Association of mercury exposure with blood pressure among adults near artisanal and small-scale gold mining in Madre de Dios, Peru.

There have been few studies investigating the association between mercury exposure and blood pressure, with inconsistent results. In this study, the association between hair mercury concentration with mean arterial pressure (MAP) and hypertension were evaluated using data collected in a 2015 cohort study, which sampled 23 communities in Madre de Dios, Peru. This area has recently experienced a rapid increase in artisanal and small-scale mining, which is the main anthropogenic source of mercury emissions. Generalized estimating equations were used to account for correlation within communities. Analyses for MAP and hypertension were performed using linear and logistic models, respectively, and confounding variables were included in both models. Due to the significant (p-value < 0.05) interaction between sex and mercury in both models, the analysis was stratified by sex. In women, there was an inverse association between hair mercury concentration with hypertension (OR: 0.84; 95% CI: 0.50–1.41) and MAP (gMR: 0.99; 95% CI: 0.98–1.008), but these associations were not significant at a 5% significance level. In men, the associations between hair mercury concentration with hypertension (OR: 3.07; 95% CI: 1.36–6.92) and MAP (gMR: 1.024; 95% CI: 1.01–1.04) were positive and significant at a 5% significance level. Differences observed between sex could be attributable to differences in exposure, men eating greater amounts of mercury-contaminated fish, or sex hormones, which regulate the distribution and excretion of mercury in the body.