Selenium dietary intake, urinary excretion, and toxicity symptoms among children from a coal mining area in Brazil

Selenium (Se) is necessary for several physiological functions in the human body; however, high concentrations of this element in coal mining areas raise the possibility of Se-related health risks. Children are much more vulnerable and at risk to environmental hazards than adults. The largest coal mining area of Brazil is located in the city of Candiota, where previous studies point to significant urinary Se concentrations among children. Food intake is the main Se source. The study aimed to evaluate dietary Se intake, as well as urinary Se excretion and classic symptoms of Se intoxication among children from Candiota and a control city in the same region. A cross-sectional study was carried out, with participation from 242 children between 6 and 12 years old in two cities in Rio Grande do Sul state, Brazil. Socioeconomic variables, dietary intake, and Se toxicity symptoms were evaluated through a structured questionnaire, and urinary Se levels were measured. Children from both cities had normal levels of Se intake and urinary excretion; however, children from Candiota had significantly higher levels of Se in both parameters in relation to the control city, especially for Se urinary excretion. There was low prevalence of Se toxicity symptoms. We conclude that coal mining activities may increase Se intake in children and consequently its urinary excretion.