attempt correction where appropriate, but for reasons outlined elsewhere, we were unable to make use ofthis effort Many ofthe changes in work history, elicited by `blind' field inquiry and checked against company files, were certainly justified but we have not made them, and so allowed errors to remain." [Emphasis added] (Liddell et al. 1984) Even after recognizing their errors they ignored them: "However, this type of error appears to have been distributed unevenly, and so like might not have been compared to like. In case-referent comparisons, minor random unbiased exposure errors are probably less serious than bias; we therefore returned to the situation that existed before the field work was instituted." (Liddell et al. 1984) The QAMA-MeGill researchers provided no analysis of the magnitude or randomness of the errors. No effort was made to compare the interviews with the written record to determine whether or not the written records contained a systematic bias. of 2, 5, 7,10 over the next four years. 42 14256997033 2002-02-26 19:09:21 (GMT), page 44 43 Conversion factors First Gibbs (1974) and later Liddell (1984 and 19981 evaluated the merits of converting particle to fiber counts. (Gibbs and LaChance 1974;Liddell et al. 1984;Liddell et al. 1998b) In addition to their realization that worker interviews indicated that the original dose estimates were even less accurate than thought, they again recognized that particle/fiber ratios were, "virtually independent of the level of exposure "(Liddell et al. 1998a) They then proceeded to create a single particle/fiber ratio standard for all years in all job categories and base these on the worker histories, which they ignored in calculating the actual particle counts because the histories would t' introduce a "systemic baas" into their analysis. "The conversion factor should be amended because many more histories have led to more reliable estimates. We have made four other estimates: the fibre and dust slopes for pneumoconiosis and for lung cancer were in the ratios 3.67 and 3.57 (fimiympcf; while, based on mean exposures for all subjects, the ratio was 3.46 (fimiympcf in this report, and was 3.44 in a study of elderly male workers in Thetford Mines. These factors, all based on substantial groups of persons, show little variation. However, the ratios calculated for each ofthe 2535 non-zero pairs of exposures in this study ranged between 0.32 and 30 (Fmiympcf while the correlation of the fibre/dust ratio and its denominator, in fire 2535 sets, was so small that the ratio could be thought of as virtually independent of the level of exposure. Nevertheless, any ` `average" must depend on each specific group of workers, and on the method of obtaining it. Further, all the above estimates are for workers at Asbestos and Thetford Mines in the period from 1904-66; there is no assurance that they might apply in different circumstances. We would add that there is 43 14256997033 2002-02-26 19:09:21 (GMT), page 45 44 great assurance that the particle/fiber ratio applied in the circumstance under investigation." [Emphasis added](Liddell et al. 1998c) Liddell (1998) again recognized the inadequacy of their dose estimates. "Liddell et al. (1984) estimated a factor to convert dust counts to fibre counts as about 3.5 (fibres/mlX mpcfbut stated this would he quite unreliable except applied to mean dust levels for substantial groups of Quebec asbestos workers. For the many jobs in which the2217 menincluded in their studyhad worked, the fibre:dustratioshad ranged from 0.3 to 30 (fibres:ml):mpcf virtually independently of the dust level; in the ' ' current study ratiosjob byjob must have varied similarly so that the classification ofjobs by dust category would not be a reliable classification by fibre count" [Emphasis added] (Liddell et al. 1998c) They also understood why the dose estimates were so inaccurate. Fiber dust ratios differed by orders ofmagnitude for different types of work. In addition fiber dust ratios differed by orders of magnitude for the same work process at different points in time. "The two important reports by Gibbs and Lachance (1972); Gibbs and Lachance (1974) give some indication ofthe inherent complexity; a simple example is that work cm the tailings dump in 196X was extremely dusty but, as most of the fibre would have been . extracted the fibre: dust ratio must have been quite low."|m| The exposure data was so inaccurate that "taken at face value" exposures were protective for the workers. In other words, un-manipulated, the exposure data indicated that chrysotile exposure prevented workers from developing pneumoconiosis, lung cancer or mesothelioma. The QAMA- McGill researchers realized that this result was so extreme the scientific community would not accept it It would expose the inadequacies of the entire 40-year study program and 44 14256997033 2002-02-26 19:09:21 (GMT), page 46 45 hundreds of publications. The researchers did not even consider the possibility that their data was correct and revealed real relationships. It was possible that the workers with the highest exposures died from nonmalignant disease before the latent period for the induction of cancer had been attained. Instead, since they believed an inverse exposure relationship was ludicrous, they manipulated the exposure estimates until the dose-response curve fit their apriori understanding ofthe proper form for the dose-response relationship. The researchers discarded all of the exposure levels that were inversely related to disease. They described this manipulation in an appendix titled "elimination of negative regression coefficients" and proceeded to "revise" the exposure data to make it appear credible and to create a result that ' would allow them to argue that chrysotile exposure was "innocuous." They described the manipulation as follows: "In all die conditional regression analyses of the full model i.e. with 13 exposure measures, there was at least one negative regression coefficient, which taken at face value would imply a protective effect of exposure. Years in the highest relevant dust category were pooled with those in the adjacent category and the analysis was repeated. This process was iterated until either all coefficients had become positive, when it was terminated, or until the only negative coefficient was for category I; in that circumstance, category 1 was eliminated from the model, which was equivalent to setting the coefficient to zero and the odds ratio to unitv. Admittedly, there was a degree of arbitrariness in some ofthe pooling carried out but every effort was made to retain anv `significant' effects."[Emphasis added] (Liddell et al. 1998a) Apparently the QAMA-McGill researchers knew what effects were `significant1 before they began the studies and fitted the data make it comport to these pre-determined effects. 45 14256997033 2002-02-26 19:09:21 (GMT), page 47 46 Years of Exposure Correction In 1980, McDonald commented on the exposure data and noted, "Relative risks of lung cancer were considered in detail by Liddell et al. and it appeared that there was little to suggest that the way in which dust exposure had been accumulated played any part in determining the risk.. .It therefore seemed appropriate to base a second series of analyses on dust exposure accumulated to a certain age, arbitrarily taken as 45 years, at which age most men had completed their service. After the cohort had been divided by exposure to age 45, two further, but separate, subdivisions were made by mining area (Asbestos and Thetford Mines) and by smoking habit; ' those whose smoking habit was unknown being added to the largest group--that is, moderate smokers. The study interval started at age 45." {Emphasis added] (McDonald et al. 1980a) Since this conclusion would reveal that the study was worthless, they "arbitrarily" divided the cohort into two groups by age and by geographic location. This allowed them to generate a linear doseresponse graph for lung cancer and exposure. Even after this supposed validation of the dose estimates the QAMA-McGill researchers unequivocally concl uded that the dose estimates were worthless when Gibbs wrote, "thus it is clear that there is no single overall conversion factor that can be applied to the mining no data.(Gibbs 1994) 46 14256997033 2002-02-26 19:09:21 (GMT), page 48 47 Another Dose Correction In the 1980 paper McDonaldjustified the age 45 cut off because "by this time most of the men had completed their service" but this was not true.(McDonald et al. 1980b) In 1997 they revealed that over 2400 men in the 1890-1920 study cohort were still employed in 1967 and the youngest of these was 47. Since the age 45 cut offno longer produced the linear dos-response curve they sought, in 1997 they calculated exposures up to age 55. Rather than using exposure data that had been obtained after 1966, the year the QAMA-McGi11 studies began, they used the already discredited pre-1966 data to estimate these exposures. They also altered the dose % calculation methodology because, "it did not prove feasible to use the same methods as ' previously.''(Liddell et al. 1997a) They do not provide any rational for this change (except perhaps for large computer file size) nor do they provide a comparative analysis of results using the "old" and "new" dose estimate methods. "As over 2400 men in the cohort were still employed in 1967, attempts were made to estimate exposures yearly up to 1985, when the last man had retired. It did not prove feasible to use the same methods as previously. Instead, each man was allocated dust levels as follows: for 1967, the same level as in 1966; for each subsequent year, a proportion ofthat level in accordance with the average trend of fibre concentration for his specific mine or mill. From these levels, we estimated yearly exposures from 1967 to 1985 (McDonald et. al., 1993), and extended each man's exposure record by a further 19 years. To give much-needed greater flexibility for the calculation of exposures-to the age of 55, for instance, or, for case-referent analyses, in relation to the age at death of the case-the exposure file was re-organized: first, the annual record ofexposure, incorporating the adjustment for length ofthe working week, was changed to the dust 47 14256997033 2002-02-26 19:09:21 (GMT), page 49 48 level, with an indicator of the work-week adjustment, second, each man's work history was recorded annually from the year in which he started to the year in which he finished, thus reducing the maximum number ofyears from 82 to 59; and thirdly, the format was changed slightly. With these changes; the complete file was reduced in size by over one- quarter, but remained enormous (5.9 Megabytes)."|H| Despite these manipulations; foe QAMA-McGill researchers themselves cast doubt on foe reliability offoe exposure estimates for pneumoconiosis and mesothelioma. "Pneumoconiosis death rates per 100,000 subject-years were clearly associated with exposure at foe two main ' {daces of employment, but the exclusions from this table [early deaths: 12 from pneumoconiosis and 1 from mesothelioma] may have distorted these associations, and certainly make comparison between foe Asbestos mine and mill and Company 3 particularly difficult direre is little sign of corresponding associations with mesothelioma." [Emphasis added] (Liddell et al. 1997b) 48 14256997033 2002-02-26 19:09:21 (GMT), page 50 49 Misleading Conclusions Liddell (1998) delineated the pre-determined conclusion that die QAMA-McGill researchers planned to expound in the last paper of the series: that the health effects ofchrysotile were `innocuous." "For men first employed in Asbestos, mine or factory, they [the SMRs] were very much what might have been expected for a blue collar population without any hazardous exposure. SMRs in the Thetford Mines area were almost 8% higher, but in line with anecdotal evidence concerning socio-economic status. At exposures below 300 (million particles per cubic foot) x years, (mpcfy), equivalent to roughly 1000 (fibres/ml) x years- or, say, 10 years in the 1940s at 80 (fibres/ml)--findings were as follows. There were no discernible associations of degree of exposure and SMRs, whether for all causes ofdeath or for all the specific cancer sites examined. The average SMRs were 1.07 (all causes), and 1.16, 0.93, 1.03 and 1.21, respectively, for gastric, other abdominal, laryngeal and lung cancer. Men whose exposures were less then 300 mpcf.y suffered almost one-half of the 146 deaths from pneumoconiosis or mesothelioma; the elimination of these two causes would have reduced these men's SMR (all causes) from 1.07 to approximately 1.06. Thus it is concluded from the viewpoint of mortality that exposure in this industry to less than 300 mpcf/y has been essentially innocuous, although there was a small risk or pneumoconiosis or mesothelioma." [Emphasis added] The QAMA McGill researchers thus concluded that nearly half ofthe deaths (72) that they attributed to asbestos exposure were inconsequential because these deaths did not 49 14256997033 2002-02-26 19:09:21 <GMT), page 51 50 significantly alter overall mortality rates. Since their conclusion is a political one, perhaps a current political analogy will help shed light on this analysis. If one were to apply the same standard to the World Trade Center destruction, oik could similarly conclude that this act of terrorism, that will change the world for years to come, was "innocuous" because it did not significantly impact on the US SMR for 2001. Certainly the Canadian miners and millers who died from asbestos related disease do not consider these exposures to be "innocuous." Similarly, workers and bystanders who follow the advice of the QAMA-McGill researchers and continue to be exposed to Canadian chrysotile asbestos and who die as a result of these exposures in the % future will not consider their exposures to be "innocuous." ' 50 14256997033 2002-02-26 19:09:21 (GMT), page 52 51 Inadequate case ascertainment In addition to the overestimate of dose, a systemic underestimate of asbestos associated diseases may have also contributed to the apparent "low risk" of chrysotile exposure. In 1950, Dr. Lanza noted that this was likely in a meeting with QAMA officials: "It was pointed out that in the Province [Quebec] it is the practice not to list cancer as a cause of death even when it is, so that information on this may not be of much help to us.(1950) Metropolitan Life provided group life insurance to fire mineworkers, and began collecting mortality data and death certificates on the workers in the 1920's. Begin et al. provided further support fot this diagnostic or reporting bias when he documented, "an increasing incidence of cases ofmalignant mesothelioma in chrysotile miners and millers of the Eastern Townships of Quebec, with 49 cases in the last 23 years, and a rate of2.5 cases per year in the last 10 years in the primary industry, as compared with a rate of 0.3 per year in the years prior to 1969 [McDonald et al., 1979]." A similar eighty fold undercount of lung cancer case finding can easily account for the fifty-fold "textile mystery." There is clear evidence that this undercount occurred and was in fact organized by the main financial sponsor ofthe studies, the QAMA. In 1995, Schepers reported that Ivan Sabourin, head ofthe Conservative Party of Quebec and legal counsel to QAMA, had systematically stolen the lungs of Quebec miners with lung cancer and sequestered them at the Trudeau Institute at Saranac Lake New York.(Schepers 1995) By 1946 at least 17 cancer cases had been removed and are missing from the QAMA-MeGil1 analysis. While unprecedented, this organ snatching clearly had a differential impact on the number of cancer cases attributable to the QAMA mine operations and those reported from the control group. 51 14256997033 2002-02-26 19:09:21 (GMT), page 53 52 Because the cohort workers were bom between 1890 and 1920, some mesothelioma deaths are likely to have occurred before the disease was widely recognized by most physicians in the mid to late 1960s. Mesothelioma was not added to the ICDA system until the early 1970s. By this time, much ofthe cohort was over 65 years of age and had accumulated more than 40 years of latency. It is likely that this diagnostic bias explains the low mesothelioma rate. Underreporting by Quebec physicians must also be considered likely. As no less an authority than Pierre Elliott Trudeau noted, the QAMA mines have been the center of Canadian politics during this century. In the forward to the only book he ever wrote before he retired. The ' ' Asbestos Strike of1949, Trudeau called the strike the most important political event in Canadian politics in the twentieth century.(Trudeau 1974) The political importance, power, and influence of the QAMA during the century cannot be overestimated. This is particularly true with respect to the QAMA's recognition ofthe potential impact of asbestos health effects on profits. The mine owners began projects to influence the medical literature and individual physicians in Quebec in the 1920s when they took a "mortgage out on McGill."('Wright 1926) "It is suggested that we approach the Dean of the faculty of Medicine of McGill University with a proposal that upon the establishment of an adequate Department of Industrial Hygiene in the McGill Medical School the Metropolitan enter into an agreement with McGill to secure for the Company certain services and information relating to the health of industrial workers in Canada. ...It would be of great value to the Company to have specific information regarding such matters as: 52 14256997033 2002-02-26 19:09:21 (GMT). page 54 53 1. The distribution of industrial establishments, mines and lumbering operations with data concerning the number of employees in each establishment and district.. ...To secure such information directly would be difficult and very expensive. If it could be obtained from a department of industrial hygiene in Canada's leading university in return for a moderate annual for the Company would undoubtedly benefit... ...Such a plan involves a definite quid pro quo, payments specifically conditioned ' upon a commensurate return, the adequacy ofsuch return to be determined by the President or those to whom he may delegate the decision... ...The Sun Life might well ask - if it secured a mortgage on McGill.. .Technical guidance in regard to matters affecting community or individual health - such as, aid in preparation of publicity, occasional research matters not involving great outlays ofmoney, field investigations as of sanitation, water, or milk supplies, or industrial hazards. ...Observations ofour scheme at Harvard leads me to add that Martin should not only be prepared to render certain types of service but certain services, more or less routine perhaps, should be specified. Unless there is a definite, tangible quid pro quo the interest of a financial supporter may well languish after a few years." [Emphasis added] 53 14256997033 2002-02-26 19:09:21 (GMT), page 55 54 Initially, the QAMA was concerned with the potential financial impact of workers' compensation claims. By the mid-1930s they had already developed programs to deal with the adverse consequences of the fear of asbestos related diseases on sales.(Lanza 1937) 54 14256997033 2002-02-26 19:09:21 (GMT), page 56 55 Conclusion The Canadian asbestos mining industry has a long history of manipulation of scientific data to create outcomes that support claims that their product and the methods used to mine it are safe. Careful analysis of their data brings us to the conclusion that this is not so. 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Rejean Hebert 2002. Laval University. 1980. Rendall RE, Skikne MI. 1980. Submicroscopic fibres in industrial atmospheres. IARC Sci Publ837-843. Schepers GW. 1995. Chronology of asbestos cancer discoveries: experimental studies of the Saranac Laboratory. Am J Ind Med 27:593-606. Sebastien P, McDonald JC, McDonald AD, Case B, Harley R 1989a. Respiratory cancer in chiysotile textile and mining industries: exposure inferences from lung analysis. British Journal ofIndustrial Medicine 46:180-187. 59