Ban on Asbestos-Cement Pipe Needed, Published in the AWWA JOURNAL.
In July 1986, the US Environmental Protection Agency (USEPA) convened a hearing on the proposed ban on asbestos-cement (A-C) pipe. This proposal was initiated under the Toxic Substances Control Act and would require that substitutes be used for A-C pipe in new installations, replacements, modifications, and repairs. At the hearing, the American Water Works Association commented against the ban, stating that “there is no evidence of adverse effects from ingestion of asbestos fibres” and urging that before a ban is imposed, the health effects of various types of fibres be investigated. As a representative of water utilities nationwide, AWWA acted hastily in opposing the proposed ban. Sufficient reason exists for the water supply community to insist that the control of asbestos materials in all water supplies become official policy.
Water supplies nationwide have the potential to become contaminated with asbestos. Drinking water systems in the United States use an estimated 400,000 mi (644,000 km) of A-C pipe in transporting drinking water. (1) Highly aggressive water flowing through A-C pipes can cause asbestos fibres to be released into the water. (2) Analyses of drinking waters from utilities in areas randomly selected by the US Bureau of the Census as representative of the United States population indicate that 16-18 percent of the water utilities in the United States have highly aggressive water that is corrosive to most pipes found in a typical water system, (2) including A-C pipes.
As a representative of water utilities nationwide, AWWA acted hastily in opposing the proposed ban
The national problem of acid precipitation increases the potential for asbestos contamination in drinking water supplies. Acid precipitation in the United States has caused many bodies of water to suffer drops in pH (3) and corresponding increases in corrosivity. Corrosive water has an enhanced ability to leach materials from distribution systems. In December 1985, the water supply for the town of Woodstock, N.Y., an area that receives highly acidic precipitation, recorded high levels of asbestos fibres in drinking water. The fibres had apparently leached from a section of A-C pipe. Concentrations of asbestos fibres well above the recommended state and federal maximums were found at the taps of various homes. The section of deteriorated A-C pipe has since been replaced, but the effect of this contamination remains unknown. Because of the lag time involved in asbestos-related diseases, the health effects incurred by consumers of this water, or other such contaminated supplies, may not become apparent for decades. The USEPA is striving to reduce exposure to asbestos, and its efforts to reduce exposure from household sources, such as tap water, should be encouraged. Asbestos-cement pipe in water systems across the nation is a time bomb waiting for corrosive water, degradation, or improper tapping of pipes to release asbestos fibres into drinking water.
Because of the lag time involved in asbestos related diseases, the health effect incurred by consumers of water… may not become apparent for decades
The AWWA states that “there is no evidence of adverse effects from the ingestion of asbestos fibres.” This is simply not true. Some of the first studies of asbestos ingestion were of asbestos workers who were found to be ingesting a high percentage of inhaled fibres that were cleared from the lungs and swallowed. Several studies linked this form of asbestos ingestion to a high occurrence of digestive tract cancer. The findings of these studies were reviewed by the Safe Drinking Water Committee of the National Academy of’ Sciences, which concluded that the data “strongly suggest that ingestion of asbestos mineral fibres can result in an increased risk of cancer of several sites.” (4)
Although research to date on the effects of asbestos consumed in drinking water has been limited and somewhat contradictory, some studies have found statistical associations between asbestos fibres in drinking water and the incidence of certain cancers. (3-7) Studies conducted in Minnesota, Quebec, Connecticut, and California found evidence suggesting an association between ingestion of asbestos in drinking water and pancreatic cancer, and for all of these areas except Connecticut, there were similar findings for stomach cancer. (6) Some of these area specific studies were statistically analysed for agreement. Although no causality was established, the agreement in excess cancers of the stomach, oesophagus, pancreas, and prostate for different areas was considered unlikely to be due to chance alone. (8)
Asbestos-cement pipe in water systems across the nation is a time bomb …
Numerous studies have documented the Occurrence of lung diseases and cancers from the inhalation of airborne asbestos fibres. Asbestos fibres could become airborne and enter the lungs from water that is used for showering, washing clothing, cleaning carpets, or in humidifiers or lawn sprinklers. All of these tap water uses, and others, could allow asbestos fibres to become airborne and enter the lungs. This potential danger provides further reason to support a ban on A-C pipe.
Scientists have failed to reach a consensus on the extent and specific carcinogenic effect of asbestos ingestion and thus are stymied when policy decisions must be made. One of the major drawbacks of asbestos ingestion studies is that they do not span long enough time periods; the latency period for certain asbestos-related tumours is as long as 40 years. (7) Short-term studies that find no adverse health effects from asbestos ingestion may be jumping to premature conclusions. We must keep in mind that it took decades for the health effects from occupational exposure to inhaled asbestos to become apparent. Evidence that we now have indicates that there may be a risk involved in ingesting asbestos in water. Taking preventive action today to remove asbestos materials from distribution systems will help avoid the cancers of tomorrow.
Short-term studies that find no adverse health effects from asbestos ingestion may be jumping to premature conclusions
The potential health effects for individuals who ingest or inhale asbestos fibres from water supplies can be avoided by the implementation of policies such as the USEPA proposed ban on A-C pipe.
Considering the risks, and the known carcinogenic potential of asbestos, it is imprudent to wait for a consensus on the health effects of asbestos ingestion. Given the accumulating evidence of health effects of the ingestion of asbestos fibres, the solid evidence linking airborne asbestos fibres to lung and other cancers, and the ability of acid deposition to enhance the leaching of distribution system materials, the USEPA should be encouraged to go ahead with the proposed ban on asbestos-cement pipe in order to help ensure healthy, risk-free water supplies nationwide.
Jane Ceraso is a staff scientist with the Environmental Defense Fund (EDF), a national nonprofit organization founded in 1967. Based in EDF ls New York City headquarters, Ceraso works on local and regional water quality and acid rain problems. Her most recent project is an assessment of the effects of acid deposition on reservoirs in the Catskill Mountains, which supply much of New York City’s drinking water.
References
(1) AWWA Opposes Ban on A-C Pipe. jour. AWWA, 78:9:16a (Sept. 1986).
(2) MILLETTE, J.R. ET AL. Aggressive Water: Assessing the Extent of the Problem. jour. AWWA, 73:5:262 (May 1980).
(3) US-Canada Memorandum of Intent on Transboundary Air Pollution. Final Rept. Washington, D.C. (Feb. 1983).
(4) Drinking Water and I-Health. Safe Drinking Water Committee, Natl. Academy of Sciences, Washington, D.C. (1977).
(5) M1LLETTE, J.R. ET AL. The Need to Control Asbestos Fibres in Potable Water Supply Systems. Sci. of the Total Envir., 18:91 (1981).
(6) POLISSAR, L. ET AL. Cancer Incidence in Relation to Asbestos in Drinking Water in the Puget Sound Region. Amer. jour. Epidemiol., 116:314 (1982).
(7) KANAREK, M.S. ET AL. Asbestos in Drinking Water and Cancer Incidence in the San Francisco Bay Area. Amer. jour. Epidemiol., 112:54 (1980).
(8) MARSH, G.M. Critical Review of Epidemiologic Studies Related to lngested Asbestos. Envir. Health Perspectives. 53:49 (1983).
