DNA-damaging disinfection by-products found in pool water
Study detects subtle changes in swimmers’ cells
By Janet Raloff
Chemicals used to disinfect swimming pools generate other chemicals, some of which damage DNA in cells, according to a trio of new papers that quantified this effect not only in the lab but also in 49 swimmers.
Chlorine and other disinfecting agents are designed to kill germs. But through interactions with other water pollutants, disinfectants can produce mutagenic chemicals. Low concentrations of such DNA-damaging chemicals have been isolated from drinking water in the past, but only one 30-year-old paper hinted at their presence in pool water.
Rates of DNA mutations in swimmers are low and might eventually be fixed by natural repair mechanisms, says environmental epidemiologist Cristina Villanueva of the Municipal Institute of Medical Research in Barcelona, who is a coauthor of all three papers. “Our study was only evaluating short-term exposures,” she notes. The development of cancers, she emphasizes, would likely require extended, chronic exposures to such mutagens.