Swimming in Allergens? Pool Use and Asthma
Spivey, Angela, Environmental Health Perspectives
Atopic asthma (inflammation of the airways caused by exposure to airborne allergens) has become increasingly prevalent since the 1960s and is now the most common chronic childhood disease in the United States and many other industrialized countries. The cause for the rise is unclear, though many hypotheses have been put forth. Now researchers provide new findings that further support one proposed reason--increased use of indoor chlorinated swimming pools by children [EHP 114:1567-1573; Bernard et al.].
The researchers studied 341 children aged 10-13 years who had attended, at varying rates, three indoor pools in Brussels, Belgium. Ambient levels of a highly reactive chlorine by-product, trichloramine, ranged from 0.25 to 0.54 mg/[m.sup.3] at these pools. Trichloramine is created when chlorine reacts with organic matter such as sweat or urine. The researchers administered various tests to the participants, including a questionnaire about health history and pool attendance, an exercise-induced bronchoconstriction test, and a measurement of total serum and aeroallergen-specific IgE (a mediator of atopic asthma).
Forty children had asthma, as indicated by previous doctor diagnosis or the exercise-induced bronchoconstriction test. Cumulative time spent at swimming pools emerged as one of the most consistent predictors of asthma, just after family history of asthma or hay fever and atopy (a genetic tendency toward developing IgE-mediated allergies).
Time spent at pools was associated with increased incidence of asthma only in children with elevated serum IgE. …