Toxic Trace Elements Research Articles

Enhanced Absorption Capacity and Fundamental Mechanism of electrospun MIL-101(Cr)-NH2/PAN nanofibrous Membranes for Mo(VI) Removal

Amidst the escalating global concern over heavy metal discharge from industrial effluents, Mo(VI), as a potentially toxic trace element, poses significant risks to human and environmental health. Traditional treatment methods such as biodegradation and ion exchange have low removal efficiency, hence, the efficient removal of Mo (VI) ions from industrial wastewater assumes paramount importance. Emerging materials, Metal-Organic Frameworks (MOFs), have garnered extensive attention in water treatment due to their strong adsorption properties, and MOFs membrane materials are hailed as the most promising adsorbents. Therefore, this study aims to prepare a novel membrane material with high efficiency for the removal of Mo (VI) by loading MOFs into nanofibers. Given the water stability of MIL-101, MIL-101-R(-H, -NH2, -NO2) with different functional groups were prepared and subsequently loaded into PAN nanofibrous for the adsorption of Mo(VI). Adsorption kinetics and isotherm studies revealed PAN/MIL-101(Cr)-NH2 to exhibit superior adsorption performance, achieving a maximum adsorption capacity of 171.81 mg/g. Density functional theory (DFT) calculations and molecular dynamics simulations elucidated the adsorption mechanism, highlighting the role of amino modification in facilitating Mo(VI) adsorption through electrostatic attraction and high reactivity. This work not only offers novel materials and approaches for Mo(VI) wastewater treatment but also advances the industrial application of MOF materials in the domain of heavy metal wastewater treatment.

Measuring the impact: Severity of harm from laboratory errors in 195 tests.

This study aimed to objectively assess the potential severity of harm associated with erroneous results in 195 laboratory tests by surveying 514 specialist physicians and medical biochemistry experts. The survey obtained participants' (75 medical biochemists, 439 clinicians) opinions on severity of harm for the erroneous results of 195 tests. The comprehensive list of errors and their effects on test results were obtained from the literature, and then matched with severity of harm scores, from 1 (negligible effect) to 5 (life-threatening injury/death), obtained from the survey responses. Participants perceived tests such as cardiac biomarkers, blood gases, coagulation parameters (activated partial thromboplastin time, prothrombin time, international normalized ratio, and dimerized plasmin fragment D), critical ions (potassium, sodium), toxic trace elements (lead, mercury), and specific serum drug levels (lithium, digoxin) to have a greater potential for patient harm in case of errors. Medical biochemistry specialists assigned higher severity scores to some laboratory tests, including total bilirubin, pseudocholinesterase, platelet indices, and some drug levels (cyclosporine, methotrexate, vancomycin). A substantial agreement (91%) was observed between medical biochemists and clinicians in terms of the most frequently chosen severity of harm score. The study provided objective severity scores and identified high-risk tests for targeted quality improvement.

Human biomonitoring of essential and toxic trace elements (heavy metals and metalloids) in urine of children, teenagers, and young adults from a Central European Cohort in the Czech Republic.

Exposure to toxic trace elements, which include metals and metalloids, can induce adverse health effects, including life-threatening diseases. Conversely, essential trace elements are vital for bodily functions, yet their excessive (or inadequate) intake may pose health risks. Therefore, identifying levels and determinants of exposure to trace elements is crucial for safeguarding human health. The present study analyzed urinary concentrations of 14 trace elements (arsenic, cadmium, cobalt, chromium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, and zinc) and their exposure determinants in 711 individuals, spanningfrom children to young adults from a Central European population from the Czech Republic. Multivariate linear regression and non-parametric Kruskal-Wallis ANOVA were used to investigate exposure determinants. Estimates of 95th percentile concentrations and confidence intervals were carried out to establish reference values(RV95). The study also assessed the percentage of population exceeding health-based guidance values (GVs) to gauge health risks. Young adults showed elevated toxic element concentrations, whereas children exhibited higher concentrations of essential elements. Mercury concentrations were associated with both dental amalgam filling count and seafood intake; arsenic concentrations were associated with seafood, rice, and mushroom consumption. Mushroom consumption also influenced lead concentrations. Sex differences were found for cadmium, zinc, nickel, and cobalt. Between 17.9% and 25% of the participants exceeded recommended GV for arsenic, while 2.4% to 2.8% exceeded GV for cadmium. Only one participant exceeded the GV for mercury, and none exceeded GVs for chromium and thallium. Essential trace elements' GVs were surpassed by 38% to 68.5% participants for zinc, 1.3% to 1.8% for molybdenum, and 0.2% to 0.3% for selenium. The present study examines trace element exposure in a Central European population from the Czech Republic, unveiling elevated exposure levels of toxic elements in young adults and essential elements in children. It elucidates key determinants of trace element exposure, including dietary and lifestyle indicators as well as dental amalgam fillings. Additionally, the study establishes novel reference values and acomparison with established health-based human biomonitoring guidance values, which are crucial for public health decision-making. This comprehensive biomonitoring study provides essential data to inform public health policies and interventions.

Human Exposure through the Diet to Arsenic and Other Toxic Elements: A Literature Review of Scientific Studies Conducted in Catalonia, Spain, in the Current Century.

Human exposure to arsenic and other toxic elements such as cadmium, lead and mercury may lead to a wide range of adverse health effects. In relation to this, it is well established that the diet is the main route of exposure to both essential and toxic trace elements. In recent years, the levels of toxic elements in foodstuffs have been measured in numerous studies conducted all over the world. Scientific databases show that, in the current century, China and Spain have been the countries where the most surveys on this topic have been carried out. Regarding Spain, Catalonia is the region where most studies aimed at determining the concentrations of trace elements in food have been performed. The objective of this paper was to review the studies carried out in Catalonia on the concentrations of As and toxic metals (including Cd, Hg and Pb) in food, as well as their estimated dietary intakes (EDIs). The results of total diet studies (TDSs) and duplicate diet (DD) studies have been included. For most toxic elements, a continued reduction in the EDI has been observed. This reduction is associated with a decrease in their concentrations in food, and with certain changes in dietary habits. Fish and seafood is the food group showing the highest content of toxic elements. However, none of the adult groups exceeded-in general-the safety thresholds for As, Cd, Hg and Pb established by the European Food Safety Agency (EFSA).

Stable isotopes analysis combined with X-ray absorption spectroscopy reveal the fate of organic waste-borne copper and zinc in amended soils

Copper (Cu) and zinc (Zn), two potentially toxic trace elements, are commonly abundant in organic wastes (OWs) recycled in soils as fertilizer. Yet current knowledge on the long-term behavior and fate of Cu and Zn in soil following OW spreading is scant. We addressed this issue by studying the fate of OW-borne Cu and Zn in amended soils from four different long-term field experiments. By combining the stable isotope analysis and X-ray absorption spectroscopy, we identified changes in Cu and Zn concentrations, speciation and isotopic compositions in the amended soils only when OW had been applied at high rates over long periods. Under these conditions, we highlighted that: (i) all OW-derived Cu and Zn had accumulated in the topsoil layer regardless of the soil and OW type; (ii) the amended soil isotopic signatures were the result of the mixing of OW-borne and natural Cu and Zn; and (iii) Cu and Zn exhibited distinct speciation patterns in amended soils. Indeed, the unprecedented persistence of OW-borne crystallized Cu(I)-sulfide in the amended soils contrasted with the complete transformation of pig slurry-borne nanosized Zn-sulfide or household compost-derived amorphous Zn phosphate and Zn complexed by organic matter.

Microplastic Abundance, Characteristics, and Heavy Metal Contamination in Coastal Environments of Western Sri Lanka

This study was conducted to assess the abundance of microplastics and associated metal contamination from selected beaches in the Western Province of Sri Lanka. Beach sand samples were collected from four beaches: Modera, Negombo, Mount Lavinia, and Panadura. Microplastics were extracted from dried sand samples using a saturated NaCl solution and sieved. Particles were identified using Fourier Transform InfraRed spectrophotometer, and associated heavy metals; Cr, Pb, Cu, Zn, and Ni were subjected to acid digestion for 24 hours before analysis using Microwave Plasma Atomic Emission spectrometry. More than half of the extracted plastics (56.31%) were identified as microplastics. The average microplastic abundance in beach sand samples ranged from 42.0-91.3 items/kg. The lowest and highest abundances were reported from the sand collected at Mount Lavinia and Panadura beaches, respectively. Hydrodynamic factors like ocean currents, wave patterns, associated Southwest monsoon period, and human activities may have caused the variability in microplastic abundances and metal contamination. The majority of the microplastics (52.29%) were polyethylene, whereas the second most abundant microplastic type was polypropylene (35.18%), resembling the records of the most common plastic waste types in the country. The majority of microplastics were fragments (87.95%) while white was the prominent color (53.49%). The toxic trace element concentration ranged from 5.0×10-3 to 1.8×102 μg/g in beaches. Furthermore, this study establishes a baseline for the west coastline prior to the X-press Pearl Ship Disaster in 2021. Future studies are encouraged to assess the beach microplastic pollution across the entire Sri Lankan coastline.

Assessment of Ecological and Health Risks of Potentially Toxic Elements in Soil and Plant Under Long-Term Sewage Wastewater Irrigation.

This paper aimed to evaluate the ecological and health risks for some potentially toxic trace elements (PTEs) in agricultural soils irrigated with sewage wastewater for more than 50 years. Therefore, soil and plant samples were collected from 21 sites at sewage wastewater irrigated area and these samples were analyzed for their contents of PTEs i.e. Cd, Cr, Cu, Ni, and Pb. The risks of PTEs pollution in the study area were analyzed using indices such as the individual and comprehensive potential ecological risk indices (Eri and RI, respectively), hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) model. The results showed that the PTEs in soil samples ranged from 1.70 to 9.90mg/kg for Cd, from 39.9 to 183.4mg/kg for Cr, from 31.5 to 655.1mg/kg for Cu, from 18.8 to 113.1mg/kg for Ni and from 5.4 to 65.4mg/kg for Pb. The results also demonstrated that the soil samples were characterized by high to very high ecological risk for Cd. According to the health risk assessment, the mean HQ and HI of the PTEs in soil for adults and children were below the risk threshold of 1, indicating no risk for non-carcinogenic health effects. However, the HI of PTEs via plant consumption was > 1, suggesting a non-carcinogenic health risk. The CR for most plant samples was above the acceptable range. These findings may offer helpful information regarding the ecological and human risks related to PTEs exposure in soil and plants irrigated with wastewater under arid conditions.

Morphometric characteristics and spatiotemporal heterogeneity of microplastics on the north-east coast of India

The study analysed microplastics (MPs) in surface waters along the north-east coast of India and focused on the spatiotemporal distribution and morphometric characteristics of 800 particles for environmental insights. The MPs were consistently present in all water masses, with an average abundance of 0.67 ± 0.66 particles/m3 during the monsoon and 0.12 ± 0.08 particles/m3 post-monsoon. Fragments and fibers were dominant in both seasons, comprising over 83% and 12%, respectively. In terms of colours, blue was significantly dominant during the post-monsoon (H, χ2 (5) = 15.38, p < 0.01); however, such variation was absent during the monsoon. Spatially, significant variance in abundance (F4, 34 = 8.542; p < 0.01) and across colours and forms during the monsoon was correlated with land-based inputs from the Hooghly River. FTIR analysis revealed ten polymer types, predominantly polyethylene (44%). SEM observations indicated that 80% of particles exhibited polymer ageing from oxidative weathering. The size distribution of MPs varied notably, with a higher proportion of < 0.3mm (16.7%) during the monsoon, possibly due to increased particle disintegration. The study noted MPs had low to moderate circularity, with increased irregularity during the monsoon due to heavy precipitation and river flushing. An initial risk assessment of MP pollution in surface waters on the north-east coast revealed a low-risk state. Acrylonitrile butadiene styrene (ABS) was identified as the most hazardous MP polymer. A wide range of toxic trace elements were found in MPs in these waters. The findings from the study deepen our knowledge of MPs and their fate in the pelagic zone, which supports the development of science-based policies that effectively reduce MP pollution.

Trace element distribution, sources, toxicity risk characteristics associated with lacustrine groundwater discharge in boreal lakes: Implications for the eco-environmental security in the Yellow River Basin, China

Although the pollution of trace elements has been extensively studied, there is still a lack of comprehensive understanding regarding accumulation of these elements in lake ecosystems within the Yellow River basin, specifically the effects of lacustrine groundwater discharge (LGD) on trace elements. This study investigated the distribution, sources, and toxicity risks associated with 20 target trace elements (i.e., Li, Sc, Ti, V, Mn, Cr, Co, Ni, Cu, Zn, Rb, Y, Mo, Sb, Ba, W, Tl, Pb, U and Sr) in lake water (LW), groundwater (GW), and river water (RW) influenced by the LGD process in lake Ulansuhai and lake Daihai. The natural source is the primary contributor of trace elements in both LW and GW within the two lake basins, while industrial discharge plays a secondary role. The average LGD fluxes in lake Ulansuhai and Daihai basins were 6.39 × 105 m3/d and 1.07 × 105 m3/d, respectively. Additionally, the trace element fluxes from LGD in lake Ulansuhai (mean of 106,659.37 g/d) exceeded those observed in lake Daihai (mean of 3236.57 g/d). The overall toxicity risk was found to be higher in lake Ulansuhai (LW (17.36) > RW (16.81) > GW (12.76)) compared to lake Daihai (GW (10.43) > LW (9.10) > RW (4.63)). As well as the toxicity levels of trace elements in lake Ulansuhai were elevated compared to Daihai, which can be attributed to the influenced of ion compositions and water nutrients. Among them, Ca2+, Mg2+, and SO42+ were identified as key ions impacting the toxicity of trace elements in lake Ulansuhai. These findings provide crucial insights for targeted monitoring and mitigation of trace element pollution in the Yellow River basin’s lake ecosystems.

Exploring serum trace element shifts: Implications for cervical intraepithelial neoplasia

BackgroundCervical intraepithelial neoplasia (CIN) represents a premalignant state presumably related to perturbations in circulating levels of trace elements. Materials and methodsEmploying inductively coupled plasma mass spectrometry (ICP-MS), we quantified essential and toxic trace elements in the sera of 60 women diagnosed with CIN and 60 age-matched healthy counterparts. ResultsOur investigation revealed a noteworthy higher levels in serum of Mn, Zn, and Pb, as well as lower levels in Ni, Se, Rb, and Mo levels within the CIN cohort. Levels of Mn, Zn, and Pb were higher by approximately 5.5-fold, 3.0-fold, and 7.5-fold, respectively, while Mo levels exhibited an approximate 4.5-fold reduction in CIN sera compared to the control group. While the study provided valuable insights into trace element variations, it’s important to note that the adult Serbian population is considered Zn-deficient, so the Zn data should be interpreted with caution. Age stratification (30–40 vs. 40–50 vs. 50–60 years), smoking status (smokers vs. nonsmokers), and CIN severity (CIN 2 vs. CIN 3) yielded no significant disparities in elemental profiles. Among the 10 proposed ratios, 5 demonstrated a significant surge in CIN sera relative to controls: Mn/Se, Mn/Mo, Zn/Se, Zn/Mo, and Se/Mo. Correlation analysis of trace element levels revealed a predominantly consistent pattern between CIN cases and healthy subjects, except for Zn and its negative correlations (antagonistic interactions) with other analyzed trace elements. ConclusionOur findings underscore differences in serum levels of specific trace elements in CIN cases versus controls, implicating their potential involvement in the underlying pathophysiological cascades culminating in cervical neoplasms.

Quantification of Airborne Particulate Matter and Trace Element Deposition on Hedera helix and Senecio cineraria Leaves.

In both developed and developing countries, atmospheric pollution with particulate matter (PM) remains an important issue. Despite the health effects of poor air quality, studies on air pollution are often limited by the high costs of continuous monitoring and the need for extensive sampling. Furthermore, these particles are often enriched with potentially toxic trace elements and organic pollutants. This study evaluates both the composition of atmospheric dust accumulated during a certain timespan on Hedera helix and Senecio cineraria leaves and the potential for their use as bio-monitors. The test plants were positioned near automatic air quality monitoring stations at four different sites with respectively high, moderate and low traffic intensity. The gravimetric deposition of PM10 and PM2.5 on leaves was compared with data recorded by the monitoring stations and related to the weather conditions reported by Argentina's National Meteorological Service. To determine the presence of trace elements enriching the PM deposited on leaves, two analytical techniques were applied: XRF (not destructive) and ICP (destructive). The results indicated that only in the unpaved street location (site 2) did PM10 and PM2.5 concentrations (90 µg m-3 and 9 µg m-3) in the air exceed more than five times WHO guidelines (15 µg m-3 and 5 µg m-3). However, several trace elements were found to be enriching PM deposited on leaves from all sites. Predominantly, increased concentrations of Cd, Cu, Ti, Mn, Zn and Fe were found, which were associated with construction, traffic and unpaved street sources. Furthermore, based on its capability to sequester above 2800 µg cm-2 of PM10, 2450 µg cm-2 of PM2.5 and trace elements, Senecio cineraria can be taken into consideration for adoption as a bio-monitor or even for PM mitigation.

Arsenic, selenium, and mercury speciation in hypersaline lakes of the Andean Altiplano: Link between extreme levels and biodiversity repartition

Arsenic (As) and mercury (Hg) are highly toxic contaminants whereas selenium (Se) is both an essential trace element and potentially harmful at higher concentrations. The hyper-saline lakes of southern Bolivian Altiplano, which are ecological niches for endemic species, are also expected to be enriched in these toxic trace elements. The biogeochemistry of As, Hg, and Se in such high-altitude extreme environments (e.g., high UV radiation and salt content) remains poorly understood. In this study, we investigated the concentrations and chemical forms (speciation) of As, Hg, and Se in sediment, water, and air samples of Lagunas Colorada (LC), Verde (LV), and Blanca (LB) in the South Lipez region (>4200 m a.s.l.). We compared them with the repartition of biodiversity (invertebrates, algae, and bacteria). Extreme As concentrations were found in water (up to 82 mg L−1), and the main As species was inorganic As(V), with neither biogenic methylated As nor volatile As forms being detected in water and air, respectively. Se concentrations in water were of 0.1 to 1.4 μg L−1, and Se existed under different redox states, i.e., Se(IV), Se(VI), and reduced Se (0, -II), including biogenic methylated Se(-II) (trimethyl selenonium). Volatile Se compounds (e.g., dimethyl selenide) were detected in water and air samples. Hg was enriched in the surface water (6 to 30 ng L−1) compared to other regional water bodies, and a significant amount of methyl-Hg and gaseous Hg(0) was detected. The drastic disparity between As, Se and Hg concentrations and speciation between lakes has important implications for their cycling in these extreme aquatic systems. While As mostly accumulated in its oxidized and non-volatile form, Hg and Se concentrations can be controlled by significant conversion to reduced and methylated forms, allowing efficient evasion to the atmosphere. Finally, the salinity, including major ions, and high levels of As were among the main drivers of biodiversity repartition between lakes.

Transcriptomic Analysis of Antimony Response in Tall Fescue (Festuca arundinacea)

Antimony (Sb) is a toxic trace element for plants and animals. With the development of industrial applications and mining, Sb pollution is becoming more serious. Phytoremediation is regarded as an eco-friendly technique to reduce the threat of Sb to the environment and human health, and tall fescue that is highly adaptable to heavy metal stress can be a candidate species for Sb-contaminated soil phytoremediation. However, the mechanism of the Sb stress response in tall fescue is not clear. Therefore, transcriptomic analysis was used in this study to reveal the molecular mechanisms of Sb stress response regulation in tall fescue. The results suggested that the roots and leaves of tall fescue responded to Sb stress in different ways. In roots, the lignin and flavonoids might reduce the toxicity of Sb by anti-oxidation and Sb chelation. At the same time, the DEGs in leaves were mainly enriched in the pathways of glutathione metabolism, β-alanine metabolism, and glycine, serine, and threonine metabolism. Additionally, genes related to the pathways, such as 4CL, GST, AGXT2, and ALDH7A1, especially cytochrome P450 family genes (e.g., CYP73A, CYP75A, and CYP98A), might play key roles in the regulation of the Sb stress response in tall fescue. These findings provided a theoretical reference for the efficient use of tall fescue to control Sb-contaminated soil in the future.

Associations between APOE genotypes, urine 8-isoprostane and blood trace elements in middle-aged mothers (CROME study)

BackgroundThere is almost no data on the combined associations between apolipoprotein E gene (APOE) genotypes, trace elements (TEs), and lipid peroxidation in vivo. The aim of our study was to evaluate the association between APOE genotypes and TE levels in blood (B-TEs) and erythrocytes (E-TEs), and 8-isoprostane in urine (U-8-isoprostane) in women with low exposure to potentially toxic TEs and with adequate supply of essential TEs. MethodsB-TEs, E-TEs and U-8-isoprostane were determined in 172 healthy women of childbearing age (30.1–51.4 years) using ICP-MS and ELISA competitive assay, respectively. All women were divided into three APOE genotype groups according to the presence of the ɛ4 allele, ɛ2 allele or ɛ3 homozygotic allele. The associations between B-TEs, E-TE, U-8-isoprostane, and the APOE genotype groups were estimated by multiple variable linear regression models with relevant explanatory variables (e.g., age, BMI, and seafood). ResultsAll TE and U-8-isoprostane levels were inside the reference ranges for the healthy population. In the multiple variable linear regression models, our results showed that urine 8-isoprostane levels increased by up to 43.3% in the APOE4 group compared to the APOE3 group and a negligible negative modifying effect for essential TEs. However, the APOE genotype groups were associated also with some TEs. A clear positive association was found between the APOE2 and APOE4 groups (vs. APOE3) with B-molybdenum. ConclusionsOur study suggests that the APOE4 genotype played an important role in 8-isoprostane variability in a population with an adequate supply of essential and with low exposure to potentially toxic TEs. Adequate copper, zinc and selenium status seemed to be protective against, while the levels of nonessential TEs were probably too low to play a decisive role in 8-isoprostane formation. The observed impact of the APOE2 and APOE4 groups on increased B-molybdenum opens a new research topic.

Initial pedogenic processes, mineral and chemical transformations and mobility of trace elements in Technosols on dumps of the former copper mines in Miedziana Góra and Miedzianka, the Świętokrzyskie Mts., south-central Poland

Technosols develop, among others, on dumps of former copper mines which became overgrown in spontaneous plant succession. The aim of the study was to determine the effect of pedogenesis on soil properties, mineral and geochemical composition, as well as operationally defined forms of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in Technosols developed on former mine dumps of the Miedziana Góra and Miedzianka former mining areas in south-central Poland. The studied Technosols were weakly developed soils with a simple soil profile comprising (1) C horizons in the subsoil and (2) O and A (or AC) horizons in the topsoil. The pHH2O of soils was 5.5–8.1. High soil pHH2O values were due to occurrence of carbonates (up to 25 %). The highest content of total organic carbon (TOC) and total nitrogen (TN) was found in O horizons as well as in A and AC horizons including buried A horizon. Soil magnetic susceptibility (χ) was 6.0–171.3 × 10–8 m3 kg−1. In each profile, the highest χ values were typical of A horizons including the buried A horizon. The most common minerals present in all profiles were quartz, kaolinite and mica. There were also admixtures of carbonates (dolomite, calcite), feldspars (orthoclase and albite), jarosite, goethite and traces of Fe sulphides. SEM-EDS analyses showed that soil substrate was subject to transformations of sulphides into Fe oxides. Moreover, pedogenic Cu carbonates were found in pores and on coarse materials. Technosols were enriched in Ag, As, Cd, Co, Cu, Hg, Mo, Ni, Pb, Sb, Zn, U and Th. The most mobile trace elements in the studied Technosols were Cd, Cu and Zn. Topsoil horizons of the studied soils contained a considerable share of Pb, Cu, Zn and Ni bound with soil organic matter. Arsenic was mostly bound with Fe oxides. First indicators of pedogenesis in the studied Technosols are (1) accumulation of soil organic matter in the topsoil followed by the decrease of soil pH and leaching of carbonates, (2) mineral transformations in the soil substrate (alteration of sulphides into Fe oxides and jarosite; origin of pedogenic Cu carbonates due to crystallization from soil solutions), (3) increase of magnetic susceptibility in the topsoil which may be an effect of atmospheric dust fall out or pedogenic transformation of Fe oxides into the phases with higher magnetic susceptibility and (4) the effect of soil properties, mineral composition and soil organic matter on geochemical forms of potentially toxic trace elements. The novelty value of the study lies in the identification of pedogenic Cu carbonates and the potential effect of soil-forming processes on the increase of topsoil magnetic susceptibility.

From molecules to organisms: A multi-level approach shows negative effects of trace elements from sewage sludge used as soil improver on honeybees

The use of sewage sludge as a soil improver has been promoted in agroecosystems. However, sludges can contain toxic trace elements because of suboptimal wastewater treatment. Nonetheless, field studies investigating the negative effects of these practices on pollinators are lacking. We collected honeybees from an area where sewage sludge use is widespread, and one where it is precluded. Trace elements in soils and bees were quantified. Cadmium, chromium, lead, mercury, and nickel were investigated because they were the least correlated elements to each other and are known to be toxic. Their levels were related to oxidative stress and energy biomarkers, midgut epithelial health, body size and wing asymmetry of honeybees. We found increased carbohydrate content in sites with higher cadmium levels, increased histological damage to the midgut epithelium in the sewage sludge area, and the presence of dark spherites in the epithelium of bees collected from the sites with the highest lead levels. Finally, we found that honeybees with the highest lead content were smaller, and that wing fluctuating asymmetry increased in sites with increasing levels of mercury. To the best of our knowledge, this is the first comprehensive study of the concentration and effects on honeybees of trace elements potentially deriving from soil amendment practices.

Blood levels of 21 metals and metalloids in riverside villagers of the Brazilian Amazon: A human biomonitoring study with associations with sociodemographic, dietary, and lifestyle factors

Human biomonitoring of toxic and essential trace elements is critically important for public health protection. Amazonian riverine communities exhibit distinctive dietary patterns, heavily reliant on locally sourced fish, fruits, and vegetables. These habits may result in unique exposure profiles compared to urban populations. However, comprehensive assessments of their exposure to toxic and essential metals are lacking, representing a critical gap in understanding the health risks faced by these communities. This study aimed to establish baseline levels of 21 metals and metalloids in human blood and explore the influence of sociodemographic factors, dietary habits, and lifestyle choices as potential sources of exposure to these elements. A cross-sectional biomonitoring investigation was conducted with 1,024 individuals from 13 communities in the Tapajós and Amazon Basins (Pará, Brazil). Most of the elements in study was determined for the first time in the region. Blood samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The levels of all elements were summarized by quantiles and compared with cutoff values from other Brazilian populations. Multiple linear regression was used to assess possible associations between element concentrations and sociodemographic characteristics, dietary habits, and lifestyle choices. High detection rates (64%–100%) were observed, indicating the widespread presence of these elements. Elevated blood concentrations were found for mercury (median 21.1 μg.L−1, interquartile range: 12–34 μg.L−1), selenium (median 166 μg.L−1, interquartile range: 137–208 μg.L−1), and lead (median 34 μg.L−1, interquartile range: 20.8–64 μg.L−1). Regression analysis revealed a positive association between mercury levels and fish consumption, while manioc flour intake showed no relationship to lead levels. In conclusion, our findings emphasize the need for continued monitoring and public policy development for these vulnerable populations. Further studies should assess long-term trends and investigate the health implications of prolonged exposure to diverse chemicals in Amazonian riverside communities.

Assessment of the mobility of potentially toxic trace elements (PTEs) and radionuclides released in soils stabilized with mixtures of bentonite-lime-phosphogypsum.

Phosphogypsum (PG) is a solid by-product of the phosphate industry, rich in contaminants and produced in large quantities. Raw materials and stabilized specimens, consisting of bentonite-lime-PG mixtures, were characterized by mineralogical, microstructural, chemical, alpha-particle, and gamma-ray spectrometry analysis before hydration and after hardening. Compressive strength and leaching tests were performed on hardened specimens. The physicochemical parameters and chemical composition of leachates from raw materials and hardened specimens were determined. PG contains high concentrations of natural radionuclides, specially from U series. Uranium-238 activities are double in PG than the worldwide average for soil values. The mobility of PTEs from PG is Cd (2.43%), Zn (2.36%), Ni (2.07%), Cu (1.04%), Pb (0.25%), and As (0.21%). Cadmium is the cation most easily released by PG in water with a concentration 0.0316mgkg-1. When PG is added to bentonite-lime mixture, cadmium is no longer released. The radionuclide 238,234U and 210Po predominates in the leachates of PG. However, the activity of 210Po becomes negligible in the leachates of bentonite-lime-PG mixtures. The addition of PG to bentonite-lime mixtures facilitates the trapping of trace elements (PTEs) and radionuclides, providing potential applications for PG as road embankments and fill coatings.

Resource partitioning influences levels of toxic trace elements in sympatric tropical seabirds

Morphologically similar species that occupy resource-limited environments tend to differ in their ecological traits in order to coexist, which may result in differential exposure to environmental threats. For instance, partitioning of feeding resources may influence contaminant exposure and bioaccumulation in marine predators through different diets or foraging habitats. Here, we sampled three tropical seabird species breeding in sympatry in the southwestern Atlantic Ocean for blood and feather trace element concentrations (As, Hg, Cd, Pb), and assessed their foraging ecology with bio-logging (GPS tracks and time-depth recorders), analysis of regurgitated prey, and carbon and nitrogen stable isotope mixing models. Red-billed tropicbirds (Phaethon aethereus), brown (Sula leucogaster) and masked (S. dactylatra) boobies differed in their preferred foraging locations, the range of foraging trips, diving parameters and diets. In addition, interspecific differences were detected in blood or feathers for all trace elements analyzed, suggesting influence of the differences observed in diet and space use. Red-billed tropicbirds had the largest foraging range over the continental shelf and over the slope, suggesting lower exposure to continental sources of metals. Brown and masked boobies had higher Hg concentrations than tropicbirds, higher δ15N values (a proxy for trophic level), and δ15N correlated with Hg levels, suggesting biomagnification of Hg along the food chain. Nonetheless, red-billed tropicbirds showed comparable levels of As and Cd in blood or feathers, and higher levels of Pb in both tissues in comparison to boobies, which may suggest overall exposure of seabirds in the region, through their diets and foraging areas. Resource partitioning is critical for allowing coexistence of different seabird species in shared breeding sites where they act as central-place foragers. Nonetheless, in scenarios of environmental pollution, these species-specific strategies lead to differential bioaccumulation, and thus distinct effects of pollution on populations are expected.

Association of rare earth elements with secondary mineral phases formed during alkalinization of acid mine drainage

Rare Earth Elements (REE) are present in acid mine drainage (AMD) in micromolar concentrations and AMD discharge may lead to an environmental risk. Alkaline Passive Treatment Systems (PTS) are often used to treat AMD and trap toxic trace elements. This study was set up to identify mechanisms by which REE are trapped in or on secondary phases formed in a PTS. Batch alkalinization experiments were performed to simulate PTS by sequentially increasing the pH of AMD collected from the Tharsis mining area inside the Iberian Pyrite Belt and synthetic AMD water samples via CaCO3 addition. The solids that precipitated up to pH ~4 and between pH 4–6 were collected and characterized by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in combination with Scanning Electron Microscope/Energy Dispersive X-ray spectroscopy (SEM/EDX) and synchrotron-based X-ray Absorption Spectroscopy (XAS) and synchrotron-based Micro-X-ray Fluorescence (μ-XRF). Results reveal that REE are mostly scavenged between pH 4–6 in association with Al and Fe phases, whereas a smaller fraction is scavenged at pH ~4 by association with gypsum. Synchrotron-based analysis evidences the incorporation of La3+ into the gypsum structure by substituting Ca2+, indicating a co-precipitation mechanism with gypsum occurring mainly at low pH. Results from parallel adsorption and co-precipitation tests suggest that the REE scavenging between pH 4–6 could be due to a combination of adsorption and co-precipitation on Al(OH)3 and ferrihydrite. This implies that in PTS, REE would be mainly found in Al- (and Fe-) oxyhydroxides occurring in deeper layers of the PTS, i.e., where higher pH-values occur, though a small fraction, especially the light REE, could also be found incorporated into gypsum in the upper layers.