Water treatment byproducts linked to thousands of bladder cancers in Europe

Around 5% of all cases of bladder cancer in Europe can be attributed to exposure to trihalomethanes (THMs) that form in drinking water, according to a new study. The team conclude that countries with higher than average THMs should take action to cut levels of disinfectant byproducts in tap water. Chlorine is the most widely used disinfectant for drinking water. However, when free chlorine reacts with organic compounds in water it can generate disinfection byproducts including THMs, which have been associated with bladder cancer.