News from ISGlobal
Each year, more than 6,500 cases of bladder cancer — nearly 5% of all cases in Europe — can be attributed to exposure to trihalomethanes (THMs) in drinking water. This is one of the conclusions of a large-scale study led by the Barcelona Institute for Global Health (ISGlobal) that analysed for the first time the presence of these chemical compounds in the tap water of 26 European Union countries.
Trihalomethanes are formed as an unintended consequence of water disinfection. Earlier research has found an association between long-term exposure to THMs — whether through ingestion, inhalation or dermal absorption — and increased risk of bladder cancer.
The authors of the study analysed recent data on trihalomethanes levels in European municipal tap water and estimated the burden of disease for bladder cancer attributable to exposure to these compounds.
"The biggest challenge was collecting representative data on national trihalomethaneslevels for all EU countries", explained Cristina Villanueva, the ISGlobal researcher who coordinated the study. "We hope that these data will become more readily available in the future".
The findings revealed considerable differences between countries. The average level of trihalomethanes in drinking water in all countries was well below the maximum permissible limit in the EU —11.7 µg/L versus 100 µg/L— but the maximum reported concentrations did exceed the limit in nine countries (Cyprus, Estonia, Hungary, Ireland, Italy, Poland, Portugal, Spain and the United Kingdom).
Iro Evlampidou, Laia Font-Ribera, David Rojas-Rueda et al. Trihalomethanes in Drinking Water and Bladder Cancer Burden in the European Union. Environmental Health Perspectives, January 2020. doi.org/10.1289/EHP4495.