Assessment of environmental pollution and human health risks of mine tailings in soil: after dam failure of the Córrego do Feijão Mine (in Brumadinho, Brazil).

The dam failure of the Córrego do Feijão Mine (CFM) located in Minas Gerais State, Brazil, killed at least 278 people. In addition, large extensions of aquatic and terrestrial ecosystems were destroyed, directly compromising the environmental and socioeconomic quality of the region. This study assessed the pollution and human health risks of soils impacted by the tailing spill of the CFM dam, along a sample perimeter of approximately 200 km.

Attenuation of wind intensities exacerbates anoxic conditions leading to sulfur plume development off the coast of Peru.

The release of vast quantities of sulfide from the sediment into the water column, known as a sulfidic event, has detrimental consequences on fish catches, including downstream effects on other linked element cycles. Despite being frequent occurrences in marine upwelling regions, our understanding of the factors that moderate sulfidic event formation and termination are still rudimentary. Here, we examined the biogeochemical and hydrodynamic conditions that underpinned the formation/termination of one of the largest sulfur plumes to be reported in the Peruvian upwelling zone.

Carbon fluxes in a carbonate rock dominated microbasin of the Quadrilátero Ferrífero, Brazil.

This study evaluated carbon dynamics in a carbonate microbasin (Bule stream), located in an important metallogenetic area (QF) in Brazil. River water collections were performed on a base and high flow. The microbasin showed high DIC, with HCO being the main component, followed by CO.

Mercury distribution in water masses of the South Atlantic Ocean (24°S to 20°S), Brazilian Exclusive Economic Zone.

Mercury (Hg) is a toxic globally spread pollutant that has been found at increasing concentrations in the South Atlantic Ocean. The present work provides the first insight into the total mercury (HgT, unfiltered waters) content in the water of the Brazilian Exclusive Economic Zone (BEEZ), within a 24°S to 20°S. Water samples were collected from surface to 3400 m depth along transects, and analyzed with atomic fluorescence.

Ecological risk assessment of trace metals in soils affected by mine tailings.

Environmental impacts caused by mine dam ruptures or inappropriate tailing depositions represent a global concern. An ecological risk assessment was performed in 18 areas affected by the collapse of a major mining dam in southeastern Brazil, in two monitoring periods (2015 and 2018). In these areas, pedogeochemical surveys, and ecological risk levels were determinate.

Residential radon exposure and seasonal variation in the countryside of southeastern Brazil.

Poorly ventilated environments such as residences can accumulate radon gas to levels that are harmful to humans and thus produce a public health risk. To assess the risk from natural radiation due to indoor radon exposure, Rn measurements, using an alpha RAD7 detector, were conducted in Timóteo, Minas Gerais state, southeastern Brazil. Indoor radon concentrations, along with meteorological parameters, were measured every 2 h during both wet and dry seasons in 2017 and 2018.

Ecotoxicological assessment after the world's largest tailing dam collapse (Fundão dam, Mariana, Brazil): effects on oribatid mites.

Worldwide, environmental tragedies involving mining dam ruptures have become more frequent. As occurred a few years ago in Brazil (on 5 November 2015, in Minas Gerais state) the Fundão Dam rupture released 60 million m of tailings into terrestrial and aquatic ecosystems. Since then, little information on the ecotoxicity of these tailings has been disclosed.

Evaluation of the bioaccumulation kinetics of toxic metals in fish (A. brasiliensis) and its application on monitoring of coastal ecosystems.

This study proposes a pro-active approach for evaluations of methylmercury (MeHg), total mercury (THg), arsenic (As), cadmium (Cd) and lead (Pb) in situ bioaccumulation in fish (Atherinella brasiliensis) muscles, using specimens from the external sector of Guanabara Bay as a study case. This approach included an hierarchical sequence: analysis of the pollutants concentrations and their comparison to safety criteria; correlations between specimens concentrations vs length (as a proxy of exposure time); projections of concentrations in key lengths (sexual maturation, asymptotic, length limits for fishing and median of fish population) through polynomial regressions, dose-response analysis (Probit), decreasing curves and incorporation rates (using only three length intervals). The incorporation rates were ascending for MeHg and THg (continued bioaccumulation) and descending for As, Pb and Cd (possible biological dilution).

Polycyclic aromatic hydrocarbons in bays of the Rio de Janeiro state coast, SE - Brazil: Effects on catfishes.

The Brazilian coast of the Rio de Janeiro State has bays of great economic, ecological and social importance. However, these ecosystems have been suffering intense anthropogenic influence, mainly due to the contamination by polycyclic aromatic hydrocarbons (PAHs) from urban-industrial activities. Moreover, PAHs are organic pollutants of high toxicity and carcinogenicity causing global concern to human and environmental health.

Foliar mercury content from tropical trees and its correlation with physiological parameters in situ.

The terrestrial biogeochemical cycle of mercury has been widely studied because, among other causes, it presents a global distribution and harmful biotic interactions. Forested ecosystems shows great concentrations from Hg and Litterfall is known as the major contributor to the fluxes at the soil/air interface, through the superficial adsorption on the leaves and by the gas exchange of the stomatal pores. The understanding of which processes control the stage of Hg cycle in these ecosystems is still not totally clear.

Food preference and ecotoxicological tests with millipedes in litter contaminated with mercury.

Worldwide, various guidelines and directives for human health and the environment aim to reduce anthropogenic mercury (Hg) emission. Forest ecosystems are natural sinks of this element, transferring it from the atmosphere to litter and soil. Millipedes play an important role in litter/soil and may be negatively affected by contamination.

Fractionation of rare earth and other trace elements in crabs, Ucides cordatus, from a subtropical mangrove affected by fertilizer industry.

Fractionation of rare earth elements (REE) and other trace metal concentrations (Th, U, Cd, Cr, Cu, Ni, Pb, and Zn) between mangrove sediments and claw muscles and shells of male crabs (Ucides cordatus) from a subtropical estuary highly impacted by fertilizer industry activities was investigated. This is the first record of REE distribution in these organisms, and the results showed higher accumulations of these metals, U and Th in shells, probably related to the replacement of Ca during molting. Contents of Cd, Cr and Ni were similar in both tissues, but Cu, Zn and Pb were mostly accumulated in the claw muscle with concentrations above those considered safe for human consumption according to the Brazilian legislation.

Mercury critical concentrations to Enchytraeus crypticus (Annelida: Oligochaeta) under normal and extreme conditions of moisture in tropical soils - Reproduction and survival.

Soil provides many ecosystem services that are essential to maintain its quality and healthy development of the flora, fauna and human well-being. Environmental mercury levels may harm the survival and diversity of the soil fauna. In this respect, efforts have been made to establish limit values of mercury (Hg) in soils to terrestrial fauna.

Ecotoxicology of mercury in tropical forest soils: Impact on earthworms.

Mercury (Hg) is one of the most toxic nonessential trace metals in the environment, with high persistence and bioaccumulation potential, and hence of serious concern to environmental quality and public health. Emitted to the atmosphere, this element can travel long distances, far from emission sources. Hg speciation can lead to Hg contamination of different ecosystem components, as well as biomagnification in trophic food webs.

Carbon accumulation rates recorded in the last 150years in tropical high mountain peatlands of the Atlantic Rainforest, SE - Brazil.

Peatlands are environmental matrices that store large amounts of organic carbon (TOC) and work as records of environmental changes. Recent record of organic carbon accumulated were assessed in two Forest National Parks, Itatiaia and Serra dos Órgãos in the Southeastern of Brazil. Based on organic and inorganic characterization, the cores from peatlands presented a predominance of organic material in an advanced stage of decomposition and those soils were classified as typical Haplosaprists Histosols.

Mercury sequestration by rainforests: The influence of microclimate and different successional stages.

Mercury (Hg) concentrations in tropical forest soils and litter are up to 10 times higher than those from temperate and boreal forests. The majority of Hg that has been stored in tropical soils, as the forest is left intact, could be trapped in deeper layers of soil and only small quantities are exported to water bodies. The quantitative approach to the Hg cycle in tropical forests is uncommon; the South America Atlantic Forest indeed is a hotspot for species conservation and also seems to be for the Hg's cycle.

First assessment of trace metal concentration in mangrove crab eggs and other tissues, SE Brazil.

The mangrove crab Ucides cordatus is widespread in the Brazilian coast, which has an important role in nutrient cycling. This species reproduces in summer and females carry eggs about a month, when they maintain contact with water and sediments. It remains unclear if trace metals can be absorbed or adsorbed by the eggs during development.

Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland.

A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C).

Ecotoxicity of mercury to Folsomia candida and Proisotoma minuta (Collembola: Isotomidae) in tropical soils: Baseline for ecological risk assessment.

Mercury (Hg) is a highly toxic nonessential trace metal. Despite its natural occurrence in the Earth's Crust, its concentrations have been steadily increasing in the environment due to anthropogenic sources. Recent studies have showed great concern about soil fauna, once the potential adverse effects of mercury concentrations in the environment of these invertebrates are still poorly understood, especially when linked to forest soils and tropical biota.

Characterization of soil fauna under the influence of mercury atmospheric deposition in Atlantic Forest, Rio de Janeiro, Brazil.

The increasing levels of mercury (Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances.

Mercury speciation in plankton from the Cabo Frio Bay, SE--Brazil.

Mercury (Hg) is considered a global pollutant, and the scientific community has shown great concern about its toxicity as it may affect the biota of entire systems, through bioaccumulation and bioamplification processes of its organic form, methylmercury (MeHg), along food web. However, few research studies deal with bioaccumulation of Hg from marine primary producers and the first-order consumers. So, this study aims to determine Hg distribution and concentration levels in phytoplankton and zooplankton in the Cabo Frio Bay, Brazil, a site influenced by coastal upwelling.

Carbon, nitrogen, and phosphorus stoichiometry of plankton and the nutrient regime in Cabo Frio Bay, SE Brazil.

This long-term study, performed during the years 2003-2005 and 2008-2009, investigated the carbon (C), nitrogen (N), and phosphorus (P) contents of the phyto- and zooplankton communities and the nutrient regime of Cabo Frio Bay, SE Brazil. The information intends to serve as baseline of the plankton C, N, and P stoichiometry for the calibration of biogeochemical and ecological models in support to future findings related to the local and regional phenomena of climatic change. Cabo Frio Bay is a small semienclosed system set adjacent to a region subject to sporadic coastal upwelling.

Mercury deposition during the previous century in an upwelling region; Cabo Frio, Brazil.

To investigate the upwelling influence on Hg biogeochemical cycles and the sedimentological changes during the previous ≈ 150 years, four sediment box-cores were sampled along an inshore offshore transect on the Southeastern Brazilian continental shelf. Mercury values were found to be relatively low, with means ranging between 8.08 and 30.

Litterfall mercury deposition in Atlantic forest ecosystem from SE-Brazil.

Litterfall is believed to be the major flux of Hg to soils in forested landscapes, yet much less is known about this input on tropical environment. The Hg litterfall flux was measured during one year in Atlantic Forest fragment, located within Rio de Janeiro urban perimeter, in the Southeastern region of Brazil. The results indicated a mean annual Hg concentration of 238 ± 52 ng g(-1) and a total annual Hg deposition of 184 ± 8.