Each year, more than 6,500 cases of bladder cancer, roughly five percent of all cases in Europe, are found to be attributable to exposure to trihalomethanes (THMs) in drinking water – and it’s all perfectly legal.
What the hell are THMs?
THMs are a class of molecule that appear as a by-product of the disinfectants used to clean drinking water. When chlorine, the main chemical used to clean drinking water, comes into contact with organic matter, it breaks down into THMs. And despite being legal up to certain levels, long-term exposure to them has been consistently associated with an increased risk of bladder cancer. The EU has set that legal limit at 100 lg=L, but anything over 50 lg=L causes a 51 percent increase in the probability of bladder cancer, in men at least. This study was undertaken at the Barcelona Institute for Global Health, in a city which has THM levels above the present regulatory maximum limit of 100 lg=L. Astonishingly, there is no provision for the lowering of this maximum in the latest European Council directive.