This paper presents a summary of some relevant documents published during the last decades regarding arsenic contamination in Brazil until December 2018, including scientific papers, reports and ...regulatory documents. Natural and anthropogenic arsenic sources were covered, excluding those related to agriculture. International “key” documents related to arsenic contamination were used to support the discussion and comparative analysis. This paper aims: (a) to summarize and discuss some available data (including Portuguese written documents) concerning arsenic contamination in Brazil, mainly geographical, geological, geochemical, environmental and health studies; (b) to critically review the published studies comparing their main findings; (c) to describe and compare ancient and recent contamination events; and (d) to highlight key knowledge gaps, and identify promising areas for future researches.
The arsenic contamination scenario in Brazil results not only from mining. Natural or anthropogenic emissions caused by great magnitude phenomena as flooding, erosion, landslide and, water scarcity equally impact arsenic mobilization/immobilization equilibria.
Our literature review demonstrates that arsenic contamination of soils, sediments and water sources is observed at least at three of the five geographically defined Brazilian regions (Northern, Southern and, Southeastern regions). Arsenic enriched soils, and waters naturally occur all around the country and anthropogenic activities have been the main contributory factor to the environmental contamination since the 18th Century. Geogenic materials (topsoil and mining tailings), and water samples could contain extremely high arsenic concentrations, i.e. 21,000 mg kg−1 or 1,700,000 μg L−1, respectively, have been found mainly at the “Iron Quadrangle”. Moreover, if we consider both the Brazilian and international parameters, the health risks associated with the human exposition to arsenic are of significant concern.
For those reasons, constant monitoring of As contaminated areas in Brazil is mandatory. Furthermore, it is necessary to learn from the mistakes made in the past in order to prevent or minimize future problems.
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•A scenario of arsenic contamination in Brazil was depicted.•Arsenic contamination from mining activities in Brazil is an ongoing concern.•Collapse of Fundão Dam led to extensive As contamination in the Rio Doce Basin.•Mobility of As in and out of different environmental compartments is complex.•Arsenic equilibrium is influenced by anthropogenic factors.
The waste rock, tailings and soil around an abandoned mine site in Gorno (northwest Italy) contain elevated concentrations of potentially toxic elements (PTE) exceeding the permissible limits for ...residential uses. Specifically, the maximum concentrations of As, Cd, Pb, and Zn were 107 mg/kg, 340 mg/kg, 1064 mg/kg, and 148 433 mg/kg, respectively. A site-specific human health risk assessment (HHRA) was conducted for residential and recreational exposure scenarios, using an approach based on Risk Based Corrective Action (RBCA) method, refined by incorporating oral bioaccessibility data.
Oral bioaccessibility analyses were performed by simulating the human digestion process in vitro (Unified BARGE Method). Detailed analysis of oral bioaccessible fraction (BAF i.e. ratio of bioaccessible concentrations to total concentrations on <250 μm fraction) indicated BAF of As (5-33%), Cd (72-98%), Co (24-42%), Cr (3-11%), Cu (25-90%), Ni (17-60%), Pb (16-88%) and Zn (73-94%). The solid phase distribution and mineralogical analyses showed that the variation of BAF is attributed to presence of alkaline calcareous rocks and association of PTE with a variety of minerals. The HHRA for ingestion pathway, suggested that bioaccessibility-corrected cancer risk reached up to 2.7 × 10−5 and 0.55 × 10−5 for residential and recreational senarios respectively (acceptable level is 1 × 10−5). The hazard index (HI) recalculated after incorporation of oral bioaccessible concentrations for a residential scenario ranged from 0.02 to 17.9. This was above the acceptable level (>1) for 50% of the samples, indicating potential human health risks. This study provides information for site-specific risk assessments and planning future research.
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•As, Cd, Pb and Zn were present in high concentrations at abandoned mine (Gorno).•Oral bioaccessibility of potentially toxic elements was highly variable.•Calcareous geology, weathering and soil forming process influenced bioaccessibility.•Oral bioaccessibility inclusion avoids over-conservative human health risk assessment.
The release dynamics of dissolved arsenic (As), barium (Ba), cadmium (Cd), copper (Cu), lead (Pb), and strontium (Sr) was determined in seven different paddy soils under controlled-redox conditions ...by using an automated biogeochemical microcosm apparatus. Seven surface soils were collected from five major rice-cultivating states in the United States (Arkansas, California, Louisiana, Mississippi, and Texas), and from two Asian regions: Hangzhou (China) and Java (Indonesia). The impact of redox potential (EH), pH, dissolved organic carbon (DOC), iron (Fe), manganese (Mn), and sulfur (S) on the release dynamics of the elements was quantified. The experiment was conducted stepwise from reducing (−270mV) to oxidizing (+676mV) soil conditions. Soil pH increased with decreasing soil EH. Concentrations of DOC and dissolved As, Fe, Mn were increased under reducing conditions as compared to oxidizing conditions. In opposite — the release of Ba, Cd, Cu, and Sr to soil solution increased under oxidizing conditions as compared to reducing conditions. The decrease of Ba, Cd, Cu, and Sr concentrations under reducing conditions could be caused by the relatively high pH and/or metal-sulfide precipitation. Lead showed an inconsistent trend with EH in the studied soils (All Soils). Factor analysis demonstrates that As, Fe, Mn, and DOC were associated in one group, while Ba, Sr, Cd, Cu, and EH were banded together in one cluster. These results indicate that the chemistry of DOC, Fe, and Mn might be stronger linked to the dynamics of As than to the dynamics of Ba, Cd, Cu, Pb, and Sr in these soils.
The canonical discrimination analysis explained 85% of the variability of the geochemical behavior of the different soils and showed that the individual soils can clearly differentiate from each other. However, the Arkansas and Louisiana soils were relatively similar in their geochemical behavior, and the Indonesian and Texas soils were close, while and the California soil showed a different geochemical behavior. The behavior of Sr, Ba, S, DOC, and EH, respectively, was mainly responsible for the discrimination of the soils. In particular, our findings suggest that aerobic conditions can lead to a release of Ba, Cd, Cu, Pb, and Sr while a release of As under anaerobic conditions was observed. These results provide critical information on the potential risk of toxic elements for the sustainable management of paddy rice soils.
•Seven paddy soils from five states in the U.S.A. and from China and Indonesia were studied.•Flooding was simulated using an automated biogeochemical microcosm apparatus.•Concentrations of As, Fe, Mn, DOC were high under anoxic conditions.•Release of Ba, Cd, Cu, and Sr was high under oxic conditions.•Individual soils can be discriminated based on their geochemical behavior.
Soil contamination in outdoor shooting ranges (OSRs) is a major threat for human health, particularly when, after the end of activities, the land is used for recreational areas or agricultural ...production. The status of land degradation of an OSR in southern Italy was assessed using a multisensor approach. It was based on: i) proximal sensors, including electromagnetic induction (EMI) for measuring soil electrical conductivity (ECa) and magnetic susceptibility (MSa), γ-ray spectrometry for K, eU and eTh analyses and ultrasonic penetrometry detecting cone index (CI) data representative of soil's strength, ii) field surveys on soil thickness (ST), and iii) laboratory analyses of potentially-toxic-elements (PTEs) by portable X-ray fluorescence spectrometry and polycyclic aromatic hydrocarbons (PAHs) by gas-chromatography. Spatial variability of measurements was modelled and mapped using geostatistical methods. The most densely measured covariate (i.e., the ECa of the topsoil) was used within kriging with external drift to improve the PTEs predictions. The PTEs maps were complemented by maps of spatial uncertainty. A robust multivariate principal component analysis (rPCA) was applied to proximal sensor and laboratory data and allowed to identify associations of PAHs, lead, CI with the topsoil ECa along the first component (PC1), highlighting the correlation between land anthropogenic effects and EMI measures; while the association between the ST (estimating the depth of underground travertine hard-layers) and the bottom soil ECa and MSa along the second component (PC2) evidenced the influence of soil stratigraphy on the EMI measures. This study demonstrates that the simultaneous use of different proximal sensors associated with laboratory analysis can allow to assess and model the spatial variability of the land degradation status of an OSR, including soil compaction, organic and inorganic contamination. The correlation between EMI data with the PTEs content highlights the potential of this technique in the field of soil contamination.
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•EMI data allows reproducing soil contamination pattern due to the shooting activity.•ECa was used as an external drift in kriging to improve PTEs prediction.•Highly compacted soil layers occurred in the areas mostly contaminated by PTEs.•Robust PCA disclosed the relations between proximal sensing data and PTEs.•PC1 might explain the anthropic effects produced by the shooting activities.
Oral bioaccessibility and solid phase distribution of potentially toxic elements (PTE) from extractive waste streams were investigated to assess the potential human health risk posed by abandoned ...mines. The solid phase distribution along with micro-X-ray fluorescence (micro-XRF) and scanning electron microscopy (SEM) analysis were also performed. The results showed that the total concentrations of PTE were higher in <250 μm size fractions of waste rock and soil samples in comparison to the <2 mm size fractions. Mean value of total concentrations of chromium(Cr), copper (Cu), and nickel (Ni) in waste rocks (size fractions <250 μm) were found to be 1299, 1570, and 4010 mg/kg respectively due to the parent material. However, only 11% of Ni in this sample was orally bioaccessible. Detailed analysis of the oral bioaccessible fraction (BAF, reported as the ratio of highest bioaccessible concentration compared with the total concentration from the 250 μm fraction) across all samples showed that Cr, Cu, and Ni varied from 1 to 6%, 14 to 47%, and 5 to 21%, respectively. The variation can be attributed to the difference in pH, organic matter content and mineralogical composition of the samples. Non-specific sequential extraction showed that the non-mobile forms of PTE were associated with the clay and Fe oxide components of the environmental matrices. The present study demonstrates how oral bioaccessibility, solid phase distribution and mineralogical analysis can provide insights into the distribution, fate and behaviour of PTE in waste streams from abandoned mine sites and inform human health risk posed by such sites .
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•Extractive waste and soil at abandoned mines pose a risk to human health.•Cr, Cu and Ni were present in high total concentrations at Campello Monti site.•Potentially toxic elements were associated with clay and Fe oxide fractions.•Mean BAF <11% for both Cr and Ni. Non-mobile form in Fe oxide fraction.•PTE were found to be embedded in mineral grains of soil.
Aims
The aim of the study was to assess human health risk stemming from
i)
contact with contaminated soil and
ii)
consumption of plants growing in contaminated soils in allotment gardens and ...farmlands located in regions heavily affected by the Zn-Pb and steel industries and in hard coal mining areas.
Methods
Based on the
pseudo
-total concentration of Potentially Toxic Elements (PTEs) measured in soil and plant samples and using the US EPA methodology, we assessed estimated daily intake (EDI), as well as non-carcinogenic and carcinogenic health risk in two exposure scenarios (recreational and residential), stemming from the contact with soil with varying degrees of PTE contamination, i.e.: Cr
(3+,6+)
, Fe, Mn, Ni, Pb and Zn. In the recreational scenario, we analyzed three exposure pathways (accidental soil ingestion, dermal contact with contaminated soil and inhalation of contaminated soil particles) for a child (0–6 years), an economically active adult (20–40 years), a senior (40–60 years) and a retiree (60–70 years). In the residential scenario, we additionally analyzed an exposure pathway associated with the intake of contaminated lettuce leaves grown in the soils studied for a child and an adult. With respect to non-carcinogenic health risk, we calculated hazard quotient (HQ) values for individual contaminants under each exposure pathway and target hazard quotient (THQ) values for different exposure pathways.
Results and conclusions
We found that the proportion of different exposure pathways in the total health risk decreased in the following order: intake of contaminated vegetables > accidental soil ingestion > dermal contact > inhalation of contaminated soil particles. Children are more exposed to toxic effects of potentially toxic elements than seniors and economically active adults.
The present study was designed to assess the concentration of potentially toxic elements (PTE
S
) in anchovy fish sauce from the Persian Gulf and estimate health risks (non-carcinogenic and ...carcinogenic risks. In the present study, the concentration of PTE
S,
including Lead (Pb), Iron (Fe), Arsenic (As), Cadmium (Cd), Nickel (Ni), and Copper (Cu) among 60 samples of anchovy fish sauce was measured using an atomic absorption spectrometer (AAS). The probabilistic health risk due to the ingestion of fish sauce content of PTEs was estimated by total target hazard quotient (TTHQ) and Cancer risk (CR) using Monte Carlo Simulation (MCS) model. The rank order of PTEs in anchovy fish sauce based on median concentration was Fe (15.72 mg/kg) > Pb (4.34 mg/kg) > As (0.79 mg/kg) > Cd (<LOD) ~ Ni (<LOD) ~ Cu (<LOD). The rank order of consumers based on the median of TTHQ was children-boy (0.731) > children-girl (0.678) > adults male (0.391) > adults-female (0.208). Also, the rank order of consumers based on CR was Adults-Male (1.54E-04) > Adults-Female (8.47E-05) > Children-Boy (1.74E-05) > Children-Girl (1.63E-05). The probabilistic health risk assessment demonstrated that ingest of anchovy fish sauce does not have a non-cancer risk but can have cancer risk for consumers. Therefore, a continuous monitoring program is recommended to reduce the concentration of PTEs in marine food.
► Levels of some toxic elements increased significantly in amended soils. ► Doses <80Mgha−1year−1 do not affect soil C & N mineralization. ► Plant growth test shows inhibition at annual doses ...>40Mgha−1. ► Sustainable N supply is achieved by distributing sludge over time.
Wastewater treatment processes generate highly biodegradable solid wastes. As their fate is an environmental issue of great concern, public administrations promote a sustainable management of urban wastes. The objective of the present study was to analyze the systematic and periodical use, for 16 years, of anaerobically digested sewage sludge as an agricultural fertilizer by assessing the effects on some soil physical–chemical, functional, and ecotoxicological properties. The results showed that the input of sludge enhances soil properties proportionally to the application doses and/or frequency. The organic amendments increased the organic matter content (and its aromaticity), the soil nitrogen, and the microbial activity, improving carbon and nitrogen mineralization processes and some enzymatic functions. However, a maximum dose was identified (40Mgha−1year−1), beyond which soil properties do not improve, and may even worsen. Regarding environmental risks, although the bioluminescent bacteria test showed no toxicity on soil extracts, potential adverse effects such as some potentially toxic elements accumulation, phytotoxicity and the likelihood of groundwater pollution by nitrates or dissolved organic matter should be taken into account. The complementarity of studying soil functioning parameters and ecotoxicological effects, together with the analysis of pollutant content, must be enhanced. This assures a more realistic assessment of long-term effects of sewage sludge-amended soils.
Contamination of the environment by microplastics (MPs), polymer particles of <5 mm in diameter, is an emerging concern globally due to their ubiquitous nature, interactions with pollutants, and ...adverse effects on aquatic organisms. The majority of studies have focused on marine environments, with freshwater systems only recently attracting attention. The current study investigated the presence, abundance, and distribution of MPs and potentially toxic elements (PTEs) in sediments of the River Kelvin, Scotland, UK. Sediment samples were collected from eight sampling points along the river and were extracted by density separation with NaCl solution. Extracted microplastics were characterised for shape and colour, and the polymer types were determined through attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Pollution status and ecological risks were assessed for both the microplastics and PTEs. Abundance of MPs generally increased from the most upstream location (Queenzieburn, 50.0 ± 17.3 particles/kg) to the most downstream sampling point (Kelvingrove Museum, 244 ± 19.2 particles/kg). Fibres were most abundant at all sampling locations, with red, blue, and black being the predominant colours found. Larger polymer fragments were identified as polypropylene and polyethylene. Concentrations of Cr, Cu, Ni, Pb and Zn exceeded Scottish background soil values at some locations. Principal component and Pearson’s correlation analyses suggest that As, Cr, Pb and Zn emanated from the same anthropogenic sources. Potential ecological risk assessment indicates that Cd presents a moderate risk to organisms at one location. This study constitutes the first co-investigation of MPs and PTEs in a river system in Scotland.
This study investigates the characteristics of potentially toxic elements in soils collected from the vicinity of a lead smelter in East Java, Indonesia. The objective is to assess the impact of the ...lead smelter on the surrounding soil. The study involves chemical composition analysis, spatial distribution mapping, and potential ecological and health risk assessments. Soil samples were collected from the surface area (0–10 cm) and subsurface (15–30 cm) within radii of 1.5 km, 3 km, and 5 km from the lead smelter. The samples were analyzed for As, Cr, Cu, Ni, Pb, and Zn using energy-dispersive X-ray fluorescence. Principal component analysis (PCA) was performed to identify the sources of potentially toxic elements in the soil. The results indicate severe Pb contamination within a 1.5 km radius of the smelter, with an average contamination factor (Cf) value of 22.0, posing a high potential health risk. The contamination factor indicated that the soils were heavily polluted by As and Pb and moderately polluted by Cu, Ni, and Zn. The results of PCA showed that smelter releases are the main source of potentially toxic element contamination in the soil, accounting for 66.2%. The health risk assessment suggested that the children and adults in the study region were exposed to non-carcinogenic risks caused by As and Pb. Oral ingestion was identified as the primary exposure route impacting health risks. The carcinogenic risk from potentially toxic elements in soil was found to exceed the acceptable level for children and adults in the study region. Therefore, it is necessary for the government to take effective measures, including designing regulations and interventions, and improving lead smelter management to mitigate potential contamination and minimize the impact of lead smelter releases on the surrounding environment, especially to protect human health, particularly that of children.
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