Urinary Triclosan Levels and Asthma Exacerbations in Inner-City School Children

Rationale: Early population studies have begun to identify an association between triclosan, a broad-spectrum antimicrobial chemical, and asthma exacerbations, but the relation is not well understood. We hypothesized that triclosan exposure would be associated with increased asthma exacerbations.  

Methods: 23 children with asthma, aged 5 – 10 years and recruited from 3 urban schools, were analyzed to determine the relation of exposure to triclosan, an environmental phenol, and pediatric asthma morbidity in the context of a pilot classroom-based air cleaner intervention to reduce classroom specific exposures.  Spot urine samples were collected at baseline and total urinary triclosan biomarkers were analyzed.

Results: The geometric mean of triclosan for the study population of 24.8 µg/L (95% 17.5 – 35.1) fell within the 50^th to 75^thpercentile, of 6-11 year olds represented in 2005 to 2010 National Health and Nutrition Examination Survey (NHANES). Frequency of shampoo use was significantly associated with higher triclosan concentrations (p-value < 0.05; 12.6 µg/L, 28.0 µg/L by frequency of use, respectively). In multivariate analyses, children with urinary triclosan levels in the highest tertile have 38.7 (95% CI: 1.0 – 1494.7, p-value 0.05) times the odds of asthma hospitalization within the past 12 months as compared to children with urinary triclosan levels in the lowest tertile.

Conclusions: Exposure to triclosan during childhood is associated with increased asthma hospitalizations among inner-city children. Further large-scale longitudinal studies are needed to evaluate the relationship between triclosan exposure and asthma morbidity in children.