The same agents that protect swimmers from pathogens lurking in pools also cause harm, sending more than 4000 people to US emergency departments each year.
The figure is based on data for 2003 to 2012 from the US Consumer Product Safety Commission’s National Electronic Injury Surveillance System. About 4250 people sought emergency care annually for injuries related to pool chemicals during that time period. In 2012, the number increased to nearly 4900 (Hlavasa MC et al. MMWR Morb Mortal Wkly Rep. 2014;63:427-430).
Pool Pathogen Killer Harms People. JAMA. 2014;312(3):223. doi:10.1001/jama.2014.8181