Placental nitrosative stress and exposure to ambient air pollution during gestation: a populations study

Abstract

The placenta plays a crucial role in fetal growth and development through adaptive responses to perturbations of the maternal environment. We investigated the association between placental 3-nitrotyrosine (3-NTp), a biomarker of oxidative stress, and exposure to air pollutants during various time windows of pregnancy. We measured placental 3-NTp of 330 mother-newborn pairs, enrolled in the ENVIRONAGE birth cohort (2010 to 2013). Daily particulate matter ≤ 2.5 µm (PM2.5), black carbon (BC), and nitrogen dioxide concentrations were interpolated for each mother’s residence using a spatiotemporal interpolation method. Placental 3-NTp levels, adjusted for covariates, increased by 35.0% (95% confidence interval (CI): 13.9, 60.0%) for an interquartile range increment in entire pregnancy PM2.5 exposure. The corresponding estimate for BC exposure was 13.9% (95% CI: -0.21, 29.9%). These results were driven by the first [PM2.5: 29.0% (95% CI: 4.9, 58.6%); BC: 23.6% (95% CI: 4.4, 46.4%)] and second gestational exposure window [PM2.5: 39.3% (95% CI: 12.3, 72.7)]. This link between placental nitrosative stress and exposure to fine particle air pollution during gestation is in line with experimental evidence on cigarette smoke and diesel exhaust exposure. Further research is needed to elucidate potential health consequences later in life through particle-mediated nitrosative stress during fetal life.