According to the results of a large-scale study, led by the Barcelona Institute for Global Health (ISGlobal), more than 6,500 bladder cancer–almost 5% of all cases in Europe–are due to exposure to trihalomethanes (THMs). For the first time in the tap water in 26 EU countries, the analysis studied the presence of this chemical compound.
The unintended result of water disinfection is trihalomethane. In previous research, there has been a link between long-term THM exposure-whether swallowed, inhaled or dermal-and an increased risk of blood bladder cancer.
They sent questionnaires to municipal water quality bodies requesting information concerning the concentration in the tap, the distribution network and water treatment facilities of total and individual trihalomethanes (chloroform, bromodichloroma, dibromochloromethin, and bromoform).
For 26 EU countries-all but Bulgaria and Romania, where less information is available-trihalomethanes data were obtained between 2005 and 2018, covering 75% of the population.
The average levels of trihalomethanes for drinking water were well below the EU maximum limit of 11.7 μg / L compared with 100 μg / L in all nations, but in nine countries (Cyprus, Estonia, Hungary, Ireland, Italy, Poland, Portugal, Spain, and the UK) the actual recorded levels exceeded the EU maximum limit of 100 μg / L.
A statistical equation compares the average concentrate in trihalomethanes with available international data for bladder cancer incidence rates for each country estimates the number of attributable bladder cancer cases.
In total, 6,561 cases of bladder cancer are reported to be due to exposure to trihalomethanes within the EU per year. The most attributable cases of bladder cancer-1 482 and 1.356, respectively-were found in Spain and the United Kingdom because of the high incidence and population of bladder cancer.
Cypress (23%), Malta (17%), Ireland(17%), Spain (11%) and Greece(10%) have been among the countries most likely to have a bladder cancer exposure. Denmark (0.0%), the Netherlands (0.1%), Germany (0.2%), Austria (0.4%) and Lithuania (0.4%) were the lowest percentages.