The Effect of Nitric Oxide Pollution on Oxidative Stress in Pregnant Women Living in Durban, South Africa

The purpose of the study was to evaluate the effect nitric oxide (NOx) pollution had on maternal serum 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG) levels and neonatal outcomes in pregnant women living in Durban, South Africa (SA). Women, in their third trimester with singleton pregnancies, were recruited from the heavily industrialised south (n = 225) and less industrialised north (n = 152). Biomarker levels of serum 8-OHdG concentrations were analysed, and the women were genotyped for glutathione-S-transferases pi 1 (GSTP1) and glutathione-S-transferases mu 1 (GSTM1) polymorphisms. The level of NOx pollution in the two regions was determined by using land use regression modelling. The serum 8-OHdG was shown to correlate significantly with NOx levels; this relationship was strengthened in the south (p < 0.05). This relationship was still observed after adjusting for maternal characteristics. GSTP1 was significantly associated with the south region, where the variant (AG+GG) genotype was associated with increased 8-OHdG levels as a result of NOx exposure (p < 0.05). GSTM1 null genotype was associated with a positive correlation between NOx and 8-OHdG levels (p < 0.05). NOx levels were found marginally to reduce gestational age (p < 0.05) with mothers carrying male neonates. Variant GSTP1 and living in the north were factors that contributed to gestational age reduction (p < 0.05). Our study demonstrated that NOx exposure resulted in increased 8-OHdG levels in pregnant women living in Durban, SA, which led to gestational age reduction. The GSTP1 variant increased susceptibility of individuals to harmful effects of NOx.