Metal exposure and oxidative stress biomarkers in a Brazilian agricultural community.

We examined the association between exposure to metals, metalloids, and oxidative stress biomarkers among rural community residents in Brazil. Multiple linear regression was used to evaluate associations between serum metal and metalloid concentrations and blood oxidative stress biomarkers, adjusting for sex, age, education, smoking, and alcohol use. After adjustment for covariates, glutathione peroxidase activity (GPx) was inversely and significantly associated with an increase in serum arsenic (As) levels. Positive and significant associations were seen between elevated glutathione reductase (GR) activity and serum cadmium (Cd), barium (Ba), and lead (Pb) concentrations. In addition, we observed a significant increase in malondialdehyde (MDA) levels in association with an increase in Ba levels. These findings suggest that toxic metals and metalloids such as As, Ba, Cd, and Pb alter antioxidant enzyme activities. In addition, Ba seems to promote lipid peroxidation.