On talc, tremolite, and tergiversation

Our plain-English summary of On talc, tremolite, and tergiversation, by R. Reger, W.K. Morgan (British Journal of Industrial Medicine, 1990).

The study

• Authors: R. Reger, W.K. Morgan
• Journal: British Journal of Industrial Medicine
• Published: 1990;47(8):505-7
• Type of article: Review
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 003869).

Summary of the article

In this editorial, the authors considered whether non-asbestiform anthophyllite, tremolite and actinolite should be regulated in the same way as asbestos. The 1986 US Occupational Safety and Health Administration standard, which set a limit of 0.2 f/ml, treated them as asbestos. The authors reviewed animal experiments in which fibres were injected into the pleural or peritoneal cavities of rats or hamsters. In these, asbestiform tremolite produced mesotheliomas or other tumours, but non-asbestiform tremolite did not. They reviewed mortality studies of gold and taconite miners exposed to cummingtonite-grunerite, the non-asbestiform analogue of amosite, which showed no excess or trend for respiratory cancer. They then reviewed studies of talc miners and millers in upstate New York. Early studies reported excess lung cancer, including 12 of 108 deaths in one study and nine deaths (SMR 270) among 398 workers in another, but lacked smoking histories. In the latter study, five of the lung cancer cases had worked at the facility for one year or less. A later update included a nested case-control study of 22 lung cancer cases, each matched to three controls. It found a strong association with cigarette smoking and an apparent inverse relation between exposure and lung cancer. The authors also noted that US consumer product and mine safety agencies distinguished between the two mineral forms. They concluded that the overall results argued convincingly against a causal connection between lung cancer and non-asbestiform tremolite. They added that animal studies suggested any risk from non-asbestiform amphiboles was markedly less than that from asbestos.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This was an editorial, not an original study. The authors reviewed animal experiments and studies of workers. Their question was whether non-asbestiform tremolite, and the non-asbestiform forms of other asbestos minerals, carry the same cancer risk as asbestos. A 1986 United States Occupational Safety and Health Administration standard assumed they did by regulating non-asbestiform anthophyllite, tremolite and actinolite like asbestos. The authors described rat and hamster experiments in which asbestiform tremolite caused tumours while non-asbestiform tremolite did not. They called mortality studies of workers exposed to non-asbestiform cummingtonite grunerite uniformly negative. For New York talc miners and millers, they discussed several earlier studies and analyses. Brown and colleagues found nine bronchogenic cancer deaths (standard mortality ratio 270) among 398 workers but had no smoking histories. A later update by Gamble and Piacitelli showed a strong link between lung cancer and smoking and an apparent inverse relation between exposure and lung cancer. The authors acknowledged that animal results may not rule out human risk under all conditions. They concluded that the overall results argue convincingly against a causal connection between lung cancer and non-asbestiform tremolite.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Editorial reviewing published animal experiments, worker mortality studies and regulatory positions on non-asbestiform minerals
• Who was studied: Studies reviewed: injection experiments in rats and hamsters; mortality studies of gold miners and taconite miners exposed to cummingtonite grunerite; and several studies and analyses of talc miners and millers in upstate New York (Kleinfeld and colleagues, Brown and colleagues, Stille and Tabershaw, Lamm and coworkers, Gamble and Piacitelli)
• Exposure: Non-asbestiform tremolite, anthophyllite and actinolite (the forms the 1986 United States OSHA standard regulated like asbestos), compared with asbestiform tremolite; also non-asbestiform cummingtonite grunerite (the non-asbestiform analogue of amosite) and talc containing tremolite
• Main results:
  • In the animal studies the authors described, asbestiform tremolite produced tumours, while animals injected with non-asbestiform tremolite stayed free of tumours (for example, in hamster experiments by Smith and colleagues)
  • The authors described mortality studies of workers exposed to non-asbestiform cummingtonite grunerite as uniformly negative; for example, McDonald and colleagues found no excess or trend for respiratory cancers among gold miners
  • In an earlier proportionate mortality study of New York talc workers (Kleinfeld and colleagues), there were 108 deaths, including 12 attributed to lung cancer, one to fibrosarcoma of the pleura and one to peritoneal mesothelioma. The authors said such small numbers are difficult to interpret without necropsy, smoking and environmental data
  • In Brown and colleagues' cohort of 398 workers at one New York talc mine and mill, there were nine deaths from bronchogenic cancer (standard mortality ratio 270) and one mesothelioma the editorial called likely unrelated. The editorial noted that no smoking histories were available and that five of the lung cancer cases had worked there one year or less
  • In Gamble and Piacitelli's update of the New York talc cohort, a nested case-control study matched 22 lung cancer cases each with three controls. It showed a strong association between lung cancer and cigarette smoking and an apparent inverse relation between exposure and lung cancer
• The authors' conclusion: The authors concluded that animal studies suggest that any risk from non-asbestiform amphiboles is markedly less than that from asbestos. They also concluded that the overall results argue convincingly against a causal connection between lung cancer and non-asbestiform tremolite
• Limitations the authors state:
  • The authors stated that animal results may not necessarily establish a lack of carcinogenicity for non-asbestiform amphiboles in humans under all exposure conditions
  • The authors stated that the hypothesis linking cancer-causing ability to fibre length and width remains unproven
  • The authors noted that Gamble and Piacitelli acknowledged shortcomings in their analysis

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Talc and vermiculite, Tremolite.

Medical terms in this study, explained in our Lexicon: Talc, Tremolite, Non-Asbestiform, Anthophyllite, Actinolite, Asbestiform Tremolite, Mesothelioma, Taconite.

Related studies

• On talc, tremolite, and tergiversation. Ter-gi-ver-sate: 2: to use subterfuges — B.W. Case (1991)
• On talc, tremolite, and tergiversation — A.M. Langer, R.P. Nolan, et al. (1991)
• Cohort study of mortality of vermiculite miners exposed to tremolite — J.C. McDonald, A.D. McDonald, et al. (1986)
• Chrysotile, tremolite, and malignant mesothelioma in man — A. Churg (1988)
• Mesothelioma in Cyprus: the role of tremolite — K. McConnochie, L. Simonato, et al. (1987)
• Association of Metsovo lung and pleural mesothelioma with exposure to tremolite-containing whitewash — A.M. Langer, R.P. Nolan, et al. (1987)

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