A recent study has raised alarm bells about the presence of cancer-causing chemicals in various drinking water sources, including tap and bottled water. Researchers from California examined a wide range of water samples, comprising 603 from the tap, 100 from bottled water, and 111 from household-treated tap water. Their analysis revealed potential health risks associated with all three drinking water options within the San Francisco Bay Area. The primary concern was the existence of ‘trihalomethanes’ (THMs), which are by-products of water disinfection using chlorine. While chlorine disinfection is crucial for preventing waterborne diseases, prolonged exposure to THMs has been linked to increased cancer risks and potential kidney and liver damage.
The study authors emphasised the need for more information on the quality of different drinking water sources, stating that alternatives such as bottled water and household-treated tap water are becoming more popular. The research indicated that tap water exhibited significantly higher average potential toxicity compared to bottled water and household-treated tap water. This challenges the notion that bottled water is a superior alternative to tap water, particularly when considering the environmental and financial implications. The study suggested that addressing potential toxicity in household-treated tap water could be achieved through tailored treatment methods in collaboration with water systems.
Although the study focused on San Francisco, concerns about water quality are not exclusive to the region. In the UK, similar issues have been raised regarding tap water. In 2023, the World Health Organisation categorised perfluorooctanoic acid (PFOA), found in drinking water samples across England, as carcinogenic. PFOA belongs to a group of compounds known as “forever chemicals” and has been detected in significant amounts in water sources. Despite regulatory actions to ban certain chemicals like PFOA and perfluorooctanesulfonic acid (PFOS), their persistence in the environment remains a cause for concern.
The study’s findings underscore the importance of ongoing monitoring and assessment of drinking water quality to safeguard public health. As discussions around water safety and contamination continue, it is essential for authorities to address these issues promptly and implement measures to ensure the delivery of clean and safe drinking water to the population.