Public Health Aspects of Asbestos Fibers in Drinking Water

Our plain-English summary of Public Health Aspects of Asbestos Fibers in Drinking Water, by R.C. Cooper, W.C. Cooper (1978).

The study

• Authors: R.C. Cooper, W.C. Cooper
• Published: Journal AWWA 338-340 June (1978)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This 1978 article reviewed published work on asbestos fibers in drinking water. The authors described the 1973 discovery of asbestos in the water supply of Duluth, Minnesota, and noted that similar amounts had been reported in other US and Canadian supplies. Lake Superior fibers were amphiboles, mostly of the cummingtonite-grunerite series, and northern California fibers were chrysotile. The authors summarized a Selikoff study in which stomach, colon and rectum cancers among New York-New Jersey insulators twenty or more years after first exposure were over three times the number expected in the general US population. They called the animal evidence on whether swallowed fibers penetrate the gut conflicting. They said no experiment had produced gut tumors in animals through ingestion, even of large amounts. In rat experiments by others, fibrous asbestos or fibrous glass implanted in the pleura produced mesotheliomas, and tumor formation depended on fiber length and diameter. The authors concluded there was no concrete evidence that asbestos ingested in drinking water causes human disease. To their knowledge, no published reports compared death rates of lifelong residents of areas with naturally occurring drinking-water asbestos against relatively asbestos-free areas.

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: Review of published literature on the health aspects of asbestos fibers in drinking water
• Who was studied: No study population of its own. The review covered reports of asbestos in water supplies (Duluth, Minnesota; Canadian cities; northern California), occupational studies of asbestos workers, and animal and human feeding studies done by others.
• Exposure: Asbestos fibers in drinking water: amphibole fibers, mostly of the cummingtonite-grunerite series, in Lake Superior (Duluth) water, from taconite ore processing washings; chrysotile from natural serpentine in northern California waters; and possible fibers from asbestos-cement pipe
• Main results:
  • The authors stated that the Duluth situation was not an isolated incident, since similar amounts of asbestos had been reported in various US and Canadian water supplies
  • The authors reported that, to date, there had been no evidence that asbestos-cement pipes contribute significant amounts of asbestos to the water they carry
  • In the Selikoff study the authors cited, cancers of the stomach, colon and rectum among New York-New Jersey insulators with twenty or more years since first exposure were over three times the number expected in the general US population
  • A cited estimate (Speil) put total intake at 0.3 g of asbestos over a 70-year lifetime of drinking 2 liters a day of water containing 6 million fibers per gallon. The authors judged that the fibers insulation workers swallow after inhaling them must be considerably greater than this.
  • The authors found the evidence on whether ingested asbestos fibers can penetrate the gut of animals to be conflicting. They found no experiment in which ingestion, even of large amounts of asbestos, had produced gut tumors in animals.
  • In rat experiments by Stanton and colleagues, fibrous asbestos or fibrous glass was implanted in the pleura (not swallowed). These implants produced pleural mesotheliomas, and tumor formation depended on fiber length and diameter.
• The authors' conclusion: The authors concluded that there was, at present, no concrete evidence that asbestos ingested in drinking water causes disease in humans. They called for research on detection methods, fiber geometry, animal feeding studies, epidemiological studies, and removal of fibers by water treatment.
• Limitations the authors state:
  • The authors knew of no published reports comparing the death rates of people who had spent their lives where asbestos occurs naturally in drinking water with those of people in relatively asbestos-free areas
  • The authors noted that no gross geographical differences had been seen, but small differences could have been missed
  • The authors stated that the experimental data on whether asbestos penetrates the animal gut were still inconclusive

Topics

Medical terms in this study, explained in our Lexicon: Discovery, Amphibole Group, Cummingtonite-Grunerite, Chrysotile, Insulator, Pleura, Mesothelioma, Fiber Length.

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