Swimming Pool Chlorine Linked to Asthma

BRUSSELS, Belgium (Ivanhoe Newswire) -- A new study demonstrates an association between chlorine used to disinfect indoor swimming pools and the surge of childhood asthma in developed countries.

Researchers say trichloramine -- or nitrogen trichloride, a highly concentrated volatile by-product of chlorination -- seems to be the culprit. It is readily generated and inhaled during contact between chlorine and organic matter such as urine and sweat.

Researchers from the Catholic University of Louvain in Brussels, Belgium, measured levels of lung proteins, associated with cellular damage, in the blood of 226 healthy primary school children. The children had all been regular swimmers at indoor pools since early childhood.

Researchers assessed the prevalence of childhood asthma, using data from a survey of almost 2,000 children between ages 7 and 14.

Study results indicate that regular attendance at indoor swimming pools was consistently associated with the destruction of the cellular barriers protecting the deep lung, making them more vulnerable to the passage of allergens. Moreover, asthma was linked to the cumulative amount of time spent at indoor pools.

Levels of trichloramine can vary greatly, depending on how crowded a pool is, how clean the swimmers are, and how well the area is ventilated.

The authors conclude, “The question needs to be raised as to whether it would not be prudent in the future to move toward non-chlorine based disinfectants, or at least to reinforce water and air quality control in indoor pools, in order to minimize exposure to these reactive chemicals.”

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SOURCE: Occupational Environmental Medicine, 2003;60:385-394