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.

Health impact assessment of air pollution in an area of the largest coal mine in Brazil.

Coal exploration and burning activities are among the activities with the greatest potential to cause atmospheric pollution due to the combustion process of this mineral and the consequent release of particles that, in significant quantities, can pose a potential health risk, mainly respiratory and cardiovascular diseases. The Candiota region, in the extreme south of Brazil, concentrates 40% of the national reserves of mineral coal, and its burning is capable of releasing air pollutants, including particulate matter (PM). Some environmental and epidemiological studies have been carried out in the region, but so far, there is no investigation to estimate the impact of PM on health outcomes. The current study aimed to estimate the mortality attributed to the PM, as well as the benefits in health indicators associated with the reduction of air pollution to the limits set forth in local legislation and the WHO. Daily data on PM levels collected from an air quality monitoring station over a year were used, as well as population data and health indicators from 7 cities influenced by mining activities, such as total mortality and cardiovascular diseases and hospitalizations for cardiac and respiratory problems. In a scenario where PM levels are within legal limits, a percentage greater than 11% of cardiovascular deaths was attributed to pollution by PM2.5, and the reduction in PM10 and PM2.5 levels may be responsible for the increase in the expectation of life in up to 17 months and monetary gains of more than $ 24 million, due to the reduction in hospitalizations and mortality. Studies of this nature should be important tools made available to decision-makers, with a view to improving environmental laws and a consequent improvement in the quality of life and health indicators of the population.

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.

Ecotoxicity of triclosan in soil: an approach using different species.

Triclosan is an antimicrobial agent widely used in personal care products and an emerging contaminant with potential to have harmful effects to edaphic organisms. This study aimed to evaluate the impacts of exposure to triclosan on the microbiota, plants, and edaphic animals using isolated bioassays and a microcosm scale representation (multispecies system). Among the isolated bioassays, the phytotoxicity test with Lactuca sativa, avoidance test with Eisenia andrei, and acute toxicity with E. andrei and Armadillidium vulgare were used. The multispecies system used seeds of L. sativa and Sinapis alba, together with earthworms and terrestrial isopods. This system also evaluated microbial activity through alkaline phosphatase and the metabolic profile using Ecoplate™, BIOLOG microplates. Exposure to triclosan impacted seedling growth in the isolated bioassay and germination and root growth in the microcosm scale assay; it also caused mortality in terrestrial isopods, earthworm avoidance and alteration of alkaline phosphatase, and the consumption profile of carbohydrates and carboxylic acids in the microbiota. The ecotoxicological effects evaluated in the multispecies system were perceived even in low concentrations of triclosan, indicating that the interaction of this xenobiotic with the environment and organisms in a more realistic scenario can compromise ecosystem services.

Bioassays for the evaluation of reclaimed opencast coal mining areas.

This study aimed to use bioassays (single and multispecies) with organisms from different trophic levels to assess soil quality in reclaimed coal mining areas. Soil samples were collected from four sites: two sites with recent reclaim processes (one using topsoil and other using clayey soil), an natural attenuation site, and a control soil. The evaluated parameters were divided into (1) ecotoxicological tests (avoidance test with Eisenia andrei (earthworms) and Armadillidium vulgare (isopods); germination test with Sinapis alba seeds (mustard); reproduction tests with Folsomia candida (collembolans); bacterial toxicity test); (2) population and community assessments (a fungal count; microbial community analysis using Biolog EcoPlatesTM); (3) microcosms scale evaluation (the MS-3 multispecies system); and (4) chemical analysis (soil parameters, soil metal, and cations and anions in soil leachate). Results pointed to toxicity in the natural attenuation site that compromised of habitat function, probably due to low pH and low nutrient levels. The most recent reclaim process, using topsoil and clay soil, improved soil quality and fertility, with a further increase in habitat quality and heterogeneity. This study shows that some techniques used to reclaim degraded mining areas are effective in rebuilding habitats, sustaining soil biota, and reestablishing ecosystem services.