Air pollution during pregnancy and cord blood immune system biomarkers

Objectives: We aimed to determine whether average and trimesterspecific exposures to ambient measures of nitrogen dioxide (NO₂) and particular matter (PM_2.5) were associated with elevated cord blood concentrations of immunoglobulin E (IgE) and two epithelial cell produced cytokines: interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP). Methods: This study utilized data and biospecimens from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study. There were 2001 pregnant women recruited between 2008 and 2011 from 10 Canadian cities. Maternal exposure to NO₂ and PM_2.5 was estimated using land use regression and satellite-derived models. Results: We observed statistically significant associations between maternal NO₂ exposure and elevated cord blood concentrations of both IL-33 and TSLP among girls but not boys. Conclusions: Maternal NO₂ exposure may impact the development of the newborn immune system asmeasured by cord blood concentrations of two cytokines.