Is Chlorine Ruining Competitive Swimmers' Lungs?

Getting the perfect breathing rhythm for competitive swimming is hard enough, but a new study is suggesting that for elite swimmers training hours a day in an indoor pool, the chlorine may be making it even harder.

According to Reuters, a study of competitive swimmers from French and Canadian researchers found that the lung tissue and breathing test results of the swimmers were similar to that of patients with mild asthma. Both swimmers and asthmatics showed evidence of scar tissue in lungs while healthy, non-competitive swimmers did not.

Valérie Bougault at the Lille 2 University of Health and Law in France who lead the study, according to Reuters, said that swimmers inhale large amounts of chlorine byproducts during hours of exercise in a pool, which can make them more sensitive to allergens. Of the 23 swimmers involved in the study, published in the Journal of Allergy and Clinical Immunology, 18 had at least one allergy. Bougault notes that the scar tissue seen in each of the swimmers lungs were also present in the non-allergic subjects as well, suggesting that the chlorine byproducts are causing the damage.

At the same time, Reuters reports Dr. Sally Wenzel, a pulmonologist at the University of Pittsburgh, as saying these results don't mean that swimmers will develop asthma. Wenzel also notes that it is unlikely the health risks of chlorine will outweigh the exercise benefits gained from swimming.

The researchers state that more long-term consequences from this finding still have to be studied.