Early life swimming pool exposure and asthma onset in children – a case-control study

Abstract

BackgroundTrichloramine exposure in indoor swimming pools has been suggested to cause asthma in children. We aimed to investigate the risk of asthma onset among children in relation to individual trichloramine exposure.MethodsA longitudinal nested case-control study of 337 children with asthma (cases) and 633 controls aged 16–17 years was performed within a population-based cohort from The Obstructive Lung Disease in Northern Sweden studies (OLIN). Year of asthma onset and exposure time at different ages were obtained in telephone interviews. Trichloramine concentrations in the pool buildings were measured. Skin prick test results for inhalant allergens were available from previous examinations of the cohort. The risk for asthma was analyzed in relation to the cumulative trichloramine exposure before onset of asthma.ResultsThe participation rate was high in the original cohort (88 to 96%), and in the case-control study (80%). Trichloramine concentrations ranged from 0.020 to 0.55 mg/m3 (mean 0.15 mg/m3). Swimming pool exposure in early life was associated with a significantly higher risk of pre-school asthma onset. A dose-response relationship between swimming pool exposure and asthma was indicated in children with asthma onset at 1 year of age. Children who were both sensitized and exposed had a particularly high risk.ConclusionsEarly life exposure to chlorinated swimming pool environments was associated with pre-school asthma onset.Electronic supplementary materialThe online version of this article (10.1186/s12940-018-0383-0) contains supplementary material, which is available to authorized users.

Machine learning–driven identification of early-life air toxic combinations associated with childhood asthma outcomes

“…Ten air toxics in the combinations contained chlorine, three included heavy metal compounds, and many were acidic chemicals. This aligns with prior literature implicating acidic chemicals, chlorinated chemicals, and heavy metal compounds as risk factors for asthma and asthma severity (8,(41)(42)(43)(44). However, an understanding of the biological mechanisms through which these combinations of air toxics can jointly affect respiratory health and asthma merits further study.…”

Impact of swimming school attendance in 3-year-old children with wheeze and rhinitis at age 5 years: A prospective birth cohort study in Tokyo

“…In another study, the same authors also reported the absence of any relationship between swimming attendance up to age 4 years and the development of hay fever symptoms at ages 7 and 10 years [11]. Andersson et al reported the absence of any relationship between a history of swimming before age 1 or 2 years and the development of wheeze by school-age [30]. The findings of these studies were thus in line with our own.…”

Health effects of exposure to chlorination by‐products in swimming pools

“…43 Two studies in Sweden confirmed these observations while showing that the risk of allergic asthma correlated with the cumulative inhalation exposure to NCl 3 . 84,85 Associations between asthma and recreational swimming in chlorinated pools were also reported in Ireland, 86 Italy, 87 and Portugal. 88 Several other studies, however, provided no evidence of an increased asthma risk in recreational swimmers.…”

“…Important to note also that the risk of allergic asthma was more strongly linked to pool attendance during early childhood 43 . Two studies in Sweden confirmed these observations while showing that the risk of allergic asthma correlated with the cumulative inhalation exposure to NCl 3 84,85 …”