If a recent study published in the peer-reviewed journal Environmental Health Perspectives (EHP) is to be believed, then yes. Swimming in indoor pools that have been chlorinated has been found to possibly induce genotoxicity (in common parlance, that means damage to a person’s DNA that could potentially lead to cancer) and also cause respiratory effects.
According to the study, disinfection by-products (DBPs) are formed in indoor swimming pools due to the reactions between disinfectants used in pools such as chlorine; and organic material that either occurs naturally in the pool or is introduced by swimmers, such as sweat, skin cells, and urine. Previous epidemiologic studies have found an association between exposure to DBPs in drinking water and risk of bladder cancer. According to the press release, “evidence of genotoxic effects was seen in 49 healthy adults after they swam for 40 minutes in a chlorinated pool.”
The scientists have studied several chemicals known as “biomarkers” that are present in the body in order to estimate the levels of exposure to certain genotoxic agents, and found that one biomarker that is associated with cancer risk and another that is associated with urine mutagenecity had increased in healthy subjects due to exposure to genotoxins.
The authors also identified more than a hundred DBPs in the pool waters, some that had never before been reported in swimming pool water or chlorinated drinking water. The study showed that the swimming pool water was capable of inducing mutation at levels similar to that of drinking water but was more deadly than drinking water.
Having never heard of this research before, a swimming coach in Delhi (who did not wish to be named) was wary of accepting that it could be something dangerous. “This has been going on for years,” he said, “nothing life threatening has occurred.” “If international associations approve it, then we will also take steps,” he assured, “but until then, let us not jump to any hasty conclusions.”
Swimmers too reacted to the findings with caution. Anshul, 17, a school-going swimmer said, “I trust my coach. If he says it’s ok, it is.”