Search Results (95)

The rational design of functional and sustainable polymers is central to addressing global environmental challenges. In this context, unmodified lignin derived from Sarkanda grass (Tripidium bengalense), an abundant agro-industrial lignocellulosic byproduct, was systematically investigated as a natural polymeric adsorbent for the remediation of aqueous media contaminated with heavy metals. The study evaluates lignin’s behavior toward nine metal(loid) ions: arsenic, cadmium, chromium, cobalt, copper, iron, nickel, lead, and zinc. Adsorption performance was systematically investigated under static batch conditions, optimizing key parameters, with equilibrium and kinetic data modeled using established isotherms and rate equations. Surface characterization and seed germination bioassays provided supporting evidence. Unmodified Sarkanda grass lignin demonstrated effective adsorption, exhibiting a clear preference for Cu(II) followed by other divalent cations, with lower capacities for As(III) and Cr(VI). Adsorption kinetics consistently followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. Thermodynamic studies revealed spontaneous and endothermic processes. Bioassays confirmed significant reduction in aqueous toxicity and strong metal sequestration. This work positions unmodified Sarkanda grass lignin as a bio-based, low-cost polymer platform for emerging water treatment technologies, contributing to circular bioeconomy goals and highlighting the potential of natural polymers in sustainable materials design. Full article

The gastrointestinal tract mediates the absorption of nutrients from the diet, which is increasingly contaminated with toxic metal(loid) species (TMs) and thus threatens food safety. Evidence in support of the influx of TMs into the bloodstream of the general and vulnerable populations (babies, children, pregnant women, and industrial workers) has been obtained by accurately quantifying their blood concentrations. The interpretation of these TM blood concentrations, however, is problematic, as we cannot distinguish between those that are tolerable from those that may cause the onset of environmental diseases. Since TMs that have invaded the bloodstream may perturb biochemical processes therein that will eventually cause organ damage it is crucial to better understand their bioinorganic chemistry as these processes collectively determine their organ availability. Thus, bioinorganic processes of TMs in the bloodstream represent selectivity filters which protect organs from their influx and ultimately determine the corresponding exposure-response relationships. The need to better understand selectivity filters prompted us to mechanistically disentangle them into the major bioinorganic chemistry processes. It is argued that the detoxification of TMs in the bloodstream and the biomolecular mechanisms, which mediate their uptake into target organs, represent critical knowledge gaps to revise regulatory frameworks to reduce the disease burden. Full article

The occurrence of toxic metal(loid)s in surface freshwater is a global concern due to its impacts on human and ecosystem health. Conceptual and quantitative metal(loid) models are needed to assess the impact of metal(loid)s in watersheds affected by acid rock drainage. Few case studies have focused on arid and semiarid headwaters, with scarce hydrological and hydrochemical information. This work reports the use of WASP8 (US EPA) to model Al, Fe, As, Cu, and SO₄²⁻ concentrations in the Upper Elqui River watershed in north–central Chile. Calibrated model performance for total concentrations was “good” (25.9, RRMSE; 0.7, R²-d) to “very good” (0.8–0.9, R²-d). The dissolved concentrations ranged between “acceptable” (56.3, RRMSE), “good” (28.6, RRMSE; 0.7 d), and “very good” (0.9, R²-d). While the model validation achieved mainly “very good” (0.8–0.9, R²-d) predictions for total concentrations, the predicted dissolved concentrations were less accurate for all indicators. Sensitivity analysis showed that the partition coefficient is a sensitive constant for estimating dissolved concentrations, and that integrating sorption and sediment interaction reduces the model error. This work highlights the need for detailed and site-specific information on the reactive and hydrodynamic properties of suspended solids, which directly impact the partition coefficient, sedimentation, and resuspension velocity calibration. Full article

In 2019, an unusual mortality event (UME) affected bottlenose dolphins (Tursiops truncatus) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and electrolyte imbalances in dolphins. Additionally, the influx likely altered the MSS’s environmental chemical composition, including levels of heavy metals and metalloids; thus, we quantified heavy metals, metalloids, and essential elements in the tissues of dolphins that stranded in the MSS before and after the 2019 UME. We hypothesized that levels of heavy metals and metalloids (such as mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd)) would not show significant changes post-UME. Indeed, we found no major changes associated with the UME in most metals; sodium (Na) and magnesium (Mg) levels were lower in several tissues after 2019, which correlated with the average yearly salinity measured from the MSS. Toxic metals and metalloids were detectable with some changes over time; however, the selenium (Se):Hg molar ratio increased in some tissues post-2019. Additionally, we confirmed that Hg can bioaccumulate, with positive correlations between Hg levels and dolphin size as assessed by straight length. Overall, our findings indicate that freshwater incursions into the MSS can alter dolphin exposure to essential and toxic elements. Full article

Evaluating the bioaccessibility and health risks of seafood is extremely important because, although it is a significant source of vital minerals, it may also contain potentially toxic elements. This study aimed to determine the content of metals and minerals in different seafood species before and after thermal processing. Also, given the risk of overestimating the actual final concentration available in the body, a study was carried out to determine the bioaccessibility of these elements by simulating the digestion process in the gastrointestinal tract. Assessment of the potential toxic effects on consumer health in terms of exposure to heavy metals was carried out through risk analysis by Estimated Daily Intake, Hazard Index, and Cancer Risk parameters. Three bivalve mollusks, one gastropod mollusk, four cephalopod mollusks, and one crustacean species were analyzed in terms of minerals (P, S, K, Ca, and Se) and heavy metals (Cd, Pb, Ni, Cr, Fe, Zn, Co, Mn, and As) content. The lead (Pb) concentration recorded the strongest bioaccessibility increase, even reaching 100% in P. vannamei. Generally, the bioaccessibility of all metalloids dropped below 100%, which suggests that only a part of the amount of metal in the initially ingested sample can be absorbed by the human organism. Potassium and sulfur registered the greatest value, up to 23% for minerals’ bioaccessibility in the same samples. The highest intake rate of metals occurred after the consumption of M. gigas, which registered the highest Estimated Daily Intake for Cr (chromium) (0.321 mg kg⁻¹ d⁻¹), Cu (copper) (10.15 mg kg⁻¹ d⁻¹), and Zn (zinc) (12.67 mg kg⁻¹ d⁻¹). The Hazard Index values indicated no significant risk of poisoning. All calculated Cancer Risk scores remained below the acceptable threshold. Moreover, the Pearson coefficient revealed a positive correlation between the Hazard Index and the most abundant elements in the samples, Cr, Zn, and Cu. This study could provide a framework for evaluating both the nutritional benefits and toxicological concerns of seafood intake in public health applications. Full article

Arsenic (As) and cadmium (Cd) contamination in groundwater poses significant risks to human health and environmental sustainability. Iron–manganese minerals and associated microorganisms in subsurface environments exhibit remarkable potential for immobilizing and transforming toxic metal(loid)s through adsorption, redox reactions, and co-precipitation. This study integrates bibliometric analysis with mechanistic review strategies to systematically evaluate the roles of iron–manganese biomineralization in As/Cd stabilization. Bibliometric insights identify emerging research trends, including the application of biogenic oxides and microbial redox cycles in groundwater remediation. Mechanistic analysis reveals how microbial–mineral interactions regulate As/Cd sequestration, emphasizing the influence of environmental factors such as pH, redox conditions, and microbial metabolic pathways. Case studies demonstrate the viability of in situ remediation technologies leveraging these biogeochemical processes, though challenges persist in achieving consistent field-scale performance and long-term stability. Future efforts should prioritize optimizing microbial consortia, advancing real-time monitoring systems, and integrating biogeochemical strategies with engineered barriers. By synthesizing quantitative trends and mechanistic principles, this work provides actionable frameworks for enhancing natural attenuation and designing sustainable remediation systems for metal-contaminated groundwater. Full article

Soil pollution is a global threat that seriously affects biodiversity in (agro)ecosystems and may compromise water and food quality. Therefore, the ability of tree species (Populus tremula, Salix caprea, and Betula pendula) to accumulate and phytoextract specific toxic heavy metals from soil was investigated. The study was conducted in and near relict mining areas of Freiberg (Germany) and sampling sites selected according to their spatial location relative to potential sources of metal(loid)s. The concentrations of geogenic (P, Fe, Mn, Ca) and pollutant (Pb, Cd, Zn, As) elements in soil and the present trees were measured using ICP-MS. The highest total soil concentrations of As (8978 µg g⁻¹) were found within the Davidschaft mining area, and for soil Pb, both in the Davidschaft vicinity (328 µg g⁻¹) and mining area (302 µg g⁻¹). Unexpectedly, the highest soil Zn (0.64 mg g⁻¹) and Cd (3.5 mg g⁻¹) concentrations were found in Freiberg city Forest. The lowest soil concentrations of pollutants (As, Cd, Pb, and Zn) were recorded for Seifersdorf. Total soil P was highest in Colmnitz, but Ca, Mn, and Fe concentrations were very similar across all sites. The available concentration of all measured toxic elements in the soil generally decreased in the order Davidschaft > Davidschaft vicinity, Colmnitz > Seifersdorf = Freiberg city forest. All studied tree species had higher concentrations of the essential elements in leaves than in branches. Generally, higher values of bioaccumulation coefficients (especially for Cd) were found for Salix caprea compared with Populus tremula and Betula pendula. Full article

This study evaluates the impact of phosphogypsum stacks on the chemical composition of rainwater in the Huelva metropolitan area, a metal-polluted area with high cancer and heart disease mortality rates. A total of 612 rainwater samples were collected using 17 rain gauges located around the study area between January 2021 and December 2022. The pH, conductivity, major ions, and trace metals were detected in the soluble fraction of rainwater. The results revealed spatial variability in the rainwater quality. The highest values of As, Ca²⁺, Cr, F⁻, NH₄⁺, Ni, PO₄³⁻, SO₄²⁻, Sr, and V were detected in rain-gauges near phosphogypsum stacks, exceeding the levels of pH, F⁻, and Ni according to the guideline values for drinking water quality from the WHO. Additionally, other pollution sources also contributed: a regional source (marine factors: Ca²⁺, Cl⁻, K⁺, Mg²⁺, and Na⁺) and a local source (chemical complexes emissions: Co, Cu, Pb, and Zn). A downward trend of most toxic metal(loid) concentrations in wet depositions was detected as the distance to the affected area increased. The findings revealed that phosphogypsum stacks are a relevant source of metal(loid)s with potentially adverse environmental and public health effects that, if replicated, could be relevant for environmental monitoring and policy making. Full article

Huelva is a city in SW Spain with 150,000 inhabitants, located in the proximity of two heavy chemical industry complexes, the highest naturally occurring radioactive material (NORM) waste (phosphogypsum) stacks of Europe and a highly polluted estuary, with elevated cardiovascular disease and cancer mortality rates. This study analyses the association between cumulated exposure levels to 16 metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Tl, U, V, and Zn) measured in the toenail of a sample (n = 55 participants) of the general control population of Huelva City who were involved in the MCC-Spain study and the spatial proximity patterns to the local polluting sources. Residents of the city of Huelva have higher levels of Fe, Ni, Cr, Se, As, and Co in their toenails compared to the levels found in populations with similar characteristics living in non-polluted areas. Moreover, the highest concentrations of As, Pb, Cd, Mo, and Se were found in toenails of participants living near the NORM waste stack, while the highest Cu, Zn, and Al contents corresponded to people residing near the industrial area. The spatial distribution of most of the metal(loid)s studied appears to be mainly controlled by anthropogenic factors. Full article

The contamination of rivers by potentially toxic elements (PTEs) is a problem of global importance. The Valles River is Ciudad Valles’ (Central Mexico) main source of drinking water. During the four seasons of the year, water samples (n = 6), sediment samples (n = 6), and Phragmites australis plants (n = 10) were taken from three study sites selected based on the presence of anthropogenic activities in the Valles River. A graphite atomic absorption spectrophotometer estimated elements in the water, and an energy-dispersive X-ray fluorescence spectrometer quantified elements in sediments and plant samples. Phragmites australis accumulated metal(loid)s mainly in the roots during all seasons of the year. Water samples from all sites recorded PTEs (As, Pb, Cd, and Hg), with primary sources identified as the sugar industry, urban and industrial wastewater, and the combustion of fossil fuels. Sediment samples showed concentrations of Hg, Mn, Ni, Zn, Pb, V, Cu, Cr, and Cd, attributed to agricultural practices, industrial activity, and urbanization. P. australis is an alternative for in situ phytoremediation because this macrophyte can bioaccumulate different elements in its roots, such as Mn, Rb, V, Sr, Cu, Zn, Pb, Ni, and As. Full article

Endocrine-disrupting compounds (EDCs) are emerging pollutants that can potentially accumulate in aquatic ecosystems at significant levels, with the potential to impact the health of both animals and humans. Many scientists have correlated human exposure to high concentrations of EDCs with critical physiological impacts, including infertility, thyroid imbalance, early sexual development, endometriosis, diabetes, and obesity. Several substances, such as heavy metals, belong to this family, ranging from natural to synthetic compounds, including pesticides, pharmaceuticals, and plastic-derived compounds. Domestic sewage represents a significant source of EDCs in the surrounding aquatic ecosystems. To this day, most rural and urban domestic wastewater in the municipality of Maricá is directly discharged into local aquatic environments without any treatment. The present study aimed to assess the potential contamination of the riverine and lagoonal environment in the municipality of Maricá. Water and sediment samples were collected seasonally at 18 sites along the Maricá watershed and the main lagoon, into which most of the watershed’s contributors flow. Water physico-chemical parameters (pH, reduction–oxidation potential—Eh, dissolved oxygen levels, salinity, turbidity, temperature, and fecal coliforms) were analyzed to characterize the urban influence on the aquatic environment. Sediment samples were also analyzed for grain size, total organic carbon percentage, potential bioavailable fraction of trace metals (Cd, Pb, Cu, Cr, Hg, Ni, Zn), and metalloid As. Finally, the sediment toxicity was assessed using yeast estrogen screen (YES) assays. The results obtained already demonstrate the presence of estrogenic effects and raise concerns about water quality. The current study indicates that, despite the absence of agricultural and industrial activities in the city of Maricá, EDCs are already present and have the potential to impact the local ecosystem, posing potential risks to human health. Full article

The use of sulfur (S) in polluted soils can reduce metal(loid) toxicity and enhance phytoremediation effectiveness. Here we studied the response of barley plants to As in soil amended with sulfate or elemental sulfur throughout the growing cycle. A greenhouse experiment was carried out using 4-L pots filled with clay-loam soil spiked with 60 mg kg⁻¹ As (Na₂HAsO₄·7H₂O). Two chemical forms of sulfur (elemental sulfur (S⁰) or sulfate (CaSO₄·2H₂O)) were applied at a dose of 1 and 3 Mg ha⁻¹, respectively, and two previously seeded barley plants were transplanted in each pot, using eight pots per treatment. At the end of the growing cycle, the biomass, nutrients, and metal(loid) content, as well as several physiological and biochemical parameters of the plants were analyzed. Moreover, the effect of the treatments on soil characteristics was also evaluated, including soil pore water. The treatment with sulfur promoted the growth of barley plants through their vegetative cycle, enhancing photosynthesis, although biomass did not significantly increase. Both sources of S promoted the accumulation of As in the root, thereby limiting its translocation to the aerial part of the plant, sulfate being more effective (an increase of 300%) than elemental S (an increase of 82%). The addition of S decreased soil pH. Furthermore, both treatments, but particularly sulfate, increased soluble sulfate and stimulated soil biological properties. In conclusion, the application of sulfate to As-polluted soil can enhance As phytostabilization by barley plants while simultaneously improving the biological properties of the soil. Full article

This study explores the encapsulation in alginate/bentonite beads of two metal(loid)-resistant bacterial consortia (consortium A: Pseudomonas sp. and Bacillus sp.; consortium B: Pseudomonas sp. and Bacillus sp.) from the Atacama Desert (northern Chile) and Antarctica, and their influence on physiological traits of Chenopodium quinoa growing in metal(loid)-contaminated soils. The metal(loid) sorption capacity of the consortia was determined. Bacteria were encapsulated using ionic gelation and were inoculated in soil of C. quinoa. The morphological variables, photosynthetic pigments, and lipid peroxidation in plants were evaluated. Consortium A showed a significantly higher biosorption capacity than consortium B, especially for As and Cu. The highest viability of consortia was achieved with matrices A1 (3% alginate and 2% bentonite) and A3 (3% alginate, 2% bentonite and 2.5% LB medium) at a drying temperature of 25 °C and storage at 4 °C. After 12 months, the highest viability was detected using matrix A1 with a concentration of 10⁶ CFU g⁻¹. Further, a greenhouse experiment using these consortia in C. quinoa plants showed that, 90 days after inoculation, the morphological traits of both consortia improved. Chemical analysis of metal(loid) contents in the leaves indicated that consortium B reduced the absorption of Cu to 32.1 mg kg⁻¹ and that of Mn to 171.9 mg kg⁻¹. Encapsulation resulted in a significant increase in bacterial survival. This highlights the benefits of using encapsulated microbial consortia from extreme environments, stimulating the growth of C. quinoa, especially in soils with metal(loid) levels that can be a serious constraint for plant growth. Full article

Chemometric evaluation of potentially harmful volatile compound and toxic metal(loid) distribution patterns in fruit spirits relating to distinct fruit classes most commonly used in spirit production highlighted the potential of several volatiles as candidates for differentiation markers while dismissing toxic metal(loid)s. Pome fruit and grape pomace spirits were mostly characterized by a lower abundance of n-propanol, methanol, ethyl acetate and acetaldehyde, while stone fruit spirits contained lower amounts of isoamyl alcohol and isobutanol. Chemometric analysis of the fruit spirit composition of aromatics identified additional potential markers characteristic for certain fruits—benzoic acid ethyl ester, benzyl alcohol, benzaldehyde, butanoic acid 3-methyl-ethyl ester, butanoic acid 2-methyl-ethyl ester and furfural. This study explored the variability in the risk potential of the investigated spirits, considering that some chemicals known to be detected in spirits are potent health hazards. Ethyl carbamate in combination with acetaldehyde showed a higher potential risk in stone fruit spirits, methanol in stone and pome fruit spirits and acetaldehyde in grape pomace spirits. It is of great interest to evaluate to what extent consumers’ preference for spirits of distinct fruit types affects health risks. Consumers of stone fruit spirits are potentially at higher risk than those consuming pome fruit or grape pomace spirits. Full article

In this study, the oral bioavailability of Pb, Cd, and As in three types of traditional Chinese medicines (TCMs) and TCM decoctions were investigated through in vitro PBET digestion/MDKC cell model. Furthermore, a novel cumulative risk assessment model associated with co-exposure of heavy metal(loid)s in TCM and TCM decoction based on bioavailability was developed using hazard index (HI) for rapid screening and target organ toxicity dose modification of the HI (TTD) method for precise assessment. The results revealed that the bioavailability of Pb, Cd, and As in three types of TCM and TCM decoction was 5.32–72.49% and 4.98–51.97%, respectively. After rapid screening of the co-exposure health risks of heavy metal(loid)s by the HI method, cumulative risk assessment results acquired by TTD method based on total metal contents in TCMs indicated that potential health risks associated with the co-exposure of Pb, Cd, and As in Pheretima aspergillum (E. Perrier) and Oldenlandia diffusa (Willd.) Roxb were of concern. However, considering both the factors of decoction and bioavailability, TTD-adjusted HI outcomes for TCMs in this study were <1, indicating acceptable health risks. Collectively, our innovation on cumulative risk assessment of TCM and TCM decoction provides a novel strategy with the main purpose of improving population health. Full article