Human health risk assessment of air pollutants in the largest coal mining area in Brazil.

The Candiota region, located in the extreme south of Brazil, has the largest mineral coal deposit in the country, and this activity is capable of releasing pollutants in which they are associated with the contamination of different matrices (soil, water, and air). The present study aimed to carry out a risk assessment to human health of atmospheric pollutants NO2 and SO2 and PM10-bound metal(loid)s in the municipality of Candiota, in addition to evaluating the correlation of meteorological parameters for the dynamics and potential risk of these pollutants. Pollutants were sampled from stations located almost 4 km from coal exploration activities, and the trace elements As, Cd, Se, Pb, and Ni, in addition to NO2 and SO2, were evaluated. Risk assessment was conducted taking into account the risk to adults via the inhalation route. During the sampling period, all pollutants presented values lower than national legislation or internationally accepted values, and Pb was the element that presented the highest values throughout the sampled period. The risk assessment showed no carcinogenic and non-carcinogenic risks, even when considering the sum of the risk of all analyzed pollutants. It can be observed that the highest levels of Pb, As, and Se occurred in the winter season, while the levels of Ni and Cd were higher in the spring, and the meteorological parameters were correlated with the pollutants, even using a temporal lag of 5 days. Although the air pollutants evaluated did not present a risk to human health, continuous monitoring of regions with strong mineral exploration activity must be carried out with a view to maintaining the well-being of exposed populations, mainly because there are people living in areas closer to sources of coal pollution than distance to air quality monitoring stations.

Arsenite and arsenate toxicity in the earthworm Eisenia andrei (Bouché 1972) in natural soil and tropical artificial soil.

Inorganic forms of As (arsenite - As(III) and arsenate - As(V)) are prevalent in soil and recognized for their high toxicity. Once in the soil, these forms of As can compromise key organisms for ecological processes, such as earthworms. The aim of the study was to evaluate the toxicity of arsenite and arsenate in the Californian earthworm Eisenia andrei exposed in natural soil and tropical artificial soil (TAS). Adverse effects were evaluated using avoidance test, acute toxicity test, and a sublethal concentration test to assess biochemical parameters. LC50 values for arsenite were 21.27 mg/kg in natural soil and 19.0 mg/kg in TAS and for arsenate were 76.18 mg/kg in natural soil and above 120 mg/kg in TAS. In the avoidance test, this behavior was shown to be significantly higher in the natural soil and for earthworms exposed to arsenite, while total antioxidant capacity, glutathione levels, lipid damage, and DNA damage were significantly higher in animals exposed to arsenite, but without differences in relation to the two types of soil tested. Animals exposed to As(V) showed increased activity of enzymes related to glutathione metabolism. The results obtained in the present study show the impact of As exposure on the health of the Californian earthworm E. andrei, especially in the form of arsenite, and alert the public authorities that legal limits should, whenever possible, consider the soil properties and also the different chemical species of the contaminants.

Antifouling paint particles in soils: toxic impact that goes beyond the aquatic environment.

Antifouling paint particles (APPs) originate from vessel maintenance and cleaning activities and their potentially toxic components are found at high concentrations in nearby soils, yet no studies have investigated their toxicity to soil organisms. We investigated the effects of exposure to soils containing APPs on the mortality, biomass, and reproductive performance of the earthworm Eisenia andrei. Earthworms were exposed to contaminated soil from a boatyard and non-contaminated soils treated with different concentrations of APPs (0.01, 0.14 and 1.50%, w/w) for 56 days. An ecological risk assessment using a Hazard Quotient (HQ) was also carried out. Exposure to contaminated soils reduced worm survival, biomass, and reproductive performance and these effects were concentration-dependent. The HQ was high in soil samples with APPs in both acute and chronic tests, and copper contributed the most to the HQ. Copper, zinc, and lead had the highest concentrations and exceeded the Brazilian legal limits. A principal component analysis (PCA) was performed and showed that biomass and number of juveniles parameters was associated with the metals Cu, Sn and Zn, while the mortality parameter had no association with any analyzed metal. These findings highlighted that the synergistic effects of compounds present in the APPs, such as the booster biocides DCOIT, and metal mixtures should not be overlooked. We conclude that soils contaminated with APPs are toxic to earthworms. This reveals that the ecological impact of APPs goes beyond effects on aquatic environments, compromising key organisms of edaphic ecological processes.