Since the early 1900s many water pipes were concrete with added asbestos for increased tensile strength. This piping has a lifespan of 50-70 years and is failing - right now.
I wondered about ingested asbestos; the dangers of inhalation are well documented but there is disagreement about asbestos in drinking water.
Asbestos is a known carcinogen to humans, meaning it is capable of causing cancer. When asbestos fibres become airborne and are inhaled, they are known to lodge in the lungs and other parts of the airways, where they can cause scarring, inflammation, asbestosis an inflammatory condition leading to permanent lung damage and cell damage that lead to cancers, including mesothelioma, an incurable cancer of the lining that covers organs such as the lungs. For decades, however, the risk from swallowing asbestos has been thought of as small as most fibres were assumed to pass through the gut and be expelled in faeces.
Currently, the World Health Organisation (WHO) does not consider ingestion of asbestos in drinking water to be a serious risk to human health. The evidence is contradictory, with some epidemiological studies showing a correlation between asbestos exposure through drinking water and incidences of stomach and gut cancers. But others have failed to find such a link, and animal studies have also not provided definitive evidence that it can lead to cancers in the gastrointestinal tract.
https://www.bbc.com/future/article/20240124-asbestos-in-drinking-water-an-overlooked-health-risk
The UK and Australia and heaven knows how many other countries have thousands of miles of this concrete/asbestos water pipe. From the same BBC article:
"My concern is that it is in drinking water," says Arthur Frank, professor of public health and professor of medicine at Drexel University in Philadelphia. He is one of the leading international experts on asbestos and has been sounding the alarm about ingestion as a possible mechanism for asbestos-related conditions. "The risk may not be great. But it is generally accepted that there is no safe level of exposure to asbestos."