The Argentine journal Salud Ocupacional recently published a series of very brief articles entitled "Five Important Studies of the Breadth of the Problem of Mesothelioma" (Salud Ocupacional 1997;67:26-33). The authorship is attributed to The Asbestos Institute, 1995.

There appears to be no rationale as to why these articles were selected for publication, and no evidence that any peer review by the journal ever took place. We note with dismay that well known consultants and advocates of the asbestos industry are listed as members of the Editorial Board of Salud Ocupacional.

The articles are asbestos industry propaganda, not reviews of the scientific literature, and they are wrong.

The first article presents the familiar assertion of the asbestos industry, that "Of the thousands of mesotheliomas associated with asbestos, almost all can be directly attributed to amphibole exposure". Authors of the articles cited for the relative safety of chrysotile over amphiboles are the usual proponents of the asbestos industry. Notably absent are the many studies that dispute this familiar argument of the Asbestos Institute.

The second article dismisses animal studies that do not agree with the epidemiologic studies selected by the Asbestos Institute that chrysotile asbestos does not present a substantive risk to workers. It advances the convenient theory that "amphibole fibers have notably higher potential than chrysotile in the production of asbestosis, cancer and pulmonary mesothelioma". Again, the references conveniently ignore numerous international studies with contrary conclusions.

The third article accepts that "it has been demonstrated that a weak association exists between the exposure to chrysotile and mesothelioma", but in the view of the author, probably because of the presence of amphibole fibers. They conclude that "a good probability exists that the geologic distribution of tremolite in the chrysotile in Quebec varies… and that, with the present levels of environmental controls, any risk of mesothelioma caused by the exposure… would be below the levels of epidemiologic detection".

The fourth article asserts that the continued occurrence of mesothelioma is the result of amphibole exposure. The long latency period for mesothelioma is seen as an unfortunate reflection on safe chrysotile. "To guarantee a rapid diminution of the percentages of mesothelioma after the year 2010, it is necessary to confront successfully several challenges. First, prevent dangerous exposures to amphibole asbestos…Second, all countries should discontinue the use of amphibole asbestos."

Chrysotile asbestos is not mentioned. The fifth article states that most people exposed to asbestos do not develop mesothelioma, and that about half of patients with mesothelioma lack a documented exposure to asbestos. Asbestos Institute researchers report that exposure to asbestos was improbable in nearly one-quarter to one-third of cases. This sets the stage for reporting that virus contamination of vaccines against polio is associated with mesothelioma, which combined with the disinformation of the former articles, ought to completely confuse the reader.

The references are not recent, largely from non-scientific lay publications, and one is a publication of the Canadian Asbestos Information Center.

No medical journal should publish purposely misleading information. The authors of this letter encourage readers of Salud Ocupacional to consider the following:

Chrysotile is carcinogenic, it causes cancers including lung cancer and mesothelioma. 1-5

Canadian chrysotile that is, in fact, amphibole free produces mesotheliomas. 6

6 The strictest occupational exposure limits in the world for chrysotile (0.1 f/cc) are associated with mortal lifetime risks of 5/1000 for lung cancer and 2/1000 for asbestosis.2 Asbestos exposures in developing countries engaged in mining, manufacturing, and construction are far worse than this. 7-9

The history of asbestos is replete with assumptions that the asbestos industry was taking responsible action based on medical reports. But the reality was that the control measures were only taken under the active pressures of government regulation, labor demands, and imminent liability. Let us not be naive enough to think that manufacture and use of asbestos products will soon be voluntarily subjected to strict controls in Africa, Asia, the Middle East, Central and South America, and Central and Eastern Europe.

Asbestos in all forms, including chrysotile, has been banned by a number of countries, many recognized as leaders in occupational health: Sweden, Norway, Denmark, the Netherlands, Finland, Germany, Italy, France, and Poland. In announcing its ban on asbestos in February 1998, the United Kingdom called for a continental ban on asbestos in Europe. Scientists and responsible authorities in countries still using asbestos should have no illusions that "controlled use" of asbestos is a realistic alternative to a ban.

The journal should understand that the Asbestos Institute was established by asbestos companies and governmental bodies in Canada "to defend and promote the safe use of asbestos on a global scale.

" The Asbestos Institute has a history of publishing one-sided defenses of asbestos, analogous to the claims of the tobacco and other industries, without due respect for scientific integrity. Such claims deserve the most searching scrutiny by the scientific community. Although the Asbestos Institute’s influence is found in many publications that lack scientific peer-review, we practitioners of occupational and environmental medicine must seek a fuller understanding of the important issues at stake.

Misleading information such as the articles published in Salud Ocupacional may contribute to a continuation of the asbestos epidemic worldwide. 7,10

References

1. International Program on Chemical Safety, Environmental Health Criteria 77: Man-made mineral fibres. World Health Organization, Geneva, 1988.

2. Stayner L, Smith R, Bailer J, Gilbert S, Steenland K, Dement J, Brown D, Lemen R: Exposure-response analysis of risk of respiratory disease associated with occupational exposure to chrysotile asbestos. Occup Environ Med 1997;54:646-652.

3. Stayner LT, Dankovic DA, Lemen RA: Occupational expousre to chrysotile asbestos and cancer risk: a review of the amphibole hypothesis. Am J Public Health 1996;86:179-186.

4. Dement JM, Brown DP, Okun A: Follup-up study of chrysotile asbestos textile workers: cohort mortality and case-control analyses. Am J Ind Med 1994;26:431-437.

5. Smith AH, Wright CC: Chrysotile asbestos is the main cause of pleural mesothelioma. Am J Ind Med 1996;30:252-266.

6. Frank AL, Dodson RF, Williams MG: Lack of tremolite in UICC reference chrysotile and the implication for carcinogenicity. In, Cherry N, Ogden T (Eds.) Inhaled Particles VIII, Oxford, Pergamon, 1997, pp. 287-292.

7. Giannasi F, Thebaud-Mony A: Occupational exposures to asbestos in Brazil. Int J Occup Environ Health 1997;3:150-157.

8. Malye F: Amiante le dossier de l’air contamine. St. Amand-Montrand (Cher), France: Les Editions le Pre aux Clercs, 1996.

9. Izmerov N, Flovskaya L, Kovalevskiy E: Working with asbestos in Russia (Letter). Castleman B: (Reply). Int J Occup Envir Health 1998;4:59-61.

10. Castleman B, Lemen R: The manipulation of international scientific organizations (Editorial). Int J Occup Environ Health 1998;4:53-55.

Barry Castleman, Sc.D., Environmental Consultant, Baltimore, Maryland, USA

John Dement, Ph.D., C.I.H., Duke University School of Medicine, Durham, North Carolina, USA

Fernanda Giannasi, B.E., Occupational Health and Safety Administration, Brazilian Labor Ministry, Sao Paulo State, Brazil

Arthur L. Frank, M.D., Ph.D., University of Texas Health Center at Tyler, Texas, USA

Howard Frumkin, M.D., Dr.P.H., Emory University School of Public Health, Atlanta, Georgia, USA

Michael Gochfeld, M.D., Ph.D., Robert Wood Johnson School of Medicine, Piscataway, New Jersey, USA

Bernard D. Goldstein, M.D., Environmental and Occupational Health Sciences Institute, Piscataway, New Jersey, USA

Philippe Grandjean, M.D., Institute of Community Health, Odense University, Odense, Denmark

Joseph LaDou, M.D., University of California School of Medicine, San Francisco, California, USA

Richard A. Lemen, Ph.D., Former Deputy and Acting Director, National Institute for Occupational Safety and Health, Washington, DC, USA

Barry S. Levy, M.D., M.P.H., Tufts University School of Medicine, Boston, Massachusetts, USA

Cesare Maltoni, M.D., Secretary General, Collegium Ramazzini, Bolgona, Italy

Melissa McDiarmid, M.D., M.P.H., University of Maryland School of Medicine, Baltimore, Maryland, USA

Ellen K. Silbergeld, Ph.D., Program in Human Health and the Environment, University of Maryland, Baltimore, Maryland, USA

Daniel T. Teitelbaum, M.D., University of Colorado School of Medicine, and Colorado School of Mines, Denver, Colorado, USA

Annie Thebaud-Mony, Ph.D., National Institute for Health and Medical Research (INSERM), Val de Marne, France

David H. Wegman, M.D., Department of Work Environment, University of Massachusetts, Lowell, Massachusetts, USA