PURPOSE OF THE STUDY.
Several retrospective studies have identified attending chlorinated swimming pools during childhood as a risk factor for developing asthma and allergies later in life. These researchers collected data on a large birth cohort of children in the United Kingdom.
Data were available for 5738 children from an initial cohort of 14 062 live births.
Data on swimming were collected by questionnaire at ages 6, 18, 38, 42, 57, 65, and 81 months. Data on asthma and allergic conditions were collected at 7 and 10 years. Spirometry and allergy skin testing were performed between the ages of 7 and 8 years. Multiple confounders were considered in the statistical models.
Fourteen percent of the children swam before 4 years of age, and 50% attended pools at least once per week between 4 and 7 years of age. From birth to 7 years of age, children with a high versus low cumulative swimming-pool attendance rate had an adjusted odds ratio of 0.88 (95% confidence interval [CI]: 0.56–1.38) and 0.5 (95% CI: 0.28–0.87) for asthma ever and current asthma, respectively, and a 0.2-SD (95% CI: 0.02–0.39) increase in forced midexpiratory flow. Children with a history of asthma ever, with a high versus low cumulative swimming exposure rate, had an odds ratio of 0.34 (95% CI: 0.14–0.80) for current asthma at the age of 10 years.
Among those with previous asthma, swimming was associated with decreased asthma symptoms at the age of 10 years. It was also associated with increased lung function at 7 years of age. Swimming did not affect the incidence of asthma.
The results of this study are a nice addition to the previously available data regarding the impact that exposure to swimming pools and their chemical irritants has on asthma. Swimming was not found to increase asthma or asthma symptoms; in fact, it was protective in some aspects. One weakness of this study was its inability to determine if swimming was linked to other healthy lifestyle characteristics that affected the outcomes.
- Copyright © 2011 by the American Academy of Pediatrics