Brief Report: Low-level Mercury Exposure and Risk of Asthma in School-age Children.

BACKGROUND: Although mercury exposure has been associated with several adverse health effects, the association with childhood asthma is under investigated. Therefore, we explore the association between mercury and childhood asthma in a population with low mercury levels.

METHODS: Mercury levels were measured in blood and urine in 1,056 children ages 5-14 years. In addition to including questions about asthma diagnosis and wheezing, the study measured bronchial hyperresponsiveness and allergic sensitization to common aeroallergens. Logistic regression analysis adjusted for major potential confounders.

RESULTS: Overall the adjusted odds ratios (aOR) between log blood mercury and the outcomes were 0.8 (95% CI: 0.63, 1.11) for asthma, 0.9 (95% CI: 0.79, 1.14) for wheeze, 1.1 (95% CI: 0.60, 2.03) for bronchial hyperresponsiveness, and 1.0 (95% CI: 0.80, 1.17) for allergic sensitization. Urine mercury adjusted for creatinine was also not associated with any of these allergy-related outcomes.

CONCLUSIONS: While the results did not support an association between mercury exposure and asthma, studies are needed to assess prenatal and lifetime exposure to mercury and asthma.