The risks to health of asbestos in drinking water

The BBC has cooperated with journalists throughout Europe to investigate the largely overlooked issue of asbestos contamination in drinking water, highlighting the potential health risks associated with this exposure.

Although asbestos is widely known for its dangers when inhaled, its presence in water supplies is a lesser-known concern. Asbestos fibres can enter drinking water through the degradation of asbestos-cement pipes, which were commonly used in water infrastructure from the 1930s to 1980s. Even today, many countries, including the UK, Denmark, and Slovenia, continue to have significant lengths of asbestos-cement piping in use.

The ingestion of asbestos fibres through contaminated water poses potential health risks, though the extent remains controversial. While inhaled asbestos is a well-established cause of lung cancer and mesothelioma, the dangers of ingesting it are less certain. Some studies suggest a correlation between asbestos exposure in drinking water and increased rates of gastrointestinal cancers, such as stomach and colorectal cancers. However, the evidence is inconsistent, and no global consensus exists on safe levels of asbestos in drinking water. The World Health Organisation (WHO) acknowledges the potential risks but does not mandate specific limits for asbestos in water, resulting in varying regulations across countries.

In regions where asbestos-cement pipes are prevalent, pipe deterioration over time leads to increased risk of fibre release, especially during water main breaks. For example, some UK water companies report significant portions of their networks contain asbestos, with higher pipe failure rates observed as the infrastructure ages. Despite the potential risks, routine testing for asbestos fibres in water is not widely implemented, and many health authorities have not prioritised this issue, often due to the lack of clear evidence linking ingestion to severe health outcomes.

Experts argue that while the ingestion risks may not be as acute as inhalation, the long-term exposure from drinking water contaminated with asbestos fibres still warrants further research and monitoring. The situation underscores the need for regular assessment of asbestos levels in water supplies and the gradual replacement of old asbestos-cement pipes to mitigate potential health threats.

The investigation involved journalists in Poland, Denmark, Slovenia, Croatia and Italy. The report is here.