Hydrogeochemical appraisal, sources, quality and potential health risk assessment in Holocene and Pleistocene aquifers in Bangladesh.

This study integrated hydrochemical analysis, isotopic analysis, the integrated water quality index (IWQI), and the health risk assessment model to analyze hydrochemical characteristics, quality, and nitrate health risks in a typical agricultural and industrial (i.e., Holocene and Pleistocene) simultaneously affected by anthropogenic activities, as well as to explore the recharge mechanisms of the groundwater. The shallow groundwater is mainly Ca-HCO3- and deep groundwater is mainly Na-HCO3- types. In shallow and intermediate aquifers (Holocene), rainfall recharge is seen, but in deep aquifers (Holocene) and the Madhupur tract (Pleistocene), there is no evidence of recent recharge from the stable isotopic (δ2H‰ and δ18O‰) composition of groundwater. Anthropogenic sources significantly impacted the groundwater chemistry of shallow and intermediate aquifers more than geogenic sources. Most metalloids, and metals (As, and Cr, Fe, Ni, Pb, and Mn) and NO3- exceed the WHO-2011 and BD acceptable limit from shallow and intermediate groundwater. PCA analysis revealed the contamination of shallow and intermediate aquifers by metalloids, metals and from various anthropogenic activities. Based on the IWQI, HPI, HEI, and DC, groundwater samples from shallow and intermediate aquifers are unsuitable for oral consumption. The NPI shows that the metalloids, and metals are responsible for groundwater pollution in a descending order of As > Fe > Pb > Ni > Cr > Mn. Health risk assessment indicates oral and dermal consumption of contaminated water from shallow and intermediate aquifers can pose carcinogenic and non-carcinogenic health risks for both the adults and the children. The HQ and HI values of shallow and intermediate groundwater indicates higher non-carcinogenic risk. Carcinogenic risk through oral and dermal consumption follows an order of As > Ni > Cr > Pb and Ni > Cr > As > Pb, respectively. Compared to adults, children are more susceptible to both carcinogenic and non-carcinogenic risks. Potential threats to the health of people living in the study region need immediate attention from the public, government, and the scientific community.

Arsenic and metal levels in snake tissues from Lagoa Santa Karst, Brazil.

Concentrations of one metalloid (As) and eight metals (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) were determined in tissues (muscle, liver, and kidney) of eight snake species (Bothrops neuwiedi, Crotalus durissus, Dipsas mikanii, Epicrates crassus, Helicops modestus, Micrurus carvalhoi, Oxyrhopus guibei, and Oxyrhopus trigeminus) from Lagoa Santa Karst. Except for Cu and Zn, all other analyzed elements were detected in concentrations within the ranges previously reported for snakes inhabiting polluted areas, emphasizing Hg (specific Hg mean concentrations varied from 0.87 to 9.76 µg g-1 d.w). The highest mean concentrations of all elements except Zn were found in muscle samples of the false corals O. guibei (means ranged from 2.01 [Pb] to 9.76 [Hg]). The highest Zn mean concentration (13.77 µg g-1 d.w) was detected in the kidney of the water snake H. modestus. No significant correlation was found between element concentrations and body size for all species. Significant interorgan differences were observed for As, Cr, Cu, Hg, Mn, Pb, and Zn concentrations in the three tissues in H. modestus. Significant interspecific differences were found in at least one organ for all elements. Significant pairwise differences were found between diet specialist species and between these species and broader diet species, while no significant difference was found between the broader diet species. The bioaccumulation of As and metals in snakes from Lagoa Santa Karst could be associated with natural rock dissolution and erosion processes but also with the wide-scale mining in the region and the increased agriculture and urbanization.

Impacts of atmospheric particulate matter deposition on phytoplankton: A review.

In many rapidly urbanizing and industrializing countries, atmospheric pollution causes severe environmental problems and compromises the health of humans and ecosystems. Atmospheric emissions, which encompass gases and particulate matter, can be transported back to the earth's surface through atmospheric deposition. Atmospheric deposition supplies chemical species that can serve as nutrients and/or toxins to aquatic ecosystems, resulting in wide-ranging responses of aquatic organisms. Among the aquatic organisms, phytoplankton is the basis of the aquatic food web and is a key player in global primary production. Atmospheric deposition alters nutrient availability and thus influences phytoplankton species abundance and composition. This review provides a comprehensive overview of the physiological responses of phytoplankton resulting from the atmospheric deposition of trace metals, nitrogen-containing compounds, phosphorus-containing compounds, and sulfur-containing compounds in particulate matter into aquatic ecosystems. Knowledge gaps and critical areas for future studies are also discussed.

Excess copper promotes an increase in the concentration of metabolites in Tridax procumbens L.

The study investigated the effects of cultivating Tridax procumbens in hydroponic conditions with different concentrations of copper ions, aiming to understand the physiological changes and the impact on the biosynthesis of secondary metabolites. The treatments consisted of a completely randomized design, with five increasing concentrations of copper (T0 = 0.235, T1 = 12.5, T2 = 25, T3 = 50, T4 = 100 µmol L-1 of Cu), under controlled conditions for 36 days. Analysis of bioactive compounds in leaves was performed by HPLC-DAD and ESI-MS. Several phenolic compounds, alkaloids, phytosterols and triterpenoids were identified, demonstrating the plant's metabolic plasticity. The highest dose of copper (100 µmol L-1) significantly promoted voacangine, the most predominant compound in the analyses. Notably, 66.7% of the metabolites that showed an increase in concentration, were phenolic compounds. Furthermore, treatments with 12.5 and 25 µmol L-1 of copper were identified as promoting the biosynthesis of phytosterols and triterpenoids. These biochemical adaptations can play a fundamental role in the survival and development of plants in environments contaminated by metals, and from this it is possible to determine cultivation techniques that maximize the biosynthesis of the compound of interest.

Trace metal speciation trends in Mazowe dam, Zimbabwe, a typical sub-tropical dam ecosystem impacted by gold mining and agriculture.

The present study aimed to assess trace metal speciation trends in the water and sediments of Mazowe Dam, a typical sub-tropical dam ecosystem impacted by gold mining and agriculture in Zimbabwe. The elements studied include Al, As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb, and Zn. Elemental speciation in the water column was determined using Visual MINTEQ version 3.1 geochemical computer modelling, while speciation in the sediment phase was determined using sequential extraction techniques. For each element, the data obtained were subjected to extensive correlation analysis to identify intra- and inter-metal species interactions in the water column and the sediment phase, as well as across the water-sediment interface. Possible mechanisms to account for the observed species interactions are proposed. In the water column, Co was predicted to have the highest number of chemical species (9), Cd and Zn (8), Mn and Fe (7), Ni (6), Pb (5), Al and Cu (3), Cr, Hg, and As have the least (2). In the sediment, Al, As, Co, Cr, Cu, Fe, Ni and Fe mainly exist in the residual fraction, while Zn and Mn concentrations in fractions vary per sampling site, with no fraction that is dominant across the sampling sites. Equilibrium exchange reactions across the water-sediment interface were observed e.g., for Cd species /FA2Cd (aq) and Co species /FACo+2G (aq), and /FA2Co (aq). This study is valuable in highlighting trace metal speciation in a tropical dam ecosystem in Africa and adds to the growing knowledge about the behaviour of trace metals in aquatic ecosystems in the region and globally.

Exploring spatial and temporal symptoms of the freshwater salinization syndrome in a rural to urban watershed.

The freshwater salinization syndrome (FSS), a concomitant watershed-scale increase in salinity, alkalinity, and major-cation and trace-metal concentrations, over recent decades, has been described for major rivers draining extensive urban areas, yet few studies have evaluated temporal and spatial FSS variations, or causal factors, at the subwatershed scale in mixed-use landscapes. This study examines the potential influence of land-use practices and wastewater treatment plant (WWTP) effluent on the export of major ions and trace metals from the mixed-use East Branch Brandywine Creek watershed in southeastern Pennsylvania, during the 2019 water year. Separate analysis of baseflow and stormflow subsets revealed similar correlations among land-use characteristics and streamwater chemistry. Positive associations between percent impervious surface cover, which ranged from 1.26 % to 21.9 % for the 13 sites sampled, and concentrations of Ca2+, Mg2+, Na+, and Cl- are consistent with road-salt driven reverse cation exchange and weathering of the built environment. The relative volume of upstream WWTP was correlated with Cu and Zn, which may be derived in part from corroded water-conveyance infrastructure; chloride to sulfate mass ratios (CSMR) ranged from ~6.3 to ~7.7× the 0.5 threshold indicating serious corrosivity potential. Observed exceedances of U.S. Environmental Protection Agency Na+ and Cl- drinking water and aquatic life criteria occurred in winter months. Finally, correlations between percent cultivated cropland and As and Pb concentrations may be explained by the persistence of agricultural pesticides that had been used historically. Study results contribute to the understanding of FSS solute origin, fate, and transport in mixed-use watersheds, particularly those in road salt-affected regions. Study results also emphasize the complexity of trace-metal source attribution and explore the potential for FSS solutes to affect human health, aquatic life, and infrastructure.

Opportunistic omnivory impairs the use of the Atlantic blue crab Callinectes sapidus as a trace metal biomonitor in invaded Mediterranean coastal waters.

The contribution of non-indigenous species to the transfer of contaminants in invaded food webs represents an active research area. Here we measured trace metals and CN stable isotopes in five populations of the invasive Atlantic blue crab Callinectes sapidus and in baseline bivalve species from Spain, Italy and Greece. They were used to estimate trophic transfer effects and the trophic position and isotopic niche of C. sapidus. Maximum trophic transfer effects occurred where the crab showed the largest isotopic niches and highest trophic positions; furthermore, the consistency of trace metal profiles between bivalves and crabs co-varied with the trophic position of the latters. Omnivory may influence the success of an invasive species, but also limit its effectiveness for biomonitoring. However, our results indicated that stable isotopes analysis provides a clarifying background where to cast patterns of contamination of the blue crab as well as of other omnivorous biomonitor species.

Controlling exposure to As and Cd from rice via irrigation management.

Irrigation management controls biogeochemical cycles in rice production. Under flooded paddy conditions, arsenic becomes plant-available as iron-reducing conditions ensue, while oxic conditions lead to increased plant availability of Cd in acidic soils. Because Cd enters rice through Mn transporters, we hypothesized that irrigation resulting in intermediate redox could simultaneously limit both As and Cd in rice grain due to As retention in soil and Mn competition for Cd uptake. In a 2 year field study, we used 6 irrigation managements that varied in extent and frequency of inundation, and we observed strong effects of irrigation management on porewater chemistry, soil redox potentials, plant As and Cd concentrations, plant nutrient concentrations, and methane emissions. Plant As decreased with drier irrigation management, but in the grain this effect was stronger for organic As than for inorganic As. Grain organic As, but not inorganic As, was strongly and positively correlated with cumulative methane emissions. Conversely, plant Cd increased under more aerobic irrigation management and grain Cd was negatively correlated with porewater Mn. A hazard index approach showed that in the tested soil with low levels of As and Cd (5.4 and 0.072 mg/kg, respectively), irrigation management could not simultaneously decrease grain As and Cd. Many soil properties, such as reducible As, available Cd, soil pH, available S, and soil organic matter should be considered when attempting to optimize irrigation management when the goal is decreasing the risk of As and Cd in rice grain.

Organic carbon, major and trace element release from and adsorption onto particulate suspended matter of the Ob River, western Siberia.

Particulate suspended matter (PSM) of rivers is a significant factor for carbon, nutrient, and trace metal transfer from land to ocean. Towards better understanding the role that PSM exerts on major and trace elements in riverine systems, here we report the results of an experimental study which utilizes a two-fold approach to assess interaction between PSM and riverine solutes. First, we measured element leaching (via desorption and dissolution in distilled water, simulating snow melt) from PSM of the largest Siberian river, the Ob River. Second, we quantified the capacity of PSM to adsorb dissolved organic carbon (DOC), macro- and micronutrients and trace elements from organic-rich waters of the river floodplain. We documented sizable desorption of organic carbon, some major and trace metals, oxyanions and insoluble elements from PSM; the majority (>50 %) of elements were released over the first hour of reaction. In contrast, PSM of the Ob River was capable of removing 20 to 90 % of dissolved OC, nutrients (Si, P), and trace elements from the tributary and floodplain fen. Our experiments demonstrated preferential adsorption of aromatic compounds large molecular size colloids. Taken together, the adsorption of solutes by PSM can sizably decrease the concentration and modify the molecular size distribution, and therefore the potential bioavailability of major (DOC, P, Si) and trace micronutrients. Overall, the PSM of the Ob River exhibited high reactivity with respect to natural waters and was capable of modifying the elemental composition of the tributary and floodplain fen waters. This transfer of organic carbon and nutrients in the surface-adsorbed (particulate) form is especially important during spring flood and requires specific consideration in short-term biogeochemical cycles of elements in continental waters.

Efficacy of anthocyanin, kaolinite and cabbage leaves-derived biochar for simultaneous removal of lead, copper and metoprolol from water.

Simultaneous removal of toxic elements and pharmaceutical compounds at environmentally relevant concentrations in aqueous solution is challenging. Modification of biochar using environmental materials has attracted significant attention in wastewater treatment, while pristine biochar has several limitations in the simultaneous removal of Lead (Pb2+), Copper (Cu2+), and metoprolol. We investigated the efficacy of biochar composites using waste cabbage leaves-derived biochar with kaolinite, and anthocyanin for simultaneous removal of Pb2+, Cu2+, and metoprolol from water. Using ball milling, the surface area and functional groups of adsorbents were improved via breaking the biochar grains into ultrafine particles. Ball-milled biochar derived from waste cabbage leaves significantly increased Pb2+, Cu2+, and metoprolol adsorption by 105, 71, and 213%, respectively. Results of Brunauer Emmett Teller surface area, Fourier transform infrared and X-ray photoelectron spectroscopies showed that surface area of non-milled biochar improved nearly ten-fold following ball-milling, while several oxygen containing acidic functional groups also increased. The adsorbents resulted in high removal efficiency for Pb2+ (162.9 mg/g) and Cu2+ (48.5 mg/g) in ball milled-kaolinite composite biochar (BMKB) and 76.3 mg/g (metoprolol), respectively in ball milled-anthocyanin composite biochar (BMAB). The simultaneous sorption of Pb2+, Cu2+, and metoprolol in an aqueous solution to BMAB and BMKB, showed that the adsorption capacity followed the order of Pb2+ >Cu2+ > metoprolol in both types of ball-milled biochars. BMKB achieved a high adsorption capacity for Pb2+ and Cu2+ (59 mg/g and 50 mg/g), respectively, while BMAB exhibited an adsorption capacity 22.3 mg/g for metoprolol. It was postulated that sorption of Pb2+, Cu2+ and metoprolol involved multiple adsorption mechanisms namely surface complexation, π-π interaction, H-bond, pore filling, and ion bridging. The findings of this study revealed that ball milling is a potential technology in producing a highlyefficient adsorbent to remediate multi-contaminants in aqueous solution.

Heavy Metal Accumulation in Fish, Sediment and Water from Three Riverine Ecosystems in the South-western Bangladesh and Nexus to Human Health.

This study investigated heavy metal accumulations in fish, water and sediment from three rivers around a major urban area in Bangladesh, namely the Rupsha, the Atai, and the Bhairab with a view to assessing the ecological and human health risks. Samples were collected from 10 stations over two seasons (summer and winter) and concentrations of 11 metals (As, Se, Pb, Be, Cd, Co, Cr, Cu, Mn, Ni, V) were measured using ICP-MS. Heavy metals in water of these rivers were above the WHO higher thresholds. The Rupsha River, which runs close to industrially dense areas and the downstream part of the three-river network, demonstrated the highest As, Cu, and V concentrations during both seasons. On the other hand, As, Mn and Cr were highest in the Bhairab which is the upstream to the Rupsha and connected to several industrial setups which differ from Bhairab. The less anthropogenically connected Atai River only showed elevated concentrations of Cu and Se. Ecological risk indices indicated low pollution in the rivers during both seasons. In all three rivers and in nearly all fish species, the contamination was higher in winter than summer. Benthic and carnivorous fish species such as, Cynoglossus lingua, Glossogobius giuris, Pseudapocryptes elongatus showed higher metal accumulation compared to other species. Health risk indices like the target hazard quotient (THQ) and carcinogenic risk (CR) suggested low risks but pointed potential risks to human health. The outcomes of this research reports insights into metal contamination pattern in interconnected river systems.

Trace metal accumulation through the environment and wildlife at two derelict lead mines in Wales.

Trace metal pollution is globally widespread, largely resulting from human activities. Due to the persistence and high toxicity of trace metals, these pollutants can have serious effects across ecosystems. However, few studies have directly assessed the presence and impact of trace metal pollution across ecosystems, specifically across multiple environmental sources and animal taxa. This study was designed to assess the environmental health impacts of trace metal pollution by assessing its extent and possible transfer into wildlife in the areas surrounding two abandoned metalliferous mine complexes in Wales in the UK. Water, sediment, and soil at the mine sites and in areas downstream had notably elevated concentrations of Pb, Zn, and, to a lesser extent, Cd and Cu, when compared to nearby control sites. These high trace metal concentrations were mirrored in the body burdens of aquatic invertebrates collected in the contaminated streams both at, and downstream of, the mines. Wood mice collected in contaminated areas appeared to be able to regulate their Zn and Cu tissue concentrations, but, when compared to wood mice from a nearby control site, they had significantly elevated concentrations of Cd and, particularly, Pb, detected in their kidney, liver, and bone samples. The Pb concentrations found in these tissues correlated strongly with local soil concentrations (kidney: ρ = 0.690; liver: ρ = 0.668, bone: ρ = 0.649), and were potentially indicative of Pb toxicity in between 10 % and 82 % of the rodents sampled at the mine sites and in areas downstream. The high trace metal concentrations found in the environment and in common prey species (invertebrates and rodents) indicates that trace metal pollution can have far-reaching, ecosystem-wide health impacts long after the polluting activity has ceased, and far beyond the originating site of the pollution.

PM10-bound microplastics and trace metals: A public health insight from the Korean subway and indoor environments.

Inhalable airborne microplastics (MPs) presented in indoor and outdoor environments, can deeply penetrate the lungs, potentially triggering inflammation and respiratory illnesses. The present study aims to evaluate human health risks from respirable particulate matter (PM)-bound trace metals and MPs in indoor (SW- subway and IRH- indoor residential houses) and outdoor (OD) environments. This research provides an initial approach to human respiratory tract (HRT) mass depositions of PM10-bound total MPs and nine specific MP types to predict potential human health threats from inhalation exposure. Results indicate that PM-bound trace metals and MPs were around 4 times higher in SW microenvironments compared to OD locations. In IRH, cancer risk (CR) levels were estimated 9 and 4 times higher for PM10 and PM2.5, respectively. Additionally, MP particle depositions per gram of lung cell weight were highest in IRH (23.77), followed by OD and SW. Whereas, lifetime alveoli depositions of MPs were estimated at 13.73 MP/g, which exceeds previously reported respiratory disease fatality cases by 10 to 5 times. Prolonged exposure duration at IRH emerged as a key factor contributing to increased CR and MP lung deposition levels. This research highlights severe lung risks from inhaling PM-bound MPs and metals, offering valuable health insights.

Assessment of Amphibola crenata as a bioindicator of estuarine trace element pollution using biochemical and physiological endpoints.

To assess its utility as a bioindicator of estuarine contamination, Amphibola crenata, a pulmonate mud snail, was collected from 17 estuaries in New Zealand. Whole-body soft tissue trace element concentrations were measured via quadrupole inductively coupled plasma mass spectrophotometer (Q-ICP-MS) and were found to be significantly positively correlated with sediment trace element profiles for arsenic, copper and lead. Snails from polluted estuaries generally displayed higher ammonia excretion rates, elevated whole-body soft tissue catalase activity and lipid peroxidation compared to snails from reference sites. Across all sites haemolymph glucose was positively correlated with the tissue burdens of arsenic, copper, nickel and zinc, while haemolymph protein was negatively correlated with arsenic, cadmium and zinc soft tissue concentrations, indicative of altered energy metabolism associated with trace element contamination. Overall, sites were distinguishable by application of the array of measures employed. Our findings suggest that gastropods have significant value as bioindicators of estuarine health.

Pharmaceutical and Trace Metal Interaction within the Water-Soil-Plant Continuum: Implications for Human and Soil Health.

Unplanned water reuse for crop irrigation may pose a global health risk due to the entry of contaminants into the food chain, undesirable effects on crop quality, and impact on soil health. In this study, we evaluate the impact derived from the co-occurrence of pharmaceuticals (Phs), trace metals (TMs), and one metalloid within the water-soil-plant continuum through bioassay experiments with Lactuca sativa L. Results indicate that the co-occurrence of Phs and TMs has synergistic or antagonistic effects, depending on target contaminants and environmental compartments. Complex formations between drugs and TMs may be responsible for enhanced sorption onto the soil of several Phs and TMs. Concerning plant uptake, the co-occurrence of Phs and TMs exerts antagonistic and synergistic effects on carbamazepine and diazepam, respectively. With the exception of Cd, drugs exert an antagonistic effect on TMs, negatively affecting their uptake and translocation. Drug contents in lettuce edible parts do not pose any threat to human health, but Cd levels exceed the maximum limits set for leafy vegetable foodstuffs. Under Ph-TM conditions, lettuce biomass decreases, and a nutrient imbalance is observed. Soil enzyme activity is stimulated under Ph-TM conditions (ß-galactosidase) and Ph and Ph-TM conditions (urease and arylsulfatase), or it is not affected (phosphatase).

Distribution of trace metals and metalloids in tissues of Eurasian Woodcock (Scolopax rusticola) from Southern Italy.

Heavy metals and metalloids in the environment are recognised as a threat to the health of organism. Terrestrial birds are ideal subjects for the examination of these pollutants because of their high mobility and high intra- and interspecific variation in trophic levels. We examined the contents of 6 trace metals (Cd, Pb, Cr, Sb and V) and metalloids (As) in the liver, kidney, muscle, and feathers of woodcocks (Scolopax rusticola) from Southern Italy by a validated ICP-MS method. Significant differences in trace elements were found in all the tissues examined (p < 0.05). The highest Sb and Cr levels were found in feathers samples with mean values of 0.019 mg/Kg and 0.085 mg/Kg, respectively. High Pb levels were found in muscle, with 23 % of the samples exceeding the limits set by the European Union. Cd was predominantly found in the kidney samples (0.76 mg/Kg). Vanadium was the less abundant trace metal, showing the highest concentrations in the liver (0.028 ± 0.011 mg/Kg). Higher As levels were found in muscle (0.02 ± 0.015 mg/Kg). No significant differences between sex and age classes (juveniles vs. adults) were found, nor were there correlations between morphometric parameters and trace metal/metalloid contents. Principal Component Analysis determined differences in metal accumulation between tissues. Feathers were confirmed as useful indicators of metal contamination. The results of this work confirmed that the accumulation of toxic elements in the tissues of woodcocks is primarily influenced by ecological traits such as feeding habits and migration status. Statistical analysis of the tissues would seem to exclude important accumulation phenomena of Pb. The high levels found in the muscle could be due to lead ammunition. This work provides the first data on the accumulation of As, Cr, Sb, and V in woodcocks tissue, providing a more comprehensive insight into the potential impact of these pollutants on birds.

Fronts divide diazotroph communities in the Southern Indian Ocean.

Dinitrogen (N2) fixation represents a key source of reactive nitrogen in marine ecosystems. While the process has been rather well-explored in low latitudes of the Atlantic and Pacific Oceans, other higher latitude regions and particularly the Indian Ocean have been chronically overlooked. Here, we characterize N2 fixation and diazotroph community composition across nutrient and trace metals gradients spanning the multifrontal system separating the oligotrophic waters of the Indian Ocean subtropical gyre from the high nutrient low chlorophyll waters of the Southern Ocean. We found a sharp contrasting distribution of diazotroph groups across the frontal system. Notably, cyanobacterial diazotrophs dominated north of fronts, driving high N2 fixation rates (up to 13.96 nmol N l-1 d-1) with notable peaks near the South African coast. South of the fronts non-cyanobacterial diazotrophs prevailed without significant N2 fixation activity being detected. Our results provide new crucial insights into high latitude diazotrophy in the Indian Ocean, which should contribute to improved climate model parameterization and enhanced constraints on global net primary productivity projections.

Source apportionment of major ions and trace metals in the lacustrine systems of Schirmacher Hills, East Antarctica.

The fabric of the Antarctic lacustrine system has a crucial role in assimilating the anthropogenic inputs and mitigating their long time impacts on climate change. Here, we present the changes in the concentrations of major ions and trace metals in the surface water of the lacustrine system to understand the extent of anthropogenic impacts from the adjacent Schirmacher Hills, East Antarctica. The results show that the land-locked lakes (closed-basin lakes surrounded by topographical barriers such as mountains or bedrock formations) in the region have a moderate enrichment in elemental concentrations compared to the pro-glacial lakes (marginal freshwater bodies that form at the terminus of a glacier or ice sheet). The water quality index (WQI: 7.58-12.63) and pollution evaluation index (PEI: 1.36-2.35) remained normal, indicating that the water in these lake are of good quality. However, a significant correlation between lithogenic elements (Al, Fe) and potentially toxic elements (Cd, Cr, and Ba), suggests an increase in the anthropogenic impacts. Based on the principal component analysis (PCA), the source of trace metals to the lacustrine systems appears to be the surrounding environment, followed by aerosol dust particles. Hierarchical cluster analysis (HCA) revealed that regional topography significantly impacts the supply of major ions/trace metals to these lakes. The present study provides baseline data and can be used to estimate and forecast future local and/or global anthropogenic contaminations in the lacustrine system of Schirmacher Hills, East Antarctica. Moreover, the presence of research stations (Maitri and Novolazarevskaya), tourist activities, and the potential for anthropogenic stressors necessitate continued monitoring and impact assessment programs within the Schirmacher Hills lacustrine systems. These programs are crucial for safeguarding this pristine ecosystem from future environmental disturbances under a changing Antarctic climate, as mandated by the Antarctic Treaty System and the Indian Antarctic Act.

Groundwater quality appraisal and zone mapping for agriculture utilities in Wadi Fatima, Saudi Arabia using water quality indices, boron and trace metals.

Groundwater quality in Wadi Fatimah is evaluated and demarcated for agriculture utilities using comprehensive approaches namely, international standards, agricultural water quality (AWQ) indices, irrigation water quality index (IWQI), and trace metals. Groundwater samples were collected (n = 59) and analysed for EC, pH, major and minor ions and trace metals. According to FAO recommendations, 42% of samples (EC > 3000 µS/cm) are inappropriate for agricultural uses. AWQ indices including salinity hazard, Kelly's ratio and Na% show that 50%, 19% and 37% of samples, respectively, are unsuitable for agricultural uses. USSL classification reveals that groundwater is preferable only for high-permeability soils and salt-tolerant crops. IWQI suggests that 88% of samples are moderately usable for agriculture. The interrelationship between water salinity and crop yield justified that 73%, 59%, 51% and 25% of samples are desirable to yield 90% in date palm trees, sorghum, rice and citrus fruits, respectively. Groundwater is appropriate for date palm trees except in downstream regions. Boron concentration suggests that 52%, 81% and 92% of samples are suitable for sensitive, semi-tolerant and tolerant crops, respectively. Groundwater in the central part (suitable for sensitive crops), central and upstream regions (semi-tolerant crops) and all regions except downstream (tolerant crops) are suitable for cultivation. Trace metals contents illustrate that 36%, 34%, 22%, 8%, 5% and 100% of samples are inappropriate for agriculture due to high concentrations of Cr, Cu, Ni, V, Mn and Mo, respectively in the groundwater. Further, AWQ indices, IWQI, USSL classifications and trace metals ensure that groundwater in the downstream, and a few pockets in the upstream are unfit for agricultural uses. This study recommends that groundwater in this basin is more suitable for tolerant crops (ie. date palm, sorghum) followed by semi-tolerant and sensitive crops.

Bioaccumulation of trace metals in edible terrestrial snails, Theba pisana and Otala spp., in a dumpsite area in Morocco and assessment of human health risks for consumers.

This study assessed the bioaccumulation patterns of five trace metals (Cd, Cr, Co, Cu, and Zn) in two edible snail species, Theba pisana and Otala spp., collected from a dumpsite in Safi City, Morocco. The results indicated that bioaccumulation might be species-specific, as metal concentration profiles varied between the two snail species. Additionally, higher metal levels in the dumpsite snails confirmed their potential as bioindicators of trace metal pollution in terrestrial environments. However, the distribution of trace elements within the edible parts of the snails showed marked unevenness, with the viscera accumulating more metals than the foot. The study also evaluated the potential human health risks associated with consuming these snails. Trace metal levels in the edible parts exceeded most international safety thresholds. The estimated daily intakes (EDIs) of trace metals through snail consumption were below the provisional tolerable daily intakes (PTDIs) for both children and adults, suggesting that daily consumption is generally safe. Nonetheless, the hazard index (HI) indicated that children might face health risks from long-term consumption of contaminated snails (HI > 1), while adults are less likely to experience such complications (HI < 1). The total target carcinogenic risk (TTCR) was below 1E-04 for both children and adults, indicating negligible to acceptable carcinogenic risks for all consumer groups.