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The rupture of an iron mining tailing dam in Brumadinho, Brazil, released around 10 million cubic meters of tailings, of which 1.6 Mm3 reached the Paraopeba River. In this work, a total of 30 samples from three bottom sediment cores were collected in the lower course of the Paraopeba River basin and analyzed for major, trace and rare earth elements by ICP-OES and ICP-MS. The sediments presented a range of compositions with different weathering histories, overall marked by depleted Ca2+, Na+ and K+ compared with the average UCC, PAAS and NASC and some advanced weathering trends. The samples presented a fractionation pattern characterized by a continuous depletion of light REEs from La to Sm and a regular decreased distribution of heavy REEs from Gd to Yb, and the Co/Th vs. La/Sc diagram indicates a predominant intermediate source. The upper samples presented the highest contents of REEs, probably due to the higher presence of iron and aluminum oxides and hydroxides, which can be related to more advanced weathering. The Al, Cu, Ni, V, Zn, Co, Mn, Ti, Fe and Si concentrations and the CF, EF and Igeo index values varied across the sediment core samples, demonstrating that there were long periods of geogenic or anthropogenic contributions. [ABSTRACT FROM AUTHOR]

The Três Marias Reservoir is the ninth largest reservoir in Brazil, becoming crucial for national strategic development. However, many anthropic activities may affect the sediment quality, promoting the need for a proper environmental assessment. This research appraised the seasonal influences on the Três Marias Reservoir's sediment geochemistry, elucidating possible anthropogenic impacts. The concentrations of Mg, Al, Ca, Cr, Fe, Co, Cu, Cd, Ti, Mn, Ni, Zn, Ba, and Pb were measured in 78 samples of bottom sediments regarding the two seasons of the area, a dry winter and rainy summer. The median ± 2 median absolute deviation (MAD) settled the geochemical background and environmental thresholds for the two seasons. The sediment quality guidelines CONAMA 344/12 highlight the possible adverse ecological effects of pollutants. The hierarchical clustering analysis, the geoaccumulation index, and the pollution load index delineated the polluted zones. The pollution load index ranges from 0.25 to 2.28 in the dry season and 0.56 to 2.11 in the rainy season, defining three affected zones in the reservoir. Forestry and agriculture are the probable pollution sources, reaching warning levels that should be considered in further environmental strategies. [ABSTRACT FROM AUTHOR]

Studies related to heavy metal concentrations in coastal sediments are important to monitor and assess environmental health of estuarine ecosystems. Twenty-eight samples from Parnaíba River Delta, the largest open-ocean delta in the Americas, northeastern of Brazil were tested for heavy metals concentrations (Cd, Cr, Cu, Mn, Ni, Pb, Zn, Al and Fe), grain-size and easily oxidizable carbon. The relations of the heavy metals with sediment composition were evaluated using a multivariate statistical analysis. Sediment pollution assessment was carried out by enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF) and potential ecological risk index (PERI). The average concentrations were 0.50 ± 0.09 mg Cd kg−1, 6.95 ± 2.13 mg Pb kg−1, 19.02 ± 8.75 mg Cu kg−1, 23.20 ± 5.04 mg Ni kg−1, 33.52 ± 6.82 mg Cr kg−1, 43.99 ± 7.47 mg Zn kg−1, 165.73 ± 86.71 mg Mn kg−1, 2.93 ± 0.89% to Fe and 3.78 ± 1.17% to Al. The results indicate lower concentrations of heavy metals relative to limit concentrations defined by the Brazilian regulatory framework. The multivariate analysis reflected the binding of heavy metals to clay minerals and organic carbon. The different geochemical indices indicated sediments minimally enriched by metals and a low potential ecological risk level. Our assessment confirms the pristine conditions of Parnaíba Delta protected area to heavy metal contamination, except Igaraçú channel near Parnaíba city. [ABSTRACT FROM AUTHOR]

In this work the urban area of Aracaju city, located in the State of Sergipe, Northeastern Brazil was the site for simultaneous collection of suspended particles (TSP) and inhalable particulate matter (PM 10) aiming an evaluation of the air quality parameters. Concentrations of Cd, Co, Cu, Fe, Mn, Ni, Pb and V in TSP and PM 10 were determined by inductively coupled plasma mass spectrometry (ICP-MS). Iron was the most abundant element found in both particulate samples. Through chemometric tools, it was possible to point out that the contributions to the TSP and PM 10 formation are similar, and strong correlations were observed between Fe-Mn (0.83) and Cd-Pb (0.93) in TSP, and Fe-Mn (0.90), Fe-Cu (0.81) and Cd-Pb (0.97) in PM 10 , an evidence that these species are from sources related mainly to soil resuspension and vehicular traffic. Enrichment factor (EF) and geoaccumulation index (I geo) showed an influence of fossil fuel burning in the composition of TSP and PM 10. Through principal component analysis (PCA) and hierarchical cluster analysis (HCA) it was observed particle size distribution groupings according to its aerodynamic size. Evaluation of the concentrations obtained for the collected samples according to the seasons (dry and rainy), indicated the influence of both, biogenic (resuspension of soil and marine aerosols) and anthropic (vehicle traffic and biomass burning) sources. Image 1 • Study considering seasonal source of TPS and PM 10 in Aracaju city was investigated. • Concentrations of Cd, Co, Cu, Fe, Mn, Ni, Pb and V in TSP and PM 10 were determined. • Enrichment factor and geoaccumulation index were calculated for airborne trace elements. • Concentrations of Cu, Pb, Cd and Co suggest anthropic contribution. • Correlations between Fe-Cu and Fe-Mn showed a relation to natural sources. [ABSTRACT FROM AUTHOR]

The Araguaia River floodplain is an important biogeographic boundary between the two largest South American biomes: the Cerrado (Brazilian Savanna) and the Amazon rainforest. The large-scale degradation due to land use conversion experienced in the Araguaia River watershed represents a potential source of mercury (Hg) transport to aquatic ecosystems. However, more information is needed about the dynamics of Hg distribution in savanna floodplains, including the Araguaia River floodplain. We analyzed total mercury (THg) concentrations in the bottom sediments of 30 lakes connected to the Araguaia River and four tributaries, aiming to evaluate the environment's integrity based on the geoaccumulation index (I geo) and the ecological risk index (ERI). The principal component analysis was applied to examine associations between Hg concentrations, environmental conditions, and land use intensity among lakes associated with different river systems. We used indicator cokriging to identify areas with a greater probability of Hg pollution and ecological risk associated with land use intensity. The land use data showed the predominance of areas used for pasture in the Araguaia River basin. THg concentrations in the sediments varied between 22.6 and 81.9 ng g−1 (mean: 46.5 ± 17.7 ng g−1). Sediments showed no significant pollution (I geo : 1.35 - 0.50; Classes 1 and 2) and low to considerable ecological risks (ERI: 23.5–85.1; Classes 1 to 3). THg in bottom sediments was associated with land use, water turbidity and electrical conductivity, and sediment organic matter. The indicator cokriging indicates a moderate to strong spatial dependence between land use intensity and Hg, confirming the contribution of anthropic sources to the increment of ecological risk but also the influence of extrinsic factors (such as environmental conditions, geology, and hydrology). Integrating sediment assessment and land use indices with geostatistical methods proved a valuable tool for identifying priority areas for Hg accumulation at a regional scale. • [THg] were determined in the bottom sediments of 30 savanna floodplain lakes. • [THg] in bottom sediments is related to land use intensity and organic matter. • The lakes present no significant pollution and low to moderate ecological risks. • A moderate to strong spatial dependence exists between Hg and land use intensity. • Indicator cokriging is an efficient method for identifying [THg] regional hotspots. [ABSTRACT FROM AUTHOR]

The coast of Espírito Santo state (Southeast Brazil) is recognized for its environmental arsenic (As) enrichment and, over the years, mining operations have potentialized it. We aimed to evaluate the effect of Rio Doce discharge on As inputs and the role of iron ore tailings from the Fundão dam disaster in enhancing As contamination in the marine sediment. Two scenarios were evaluated: Predisaster and Postdisaster; dry and wet conditions were considered in each period. High As concentrations were found in the Predisaster (28.44 ± 13.53 µg g -1 ), but a significant increase in As was remarkable during the Postdisaster in the wet season, one year after the disaster (maximum of 58.39 µg g -1 ; geoaccumulation index (I geo ) Class 3, moderately severe pollution). On that occasion, iron (Fe) oxy-hydroxides from tailings were remobilized from the Rio Doce channel and deposited on the continental shelf bottom. Therefore, chemical interactions among Fe, As, and carbonates were enhanced, resulting in As and Fe coprecipitation and the trapping by carbonate adsorption. Rio Doce discharge seems to be the main factor in As inputs to the inner continental shelf when flooding do not occur previously in samplings, which allows further dispersion of contaminants, although this hypothesis should be tested further. Integr Environ Assess Manag 2024;20:159-168. © 2023 SETAC., (© 2023 SETAC.)

Freshwater ecosystems are essential to human and wildlife survival. They harbor a wide biodiversity that contributes to ecosystem services. In the ecosystem of the Brazilian Savanna, anthropic activities related to environmental pollution that includes mercury (Hg) is of concern. We studied total mercury concentrations ([THg]) in bottom sediments and macrophytes to assess its short-term (2012 and 2019) impact on a natural lake. Temporal changes in [Hg] were assessed with the geoaccumulation index (I geo ) and the sediment quality guidelines (SQG). The land use index (LUI) was used to assess differences in anthropogenic activities and the Normalized Difference Aquatic Vegetation Index (NDAVI) was used to assess macrophyte biomass density. The bioaccumulation factor (BAF) was used to assess Hg accumulation in macrophytes relative to sediments. The LUI showed an increase in the intensity of agricultural activities in the vicinities of the lake. The NDAVI indicated an increase in the density of macrophytes in the evaluated period. The I geo indicated that in all sampling sites, pollution levels in sediments increased in 2019 (I geo > 0), with concentrations exceeding the SQG in 2019. In 2012, [THg] in sediments ranged from 20.7 to 74.6 ng g -1 , and in 2019 they ranged from 129.1 to 318.2 ng g -1 . In macrophytes, [THg] ranged from 14.0 to 42.1 ng g -1 in 2012, to 53.0 and 175.3 ng g -1 in 2019. [THg] in bottom sediments and macrophytes were significantly higher in the second collection period (p < 0.05). There was no significant difference in BAF values between the periods and no significant bioaccumulation in macrophytes (BAF <1). Our results demonstrated that the macrophytes are not sensitive indicators of Hg pollution in lentic environments of the Brazilian Savanna; however, the increased land use intensity (agriculture, automotive traffic, and urban infrastructure) could increase Hg accumulation in sediments and macrophytes in a short time interval., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Water bodies can be considered the ultimate receptor of pollutants produced or remobilized as a result of anthropogenic activities. Whereas diffuse pollution occurs throughout the Piabanha river basin, the aim of this work was to evaluate the distribution of trace elements and persistent organic pollutants in its sediments over time and space, gathering information to assess the risks to the ecosystem and the population. And also to provide data to orient governmental institutions management of water resources in this region. The levels of organic pollutants highlight the influence of the historical use of pesticides in farming and industrial activities, mainly for Posse (203.36 ng/g dry weight) and Fagundes river (198.33 ng/g d.w) during the dry season and Moura Brazil (77.50 ng/g d.w) and Garagem (77.06 ng/g d.w) in the rainy season. In relation to available trace elements, the most contaminated locations were within and around Petrópolis center, possibly by industrial and domestic effluents, where Liceu (44-245 μg/g d.w) and Garagem (15-189 μg/g d.w) showed the highest concentrations of zinc. Furthermore, Liceu (5-58 μg/g d.w) also excelled in concentrations of lead. Cadmium was the element with major contribution to the contamination of the locations studied (Geoaccumulation index from 3 to 5 in all collected points), mainly because of its high mobility and the river flow. In addition, Poço do Ferreira river presented trace elements levels that exceeds the level 2 of the National Environment Council (CONAMA) classification. The authors highlight the need for a monitoring program on this region for the contaminants analyzed. [ABSTRACT FROM AUTHOR]

In this work, studies using samples collected in an urban area of Aracaju city, Sergipe State, Northeast, Brazil revealed that soil dust in suspension was the main source of total airborne particulate matter (TAPM), followed by vehicular pollution. The concentration profiles for Cu, Fe, Mn, Ni, V and Ti were established for the collected TAPM samples. The concentrations of SO 2 and smoke were also measured all along the 42 sampling days. Through multivariate data analysis of the results a correlation between Fe, Mn, Ni and Ti in the mineral composition of the particles was established, indicating soil dust in suspension as the main source of TAPM. The concentrations of Cu and smoke were found to be related to vehicular traffic, and the second largest source of TAPM. Enrichment factors (EF) were calculated for the studied elements, and only Cu was found to be enriched. The concentrations of the elements in TAPM were evaluated using the geoaccumulation index (I geo ), and Fe, Mn, Ni, V and Ti were found to derive from natural sources, in TAPM. However, approximately 55% of the samples did not presented Cu contamination (I geo ≤0), and the remaining 45% presented Cu concentrations levels that indicated between low to moderate (0