Childhood Asthma and Environmental Exposures at Swimming Pools: State of the Science and Research Recommendations

Abstract

ObjectivesRecent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children’s exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue.Data sourcesA workshop was held in Leuven, Belgium, 21–23 August 2007, to evaluate the literature and to develop a research agenda to better understand children’s exposures in the swimming pool environment and their potential associations with new-onset asthma. Participants, including clinicians, epidemiologists, exposure scientists, pool operations experts, and chemists, reviewed the literature, prepared background summaries, and held extensive discussions on the relevant published studies, knowledge of asthma characterization and exposures at swimming pools, and epidemiologic study designs.SynthesisChildhood swimming and new-onset childhood asthma have clear implications for public health. If attendance at indoor pools increases risk of childhood asthma, then concerns are warranted and action is necessary. If there is no such relationship, these concerns could unnecessarily deter children from indoor swimming and/or compromise water disinfection.ConclusionsCurrent evidence of an association between childhood swimming and new-onset asthma is suggestive but not conclusive. Important data gaps need to be filled, particularly in exposure assessment and characterization of asthma in the very young. Participants recommended that additional evaluations using a multidisciplinary approach are needed to determine whether a clear association exists.

Avaliação espirométrica e da hiper-responsividade brônquica de crianças e adolescentes com asma atópica persistente moderada submetidos a natação

“…2 The harmful effects of chlorine appear to be dependent on concentration and length of exposure, and still require further study. 2,14 A 2009 study by Bemanian et al 15 showed significant improvement in peak expiratory flow rates in asthmatics after swimming, and suggested that indoor swimming is useful for patients with asthma, regardless of the potentially toxic effects of chlorine.…”

“…2 The benefits of swimming are also due to the horizontal position of the body, which provides a more adequate and constant breathing pattern compared with other forms of exercise, and to the high humidity present in pools. [2][3][4][5][6][7] The few studies published thus far (Table 1) on the effects of swimming in asthmatic individuals cannot be compared among one another due to methodological differences, which include type and duration of swimming program used, choice of outcomes, absence of a control group, and sample size determination issues.…”

“…The results of this workshop showed that the current evidence of association between swimming and childhood asthma is suggestive but not conclusive, and that additional studies are required if current doubts are to be addressed. 2 On the other hand, increased asthma risk has been associated with asthmatic children swimming in pools, but the evidence is inconsistent and inconclusive. In an attemt to address the issue, Font-Ribera et al 14 studied the effects of swimming and of the hazards associated with pool irritants on Spanish children, and found no increase in asthma risk.…”

A Review of Chlorine in Indoor Swimming Pools and its Increased Risk of Adverse Health Effects

“…Epithelial and mucosal damage caused by the exposure to chlorine products in children less than five years of age, pool attendants and competitive swimmers causes an early onset of asthma (Bernard et al, 2006). Children and youth are most susceptible to developing health effects because of the increasing use in youth for physical activity (Bougault et al, 2009) and they are likely to be swimming in water which is warmer and have higher levels of disinfectant (Weisel et al, 2009). …”

Vocal Cord Dysfunction after an Inhalation Exposure

“…Some competitive swimmers develop VCD [59]. Children and adolescents who repeatedly swam, and were exposed to chlorine additives for water disinfection, could become symptomatic [75,[77][78][79][80][81][82]. Apparently, chlorine dissolved in swimming pool water would not pose a danger for the majority of swimmers.…”