A multi-biomarker approach to verify chronic effects on Eisenia andrei earthworms exposed to tailings from one of the world's largest mining disasters.

Mining is of great relevance to the global economy, but its activities are challenging due to socio-environmental impacts. In January 2019, an iron ore tailings dam collapsed in Brumadinho (Minas Gerais, Brazil) releasing 12 × 106 m3 of tailings, causing human losses and devastation around 3.13 × 106 m2 of a watershed. In this context, the present study aimed to investigate the potential toxic effects of tailings from the collapsed dam using earthworms Eisenia andrei as a model organism for terrestrial environments. An extensive set of tests was performed, including behavioral (avoidance), acute (mortality and biomass) and chronic tests, such as biomass, reproduction and cytotoxicity (viability and cell density and change in coelomocyte pattern). The physical-chemical characterization revealed a higher density of the tailings in relation to the control soil, which can result in physical changes, such as soil compaction and surface sealing. Aluminum, Ca, Fe, Hg, Mg, Mn, K, Na and P registered higher concentrations in the tailings compared to the control soil, while Total Nitrogen, Total Organic Carbon and Organic Matter were higher in the natural soil. Based on the avoidance test, an EC50 of 27.18 ± 2.83% was estimated. No lethality was observed in the acute exposure, nor variations in biomass in the acute and chronic assays. However, there was a tendency to reduce the number of juveniles in relation to cocoons in the proportions of 3125; 12.5 and 25%. Significant changes in viability, cell density and pattern of amebocytes and eleocytes were observed up to the 35th day of exposure. A multi-biomarker approach (Integrated Biological Response version 2) indicated concentration-dependent effects and attenuation of cellular changes over time. These are the first results of chronic effects on earthworms exposed to tailings from the B1 dam. Despite being conclusive, we highlight the possible heterogeneity of the tailings and the necessary care in extrapolating the results.

First assessment of atmospheric pollution by trace elements and particulate matter after a severe collapse of a tailings dam, Minas Gerais, Brazil: An insight into biomonitoring with Tillandsia usneoides and a public health dataset.

In this study, samples of bromeliad Tillandsia usneoides (n = 70) were transplanted and exposed for 15 and 45 days in 35 outdoor residential areas in Brumadinho (Minas Gerais state, Brazil) after one of the most severe mining dam collapses in the world. Trace elements aluminum (Al), arsenic (As), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), nickel (Ni) and zinc (Zn) were quantified by atomic absorption spectrometry. Scanning electron microscope generated surface images of T. usneoides fragments and particulate matter (PM2.5, PM10 and PM > 10). Aluminum, Fe and Mn stood out from the other elements reflecting the regional geological background. Median concentrations in mg kg-1 increased (p < 0.05) between 15 and 45 days for Cr (0.75), Cu (1.23), Fe (474) and Mn (38.1), while Hg (0.18) was higher at 15 days. The exposed-to-control ratio revealed that As and Hg increased 18.1 and 9.4-fold, respectively, not showing a pattern associated only with the most impacted sites. The PM analysis points to a possible influence of the prevailing west wind on the increase of total particles, PM2.5 and PM10 in transplant sites located to the east. Brazilian public health dataset revealed increase in cases of some cardiovascular and respiratory diseases/symptoms in Brumadinho in the year of the dam collapse (1.38 cases per 1000 inhabitants), while Belo Horizonte capital and its metropolitan region recorded 0.97 and 0.37 cases, respectively. Although many studies have been carried out to assess the consequences of the tailings dam failure, until now atmospheric pollution had not yet been evaluated. Furthermore, based on our exploratory analysis of human health dataset, epidemiological studies are required to verify possible risk factors associated with the increase in hospital admissions in the study area.

Atmospheric Occurrence of Organochlorine Pesticides and Inhalation Cancer Risk in Urban Areas at Southeast Brazil.

Organochlorine pesticides (OCPs) have been produced for almost a century and some of them are still used, even after they have been proved to be toxic, persistent, bioaccumulative and prone to long-range transport. Brazil has used and produced pesticides in industrial scales for both agricultural and public health purposes. Urban and industrial regions are of special concern due to their high population density and their increased exposure to chemical pollution, many times enhanced by chemical production, application or irregular dumping. Therefore, we aimed to investigate the occurrence of OCPs in outdoor air of urban sites from two major regions of southeast Brazil. Some of these sites have been affected by OCP production and their irregular dumping. Deterministic and probabilistic inhalation cancer risk (CR) assessments were conducted for the human populations exposed to OCPs in ambient air. Ambient air was mainly affected by Æ©-HCH (median = 340 pg m-3) and Æ©-DDT (median = 233 pg m-3), the only two OCPs registered for domissanitary purposes in Brazil. OCP concentrations tended to be higher in summer than in winter. Dumping sites resulted in the highest OCP atmospheric concentrations and, thus, in the highest CR estimations. Despite of all limitations, probabilistic simulations suggested that people living in the studied regions are exposed to an increased risk of hepatic cancer. Infants and toddlers (0 < 2 y) were exposed to the highest inhalation CRs compared to other age groups. Other exposure pathways (such as ingestion and dermic uptake) are needed for a more comprehensive risk assessment. Moreover, this study also highlights the need to review the human exposure to OCPs through inhalation and their respective CR in other impacted areas worldwide, especially where high levels of OCPs are still being measured.

First year after the Brumadinho tailings' dam collapse: Spatial and seasonal variation of trace elements in sediments, fishes and macrophytes from the Paraopeba River, Brazil.

On January 2019, the B1 iron ore tailings' dam collapsed in Brumadinho, Brazil, being one of the worst mining-related disasters, with 270 human deaths (11 of them still missing) and 12.106 m3 of tailings released to the environment. The tailings devastated the Córrego do Feijão brook and reached the adjacent Paraopeba River, the region's main watercourse and a major tributary of the São Francisco basin. Although physicochemical parameters of the river were strongly impacted, and acute toxicological effects have been reported from exposure experiments, contamination of aquatic biota had not yet been assessed. Therefore, the aim of this study was to evaluate contamination by trace elements (As, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn) in sediment, fish and macrophytes along the Paraopeba River, upstream and downstream from the dam failure site, during the dry and wet season. With the exception of Cd and Hg, all elements in sediment samples had lower median concentrations downstream. An inverse pattern was observed for the aquatic biota, with significant higher concentrations of Fe, Mn, Ni and Zn in fishes, and increased concentrations of most elements in macrophytes, indicating an increase in element bioavailability. A significant seasonal variation was observed with increased concentrations of As (dry season) and Pb (wet season) in fish samples, with the same trend occurring in macrophytes. Concentrations of potentially toxic elements in fish samples in wet weight (Cr: 1.80 ± 1.31 mg kg-1, Hg: 0.21 ± 0.11 mg kg-1 and Pb: 0.79 ± 0.80 mg kg-1) were lower than those reported before the disaster. Furthermore, As and Pb concentrations exceeded the safety threshold for fish consumption in 3% and 41% of samples, respectively, representing a matter of concern for public health.

Biomonitoring mercury contamination using fur from roadkilled giant anteaters.

The giant anteater (Myrmecophaga tridactyla) can occur in both preserved and anthropogenic environments in Brazilian biomes. The Cerrado biome, where the samples were collected, is considered one of the world's biodiversity hotspots; however, a large part of it has been converted to pasture and agricultural land. In this environment, animals may be exposed to contaminants, such as mercury (Hg). Despite its immense biodiversity, there are few studies investigating Hg contamination in terrestrial mammals in Brazil. This study aimed to create a baseline for Hg levels in giant anteater fur and establish which biotic and abiotic variables can influence its concentration. Total Hg (THg) concentrations were determined by cold vapor atomic absorption spectrometry in 141 individuals sampled on highways between January and October 2017, in the state of Mato Grosso do Sul, Brazil. THg concentrations in fur ranged from 0.27 to 4.77 µg g -1. The decomposition stage of the carcasses and vehicular traffic volume on highways did not influence the THg concentrations. Juveniles presented lower THg concentrations than adults. A spatial pattern of higher concentrations in the eastern-southeastern region of the state was found, which could be related to anthropogenic impacts; however, no clear links have been established. The THg concentrations in giant anteaters' fur seems higher than expected considering the trophic position of the species. Despite this, the range was in accordance with studies of other Brazilian terrestrial mammals and within safe threshold levels. This study indicates the potential of utilizing roadkilled fauna to monitor large-scale contamination in wildlife.

Fluoroquinolones and trace elements in poultry litter: estimation of environmental load based on nitrogen requirement for crops.

Poultry litter soil application contributes to sustainability of agricultural systems and is in accordance with the United Nations Sustainable Development Goals (UN-SDG). Poultry litter recommended rates are based on crop nitrogen (N) needs, however, their application can be a potential source of antibiotics and trace elements overload. The aim of the study was to estimate the role of poultry litter application on soil contamination by fluoroquinolones [enrofloxacin (ENR) and ciprofloxacin (CIP)] and trace elements, based on N requirements for crops. Analytical and sampling techniques were used to estimate the loads from poultry litter application. Only CIP was found in poultry litter samples (283 ± 124 µg kg-1) and its load was estimated to be of 9.89 ± 4.33 g ha-1, for the poultry litter application (35 t ha-1). The estimated loads (g ha-1) of trace elements were: Cr 9.19 ± 3.26, Ni 12.3 ± 4.93, Pb 22.0 ± 8.26, Cu 229 ± 85.6, Mn 691 ± 259 and Zn 1,011 ± 378. These estimates were 900% higher than those recommended by the technical guidance, while N exceeded 600% the recommended application. In order to achieve UN-SDGs, local policies to disseminate knowledge and technologies are required for consolidating sustainable agricultural practices.

Selenium in sediment and food webs of the Tapajós River basin (Brazilian Amazon) and its relation to mercury.

BACKGROUND: We investigated Se levels along the Tapajós River basin - which is an important tributary of the Amazon River - and the possible antagonistic effect of Se in Hg availability. This is the first study to investigate Se transfer from abiotic to biotic compartments and along the food chain in aquatic ecosystems of the Amazon basin. METHODS: Se concentrations were measured in superficial sediment (n = 29), plankton (n = 28) and fishes (n = 121) along two stretches of the Tapajós River basin (Tapup/mi and Taplow), comprising approximately 500 km with different hydrological characteristics. RESULTS: Se concentrations in sediment were significantly higher in the Taplow (345-664 µg kg-1) than in the Tapup/mi (60-424 µg kg-1). The seasonal flooding of the Amazon River probably helps to carry selenium-rich sediment to the Tapajós mouth (Taplow stretch). We suggest that Se in sediment could decrease the bioavailability of Hg resulting in lower MeHg concentrations in fish, as observed in the Taplow (45-934 µg kg-1). Sediment and plankton were positively correlated in relation to their Se concentrations (r = 0.62; p = 0.001) suggesting that sediment can possibly be the main source of Se to plankton. Our data indicate Se uptake by primary consumers, as noted in phytoplankton levels. The decrease of Se concentrations along the food chain was also noteworthy. CONCLUSION: This work elucidates some aspects of Se biogeochemistry in the Amazon basin and shows its importance regarding Hg cycles in aquatic ecosystems.

Total mercury in wild felids occurring in protected areas in the central Brazilian Amazon

This is the first study to investigate mercury (Hg) contamination in felid species in the Brazilian Amazon. We collected 26 fur samples from wild felids of four species (Puma concolor, Panthera onca, Leopardus pardalis and Leopardus wiedii) occurring in the Mamirauá and Amanã sustainable development reserves, in the state of Amazonas. Samples were from museum specimens, except for five P. onca samples collected from free-living individuals. Total Hg concentrations ranged from 0.12 to 48.1 µg g-1. Concentrations of Hg did not differ significantly between museum specimens and live individuals of P. onca, but varied significantly among species, with significantly higher concentrations for P. onca and L. pardalis, which could be related to factors such as diet and habitat. (AU)

Environmental Risk of Metal Contamination in Sediments of Tropical Reservoirs.

Reservoir sediment can work as both sink and source for contaminants. Once released into the water column, contaminants can be toxic to biota and humans. We investigate potential ecological risk to benthic organisms by metals contamination in six reservoirs in Southeast Brazil. Results of the bioavailable fraction of copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), zinc (Zn), and iron (Fe) in sediment samples are presented. Considering Cu, Cd, and Zn concentrations, about 6% of the samples exceeded the threshold effect levels of sediment quality guidelines. The comparison to sediment quality guidelines is conservative because we used a moderate metal extraction. Control of contaminant sources in these reservoirs is key because they are sources of water and food. The mixture toxicity assessment showed an increased incidence of toxicity to aquatic organisms showing that mixture toxicity should be taken into account in sediment assessment criteria.

Far-reaching cytogenotoxic effects of mine waste from the Fundão dam disaster in Brazil.

On November 2015, one of Brazil's most important watersheds was impacted by the mine waste from Fundão dam collapse in Mariana. The mine waste traveled over 600 km along the Doce River before reaching the sea, causing severe devastation along its way. Here we assessed trace element concentrations and cytogenotoxic effects of the released mine waste. Water samples were collected along the Doce River ten days after the disaster in two impacted sites and one non-impacted site. Sampling points were located hundreds of kilometers downstream of the collapsed dam. Water samples were used for trace element quantification and to run an experiment using Allium cepa to test cytogenotoxicity. We found extremely high concentrations of particulate Fe, Al, and Mn in the impacted sites. We observed cytogenotoxic effects such as alterations in mitotic and phase indexes, and enhanced frequency of chromosomal aberrations. Our results indicate interferences in the cell cycle in impacted sites located hundreds of kilometers downstream of the disaster. The environmental impacts of the dam collapse may not only be far-reaching but also very likely long-lasting, because the mine waste may persist in the Doce River sediment for decades.

Multi-temporal accumulation and risk assessment of available heavy metals in poultry litter fertilized soils from Rio de Janeiro upland region.

Poultry litter is widely used as fertilizer in soils and can be a relevant source of heavy metals for agricultural environments. In this study, poultry litter fertilization of long-term (< 1-30 years) was evaluated in tropical soils. Our main goal was to investigate the occurrence of temporal variation in the available fraction of heavy metals (Cu, Cr, Zn, Pb, Cd, and Mn) in soils, in addition to their environmental loads through new indexes for risk assessment. The highest mean concentrations in poultry litter were the following: 525 mg kg-1 for Mn, 146 mg kg-1 for Zn, and 94.4 mg kg-1 for Cu. For soils, concentrations were higher for the same heavy metals: Mn (906 mg kg-1), Zn (111 mg kg-1), and Cu (26.3 mg kg-1). Significant accumulation (p < 0.05) in fertilized soils was observed for Cu, Cr, and Zn. The high estimates of poultry litter input based on geological background (LIGB) for Cu, Cr, and Zn coincided with the accumulation observed in soils, confirming the effectiveness of the index. The risk of biogeochemical transfer based on fertilized soils (LIFS) decreased for Cu, Cr, and Zn between 10 and 30 years of soil fertilization. For Mn, a very high LIFS was estimated in all long-term fertilized soils. The proposed indices, based on heavy metal concentration, can be used in risk assessments to guide future studies that analyze other environmental matrices possibly impacted by manure and poultry litter fertilization.

Linear low-density polyethylene and zirconium phosphate nanocomposites: evidence from thermal, thermo-mechanical, morphological and low-field nuclear magnetic resonance techniques.

Lamellar alpha-zirconium phosphate was synthesized by direct precipitation and also directly expanded with octadecylamine, through alcoholic solution. To produce a nanocomposite, it was incorporated in linear low-density polyethylene in the molten state, using a counterrotating twin-screw extruder set at 170-190 degrees C and 100 rpm. The differential scanning calorimetry analysis revealed a decrease in the polyolefin melting temperature and crystallinity degree. The higher onset temperature of the zirconium phosphate modified with octadecylamine and linear low density polyethylene composite indicated an increasing of thermal stability and it suggests that some polyethylene chains entered into the filler's spacing. Dynamic-mechanical analysis evidenced an increase in both moduli (storage and loss). Wide-angle X-ray diffraction showed additional peaks--diffraction angles appeared in the region beneath 12 degrees--which were attributed to partial intercalation of polyethylene chains between filler interlamellar spacing. By hydrogen low-field nuclear magnetic resonance, the two low intensity relaxation time peaks shifted to higher values, strongly suggesting interaction between the octadecylamine and polymer matrix into the filler galleries. From these results, it may be postulated that a partially intercalated and/or exfoliated nanostructure in the zirconium phosphate modified with octadecylamine and linear low density polyethylene composite was achieved.