Background:Prenatal exposure to air pollution is considered to be associated with adverse effects on child health. This may partly be mediated by mechanisms related to DNA methylation.Objectives:We investigated associations between exposure to air pollution, using nitrogen dioxide (NO2) as marker, and epigenome-wide cord blood DNA methylation.Methods:We meta-analyzed the associations between NO2 exposure at residential addresses during pregnancy and cord blood DNA methylation (Illumina 450K) in four European and North American studies (n = 1,508) with subsequent look-up analyses in children ages 4 (n = 733) and 8 (n = 786) years. Additionally, we applied a literature-based candidate approach for antioxidant and anti-inflammatory genes. To assess influence of exposure at the transcriptomics level, we related mRNA expression in blood cells to NO2 exposure in 4- (n = 111) and 16-year-olds (n = 239).Results:We found epigenome-wide significant associations [false discovery rate (FDR) p < 0.05] between maternal NO2 exposure during pregnancy and DNA methylation in newborns for 3 CpG sites in mitochondria-related genes: cg12283362 (LONP1), cg24172570 (3.8 kbp upstream of HIBADH), and cg08973675 (SLC25A28). The associations with cg08973675 methylation were also significant in the older children. Further analysis of antioxidant and anti-inflammatory genes revealed differentially methylated CpGs in CAT and TPO in newborns (FDR p < 0.05). NO2 exposure at the time of biosampling in childhood had a significant impact on CAT and TPO expression.Conclusions:NO2 exposure during pregnancy was associated with differential offspring DNA methylation in mitochondria-related genes. Exposure to NO2 was also linked to differential methylation as well as expression of genes involved in antioxidant defense pathways.Citation:Gruzieva O, Xu CJ, Breton CV, Annesi-Maesano I, Antó JM, Auffray C, Ballereau S, Bellander T, Bousquet J, Bustamante M, Charles MA, de Kluizenaar Y, den Dekker HT, Duijts L, Felix JF, Gehring U, Guxens M, Jaddoe VV, Jankipersadsing SA, Merid SK, Kere J, Kumar A, Lemonnier N, Lepeule J, Nystad W, Page CM, Panasevich S, Postma D, Slama R, Sunyer J, Söderhäll C, Yao J, London SJ, Pershagen G, Koppelman GH, Melén E. 2017. Epigenome-wide meta-analysis of methylation in children related to prenatal NO2 air pollution exposure. Environ Health Perspect 125:104–110; http://dx.doi.org/10.1289/EHP36

Exposure to road traffic noise may be associated with hypertension in subjects who are between 45 and 55 years old. Associations seemed to be stronger at higher noise levels.

Abstract-Exposure to air pollution is associated with elevated blood pressure and cardiovascular disease. We assessed the associations of exposure to particulate matter (PM 10 ) and nitrogen dioxide (NO 2 ) levels with blood pressure measured in each trimester of pregnancy and the risks of pregnancy-induced hypertension and preeclampsia in 7006 women participating in a prospective cohort study in the Netherlands. Information on gestational hypertensive disorders was obtained from medical records. PM 10 exposure was not associated with first trimester systolic and diastolic blood pressure, but a 10-g/m 3 increase in PM 10 levels was associated with a 1.11-mm Hg (95% confidence interval [CI] 0.43 to 1.79) and 2.11-mm Hg (95% CI 1.34 to 2.89) increase in systolic blood pressure in the second and third trimester, respectively. Longitudinal analyses showed that elevated PM 10 exposure levels were associated with a steeper increase in systolic blood pressure throughout pregnancy (PϽ0.01), but not with diastolic blood pressure patterns. Elevated NO 2 exposure was associated with higher systolic blood pressure levels in the first, second, and third trimester (PϽ0.05), and with a more gradual increase when analyzed longitudinally (PϽ0.01). PM 10 exposure, but not NO 2 exposure, was associated with an increased risk of pregnancy-induced hypertension (odds ratio 1.72 [95% CI 1.12 to 2.63] per 10-g/m 3 increase). In conclusion, our results suggest that air pollution may affect maternal cardiovascular health during pregnancy. The effects might be small but relevant on a population level. Key Words: air pollution Ⅲ pregnancy Ⅲ blood pressure Ⅲ hypertension Ⅲ preeclampsia A ir pollution exposure has been associated with cardiovascular morbidity and mortality. 1-3 Several potential mechanisms for this association have been proposed, including alterations in the autonomic nervous system, induction of pulmonary and systemic inflammation and oxidative stress, endothelial dysfunction, and increased blood coagulability. 1,2,4,5 Elevated blood pressure is a known risk factor for cardiovascular disease and may be implicated in the association between air pollution and cardiovascular morbidity and mortality. Although results differ among studies, 6 -18 there is increasing evidence for a relationship between air pollution exposure and elevated blood pressure levels. 19 Pregnant women are a susceptible group for hypertensive disorders, since changes in pregnancy lead to increased stress on the cardiovascular system. 20 A few previous studies observed higher risks of preeclampsia following exposure to air pollution. [21][22][23] However, the associations of air pollution exposure with blood pressure patterns during pregnancy and pregnancy-induced hypertension have not yet been examined.We investigated the associations of particulate matter (PM 10 ) and nitrogen dioxide (NO 2 ) exposure levels during pregnancy with repeatedly measured blood pressure and the risks of pregnancy-induced hypertension and preeclampsia in a population-based co...