Metal Loid Concentrations Research Articles

Factors affecting the concentration of metals and metalloids in the kidneys of a top predator, the Eurasian Buzzard (Buteo buteo) wintering in farmland in Poland.

During late autumn and winter, raptors in the western Palearctic face challenges due to food scarcity and dropping temperatures. That time they can be exposed to various elements including toxic ones ingested with food. Kidney samples from 22 females and 19 males of a medium-sized raptor, the Common Buzzard Buteo buteo found dead in farmland of Eastern Poland in winter were analyzed for a concentration of 21 elements. Elemental concentrations were analyzed regarding the age and sex of birds. Results revealed that only 4.9% of individuals had kidney lead levels exceeding 8.0mg, while 9.8% showed cadmium levels above 8.0mg/kg, indicating potential poisoning. The study also highlighted the limited entry of arsenic into agricultural ecosystems exploited by Common Buzzards. Sex differences were noted, with females accumulating more lead and vanadium than males which can be associated with foraging niche partitioning between sexes driven by body size dimorphism. Sulfur showed complex interactions with cadmium, mercury, and zinc, with a positive correlation between sulfur and zinc levels in the kidneys, emphasizing dietary needs during food scarcity. A positive correlation was found between zinc and lead concentrations, indicating zinc's role in mitigating lead's impact. The study also revealed positive correlations between selenium and highly toxic elements like mercury (Spearman correlation, rs = 0.41) and cadmium (rs = 0.51), suggesting a mitigating effect of selenium on exposure to heavy metals. This study enhances understanding of year-round environmental contamination exposure for raptors and sheds light on bioaccumulation in a top predator.

Fluid inclusions in magmatic ilmenite record degassing in basic magmas

Magmatic volatile phases play a major role in igneous systems, but indirect sampling of the magmatic fluid, especially for basic magmas, remains challenging to document. Here, we report compelling evidence of primary fluid inclusions trapped within magmatic ilmenite from two different basic intrusive settings: Armorican Massif (France) and Central Iberian Zone (Spain). Fluid inclusions have a solute chemistry dominated by sodium, calcium, chlorine, sulfur and iron, with detectable contents of metals and metalloids and thus likely record the onset of late-stage magmatic volatile saturation in these basic magmas. Hence, we argue the presence of fluid inclusions in ilmenite may be a good indicator for magma degassing in these settings and importantly records the magmatic-hydrothermal transition. Additionally, this study suggests that the trapping of the magmatic volatile phase during ilmenite (and other opaque minerals) crystallization may be more common but at present an underappreciated phenomenon in basic igneous magmatic systems.

Groundwater Quality and Potential Health Risk Assessment for Potable Use

The Ramganga River basin, comprising three rivers, the Dhela, Dhandi, and Ramganga, plays a vital role in groundwater recharge, sustaining numerous industries, urban areas, and rural communities reliant on these rivers for daily activities. The study’s primary purpose was to analyze the groundwater quality in the context of potability, irrigation, and health risks to the local inhabitants of the Ramganga River basin. In 2021–2022, 52 samples (26 × 2) were collected from 13 locations in two different seasons, i.e., pre-monsoon and post-monsoon, and 20 physico-chemical and heavy metal and metalloids were analyzed using the standard protocols. The result shows that heavy metal and metalloids and metalloid concentrations of Zn (0.309–1.787 and 0.613–1.633); Fe (0.290–0.965 and 0.253–1.720), Cd (0.001–0.002 and 0.001–0.002); As (0.001–0.002 and 0.001–0.002), Cr (0.009–0.027 and 0.011–0.029), and Pb (−0.001–0.010 and 0.00–0.010) values in mg/L are present in both seasons. The groundwater quality index (GWQI), heavy metal pollution Index (HPI), and heavy metal evaluation index (HEI) were used to assess the water quality and metal pollution in the basin area. As per GWQI values, water quality lies from excellent water quality (41.639 and 43.091) to good water quality (56.326 and 53.902); as per HPI values, it shows good (29.51 and 30.03) to poor quality (60.26 and 59.75) and HEI values show the low-level contamination (1.03–2.57 and 1.13–3.37) of heavy metal and metalloids in both seasons. According to the potential health risk assessment, infants show low risk in pre-monsoon and low risk to medium post-monsoon, while children and adults show low risk to high risk in both seasons. From the health risk perspective, it shows that children and adults have more concerns about non-carcinogenic effects, so adequate remedial measures and treatment are required to avoid the groundwater quality of the Ramganga River basin.

Human health risk assessment of trace metals and metalloids concentrations in saffron grown in Gonabad, Iran

Trace metals and metalloids are environmental contaminants that in elevated levels they may pose serious threats to human health. The aim of this research was to investigate trace metals and metalloids contamination in saffron grown in Gonabad. Potential health risks associated with the consumption of this product were also estimated. Totally, 48 samples were collected from 16 saffron farms. Then, the samples were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-OES) technique. For As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, the levels ranged between 0.01–0.36, 0.01–1.31, 0.01–0.28, 0.86–2.31, 4.98–42.04, 92.530–740.66, 14.80–26.28, 0.66–1.78, 0.07–0.84 and 24.32–56.71 mg/kg, respectively. However, levels of cadmium, iron and zinc were above the FAO/WHO limits in few samples. The results showed that all the samples had hazard quotient (HQ) values less than 1 for children, teenagers and adults, respectively, indicating that exposure to the elements via saffron consumption might not pose non-carcinogenic health risk. The estimated cancer risk among the studied groups were low and negligible, indicating that low probability of cancer development from long-term consumption of saffron.

Heavy metals and metalloid contamination and risk evaluation in the surface sediment of the Bakkhali River estuary in Bangladesh

Current state of contamination and subsequent risk of contaminated sediment of a tidal river of Bangladesh was evaluated in the present study. Sediment samples were collected from five locations in the tributary of Bakkhali River estuary during summer (April) and winter (December) season, 2020. Collected samples were processed using standard protocol and the content of heavy metals (Cd, Cr, Cu, Pb and Zn) and metalloid (As), were analyzed by the Flame Atomic Absorption Spectrometer. Sediment contamination was evaluated by pollution load index (PLI), contamination factor (CF), degree of contamination (Cd), potential ecological risk index (PERI), non-carcinogenic and carcinogenic risk (CR) due to the dermal contact of the sediment. Multivariate statistical analysis such as principal component analysis (PCA) and cluster analysis (CA) were also applied to find out the possible sources of the contaminant in the sediment. Results showed the average concentration of As, Cd, Cr, Pb, Cu and Zn was 9.74 ± 3.57, 2.00 ± 0.85, 48.75 ± 8.92, 29.78 ± 8.39, 5.44 ± 2.03 and 56.94 ± 8.57 mg/kg, respectively. Concentration of Cu, Pb and Zn were within the recommended level whereas the concentration of As, Cd and Cr were suppressed the recommended level of WHO and FAO/WHO standards. PLI, CF and Cd revealed considerably low degree of contamination of the sediment. Geo-accumulation index indicated uncontaminated to moderately contaminated condition of the sediment. Although the values of enrichment factor revealed no potential enrichment for most of the metals, Cd showed a minor enrichment during the winter season. Based on the ecological risk assessment, the sediment from all of the sample locations was found to be of moderate to low risk. PCA and CA analysis revealed the origin of contaminants mainly from anthropogenic sources. Although different metals showed non-carcinogenic risk to the inhabitants, cancer risk values for dermal contact (CRderm) were much lower than 10−6 indicating no cancer risk for adult and child. However, the findings also revealed that children were more susceptible to CRderm compared to adults. The present study concluded that long term dermal contact of the sediment of Bakkhali River estuary will be contagious to the people. Therefore, regular monitoring of the estuarine environment is necessary so that contamination does not get worse.

Enhanced soft magnetic properties in high-Ms Fe-B-Si-C-Cu-Nb alloys: Mitigated surface crystallization and controlled nanocrystallization via optimized metalloid content

The study investigated the impact of the boron/silicon ratio on the soft magnetic properties and surface crystallization of nanocrystalline Fe80(BaSib)15C1Cu1Nb3 (a:b, a=1–6, b=1,0) alloys. The addition of boron and silicon also enhances glass forming ability and nanocrystal formation, thereby affecting the magnetic properties of nanocrystalline alloys. Observations revealed variations in the glass forming ability based on the ratio, and the occurrence of surface crystallization and its adverse effects on magnetic properties were examined in alloys with inadequate amorphous formation. In subsequent experiments the iron content was increased to boost the saturation flux density after identifying the optimal ratio. The results highlighted that deficiencies in glass forming ability lead to surface crystallization. In conclusion, the results of the experiment yielded an optimal boron/silicon ratio of 5:1, showcasing magnetic properties with a coercivity of 14.7 A/m and a magnetic flux density of 1.62 T. Compared to alloys with different ratios, superior magnetic properties and reduced surface crystallization were achieved.

Pediatric kidney function and concentrations of metalloids and fluoride in drinking water in rural Mexico experiencing drought: Preliminary Results

Pediatric kidney function and concentrations of metalloids and fluoride in drinking water in rural Mexico experiencing drought: Preliminary Results

Experimental and theoretical investigation of the treatment of Cu-rich Acid Mine Drainage using iron oxide magnetic nanoparticles

Acid Mine Drainage (AMD) is a significant environmental problem in the mining industry due to its high concentration of hazardous metals and metalloids, sulfate compounds, and low pH levels. Despite the attention that iron oxide magnetic nanoparticles (MNP) have received for AMD remediation, there is still a lack of understanding of the physicochemical mechanisms behind their non-specific adsorption, particularly in distinct variations of AMD, such as Cu-rich AMD. In this study, we synthesized, characterized, and applied MNP to the two-step treatment of Cu-rich AMD. The chemical and physical properties of the MNP and magnetically separated sludges after AMD treatment are characterized. Additionally, the chemical species adsorbed onto the MNP, the oxidation state of the resultant sludge after Cu-rich AMD treatment, and the short-range ordering of metal contaminant species on the surface of the MNP are identified. Finally, first-principles calculations using Density Functional Theory were conducted to understand how different Cu ion species adsorb to the MNP surface depending on the pH of the Cu-rich AMD. The bonding between MNP and Cu species occurs primarily through metal cation-oxygen bonds on the surface of MNP, and this bonding is influenced by the pH of the solution. A combination of experimental and theoretical approaches was the key to arrive at this conclusion. This information can aid in the comprehension of how metal contaminants adhere to the surfaces of MNP and in the precise engineering of these nanoparticles.

A probabilistic risk assessment of heavy metal in water and sediment: An industrially affected urban river in Bangladesh.

Human welfare and biodiversity are at risk due to the deterioration of water and sediment quality. Particularly, in last few decades, global water and sediment quality degraded due to the rapid industrialization and urbanization. This study aimed to determine the concentration of nine heavy metals and metalloid (Pb, Cr, Cd, Hg, As, Mn, Ni, Cu, and Zn) and assess the ecological risks using different pollution indices (e.g., heavy metal pollution index [HPI], Nemerow pollution index [NI], geo-accumulation index [Igeo], contamination factor [CF], degree of contamination [CD] and pollution load index [PLI], ecological risk index [ERI]) in water and sediment of the Shitalakshya River, an industrially affected urban river of Bangladesh. For the first time, 20 water and sediment samples were collected across a wider geographical area of the Shitalakshya River during both monsoon and dry seasons and analyzed using the atomic absorption spectrometer. Average concentrations of heavy metals and metalloid in water were within the Bangladesh standard except for Cr (51.69 ppb) and Mn (228.20 ppb) during monsoon season, portraying potential ecological and human health risks. Besides, average concentration of Mn (549.75 and 370.93 ppb), Ni (549.75 and 370.93 ppb), and Cu (45.34 and 36.09 ppb) in sediment during both seasons were above international standard, implying risk to aquatic sediment biota. The average HPI values indicated moderate to high contamination, whereas the NI values implied polluted water in monsoon season with severe pollution in port area of the river. Similarly, Igeo, CF, CD, and PLI elucidated different levels of contamination in the sediment, particularly during dry season. The ERI values also referred moderate ecological risk in the sediment during dry season. Overall, our findings highlight the alarming level of heavy metal pollution in the Shitalakshya River, necessitating immediate action to protect the aquatic environment, sediment biota, and human health. PRACTITIONER POINTS: This study determined the concentration of heavy metals and metalloid in water and sediment of the Shitalakshya River, Bangladesh. The study revealed that the average concentration of Cr and Mn in water exceeded national standard, whereas Mn, Ni, and Cu in sediment exceeded international limit. Potential ecological risk of heavy metals was also assessed using different pollution indices. Calculated pollution indices indicated different degree of pollution, implying critical ecological condition due to heavy metal pollution in aquatic environment and sediment biota.

Electrochemical and bioelectrochemical treatment of steam-assisted gravity drainage water

This study compares electrochemical and bioelectrochemical approaches for treating Steam-Assisted Gravity Drainage (SAGD) water. Electrochemical treatment tests were carried out at applied voltages (Vap) of 1.4, 2.0, and 2.5 V. Bioelectrochemical treatment in a Microbial Electrolysis Cell (MEC) was conducted at the same applied voltages with microaeration of both electrode compartments. The two treatment approaches were thereafter combined in a continuous flow setup that consisted of an electrochemical cell (EC, Vap = 2.5 V) followed by MEC (Vap = 1.4 V). Chemical oxygen demand (COD), naphthenic acid, dissolved metals, and metalloid concentrations of SAGD water were substantially reduced after all treatments, thereby rendering the treated water less toxic according to ecotoxicological tests. However, the MEC treatment was more energy efficient resulting in the lowest specific energy consumption (SEC) value of 5.2 kWh/kgCOD. By replacing a Ti/IrO2-oxide current collector in the MEC with a custom-made Ti/NiCo-oxide mesh, the COD removal efficiency improved by 30%. The results suggest that a MEC equipped with Ti/NiCo-oxide current collector can provide cost-efficient treatment of SAGD water.

The impact of settleable atmospheric particulate on the energy metabolism, biochemical processes, and behavior of a sentinel mangrove crab

We use the sentinel mangrove crab, Minuca rapax, as a model to investigate the effects of metallic settleable particulate matter (SePM) on wetland. Multiple levels of energetic responses, including (i) metabolic rate and energy budget, (ii) oxidative stress, and (iii) behavioral response by righting time, were assessed as well as the metal and metalloid content in crabs exposed to 0, 0.1 and 1 g.L−1 of SePM, under emerged and submerged conditions over five days, simulating the rigors of the intertidal habitat. Al, Fe, Mn, Cr, and Y exhibited a concentration-dependent increase. Metal concentrations were higher in submerged crabs due to the continuous ingestion of SePM and direct exposure through gills. Exposure concentration up to 1 g.L−1 decreased metabolic rate and enzymatic activities, reduced assimilation efficiency and energy for maintenance, and induces a slower response to righting time, probably by metal effects on nervous system and energy deficits. In conclusion, SePM exposure affects the redox status and physiology of M. rapax depending on he submersion regime and SePM concentration. The disruption to the energy budget and the lethargic behavior in M. rapax exposed to SePM implies potential ecological alterations in the mangrove ecosystem with unknown consequences for the local population.

Differential metal and metalloid contents in fresh and cooked Charu mussels (Mytella charruana) from a southeastern Brazilian estuary and associated human health risks

Sepetiba Bay, a key estuarine ecosystem in southeastern Brazil, faces significant metal inputs, with a differential pollution gradient from the bay's entrance to inner areas, raising environmental and public health concerns. This study assessed metal levels in fresh and cooked samples of highly consumed Charu mussels (Mytella charruana) from three bay areas, one near the bay entrance (P1), with higher water renewal rates, one in the northern bay area (P2) and one the eastern bay (P3), presenting lower water renewal rates. Variations in metal and metalloid concentrations across sites were observed, with P3 exhibiting higher levels in fresh mussels for most elements, except for As, which was higher at P2 (0.35 ± 0.45 mg kg−1). Cooked samples demonstrated similar trends for Cu (1.30 ± 0.39 mg kg−1), Ni (0.28 ± 0.20 mg kg−1), and V (0.75 ± 0.28 mg/kg−1), indicating that cooking in contaminanted estuary water does not significantly reduce contamination. Significant differences were detected for Ni, Cd (0.014 ± 0.008 mg kg−1), Zn (14.28 ± 2.50 mg kg−1), and V at P1, which were significantly higher than at P3. Significant Fe (246 ± 68 mg kg−1), Al (109 ± 33 mg kg−1), and Mn increases were observed from P1 to P3. Mussels sampled from P3, near an abandoned military area and urban center, exhibited high Fe and Al levels, attributed to both natural processes and industrial activities. Metal concentrations in Charu mussels often exceeded regulatory limits set by Brazilian, North American, and European agencies. Calculated Se molar ratios indicate that while Se can mitigate Hg toxicity, high Hg levels in Sepetiba Bay's Charu mussels still pose significant health risks. Similarly, high levels of Ag, Cd, and Pb suggest ineffective Se protection. However, Se appears effective against As toxicity. The Health Benefit Value of Selenium (HBVSe) indicate Se's overall protective benefits against Hg toxicity. Higher HBVSe values in cooked mussels at P1 and P2 suggest that cooking increases Se bioavailability. However, raw mussels at P3 had higher HBVSe values than cooked ones, highlighting the need for site-specific assessments. Calculated Hazard Indices indicate general high health risks from mussel consumption, and As levels in Charu mussels indicate high carcinogenic risks. These findings emphasize the need for comprehensive Charu mussel monitoring and environmental management efforts at Sepetiba Bay.

After-effects of a closed copper mine: detailed analysis of environmental impacts in soil and plant samples

In several countries around the world, abandoned mining sites are blighted by pollution from metal and metalloids. Generated by mining processes, toxic pollutants have lasting effects on the ecosystem. The study examined the environmental impact of waste from a copper mine that was operated by the Caucasus Copper Limited Company between 1905 and 1928, revised and commissioned by Etibank in 1936, and ceased operations 75 years ago. Soil and plant samples (needles of Scotch pine, Pinus sylvestris L.) were collected from five specific regions around the mine and the levels of potentially toxic elements (PTEs) were determined, including As, Zn, Pb, Cd, Ni, Mn, Cr, Cu, Al, and Fe. The data obtained were used to calculate the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), ecological risk index (ERI), human health risk index (BCF), and plant enrichment factor (EFPlant). In soil samples, the average EF values of certain elements such as As (453), Cu (59.9), Pb (30.7), Zn (5.26) were detected at high levels. However, average Igeo values indicate high pollution levels for As (8.25), Cd (6.72), Cu (4.94), Pb (4.33) and Zn (2.42), indicating the existence of serious ecological risks in the affected areas. Additionally, the average CF values indicate serious pollution levels from heavy metals such as As (1605), Cd (584), Pb (99.4), Cu (81.9), and Zn (14.6), highlighting the extensive pollution situation resulting from mining activities. Meanwhile, average ERI values indicate that Cd, As, Cu, and Pb pose serious ecological risks in the study areas.These PTEs were found in high concentrations in the waste tail and dump. Furthermore, the analysis determined that there was enrichment for Mn, Cd, Al, Cu, Pb, and Fe elements in plant samples. These PTEs have the potential to spread more widely depending on seasonal conditions and local topography. This situation demonstrates the need to measure metal and metalloids concentrations at certain times, taking into account the potential for environmental pollution of surface runoff water and underground resources in areas with high drainage potential from acid mines, such as at the Kuvarshan mine tailings site.

Floodplain morphology influences arsenic and antimony spatial distribution in a seasonal acid sulfate soil wetland

Arsenic (As) and antimony (Sb) often co-occur in floodplain depositional environments that are contaminated by legacy mining activities. However, the distribution of As and Sb throughout floodplains is not uniform, adding complexity and expense to management or remediation processes. Identifying floodplain morphology predictor variables that help quantify and explain As and Sb spatial distribution on floodplains is useful for management and remediation. We developed As and Sb risk maps estimating concentration and availability at a coastal floodplain wetland impacted by upper-catchment mining. Significant predictors of As and Sb concentrations included i) distance from distributary channel-wetland intersection and ii) elevation. Distance from channel explained 53 % (P < 0.01) and 28 % (P < 0.01), while elevation explained 42 % (P < 0.01) and 47 % (P < 0.01) of the variability in near-total Sb and As respectively. As had a higher extractability than Sb across all tested soil extractions, suggesting that As is more environmentally available. As and Sb dry mass estimates to a depth of 0.1 m scaled to the lower coastal Macleay floodplain ranged from 113–192 tonnes and 14–24 tonnes respectively. Landscape-scale modelling of metalloid distribution, informed by morphology variables, presented here may be a useful framework for the development of risk maps in other regions impacted by contaminated upper-catchment sediments.

Estimation of Hair Toxic and Essential Trace Element and Mineral Profiles of Patients with Chronic Gout.

The objective of the present study was to evaluate hair levels of toxic and essential trace elements and minerals in male and female patients with chronic gout. A total of 223 examinees aged from 27 to 82years old including 116 healthy controls (64 women and 52 men) and 107 patients with gout (56 women and 51 men) were enrolled in the current cross-sectional study. Analysis of hair toxic and essential trace element and mineral content was performed using inductively-coupled plasma mass-spectrometry. The obtained data demonstrate that hair B, Fe, I, and Mo levels in gout patients were 67%, 8%, 46%, and 21% higher in comparison to the respective control values. Hair Cr and V content in patients was more than twofold higher than in the controls. Hair Mg and Zn levels were found to be 34% and 11% lower when compared to the respective control values. Hair toxic metal and metalloid content was also significantly affected in gout patients. Specifically, hair Al, As, and Pb levels were 24%, 43%, and 33% higher in gout patients than in healthy controls, respectively. Analysis of covariance demonstrated that sex also had a significant influence on hair trace element and mineral levels in gout patients. Specifically, gout-associated overaccumulation of hair trace elements including was more profound in male than in female patients. It is assumed that trace element dysregulation may contribute to gout development and progression, especially in men. However, further studies are required to elucidate this association and the underlying molecular mechanisms.

Potential cancer risks of metals/metalloids and radionuclides through the intake of food crops grown around the mining area

BackgroundFood crop consumption is one of the primary routes through which the environment is polluted with radionuclides, metals, and metalloids. In recent years, the negative impacts of metals, metalloids, and radionuclides on crop quality via the food-human system have jeopardized both human health and food security. Because some metals, metalloids, and radionuclides are persistent and non-biodegradable, they build up in the human body's essential organs, causing a variety of serious health issues, including cancer. It is therefore absolutely essential to evaluate the potential cancer risks of radionuclides as well as metals and metalloids in the food crops consumed in the study area to avoid negative health consequences. ObjectiveThe aim of this study was to assess the potential cancer risks of metals and metalloids (As, Cd, Cr, and Pb) and Radionuclides (U-238, Th-232, and K-40) via consumption of food crops cultivated around the Riruwai mining area, northeastern Nigeria. MethodologyThirty-three (33) food crops (15 vegetables and 18 cereal crops) were collected directly from the farmlands in the study area. The concentrations of radionuclides, metals, and metalloid in each food crop were assessed using a microwave-plasma atomic emission spectrometry (MP-AES) and a high-purity germanium (HPGe) gamma-ray spectrometer, respectively. The measured concentrations of radionuclides, metals, and metalloid were used to calculate their lifetime cancer risks (LTCRs). ResultsThe findings of the study revealed that the concentrations of As, Cd, Cr, and Pb in all the investigated food crops were above the threshold limits, while lower activity concentrations in all the investigated food crops below the world average standard were observed in U-238, Th-232, and K-40. LTCRs of all the individual metal and metalloid as well as radionuclide in each food crop were determined to be below the global threshold limits, indicating no likelihood of cancer risk from consuming the food crops. However, it was discovered that the total cumulative LTCRs of all the metals and metalloid in all food crops combined were 2.51E-04, which was over twofold the acceptable limit of 1.00E-04 ConclusionThe individual metal, metalloid, and radionuclide LTCRs in each food crop were found to be below global threshold limits, indicating no cancer risk from consumption. However, the cumulative LTCRs of all the metals and metalloid in all food crops were found to exceed the acceptable level, which requires proper monitoring and government intervention. Cancer risk is influenced by factors beyond food consumption, such as alcohol consumption, heredity, and air pollution, so multidimensional studies are needed before making a final decision on cancer risks in the study area.

Legacy effects of historical gold mining on floodplains of an Australian river

The gold rush at the end of the nineteenth century in south-eastern Australia resulted in the mobilization and re-deposition of vast quantities of tailings that modified the geomorphology of the associated river valleys. Previous studies of contamination risk in these systems have either been performed directly on mine wastes (e.g., battery sand) or at locations close to historical mine sites but have largely ignored the extensive area of riverine alluvial deposits extending downstream from gold mining locations. Here we studied the distribution of contaminant metal(loids) in the Loddon River catchment, one of the most intensively mined areas of the historical gold-rush period in Australia (1851–1914). Floodplain alluvium along the Loddon River was sampled to capture differences in metal and metalloid concentrations between the anthropogenic floodplain deposits and the underlying original floodplain. Elevated levels of arsenic up to 300 mg-As/kg were identified within the anthropogenic alluvial sediment, well above sediment guidelines (ISQG-high trigger value of 70 ppm) and substantially higher than in the pre-mining alluvium. Maximum arsenic concentrations were found at depth within the anthropogenic alluvium (plume-like), close to the contact with the original floodplain. The results obtained here indicate that arsenic may pose a significantly higher risk within this river catchment than previously assessed through analysis of surface floodplain soils. The risks of this submerged arsenic plume will require further investigation of its chemical form (speciation) to determine its mobility and potential bioavailability. Our work shows the long-lasting impact of historical gold mining on riverine landscapes.

Heavy metal and metalloid concentrations in red deer (Cervus elaphus) and their human health implications from One Health perspective

The red deer is an ungulate and large game species. The contamination of the ecosystems by metal(loid)s may lead to the exposure of animals (as well as humans) through water and food resources. The direct contact of hunters and wild animal meat consumers with deer carcasses may be a potential contaminant source. This study aimed to determine the metal(loid)s’ concentrations in the liver and kidney of red deer from two regions of Portugal (Idanha-a-Nova and Lousã), and to relate these with histopathologic lesions. Thirteen young male deer were submitted to metal(loid) determination (As, Cd, Co, Cr, Cu, Pb, and Zn) by inductively coupled plasma mass spectrophotometry (ICP-MS) and histopathology examination. Renal Cd (8.072 ± 5.766 mg/kg dw) and hepatic Pb (3.824 ± 6.098 mg/kg dw) mean values were high, considering the maximum values for consumption established by the European Commission. The hepatic mean value of Cu was significantly higher in Idanha-a-Nova (150.059 ± 33.321 mg/kg dw), and it is at the Cu toxicity limit considered for ruminants (150 mg/kg). The pollution induced by Panasqueira mines (Castelo Branco) may be a possible explanation for some of the findings, especially the higher values of hepatic Cu and Pb found in Idanha-a-Nova deer. These results have high importance under a One Health perspective, since they have implications in public health, and pose at risk the imbalance of animal populations and ecosystems.

Metalloid transporters in plants: bridging the gap in molecular structure and physiological exaptation

Abstract The rhizosphere contains both essential nutrients and potentially harmful substances for plant growth. Plants, as sessile organisms, must efficiently absorb the necessary nutrients while actively avoiding the uptake of toxic compounds. Metalloids, elements that exhibit properties of both metals and non-metals, can have different effects on plant growth, from being essential and beneficial to being toxic. This toxicity arises due to either the dosage of exposure or the specific elemental type. To utilize or detoxify these elements, plants have developed various transporters regulating their uptake and distribution in plants. Genomic sequence analysis suggests that such transporter families exist throughout the plant kingdom, from chlorophytes to higher plants. These transporters form defined families with related transport preferences. The isoforms within these families have evolved with specialized functions regulated by defined selectivity. Hence, understanding the chemistry of transporters to atomic detail is important to achieve the desired genetic modifications for crop improvement. We outline various adaptations in plant transport systems to deal with metalloids, including their uptake, distribution, detoxification, and homeostasis in plant tissues. Structural parallels are drawn to other nutrient transporter systems to support emerging themes of functional diversity of active sites of transporters, elucidating plant adaptations to utilize and extrude metalloid concentrations. Considering the observed physiological importance of metalloids, this review highlights the shared and disparate features in metalloid transport systems and their corresponding nutrient transporters.

Analysis of the metals and metalloids concentrations and of the bacterial population in sediments of the Red River Delta, Vietnam.

In this study, we discuss for the first time the relationships between the diversity of the bacterial population and of the metals and metalloids concentrations in the sediments of the Red River Delta, Vietnam. The analysis of the 16S rRNA by the Illumina technology revealed a diversified population and a potential of bioremediation by the microorganisms, notably by the Bacilli relatively abundant in the Bach Dang estuary, where high metals and metalloids concentrations were highlighted. This work offers new information on the environmental context of the delta and highlights the potential impact that metals and metalloids may have on the bacterial population. Further investigations on the role of the bacteria in the biogeochemistry of this ecosystem will be of interest for the development of bioremediation processes.