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.
•Higher concentrations of particulate metals were found in impacted sites.•Cytogenotoxic effects were found in the impacted sites.•Mining waste affected genetic aspects of Allium cepa.•Impacts of the tragedy are far-reaching and long-lasting.
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•First study regarding Se biogeochemistry in the Brazilian Amazon.•Se in sediment might decrease the bioavailability of Hg.•Sediment might be the main source of Se to plankton.•Se ...concentrations decreased along the food chain.•Se probably reduces Hg bioaccumulation in carnivorous fishes.
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.
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.
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.
This work elucidates some aspects of Se biogeochemistry in the Amazon basin and shows its importance regarding Hg cycles in aquatic ecosystems.
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.
•The disaster’s effects are evident comparing the upstream-downstream river sections.•In sediment samples, the downstream section had lower concentrations of most elements.•Higher concentrations of most elements in fish occurred in the Retiro Baixo Reservoir.•The concentrations of Cd, Hg and Pb in fish are at the same level before the disaster.•Pb in fish is above the limit for human consumption and is a matter of concern.
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.
•Samples of Tillandsia usneoides were exposed for 15 and 45 days in residential areas.•Cr, Cu, Fe, Hg and Mn concentration increased (p < 0.05) over transplantation period.•Increase in PM2.5 and PM10 in some locations possibly related to prevailing wind.•Hospital admissions increased in the year of the dam collapse.•Cardiovascular and respiratory disease/symptoms should be investigated.
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 (
LI
GB
) 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 (
LI
FS
) decreased for Cu, Cr, and Zn between 10 and 30 years of soil fertilization. For Mn, a very high
LI
FS
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.
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.
Mercury (Hg) bioaccumulation can be highly variable in marine species. Its concentration is influenced by several physico-chemical and biotic processes, including size, age, diet composition and ...foraging habitats. Herein, we addressed total mercury (THg) concentrations in three small tuna species in Brazil: the frigate tuna Auxis thazard, the little tunny Euthynnus alletteratus and the skipjack tuna Katsuwonus pelamis. Samples were collected from commercial landings in the SE Brazilian coast from 2017 to 2019. The influence of trophic ecology and habitat preference on Hg accumulation was assessed through stable isotope carbon (δ13C) and nitrogen (δ15N) measurements. Additionally, the human health risk regarding the species consumption was assessed by the estimated weekly intake (EWI) and the provisional tolerable weekly intake (PTWI) for total consumers, adult men and adult women. Variables such as size and age were positively correlated to Hg, due to the bioaccumulation process. Trophic position appears to positively influence the mercury concentrations for A. thazard and K. pelamis, since relationship between δ15N and THg was significant. For E. alletteratus, the lack of relationship suggests that δ15N values do not vary much among adult fish (> 300 mm). Muscle THg concentrations in the three species did not exceed the established tolerable limit for mercury by Brazilian and international organs, as indicated by the %PTWI. This finding suggests that the consumption of those species caught off southeast Brazil at the considered amounts does not present a risk for healthy adults.
Water pollution is a global environmental issue, and aquatic sediments are important compartments that might act as sinks or sources of contaminants. Once in the environment, inorganic contaminants ...such as metals can cause cytogenotoxic effects that damage genetic material and harm the aquatic community. Biological assays such as the Allium test can be used to investigate potential cytogenotoxicity of contaminated sediments based on the alterations of cell cycle indexes and chromosomal aberration frequencies. Therefore, we aimed to assess the toxicity of sediments from four Brazilian reservoirs using the Allium test. Sediments were sampled and elutriates were prepared in a simulating sediment resuspension in the water column. The Allium test was applied to the elutriates, and the metals copper, chromium, cadmium, lead, zinc, and iron were quantified. The elutriates derived from reservoir sediments were able to reduce the mitotic and anaphase index, increase the prophase and metaphase index, and boost chromosomal aberrations compared to the negative control. The cytogenotoxic effects observed may be linked to the presence of copper, zinc, and iron. Therefore, our results showed that the Allium test was a sensitive tool for warning the occurrence of genotoxic contaminants in sediment elutriates from four Brazilian 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.
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 Ʃ-HCH (median = 340 pg m−3) and Ʃ-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.
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•First investigation of OCP occurrence in ambient air of Brazilian urban areas.•OCP former factories and dumping sites generate high OCP atmospheric concentrations.•Deterministic and probabilistic estimations resulted in increased cancer risk for humans.•Younger individuals were exposed to higher cancer risks through OCP inhalation.
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