Short-term changes in respiratory biomarkers after swimming in a chlorinated pool.
Environ Health Perspect. 2010 Sep 12. Epub 2010 Sep 12. PMID: 20833607
BACKGROUND: Swimming in chlorinated pools involves exposure to disinfection by-products (DBPs) and has been associated with impaired respiratory health. OBJECTIVES: We evaluated short-term changes in several respiratory biomarkers to explore mechanisms of potential lung damage related to swimming pool exposure. METHODS: We measured lung function and biomarkers of airway inflammation (fractional exhaled nitric oxide -FeNO- and 8 cytokines and 1 growth factor (VEGF) in exhaled breath condensate), oxidative stress (8-isoprostane in exhaled breath condensate), and lung permeability (surfactant protein D -SPD- and the Clara cell secretory protein -CC16- in serum) in 48 healthy non-smoking adults before and after swimming for 40 min in a chlorinated indoor swimming pool. We measured trihalomethanes in exhaled breath as a marker of individual exposure to DBPs. Energy expenditure during swimming, atopy and CC16 genotype (rs3741240) was also determined. RESULTS: Median serum CC16 levels increased from 6.01 to 6.21μg/L (average increase 3.3%, paired Wilcoxon test p = 0.03), regardless of atopic status and CC16 genotype. This increase was explained both by energy expenditure and different markers of DBP exposure in multivariate models. FeNO was unchanged overall but tended to decrease among atopics. We foundno significant changes in lung function, SP-D, 8-isoprostane, 8 cytokines and VEGF. CONCLUSIONS: A slight increase in serum CC16, a marker of lung epithelium permeability, was detected in healthy adults after swimming in an indoor chlorinated pool. Exercise and DBP exposure explained this association, without involving inflammatory mechanisms. Further research is needed to confirm the results, establish the clinical relevance of short-term serum CC16 changes, and evaluate the long-term health impacts.