The Hazard of Ingested Asbestos
If anyone thought that asbestos and its diseases were a problem behind us, an article in the United Kingdom’s Daily Mail of August 3, 2025, reminded the world that asbestos continues to kill many people. This particular piece noted that more military veterans have died from asbestos-related disease than died in the fighting of the Afghan wars. In Great Britain, some 90 or so deaths each year continue to be found, caused by exposure to asbestos among military personnel, and such individuals were noted to be up to ten times more likely to develop an asbestos-related disease than the general public. The article went on to note that military personnel are compensated at lower levels when compared to claimants in the general public for the same types of disease.
While the focus is almost always on the subject of mesothelioma, and the article mentions asbestosis and lung cancer, as well as other deadly diseases caused by asbestos, there is often a lack of understanding that more and more data is accumulating about other cancers. The International Agency for Research on Cancer (IARC) has also identified laryngeal cancer and ovarian cancer as diseases caused by exposure to asbestos. What is not yet fully appreciated is that it is not only the inhalation of asbestos, but also the ingestion of asbestos, that can lead to a wide variety of diseases.
As far back as the 1960s and 1970s, scientists, including Dr. Irving Selikoff, and even a well-known defense expert in asbestos litigation in America, Dr. Enterline, noted that kidney cancers were found in excess among asbestos-exposed workers. This finding has, over the years, been further corroborated by additional research. British studies with radioactively labeled asbestos, injected into animals, noted that asbestos could traverse the body and end up in many organs. In work in the United States, it has been documented that stillborn babies have had asbestos cross the placenta from their mothers' exposure into fetuses. Clearly, as asbestos finds its way to other tissues, it is not surprising that other cancers have been documented.
There is now an increasing number of peer-reviewed scientific studies that clearly document gastrointestinal tract cancers that will arise, not from inhalation, but from ingestion. This includes cancer of the esophagus, which, even a paper by Dr. Boffetta, has found to occur in excess among asbestos-exposed individuals. Other studies, including work from China and elsewhere, document excess stomach cancers as well as colorectal cancers – even a number of papers that document cancer of the small bowel, which is a particularly rare finding for the tumor types seen following exposure to asbestos. A study of Norwegian lighthouse keepers who lived on islands without electricity or piped-in water, who collected water in asbestos cement cisterns, were documented to have an excess of colorectal cancers following their ingestion of such water.
Millions of miles of asbestos cement water pipe have been used around the world, the United States alone having more than 600,000 miles of asbestos cement pipe. Unfortunately, the World Health Organization, while recommending that asbestos cement water pipes should not be used going forward, it is not fully documenting the excess cancers that can be caused by the ingestion of asbestos. Water companies that have made use of water supply pipes that contain asbestos often fail to admit to any recognition of this hazard. The drinking water inspector in the United Kingdom, for example, states unequivocally that “there is no evidence that asbestos in drinking water presents a risk to human health”. There are, in fact, few such studies, and at least one study from San Francisco does document the hazard, and there are animal studies that asbestos in the GI tract causes cancer in laboratory animals. I participated in such a study myself many decades ago.
When it comes to asbestos cement pipes, the risk takes several forms. Those workers who made the pipes were at risk, as were those who did the installation. Workers who have to repair such pipes are also at risk, and unless the material is properly disposed of, the risk of asbestos from asbestos cement can make others sick. Clearly, ingestion of fluid with asbestos carries the risk of a wide variety of cancers as noted above.
In addition, the work of Suzuki at Mount Sinai in New York showed that asbestos fibers could traverse from the inner aspect of the colon through the bowel wall and end up in the peritoneal cavity, leading to the development of peritoneal cancers in that tissue. The United Kingdom drinking water inspector also states that “there is no consistent evidence that ingested asbestos is hazardous to health,” but appears to ignore the growing trend in the literature of increasing studies from many places around the world that gastrointestinal tract cancers can be found following exposure to asbestos. Also, if one were to employ the precautionary principle, one should do all one can to eliminate the use of asbestos cement pipes and their ability to release fibers that end up in drinking water.
Water companies in other countries have been questioned about their use of asbestos cement pipe and have been asked about testing of water for its asbestos content. At present, the only country in the world that has a standard for asbestos in water is the United States, with 7 million fibers per liter. This was a somewhat arbitrary and unscientifically arrived at number, and studies around the United States have documented ranges of asbestos in water from a few hundred thousand fibers per liter to over one billion fibers per liter in some settings. This obviously cannot be a finding that makes anyone sanguine. In some international settings, testing is done, but in one place, it was once per year at the same test site where no fibers have ever been found, and in another setting, the water supply in the reservoir, before it flowed through pipes, was tested and also reported as having no fibers. Clearly, appropriate testing needs to be done on an ongoing and regular basis.
The lack of general knowledge about the ingestion of asbestos in part can be laid at the feet of politicians and government officials who, if such information became known, would be faced with the prospect of replacing, at huge cost, all asbestos cement water pipes in a timely manner. Unfortunately, such water pipe has been said to have a 50-year life expectancy, but in some settings, that has now been exceeded, often by many years, and frequent breaks with the release of fibers continue to occur. While there was a push in the United States to remove lead water pipes from the water supply system, nothing has ever been put forward regarding replacing asbestos cement pipes, and the prospect of replacing over 600,000 miles of such piping is clearly daunting.
After more than 50 years of studying the health hazards of asbestos, it is alarming that increasing amounts of exposure and increasing findings of ingestion-related asbestos disease continue to be noted in the scientific literature, with little being done to either educate the public or to educate physicians about these risks.
September 2, 2025
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1 Arthur L. Frank, MD, PhD is a Clinical Professor of Public Health at Drexel University, Philadelphia, US.
