Exposure to manganese: Health effects on the general population, a pilot study in central Mexico

To support a risk assessment of manganese exposure in two communities livin g within a manganese mining district a cross-sectional study was performed on a sample of the adult population of long-term residents. One community w as exposed to a point source from an ore primary refining plant. Manganese is an essential mineral for human life. It is also the fourth in importance for industrial metal making. Data were collected on socioeconomic living c onditions, emission sources, environmental media concentrations (air, water , soil, dust, food), respiratory symptomatology, and a neuropsychological e xamination (Mini-Mental Screening test, the Hooper Visual Organization test , the Ardila-Ostroski, and others). We examined 73 subjects (52 women), mos t of low socioeconomic status. Environmental air concentrations were 2 to 3 times higher than those in other urban concentrations. Manganese blood con centrations ranged from 7.5 to 88 mug/L, with a median concentration of 15, the upper quartile starting at 20 mug/L; the upper 10% was above 25 mug/L. Lead and manganese were highly correlated; there was an inverse relation t o hemoglobin, Reduced levels of plasma lipid peroxidation were associated w ith blood manganese. Using multivariate logistic regression, we identified B-Mn as increasing the risk of deficient cognitive performance 12 times (Mi ni-Mental score of less than 17). (C) 2001 Academic Press.