Parents may want to think twice about their children using indoor pools. A study, reported in Environmental Health Perspectives (December 2004), found that regular visits to indoor pools damage Clara cells that help prevent airway inflammation. The researchers speculated that repeated exposure to chlorine byproducts in the air around indoor pools may harm these respiratory cells.
During the study, the researchers measured lung function and blood levels of the anti-inflammatory protein CC16, produced by the Clara cells in 57 children living in Umea, Sweden. The results of the study showed 40% of the 10- to 11-year-olds had visited an indoor pool for at least an hour a month for the previous 6 months. The researchers categorized those participants as frequent indoor pool users. When compared with their peers, the children who regularly used these pools had a lower average of CC16 concentrations, which suggests damage to Clara cells.