Blood mercury concentrations in preschool children and potential risk factors in São Paulo, Brazil.

Environmental exposure of preschool children to mercury can elevate blood mercury levels (BML) and negatively affect their health. This study aimed to determine BML in preschool children from Brazil's largest city and explore potential associated risk factors. Blood samples were collected in 2013 from 2,436 children (age 1-5 years) attending 50 daycare centers (DCC) located in São Paulo, Brazil. Parents or guardians answered questionnaires collecting information on sociodemographics and potential risk factors. BML was determined by Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and categorized using a cutoff point of 2.77 µg L⁻1, corresponding to the 75th percentile. Multiple logistic regression was performed (p<0.05). Data were georeferenced and associations with air pollution, wind frequency and direction were evaluated. The results showed a geometric mean for BML of 1.65 µg L⁻1 (95%CI: 1.60-1.70), arithmetic mean of 2.15 µg L⁻1 (95%CI: 2.09-2.22), 75th percentile of 2.77 µg L⁻1 (95%CI: 2.67-2.91) and 95th percentile of 5.51 µg L⁻1 (95%CI: 5.18-5.92). DCCs located in the Northwest and East zones (p<0.001) and fish consumption in the past two days (p=0.04) were associated with high BML. The elevated BML observed in children living in the eastern zone might be attributed to the southeasterly winds passing through a petrochemical complex located nearby. The 95th percentile of BML in this study exceeded the U.S. 95th percentile by five times. BML in Sao Paulo preschool children was associated with individual and environmental risk factors. This finding highlights the need to identify and control hot spots in Sao Paulo, Brazil, especially in peripheral and surrounding areas, where individuals are more vulnerable. Further research is needed in Latin America to identify additional sources of urban environmental mercury exposure and guide interventions for protecting the environment and safeguarding children's health.

Human Health Risk Assessment Is Associated with the Consumption of Metal-Contaminated Groundwater around the Marituba Landfill, Amazonia, Brazil.

Groundwater is present in its purest form beneath the earth's surface. However, metal contamination is potentially a problem faced by many countries. For this reason, the present study aims to make an assessment of the risks associated with groundwater consumption around the Marituba landfill in an Amazon region. The present study was characterized as transversal with the use of primary data. The sampling occurred in a stratified random way, performed in two radii of action being the 1st radius of 2.5 km away from the landfill and the 2nd radius of 3.5 km away from the landfill to the neighborhoods. A total of 184 points were collected. In all communities the average daily dose (ADD) was higher than the reference oral dose (Rfd), for the metals As, Pb and Mn the risk quotient (HQ) was greater than 1 (one) in all neighborhoods, the concentration of Mn in the least exposed neighborhood was greater than 10 µg.L-1, even at a distance of 3.5 km from the landfill. The average concentrations for As and Pb did not exceed the recommended, however, they were more significant for the Beira Rio neighborhood, respectively 1.47 µg.L-1 and 1.9 µg.L-1. And the average concentration for Cu was more significant for the Uriboca neighborhood 18.20 µg.L-1, but within the recommended. The average of the general concentration of Heavy Metals Pollution Index (HPI) of the water consumed was 80.03, indicating that the water consumed by the population is contaminated by metals.