UC Irvine

Asthma is a chronic lung disease in which the airways become inflamed and produce increased mucus making air flow in and out of the lungs difficult. With the prevalence of asthma higher among children compared to adults, possible environmental exposures that may lead to asthma exacerbations in children were investigated. In-utero exposures to environmental contaminants may increase the risk for asthma development and exacerbations in children and those living near a Superfund Site may be more susceptible. Additionally, early-life exposure to particulate matter with a diameter of 2.5 micrometers or less (PM2.5) may increase the risk of asthma exacerbations.

Extensive exposure measurements available from a well-characterized longitudinal birth cohort study, the New Bedford Cohort (NBC), which consisted of mothers who were pregnant and living near the New Bedford Harbor (NBH) Superfund Site from 1993-1998, were used to develop prediction models for a much larger population-based dataset of relative sociodemographic risk factors available from the Pregnancy to Early Life Longitudinal (PELL) data system. Prediction models were created for cord-serum polychlorinated biphenyls (PCBs), ρ,ρ′-dichlorodiphenyl dichloroethylene (DDE), hexachlorobenzene (HCB), cord blood lead (Pb), and maternal hair mercury (Hg). Combinations of these contaminants along with non-chemical exposures including distance to nearest roadway and distance to the NBH were analyzed to determine whether prenatal exposures were associated with asthma exacerbations in children. Findings suggest that certain prenatal joint exposures increase the risk of asthma exacerbations among children.

The association between early-life exposure to PM2.5 and the risk of asthma or wheeze hospitalizations, emergency department visits or observational stays was also investigated among children in the PELL data system. Daily PM2.5 concentrations were estimated at a 4-km resolution using satellite remote sensing, land use, and meteorological data. Asthma or wheeze exacerbations among low birthweight children were associated with short-term increases in PM2.5 concentrations at low levels in Massachusetts in stratified analyses. Overall, results suggest that prenatal environmental exposures may increase the risk of asthma or wheeze among children.