Asbestos and health

Q.

A.     Numerous studies of workplace exposures in occupational environments have linked asbestos with three diseases: asbestosis, a fibrotic lung condition; lung cancer; and mesothelioma, a rare cancer of the surface linings of lung or abdomen tissues. The studies have also found that the lung cancer risk from asbestos exposure is closely related to individual smoking habits, with very few lung cancer cases found among non-smokers.(20,25,31)

Q.

A.     No. Studies of heavily exposed workers reviewed by the National Academy of Sciences, the Commission of European Communities, the U.S. Consumer Product Safety Commission's Chronic Hazard Advisory Panel on Asbestos and other have uniformly found that as exposure decreases, disease decreases.(2,3,13,20)  Such dose-response relationships are typical of our environment. The general population is exposed daily to many agents linked with cancer­ radiation from sunlight, the fungus aflatoxin in milk and peanut butter, saccharin in food and beverages ­ at such low levels that little or no disease is expected.

Q.

A.     They can't. At best, only estimates called "risk assessments" can be made. Government agencies often estimate low level risks by extrapolating from risks found for much higher exposures.
    In order to ensure that risks are not underestimated, risk assessors, assume that risk will occur at any exposure and further assume that low exposures are proportionately as hazardous as high exposures. For example, one-tenth the exposure is assumed to pose one-tenth the risk. Based on such assessments, government agencies have developed upper limit estimates of the risks of low level asbestos exposures.

Q.

A.     In order to understand the risks predicted for low level asbestos exposures, those risks can usefully be compared to the risks of a number of other everyday activities.
    Based on EPA estimates, the risk experienced by attending a school with 0.001 fibres/cc average asbestos exposures for 10 years would be equivalent to the risk a person would experience smoking five cigarettes, or living in a brick building for seven months.(5,29,33)

Activities posing risks equivalent to the EPA's predicted risk
from 10 years of exposure to asbestos in a school building

	Average school exposures of 0.001 fibres/cc
Riding in a motor vehicle a total of:	1,000 miles
Smoking in a lifetime a total of:	5 cigarettes
Living with a smoker for:	7 months
Radiation from living in a brick building for:	7 months

Moreover, a person would need to attend a school with an average exposure of 0.001 fibres/cc for 40,000 years to face the same risk as is posed by smoking one cigarette a day for a lifetime. Similarly, only if a person attended such a school for 225 years would the risk even equal the risk of breathing the asbestos typically found in the outside air.

Q.

A.     Not at all. It suggests that the sense of urgency felt by many is unwarranted. It is important to remember that the degree of risk in a representative school built with asbestos-containing materials is comparable to, or less than, the risks inherent in a wide variety of everyday activities. And, it is well below the predicted risk from asbestos exposure from the general environment. Even in the rare school with average exposures of 0.01 asbestos fibres/cc, many everyday activities pose a much greater risk.

Q.

A.     A number of expert governmental and scientific bodies around the world have concluded the risk of disease from exposure to asbestos in buildings is not significant. For example, the 1979 report of the United Kingdom (U.K.) Advisory Committee on asbestos, concluded:

[U]nless contaminated buildings are very much commoner than seems likely, no appreciable mortality from lung cancer can be associated with any degree of contamination by chrysotile [asbestos] likely to be encountered in the U.K. in the ambient air or in buildings not under active construction or repair.(31)

[W]e deem the risk which asbestos poses to building occupants to be insignificant and therefore find that asbestos in building air will almost never pose a health hazard to building occupants.(20)

As of this date, there are no documented cases of lung cancer associated with low-level asbestos exposure over a lifetime. Risk assessment models used to estimate the incidence of cancers from low exposures to hazardous substances predict very low levels. For example, the lifetime risk of cancer associated with nonoccupational exposures to asbestos was found to be 1,000 to 10,000 times less than the risk due to tobacco alone.

Q.

A.     There are no studies documenting any greater risk to children, as compared to adults. Upon reviewing the available information, the Ontario Royal Commission concluded:

[E]ven allowing for the hypothesis that the very young might be more susceptible to asbestos disease, the health risk to children remains insignificant because the level of exposure in asbestos-containing schools has in general been so low.(20)

References

1. Chatfield, E. Relevance of TEM Analyses to Ambient Air Control Limits.
2. Commission of the European Communities, Public Health Risks of Exposure to Asbestos (1977)
3. Consumer Product Safety Commission. Chronic Hazard Advisory Panel on Asbestos (July 1983)
4. Cooper, WC et al. Chrysotile Asbestos in a California Recreational Area, 206 Science 685-88 (Nov. 9, 1979)
5. Crouch, E & Wilson, R. Estimates of Risks, 2 Journal of Bus. Admin. U. of Br. Col. 299-317 (1979-80).
6. Dept. of Health, Education and Welfare. Asbestos: An information Resource, Pub. No. 78-1681 (May 1978).
7. Doll, R and Peto R. The Causes of Cancer: Quantitative Estimates of Avoidable Risks of Cancer in the United States Today, 66 J. NCI 1191-1308 (1981).
8. EPA. National Emission Standards for Hazardous Air Pollutants, 38 Fed. Reg. 8820 (April 6, 1973).
9. Goldstein, J. Richard, MD. Asbestos Policy Committee's Interim Report to the Governor [of New Jersey] (September 1984).
10. International Agency for Research on Cancer. Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man, Vols. 2 and 14 (1973 and 1977).
11. Millette, JR et al. Asbestos in water supplies of the United States, 53 Environ. Health Perspect. 45-48 (Nov. 1983).
12. National Academy of Sciences. Asbestos: The Need for and Feasibility of Air Polution Controls (1977).
13. National Academy of Sciences and National Research Council. Nonoccupational Health Risks of Asbestiform Fibres (1984).
14. National Academy of Sciences Safe Drinking Water Committee. Drinking Water and Health (1977).
15. National Institute of Building Sciences, Task Force Report. Asbestos in Schools and Public Buildings (July 2, 1984).
16. New Jersey Department of the Public Advocate. Asbestos in the schools: An interim report, testimony for presentation to the State Asbestos Policy Committee (Aug. 29, 1984).
17. Nicholson ,W. Environmental Protection Agency, Health Effects Update (June 1983), referencing study of Sebastien.
18. Nicholson, WJ et al. Asbestos Contamination of the Air in Public Buildings, EPA-450/3-76-004 (Research Triangle Park, NC: Environmental Protection Agency, October 1975)
19. Pinchin, DJ. Asbestos in Buildings, Royal Commission on Asbestos Study Series, No. 8 (1982)
20. Report of the Royal Commission on Matters of Health and Safety Arising from the Use of Asbestos in Ontario (1984)
21. Sawyer, RN et al. Airborne fibre control in buildings during asbestos material removal by amended water methodology (Dec. 1983).
22. Sawyer, RN & Spooner, CM. Sprayed asbestos-containing materials in buildings: A guidance document, Part 2, Environmental Protection Agency, EPA-450/2-78-014 (March 1978).
23. Schmaehl, DFK. Carcinogenic aspects of asbestos, World Symposium on Asbestos (1982).
24. Sebastien P et al. Measurement of asbestos air pollution inside buildings sprayed with asbestos, translation of document prepared for the Government of France, Ministry of Health and Ministry for the Quality of Life Environment, 1977, EPA-560/13/80-026 (Environmental Protection Agency, August 1980).
25. Selikoff, IJ et al. Mortality effects of cigarette smoking among amosite asbestos factory workers, 65 J. NCI 507-513 (1980).
26. Statement by the National Institute of Building Sciences, Hearings before the subcommittee on public buildings and grounds on potential health hazards associated with the use of asbestos-containing material in public and private facilities 313-315 (March 21, 1984).
27. Testimony of Dr. Hans Weill before the Ontario Royal Commission on Asbestos, Vol IX (1981).
28. Testimony of Julian Peto before the Ontario Royal Commission on Asbestos, Vol XXVA (1981).
29. Testimony of Dr. Kenny S. Crump before the Environmental Protection Agency Hearing on Asbestos in Buildings (Boston, Massachusetts, July 6, 1984).
30. Testimony of Dr. Robert N. Sawyer before the Environmental Protection Agency Hearing on Asbestos in Buildings (Boston, Massachusetts, July 6, 1984).
31. United Kingdom Advisory Committee, Asbestos (1979).
32. U.S. Department of Interior, Bureau of Mines, Minerals Yearbook (1972) and Asbestos: A Materials Survey (1959).
33. Wilson, R. Analyzing the daily risks of life, Technology Review 41-46 (Feb. 1979).

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