Assessment of potential human health, radiological and ecological risks around mining areas in northeastern Brazil.

Mining is responsible for the release of metallic pollutants and radioactive materials into the environment, which have the potential to disrupt ecosystems and pose significant risks to human health. Significant mining activity is concentrated in the municipality of Caetité (northeastern Brazil), where Latin America's only active uranium mine and significant iron ore deposits are located. Although previous studies have shown that the regional soil and water resources are highly contaminated by various toxic elements and that exposure to these elements is known to have adverse effects on human health, the health risks in this mining region have never been assessed. The aim of this unprecedented comprehensive investigation was to assess the health, radiological and ecological risks in this mining region, which is home to nearly 100,000 people. To achieve our goal, soil and water samples were collected in the vicinity of the mines and in the main settlements in the region. Fifteen metallic toxic elements were determined using Instrumental Neutron Activation Analysis and Inductively Coupled Plasma Optical Emission Spectrometry. The HERisk code, which follows the main methodological guidelines for risk assessment, was used to quantify human health, radiological and ecological indices. The average values of the total risk and cancer risk indices indicated that region falls into the moderate risk category (1.0 ≤ HItot < 4.0). However, 63% of the sites had high risk values, with Fe, Co and As being the metals contributing most to total and cancer risk, respectively. Near the mining areas, the potential ecological risk can be considered extreme (PERI ≥ 600). The values of the calculated radiological indices correspond to typical values ​​in natural uranium areas. However, in the communities near the mine, the dose values are slightly above the permissible limit (1 mSv y-1), so they must be continuously monitored, and risk mitigation measures must be taken.

Human Activity in Antarctica: Effects on Metallic Trace Elements (MTEs) in Plants and Soils.

Colobanthus quitensis (Kunt) is one of the two vascular plant species present in Antarctica and develops under severe environmental conditions, being found in both pristine and human-threatened environments. We determined the Cd, Cr, Cu, Mn, Ni, Pb, and Zn levels in C. quitensis roots, leaves, and soils of origin using flame atomic absorption spectroscopy. In January 2017, we collected samples from four geographical zones on the longitudinal gradient along which C. quitensis is distributed, starting from Punta Arenas (PAR) at the extreme south of mainland Chile and moving southwards to the Antarctic territory from King George Island (KGI) to Hannah Point Peninsula (PHA) and finally Lagotellerie Island (LAT). We used certified reference material to validate the plant tissues and soil samples we collected. The highest concentrations of metals that we measured in the soils and in the C. quitensis roots and leaves were in samples we collected at the KGI station, the zone with the greatest human activity. The lowest concentrations we measured were at the LAT station, an island with little human intervention and scarce fauna. The mean concentrations of metals in the roots and leaves of C. quitensis followed a similar order at all sampling locations: Mn > Zn > Cu > Ni > Pb > Cr > Cd. In contrast, in soil, they followed the following order: Mn > Zn > Cu > Cr > Pb > Ni > Cd. The concentration levels obtained for the different metals in the soil and plants tissue samples in this region of Antarctica indicated that the area was non-polluted. However, the metallic trace element (MTE) concentrations may be at an early stage of contamination, as described in other areas of the Antarctic, being a new threat to this continent.

Toxic trace elements in maternal and cord blood and social determinants in a Bolivian mining city.

This study assessed lead, arsenic, and antimony in maternal and cord blood, and associations between maternal concentrations and social determinants in the Bolivian mining city of Oruro using the baseline assessment of the ToxBol/Mine-Niño birth cohort. We recruited 467 pregnant women, collecting venous blood and sociodemographic information as well as placental cord blood at birth. Metallic/semimetallic trace elements were measured using inductively coupled plasma mass spectrometry. Lead medians in maternal and cord blood were significantly correlated (Spearman coefficient = 0.59; p < 0.001; 19.35 and 13.50 µg/L, respectively). Arsenic concentrations were above detection limit (3.30 µg/L) in 17.9% of maternal and 34.6% of cord blood samples. They were not associated (Fischer's p = 0.72). Antimony medians in maternal and cord blood were weakly correlated (Spearman coefficient = 0.15; p < 0.03; 9.00 and 8.62 µg/L, respectively). Higher concentrations of toxic elements in maternal blood were associated with maternal smoking, low educational level, and partner involved in mining.

Indoor metallic pollution and children exposure in a mining city.

Mining industries are known for causing strong environmental contamination. In most developing countries, the management of mining wastes is not adequate, usually contaminating soil, water and air. This situation is a source of concern for human settlements located near mining centers, especially for vulnerable populations such as children. The aim of this study was to assess the correlations of the metallic concentrations between household dust and children hair, comparing these associations in two different contamination contexts: a mining district and a suburban non-mining area. We collected 113 hair samples from children between 7 and 12 years of age in elementary schools in the mining city of Oruro, Bolivia. We collected 97 indoor dust samples from their households, as well as information about the children's behavior. Analyses of hair and dust samples were conducted to measure As, Cd, Pb, Sb, Sn, Cu and Zn contents. In the mining district, there were significant correlations between non-essential metallic elements (As, Cd, Pb, Sb and Sn) in dust and hair, but not for essential elements (Cu and Zn), which remained after adjusting for children habits. Children who played with dirt had higher dust-hair correlations for Pb, Sb, and Cu (P=0.006; 0.022 and 0.001 respectively) and children who put hands or toys in their mouths had higher dust-hair correlations of Cd (P=0.011). On the contrary, in the suburban area, no significant correlations were found between metallic elements in dust and children hair and neither children behavior nor gender modified this lack of associations. Our results suggest that, in a context of high metallic contamination, indoor dust becomes an important exposure pathway for children, modulated by their playing behavior.