Swimming in Pools May Increase Asthma Risk

Have you ever wondered if your child wheezes more at the indoor pool. Well your observations may be rooted in scientific fact. Research published in Occupational and Environmental Medicine shows that swimming in chlorinated indoor pools during childhood may increase the risk of developing asthma. Chlorine-the chemical used to kill bacteria in the pool-is highly volatile and produces a gaseous by-product called nitrogen trichloride when it mixes with sweat or urine. This gas is believed to make the lungs more irritable. Asthma is a chronic respiratory disease where the airways constrict, and become inflamed and covered with mucus, causing difficultly breathing. The prevalence of the disease has risen dramatically in developed regions. In the US, the percentage of children under the age of 18 with asthma has jumped to 9 percent in 2001 from 3.6 percent in 1980. Researchers conducted a study comparing the prevalence of wheezing, asthma, hay fever, allergic rhinitis and atopic eczema to the number of indoor chlorinated swimming pools per resident in study centers from 21 countries throughout Europe. The results showed that in 13 to 14 years olds, the rates of childhood asthma rose by 3 percent and wheezing also rose by nealry 3 percent for each additional chlorinated indoor swimming pool per 100 000 people. A 1.5 percent increase in the rate of asthma was found in children age 6 to 7 years old. The findings suggest that part of the rise of asthma rates in developed regions can be linked to the increasing attendance of young children at indoor swimming pools. Proper ventilation and regulation of chlorine use in indoor pools is needed to minimize nitrogen trichloride exposure. Further research will be needed to understand how the nitrogen trichloride causes damage to the lung.