Oxidative stress in a population with low blood lead concentrations, chronically exposed in a contaminated area of Zacatecas, Mexico

Many studies have focused on the toxic health effects of low blood lead concentrations in populations chronically exposed to lead-polluted environments. However, few studies have examined oxidative stress in humans under such conditions. We studied a population chronically exposed to mining waste with low blood lead concentrations, high δ-ALAD activity, and high lipid peroxidation levels. A k-means analysis revealed low-high groups based on total antioxidant capacity (TAC), superoxide dismutase (SOD), and catalase (CAT) activities. Low TAC, SOD, and CAT were associated with higher blood lead concentrations, and low SOD was also associated with higher lipid peroxidation. The results suggest that oxidative stress may lead to oxidative damage in chronically lead-exposed populations, even at low blood lead concentrations. Thus, although pathophysiological changes may not be evident at small variations in blood lead concentrations, chronic exposure could cause oxidative/antioxidant changes at blood lead concentrations below 5 μg/dL.