Transfer of heavy metals through terrestrial food webs: a review

Pollution-related changes in nest microbiota: Implications for growth and fledging in three passerine birds

Non-ferrous smelters emit toxic metals into the environment, posing a threat to wildlife health. Despite the acknowledged role of microbes in host health, the impact of such emissions on host-associated microbiota, especially in wild birds, remains largely unexplored. This study investigates the associations of metal pollution, fitness, and nest microbiota (serving as a proxy for early-life microbial environment) which may influence the nestling health and development. Our study focuses on three passerine birds, the great tit (Parus major), blue tit (Cyanistes caeruleus), and pied flycatcher (Ficedula hypoleuca), within control and metal-polluted sites around a Finnish copper-nickel smelter. The polluted sites had been contaminated with arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn). We performed bacterial 16S rRNA sequencing and metal analyses on 90 nests and monitored nestling body mass, fledging success, and various biotic and abiotic factors. Our findings revealed species-specific responses to metal exposure in terms of both fitness and nest microbiota. P. major and C. caeruleus showed sensitivity to pollution, with decreased nestling growth and fledging in the polluted zone. This was accompanied by a shift in the bacterial community composition, which was characterized by an increase in some pathogenic bacteria (in P. major and C. caeruleus nests) and by a decrease in plant-associated bacteria (within C. caeruleus nests). Conversely, F. hypoleuca and their nest microbiota showed limited responses to pollution, indicating greater tolerance to pollution-induced environmental changes. Although pollution did not correlate with nest alpha diversity or the most abundant bacterial taxa across all species, certain potential pathogens within the nests were enriched in polluted environments and negatively correlated with nestling fitness parameters. Our results suggest that metal pollution may alter the nest bacterial composition in some bird species, either directly or indirectly through environmental changes, promoting pathogenic bacteria and potentially impacting bird survival.

Heavy metal accumulation in root and shoot tapioca plant biomass grown in agriculture land situated around the magnesite mine tailings

Heavy metal pollution in soil has emerged as a major environmental concern. This can be attributed to human activities such as mining, modern agriculture, and industrialization. This study was conducted to determine how heavy metals spread from mine tailings to surrounding farmland. Metal absorption and accumulation were also investigated in the root and shoot biomass of tapioca crops grown in those farmlands. Metal concentrations in MTAS1 were 85.3 ± 1.2, 45.8 ± 1.5, 134.8 ± 1.7, 92.4 ± 2.2, and 78.95 ± 1.4 mg kg-1, respectively. Heavy metal concentrations in MTAS2 and MTAS3 were found to be 79.62 ± 1.6, 75.4 ± 1.5, 41.31 ± 1.1, 47.8 ± 1.6, 142.5 ± 2.1, 128.4 ± 1.4, 86.2 ± 1.9, 79.5 ± 1.3, and 83.4 ± 1.2 mg kg-1, respectively. Tapioca crop shoot and root biomass grown at these metal polluted sites absorbed and accumulated significant amounts of Cd, Cu, Zn, Pb, Ni, and Mn. Notably, the metal content of the tapioca crop's root and shoot biomass exceeded national standards.

Cadmium uptake and detoxification in tomato plants: Revealing promising targets for genetic improvement

Cadmium (Cd) is a hazardous heavy metal known for its detrimental effects on plants, human health, and the environment. This review article delves into the dynamics of Cd uptake, long-distance transport, and its impact on plant performance, with a specific focus on tomato plants. The process of Cd uptake by roots and its subsequent long-distance transport in the xylem and phloem are explored to understand how Cd influences plants operation. The toxic effects of Cd on tomato plants are discussed, highlighting on the challenges it poses to plant growth and development. Furthermore, the review investigates various Cd tolerance mechanisms in plants, including avoidance or exclusion by the root cell wall, root-to-shoot translocation, detoxification pathways, and antioxidative defence systems against Cd-induced stress. In addition, the transcriptomic analyses of tomato plants under Cd stress provide insights into the molecular responses and adaptations of plants to Cd toxicity. Overall, this comprehensive review enhances our understanding of Cd-plant interactions and reveal promising genes for tomato genetic improvement to increase its tolerance to cadmium.

Temporal Dynamics of Copper-Based Nanopesticide Transfer and Subsequent Modulation of the Interplay Between Host and Microbiota Across Trophic Levels

During agricultural production, significant quantities of copper-based nanopesticides (CBNPs) may be released into terrestrial ecosystems through foliar spraying, thereby posing a potential risk of biological transmission via food chains. Consequently, we investigated the trophic transfer of two commonly available commercial CBNPs, Reap2000 (RP) and HolyCu (HC), in a plant-caterpillar terrestrial food chain and evaluated impacts on host microbiota. Upon foliar exposure (with 4 rounds of spraying, totaling 6.0 mg CBNPs per plant), leaf Cu accumulation levels were 726 ± 180 and 571 ± 121 mg kg-1 for RP and HC, respectively. HC exhibited less penetration through the cuticle compared to RP (RP: 55.5%; HC: 32.8%), possibly due to size exclusion limitations. While caterpillars accumulated higher amounts of RP, HC exhibited a slightly higher trophic transfer factor (TTF; RP: 0.69 ± 0.20; HC: 0.74 ± 0.17, p > 0.05) and was more likely to be transferred through the food chain. The application of RP promoted the dispersal of phyllosphere microbes and perturbed the original host intestinal microbiota, whereas the HC group was largely host-modulated (control: 65%; RP: 94%; HC: 34%). Integrating multiomics analyses and modeling approaches, we elucidated two pathways by which plants exert bottom-up control over caterpillar health. Beyond the direct transmission of phyllosphere microbes, the leaf microbiome recruited upon exposure to CBNPs further influenced the ingestion behavior and intestinal microbiota of caterpillars via altered leaf metabolites. Elevated Proteobacteria abundance benefited caterpillar growth with RP, while the reduction of Proteobacteria with HC increased the risk of lipid metabolism issues and gut disease. The recruited Bacteroidota in the RP phyllosphere proliferated more extensively into the caterpillar gut to enhance stress resistance. Overall, the gut microbes reshaped in RP caterpillars exerted a strong regulatory effect on host health. These findings expand our understanding of the dynamic transmission of host-microbiota interactions with foliar CBNPs exposure, and provide critical insight necessary to ensure the safety and sustainability of nanoenabled agricultural strategies.

Cadmium causes cerebral mitochondrial dysfunction through regulating mitochondrial HSF1

Mitochondria, as the powerhouse of the cell, play a vital role in maintaining cellular energy homeostasis and are known to be a primary target of cadmium (Cd) toxicity. The improper targeting of proteins to mitochondria can compromise the normal functions of the mitochondria. However, the precise mechanism by which protein localization contributes to the development of mitochondrial dysfunction induced by Cd is still not fully understood. For this research, Hy-Line white variety chicks (1-day-old) were used and equally distributed into 4 groups: the Control group (fed with a basic diet), the Cd35 group (basic diet with 35 mg/kg CdCl2), the Cd70 group (basic diet with 70 mg/kg CdCl2) and the Cd140 group (basic diet with 140 mg/kg CdCl2), respectively for 90 days. It was found that Cd caused the accumulation of heat shock factor 1 (HSF1) in the mitochondria, and the overexpression of HSF1 in the mitochondria led to mitochondrial dysfunction and neuronal damage. This process is due to the mitochondrial HSF1 (mtHSF1), causing mitochondrial fission through the upregulation of dynamin-related protein 1 (Drp1) content, while inhibiting oligomer formation of single-stranded DNA-binding protein 1 (SSBP1), resulting in the mitochondrial DNA (mtDNA) deletion. The findings unveil an unforeseen role of HSF1 in triggering mitochondrial dysfunction.

Co-contamination and interactions of multiple mycotoxins and heavy metals in rice, maize, soybeans, and wheat flour marketed in Shanghai City

Mycotoxins and heavy metals extensively contaminate grains and grain products, posing severe health risks. This work implements validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) methods to quantify the concentration of 12 mycotoxins and five heavy metals in rice, maize, soybeans, and wheat flour samples marketed in Shanghai. The mixed contamination characteristics were analyzed using correlation cluster analysis and co-contamination index, and the probabilities of all cross combinations of contaminations were analyzed using a self-designed JAVA language program. The results showed that grains and grain products were frequently contaminated with both mycotoxins and heavy metals, mostly with deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON), ochratoxin A (OTA), aflatoxins, fumonisin B1 (FB1), fumonisin B2 (FB2), fumonisin B3 (FB3), arsenic (As), chromium (Cr) and cadmium (Cd). All the samples (100 %) were contaminated with two or more contaminants, and 77.3 % of the samples were co-contaminated with more than four contaminants. In cereals and cereal products, the following combinations were closely associated: (FB3 +3-ADON), (FB1 +As), (FB1 +FB2), (DON+FB1), (DON+Cd), (As+Cd), (DON+Cd+As), (FB1 +FB2 +As), and (DON+3-ADON+15-ADON). The results indicated that mycotoxins and heavy metals frequently co-occurred in Shanghai grains and grain products, and they provided primary data for safety assessments, early warnings, and regulatory measures on these contaminants to protect public health.

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.

Impact of Exposure to Leaves From Metal-Polluted Sites on the Developmental Parameters of Larvae of the Dark Sword-Grass, Agrotis ipsilon (Lepidoptera: Noctuidae)

Insects are impacted by pollutants in their environments and food sources. Herein, we set out a semi-field study to assess the impact of environmental heavy metal contamination on developmental parameters, energy reserves, and acidic and alkaline phosphatases in the larval Agrotis ipsilon (Lepidoptera: Noctuidae). Castor leaves from contaminated and uncontaminated (reference site) areas were fed to A. ipsilon larvae in all treatments. The heavy metal concentrations in the plant from different areas (contaminated and reference sites) and in the larvae were analyzed. Toxic effects were observed in the larvae feeding on the leaves from the metal contaminated areas. Larval and pupal weights, growth indices, and larval fitness were all significantly lower than in the reference group. Likewise, in the third and fourth instars, there was a significant decrease in both the survival and moth emergence rates. In contrast, the pupation duration was significantly longer. Total protein, lipid, and glycogen content showed significant reductions in treated larvae. Larval homogenate samples contaminated with heavy metals showed a significant increase in acid- and alkaline- phosphatase levels. The results obtained could provide a basis for a long-term evaluation of the risk associated with heavy metals and their impact on plant populations and important agricultural pests.

Comprehensive assessment of heavy metal pollution of agricultural soils impacted by the Kalsaka abandoned gold mine and artisanal gold mining in northern Burkina Faso

In this study, the environmental quality of agricultural soils around the Kalsaka abandoned gold mine was evaluated. A total of 117 samples including industrial mine wastes, topsoil, and control soil were collected in and around the mine, and their heavy metal concentrations were determined using ICP-MS after aqua regia digestion. Except for Zn, the average concentrations of the metals were higher in mine wastes and the agricultural soils than their average upper continental crust (UCC) counterpart, whereas those of Ag, As, and Hg exceeded the UCC in the control soils. The control soils had the lowest contaminations and the lowest pollution levels for all metals except for Hg. Based on the average concentrations and coefficients of variation, it can be concluded that Cr, Ni, and Zn abundance in the agricultural soils was controlled by natural factors, whereas that of Ag, As, Hg, Co, Cu, and Mn was mainly associated with mining. The absence of Hg in industrial mine wastes and its high contents in agricultural and control soils reflected the artisanal gold mining source of this metal. Thus, single and integrated pollution indices showed that ecological risk and toxicity are much higher when Hg is included in the index calculation, suggesting cumulative effects of industrial and artisanal gold mining on the agricultural soil quality. The results also showed that Hg and As are the pollutants of major concern in the Kalsaka abandoned gold mine. Because of its proximity to human settlements, the Kalsaka abandoned gold mine necessitates an immediate rehabilitation.

Trophodynamics and health risk assessment of heavy metals in seafood from a tropical estuary in the gulf of Guinea

Seafood is an essential protein source for coastal communities. However, they can accumulate heavy metals from human activities which could pose a potential health risk to consumers. In this study, we investigated the distribution, bioaccumulation, trophic transfer and potential human health risk of heavy metals in sediments, shell and fin fish collected from the Escravos Estuary in southern Nigeria. Heavy metals (Ni, Cd, V, Pb and Cu) in sediments, periwinkles and tongue soles from the two study sites were lower than the permissible limits for fishery products. The metal distribution in fish tissues was in the decreasing order of liver > gills > muscles > gonads > rest of the fish. Moderate to high BSAF (>1) was reported for Cd, Pb and Cu. All the studied metals, except Pb, showed evidence of biomagnification from periwinkle to tongue sole. The estimated daily intake (EDI) and hazard ratio (HR) for metals in periwinkles from both study sites were lower or within the USEPA reference doses (RfD) for the respective daily intake and HR value < 1, except for Cd, V and Pb for children. In contrast, EDI values in the muscle of tongue soles were higher than the RfD values for heavy metals except for Ni and Pb, whereas HR values > 1 except for Ni, Cd and V. In the whole fish, EDI and HR values were disproportionately high in both study sites with higher values reported for children. This study provides the first insights on the trophic transfer and risk assessment of heavy metals from petroleum and gas operations impacting the Escravos Estuary and the implications to public health.

Arthropods in landfills and their accumulation potential for toxic elements: A review

Landfills, as a source of potentially toxic elements (PTEs), pose a threat to the environment and human health. A literature review was conducted to explore the diversity of arthropods inhabiting solid waste landfills, as well as on the bioaccumulation of PTEs by arthropods. This review presents scientific papers over the last 20 years. Their importance in landfill ecosystems has been the subject of research; however, the issue of the accumulation of compounds such as toxic elements is emphasized only in a few studies. The bioaccumulation of PTEs was studied for 10 arthropod species that founded in landfills: Orthomorpha coarctata and Trigoniulus corallinus (class Diplopoda), Armadillidium vulgare and Trachelipus rathkii (class Malacostraca), the 6 species of the class Insecta - Zonocerus variegatus, Anacanthotermes ochraceus, Macrotermes bellicosus, Austroaeschna inermis, Calathus fuscipes and Harpalus rubripes.

Quantifying the bioaccumulation and trophic transfer processes of heavy metals based on the food web: A case study from freshwater wetland in northeast China

The contamination of wetlands by heavy metals, exacerbated by agricultural activities, presents a threat to both organisms and humans. Heavy metals may undergo trophic transfer through the food web. However, the methods for quantifying the bioaccumulation and trophic transfer processes of heavy metals based on the food web remains unclear. In this study, we employed stable isotope technology to construct a quantitative oriental white stork's typical food web model under a more accurate scaled Δ15N framework. On this basis, the concentrations for heavy metal (Cu, Zn, Hg, Pb) were analyzed, we innovatively visualized the trophic transfer process of heavy metals across 13 nodes and 45 links and quantified the transfer flux based on the diet proportions and heavy metal concentrations of species, taking into account biomagnification effects and potential risks. Our findings revealed that as for Cu and Pb, the transfer flux level was consistent with diet proportion across most links. While Hg and Zn transfer flux level exceeded the corresponding diet proportion in the majority of links. In summary, Hg exhibited a significant biomagnification, whereas Cu, Zn, Pb experienced biodilution. The fish dietary health risk assessment for fish consumers showed that Hg, Pb posed certain risks. This research marks a significant step forward in the quantitative assessment of multi-link networks involving heavy metals within the food web.

Polyextremophile engineering: a review of organisms that push the limits of life

Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi that thrive in nuclear radiation at Chernobyl, extreme organisms raise many questions about the limits of life. Is there any environment where life could not "find a way"? Although many individual extremophilic organisms have been identified and studied, there remain outstanding questions about the limits of life and the extent to which extreme properties can be enhanced, combined or transferred to new organisms. In this review, we compile the current knowledge on the bioengineering of extremophile microbes. We summarize what is known about the basic mechanisms of extreme adaptations, compile synthetic biology's efforts to engineer extremophile organisms beyond what is found in nature, and highlight which adaptations can be combined. The basic science of extremophiles can be applied to engineered organisms tailored to specific biomanufacturing needs, such as growth in high temperatures or in the presence of unusual solvents.

Effect of fertilization on the accumulation and health risk for heavy metals in native Andean potatoes in the highlands of Perú

Soil infertility is a global problem, amendments such as organic fertilizers and mineral fertilizers are used to improve crop yields. However, these fertilizers contain heavy metals as well as essential mineral elements. The objective of the study was to determine the effect of organic and inorganic fertilizer on the accumulation and health risk of heavy metals in tubers. The plants were cultivated at an altitude of 3970 m using four treatments (poultry manure, alpaca manure, island guano and inorganic fertilizer) and a control group. Soil contamination levels and the degree of metal accumulation in the tubers were also determined. As a result, it was found that the use of inorganic fertilizer and poultry manure increased the values of Cu and Zn in soils, exceeding the recommended standards. The accumulation of heavy metals in potato tubers did not exceed the maximum recommended limits with the exception of Pb, which exceeded the limit allowed by the FAO/WHO (0.1 mg kg-1). Poultry manure contributed to the highest accumulation of Zn, Cu and Pb in tubers with 11.62±1.30, 3.48±0.20 and 0.12 ±0.02 mg kg-1 respectively. The transfer of metals from the soil to the tubers was less than 1. Individual and total non-carcinogenic risk values were less than 1, indicating a safe level of consumption for children and adults. The cancer risk was found to be within an acceptable range. However, poultry manure and inorganic fertilizer treatments had the highest total cancer risk values in both age groups, suggesting a long-term carcinogenic risk.

Transfer and bioaccumulation of pesticides in terrestrial arthropods and food webs: State of knowledge and perspectives for research

Arthropods represent an entry point for pesticide transfers in terrestrial food webs, and pesticide accumulation in upper chain organisms, such as predators can have cascading consequences on ecosystems. However, the mechanisms driving pesticide transfer and bioaccumulation in food webs remain poorly understood. Here we review the literature on pesticide transfers mediated by terrestrial arthropods in food webs. The transfer of pesticides and their potential for bioaccumulation and biomagnification are related to the chemical properties and toxicokinetic of the substances, the resistance and detoxification abilities of the contaminated organisms, as well as by their effects on organisms' life history traits. We further identify four critical areas in which knowledge gain would improve future predictions of pesticides impacts on terrestrial food webs. First, efforts should be made regarding the effects of co-formulants and pesticides mixtures that are currently understudied. Second, progress in the sensitivity of analytical methods would allow the detection of low concentrations of pesticides in small individual arthropods. Quantifying pesticides in arthropods preys, their predators, and arthropods or vertebrates at higher trophic level would bring crucial insights into the bioaccumulation and biomagnification potential of pesticides in real-world terrestrial food webs. Finally, quantifying the influence of the trophic structure and complexity of communities on the transfer of pesticides could address several important sources of variability in bioaccumulation and biomagnification across species and food webs. This narrative review will inspire future studies aiming to quantify pesticide transfers in terrestrial food webs to better capture their ecological consequences in natural and cultivated landscapes.

Emerging Parameters Justifying a Revised Quality Concept for Cow Milk

Milk has become a staple food product globally. Traditionally, milk quality assessment has been primarily focused on hygiene and composition to ensure its safety for consumption and processing. However, in recent years, the concept of milk quality has expanded to encompass a broader range of factors. Consumers now also consider animal welfare, environmental impact, and the presence of additional beneficial components in milk when assessing its quality. This shifting consumer demand has led to increased attention on the overall production and sourcing practices of milk. Reflecting on this trend, this review critically explores such novel quality parameters, offering insights into how such practices meet the modern consumer's holistic expectations. The multifaceted aspects of milk quality are examined, revealing the intertwined relationship between milk safety, compositional integrity, and the additional health benefits provided by milk's bioactive properties. By embracing sustainable farming practices, dairy farmers and processors are encouraged not only to fulfill but to anticipate consumer standards for premium milk quality. This comprehensive approach to milk quality underscores the necessity of adapting dairy production to address the evolving nutritional landscape and consumption patterns.

Mapping soil trace metal distribution using remote sensing and multivariate analysis

Trace metal soil contamination poses significant risks to human health and ecosystems, necessitating thorough investigation and management strategies. Researchers have increasingly utilized advanced techniques like remote sensing (RS), geographic information systems (GIS), geostatistical analysis, and multivariate analysis to address this issue. RS tools play a crucial role in collecting spectral data aiding in the analysis of trace metal distribution in soil. Spectroscopy offers an effective understanding of environmental contamination by analyzing trace metal distribution in soil. The spatial distribution of trace metals in soil has been a key focus of these studies, with factors influencing this distribution identified as soil type, pH levels, organic matter content, land use patterns, and concentrations of trace metals. While progress has been made, further research is needed to fully recognize the potential of integrated geospatial imaging spectroscopy and multivariate statistical analysis for assessing trace metal distribution in soils. Future directions include mapping multivariate results in GIS, identifying specific anthropogenic sources, analyzing temporal trends, and exploring alternative multivariate analysis tools. In conclusion, this review highlights the significance of integrated GIS and multivariate analysis in addressing trace metal contamination in soils, advocating for continued research to enhance assessment and management strategies.

A critical review on the ecotoxicity of heavy metal on multispecies in global context: A bibliometric analysis

Heavy metals (HMs) have become a significant concern in the current era, with deleterious effects on diverse living organisms when exposed beyond threshold concentrations. Both nature and human beings have been constantly casting out HMs into environmental matrices through various activities. Innumerable cases of threatened diseases such as cancer, respiratory ailments, reproductive defects, skin diseases, and several others have been a cause of significant concern for humans as the number of instances has been increasing with each decade. HMs migrates via several pathways to infiltrate biological organisms and amass within them. Even though numerous treatment approaches are available for remediating HM pollution, however, they are expensive, along with other setbacks. Due to such constraints, combating HM contamination requires environmentally conscious strategies like bioremediation, which employs an array of biological systems to remove HMs from the environment. Nonetheless, to address the current global HM pollution situation, it is critical to comprehend not only how these hazardous HMs cause toxicity in various living organisms but also the knowledge gaps that currently exist concerning the subject of HM ecotoxicity. In the present investigation, data was extracted from Google Scholar using software program called Harzing's Publish or Perish. The collected information has been subsequently displayed as a network file using the VOSViewer software tool. Thus, the current review presents a significant insight with the inclusion of a readily accessible bibliometric analysis to comprehend the present status of HMs research, global research trends, existing knowledge discrepancies, and research challenges. Further, it also provides an in-depth review of HMs ecotoxicity, with a focus on arsenic (As), cadmium (Cd), and lead (Pb). Thus, as indicated by the bibliometric study, the present review will assist future investigators studying HMs ecotoxicity by providing baseline data concerning a wide range of living organisms and by addressing research gaps.

Interconnected environmental challenges: heavy metal-drug interactions and their impacts on ecosystems

Industrial expansion and inadequate environmental safety measures are major contributors to environmental contamination, with heavy metals (HMs) and pharmaceutical waste playing crucial roles. Their negative effects are most noticeable in aquatic species and vegetation, where they accumulate in tissues and cause harmful results. Interactions between HMs and pharmaceutical molecules result in the production of metal-drug complexes (MDCs), which have the potential to disturb diverse ecosystems and their interdependence. However, present studies frequently focus on individual pollutants and their effects on specific environmental parameters, leaving out the cumulative effects of pollutants and their processes across several environmental domains. To address this gap, this review emphasizes the environmental sources of HMs, elucidates their emission pathways during anthropogenic activities, investigates the interactions between HMs and pharmaceutical substances, and defines the mechanisms underlying the formation of MDCs across various ecosystems. Furthermore, this review underscores the simultaneous occurrence of HMs and pharmaceutical waste across diverse ecosystems, including the atmosphere, soil, and water resources, and their incorporation into biotic organisms across trophic levels. It is important to note that these complex compounds represent a higher risk than individual contaminants.

Changes in the Biology and Susceptibility of Weevil (Cylas formicarius) to the Insecticide Spinetoram as a Response to Cadmium Contamination

The sweet potato weevil Cylas formicarius is a notorious underground pest in sweet potato (Ipomoea batatas L.). However, little is known about the effects of cadmium (Cd) stress on weevil biology and resistance to pesticides and biotic agents. Therefore, we fed sweet potato weevils with Cd-contaminated sweet potato and assessed adult food intake and survival and larval developmental duration and mortality rates, as well as resistance to the insecticide spinetoram and susceptibility to the entomopathogenic fungus Beauveria bassiana. With increasing Cd concentration, the number of adult weevil feeding holes, adult survival and life span, and larval developmental duration decreased significantly, whereas larval mortality rates increased significantly. However, at the lowest Cd concentration (30 mg/L), adult feeding was stimulated. Resistance of adult sweet potato weevils to spinetoram increased at low Cd concentration, whereas Cd contamination did not affect sensitivity to B. bassiana. Thus, Cd contamination affected sweet potato weevil biology and resistance, and further studies will investigate weevil Cd accumulation and detoxification mechanisms.

Design of New Schiff Bases and Their Heavy Metal Ion Complexes for Environmental Applications: A Molecular Dynamics and Density Function Theory Study

Schiff bases (SBs) are important ligands in coordination chemistry due to their unique structural properties. Their ability to form complexes with metal ions has been exploited for the environmental detection of emerging water contaminants. In this work, we evaluated the complexation ability of three newly proposed SBs, 1-3, by complete conformational analysis, using a combination of Molecular Dynamics and Density Functional Theory studies, to understand their ability to coordinate toxic heavy metal (HMs) ions. From this study, it emerges that all the ligands present geometries that make them suitable to complex HMs through the N-imino moieties or, in the case of 3, with the support of the oxygen atoms of the ethylene diether chain. In particular, this ligand shows the most promising coordination behavior, particularly with Pb2+.

Comparative analysis of sediment quality indices using different reference values in an environmental protection area in Southeastern Brazil

Contamination of aquatic ecosystems by potentially toxic elements (PTEs) is a concerning environmental issue, given their persistence, toxicity potential, and ability to accumulate in living organisms. Several studies have been conducted to assess the contamination of aquatic ecosystems by PTEs, using pollution and ecological risk indices that rely on the concentration of these elements in aquatic sediments. However, many of these studies use global reference values for calculating the indices, which can lead to misleading interpretations due to substantial variations in PTEs concentrations influenced by the geological characteristics of each region. Therefore, the use of regional reference values is more appropriate when available. This study aimed to investigate variations in the results of five indices, employing global, regional, and quality reference values, based on sediment samples collected from rivers in the Ipanema National Forest, a protected area in Brazil exposed to various anthropogenic pressures. The results revealed that elements such as Al, Fe, and Mn exceeded the limits allowed by legislation in water samples, while As and Cr surpassed the limits in sediment samples. Comparative analysis highlighted significant discrepancies in the results of the indices when global reference values were used compared to regional and quality reference values, especially for As and Ba. Thus, this study underscores the importance of establishing specific regional values for an accurate assessment of sediment quality and the risks associated with contamination by PTEs in different regions worldwide.

Investigation of accumulation of element contents in some wild and cultivated dried fruits

In this study, the moisture and biogenic element quantities of most wild and cultivated edible dried fruits were investigated. Macroelements found in highest amounts in fruits were K, P, Ca, and Mg. While K quantities of the fruits are recorded between 5212.77 ("white myrtle") and 25550.60 mg/kg ("black nightshade"), P amounts of the fruits were characterized to be between 949.08 (black myrtle) and 4420.75 mg/kg ("black nightshade"). Ca and Mg amounts of the fruits were assessed to be between 359.83 (plum) and 4330.89 mg/kg ("yellow hawthorn") to 214.98 (plum) and 1852.04 mg/kg ("black nightshade"), respectively. Fe and B quantities of the fruitss were established to be between 2.69 ("black myrtle") and 60.13 mg/kg (cherry) to 3.76 ("black myrtle") and 76.25 mg/kg (sour cherry), respectively. In general, except for white and black myrtle fruits, it is thought that other fruits can be good sources of P, K, and Fe. P contents of "laurel cherry," "cherry," "black nightshade," and "Fragrant black grapes" were found partly high than those of other fruits. "Cherry laurel," "sour cherry," "cherry," "pear," "black nightshade," "black fig," and "hawthorn (yellow)" fruits contain more K than other fruits.

From soil to health hazards: Heavy metals contamination in northern India and health risk assessment

Heavy metals contamination in soil is a global concern affecting the environment with far-reaching consequences for ecosystems and the health of human beings. Heavy metals contamination of soil entails a significant threat to the environment and human health. This research paper focuses on the quantification of heavy metals contamination in soil in Kanpur district, a highly industrialized and densely populated region in India. The study was aimed to identify the sources of heavy metals, map their spatial distribution, and evaluate the potential implications on the environment and human well-being. The prime intent of the current study was quantification of heavy metals in the soil as well as the comparison of risk on the health of human being using two different methods i.e., US EPA methodology for risk assessment and epidemiological study-based risk assessment. Heavy metals like Fe, Ni, Co, Cu, Mn, Cr, and Cd were analyzed in agricultural samples of soil with the help of inductively coupled plasma optical emission spectroscopy. On the basis of epidemiological data, the attributable and relative risk came out to be 0.001 and 1.060, respectively. On the basis of the calculation of Cr alone, the values of carcinogenic risk for adults came out to be 3.87 × 10-7 and for children it was 3.01 × 10- 6. In conclusion, this research paper highlights the alarming levels of heavy metals contamination in the soil of Kanpur district, emphasizing the urgent need for remediation and mitigation efforts, thereby guiding policy makers and stakeholders in developing targeted strategies for soil protection and safeguarding human health.

Navigating the unknown: assessing anthropogenic threats to beaked whales, family Ziphiidae

This review comprehensively evaluates the impacts of anthropogenic threats on beaked whales (Ziphiidae)-a taxonomic group characterized by cryptic biology, deep dives and remote offshore habitat, which have challenged direct scientific observation. By synthesizing information published in peer-reviewed studies and grey literature, we identified available evidence of impacts across 14 threats for each Ziphiidae species. Threats were assessed based on their pathways of effects on individuals, revealing many gaps in scientific understanding of the risks faced by beaked whales. By applying a comprehensive taxon-level analysis, we found evidence that all beaked whale species are affected by multiple stressors, with climate change, entanglement and plastic pollution being the most common threats documented across beaked whale species. Threats assessed as having a serious impact on individuals included whaling, military sonar, entanglement, depredation, vessel strikes, plastics and oil spills. This review emphasizes the urgent need for targeted research to address a range of uncertainties, including cumulative and population-level impacts. Understanding the evidence and pathways of the effects of stressors on individuals can support future assessments, guide practical mitigation strategies and advance current understanding of anthropogenic impacts on rare and elusive marine species.

Exploiting the role of plant growth promoting rhizobacteria in reducing heavy metal toxicity of pepper (Capsicum annuum L.)

Microorganisms are cost-effective and eco-friendly alternative methods for removing heavy metals (HM) from contaminated agricultural soils. Therefore, this study aims to identify and characterize HM-tolerant (HMT) plant growth-promoting rhizobacteria (PGPR) isolated from industry-contaminated soils to determine their impact as bioremediators on HM-stressed pepper plants. Four isolates [Pseudomonas azotoformans (Pa), Serratia rubidaea (Sr), Paenibacillus pabuli (Pp) and Bacillus velezensis (Bv)] were identified based on their remarkable levels of HM tolerance in vitro. Field studies were conducted to evaluate the growth promotion and tolerance to HM toxicity of pepper plants grown in HM-polluted soils. Plants exposed to HM stress showed improved growth, physio-biochemistry, and antioxidant defense system components when treated with any of the individual isolates, in contrast to the control group that did not receive PGPR. The combined treatment of the tested HMT PGPR was, however, relatively superior to other treatments. Compared to no or single PGPR treatment, the consortia (Pa+Sr+Pp+Bv) increased the photosynthetic pigment contents, relative water content, and membrane stability index but lowered the electrolyte leakage and contents of malondialdehyde and hydrogen peroxide by suppressing the (non) enzymatic antioxidants in plant tissues. In pepper, Cd, Cu, Pb, and Ni contents decreased by 88.0-88.5, 63.8-66.5, 66.2-67.0, and 90.2-90.9% in leaves, and 87.2-88.1, 69.4-70.0%, 80.0-81.3, and 92.3%% in fruits, respectively. Thus, these PGPR are highly effective at immobilizing HM and reducing translocation in planta. These findings indicate that the application of HMT PGPR could be a promising "bioremediation" strategy to enhance growth and productivity of crops cultivated in soils contaminated with HM for sustainable agricultural practices.

Distribution and accumulation of Cadmium in different trophic levels affecting Serangium japonicum, the predatory beetle of whitefly Bemisia tabaci, biologically, physiologically and genetically: An experimental study

Cadmium (Cd) is a heavy metal that is of great concern in agroecosystems due to its toxicity to plants, herbivores, carnivores, and human beings. The current study evaluated the allocation and bioaccumulation of Cd from soil to cotton plants, cotton plants to herbivore pests, and herbivorous pests to a natural enemy predator. When soil was spiked with 100 mg/kg Cd, results demonstrated that cotton roots accumulated more Cd than the stems and leaves. The bioaccumulation of Cd was less in 4th instar larvae, pupa, and adults of Serangium japonicum than in Bemisia tabaci adults. The bioaccumulation in S. japonicum elongated the immature development period and reduced adult longevity, oviposition days, fertility, and total pre-oviposition duration. The net reproduction of S. japonicum was also reduced, as was female mature weight and feeding potential; as a result, Cd exposure could reduce the future population size compared to uncontaminated populations. There was decreased activity of the antioxidant enzymes (SOD, CAT, and POD) and energy-conserving lipids (glycogen, triglyceride, and total cholesterol) in Cd-contaminated S. japonicum compared to controls. The detoxifying enzyme activity of GST and P450 increased while AChE activity did not change. The qRT-PCR research showed that SOD1, CAT, POD, glycogen, and triglyceride gene expression was higher than in controls, whereas detoxification gene expression did not change. Our results indicate that Cd exposure has a physiological trade-off between its adverse effects on life history traits and elevated detoxification and antioxidation of S. japonicum, which could result from gene expression alteration. Further studies are needed to assess whether Cd exposure causes irreversible DNA damage in S. japonicum.

Concentration of metals and metalloids in livers of birds of various foraging guilds collected during the autumn migration period in Poland

During migration, birds explore various habitats at stopover sites that differ in food resources and contamination levels. In this study, hepatic concentrations of 21 elements (metals and metalloids) in 11 species of birds, representing various foraging habitats (such as aquatic, aquatic/terrestrial, and terrestrial) and migration modes (migratory and sedentary) representing various foraging guilds (omnivores, piscivores, and molluscivores), were analyzed. The samples (N = 84) were collected during the autumn migration period in Poland. The concentrations of elements determined in this study exhibited high inter-species variability, reflecting the diversity in contamination levels depending on food resources used by specific bird groups. Many of the investigated individuals from different species showed exceeded levels of subclinical toxicity and moderate clinical poisoning due to Cd and Hg. Higher concentrations of As, Hg, and Ba and lower V concentrations were found in migratory birds as compared to sedentary birds. Species foraging in terrestrial habitat had different concentrations of some elements compared to aquatic and aquatic/terrestrial species. Some specific inter-species differences in hepatic elemental concentrations were found. Differences in elemental concentrations among various groups can primarily be attributed to their foraging guilds, with certain elements, particularly As, V, and Hg, playing a significant role in the dissimilarity of elemental concentrations between foraging habitat groups and migratory mode groups. The data collected confirmed the limited ability of As to enter ecosystem pathways. The results of this study contribute to understanding the year-round exposure of migratory birds to environmental contamination, which can have carry-over effects on their performance in wintering and breeding grounds.

Early-stage growth and elemental composition patterns of Brassica napus L. in response to Cd-Zn contamination

Soil contamination caused by the presence of Cd and the excess amount of Zn is a widespread concern in agricultural areas, posing significant risks to the growth and development of crops. In this paper, the early-stage development and metal (Cd and Zn) accumulation potential of rapeseed (Brassica napus L.) grown under different metal application schemes were assessed by determining radicle and hypocotyl length and the micro- and macro elemental composition of plantlets after 24, 72, and 120 h. The results indicated that the single and co-application of Cd and Zn significantly reduced the radicle and hypocotyl lengths. Accumulation intensity for Cd and Zn was affected by Cd and the combination of Cd and Zn in the solution, respectively. In addition, both metals significantly influenced the tissue Mn and had a minor effect on Cu and Fe concentrations. Both Cd and Zn significantly affected macro element concentrations by decreasing tissue Ca and influencing K and Mg concentrations in a dose- and exposure time-dependent manner. These findings specify the short-term and support the long-term use of rapeseed in remediation processes. However, interactions of metals are crucial in determining the concentration patterns in tissues, which deserves more attention in future investigations.

Siderite's green revolution: From tailings to an eco-friendly material for the green economy

Siderite, extensively mined as a natural iron mineral, is often discarded as tailings due to the low grade of the ore and due to the high cost of current sorting technologies. Yet, this mineral has demonstrated significant potential in several pivotal areas of the environmental remediation. Siderite not only possesses exceptional adsorption, catalytic, and microbial carrier capabilities but also offers an eco-friendly and cost-effective solution for the environmental pollution management. This article consolidates research advancements and achievements over the past few decades concerning siderite's role in pollution control, delving deeply into its various remediation pathways. Initially, the paper contrasts the performance differences between natural and synthetic siderite, followed by a comprehensive overview of siderite's adsorption mechanisms for various inorganic pollutants. Furthermore, this paper analyzes the unique physicochemical attributes of siderite as both, a reductant and the catalyst, with a special emphasis on its use in the preparation of SCR catalysts and in the catalytic advanced oxidation processes for organic pollutants' degradation. This paper also enumerates and discusses the myriad advantages of siderite as a microbial carrier, thereby enhancing our understanding of biogeochemical cycles and pollutant transformations. In essence, this review systematically elucidates the mechanisms and intrinsic physicochemical properties of siderite in pollution control, paving the way for novel strategies to augment siderite's environmental remediation performance.

Fine particle pollution during megafires contains potentially toxic elements

Wildfires that raged across Australia during the 2019-2020 'Black Summer' produced an enormous quantity of particulate matter (PM) pollution, with plumes that cloaked many urban centres and ecosystems along the eastern seaboard. This has motivated a need to understand the magnitude and nature of PM exposure, so that its impact on both built and natural environments can be more accurately assessed. Here we present the potentially toxic fingerprint of PM captured by building heating, ventilation, and air conditioning filters in Sydney, Australia during the peak of the Wildfires, and from ambient urban emissions one year later (Reference period). Atmospheric PM and meteorological monitoring data were also assessed to determine the magnitude and source of high PM exposure. The wildfires were a major source of PM pollution in Sydney, exceeding the national standards on 19 % of days between November-February. Wildfire particles were finer and more spherical compared to Reference PM, with count median diameters of 892.1 ± 23.1 versus 1484.8 ± 96.7 nm (mean ± standard error). On an equal-mass basis, differences in potentially toxic elements were predominantly due to higher SO42--S (median 20.4 vs 4.7 mg g-1) and NO3--N (2.4 vs 1.2 mg g-1) in Wildfire PM, and higher PO43--P (10.4 vs 1.4 mg g-1) in Reference PM. Concentrations of remaining elements were similar or lower than Reference PM, except for enrichments to F-, Cl-, dissolved Mn, and particulate Mn, Co and Sb. Fractional solubilities of trace elements were similar or lower than Reference PM, except for enhanced Hg (12.1 vs 1.0 %) and greater variability in Cd, Hg and Mn solubility, which displayed upper quartiles exceeding that of Reference PM. These findings contribute to our understanding of human and ecosystem exposures to the toxic components of mixed smoke plumes, especially in regions downwind of the source.

Competitive adsorption mechanisms of Cd(II), Cu(II) and Pb(II) on bioinspired mesoporous silica revealed by complementary adsorption/isothermal titration calorimetry studies

This study presents the adsorption properties of a bioinspired grafted mesoporous silica material and the competitive effects between Cd(II) or Cu(II) and Pb(II) during the adsorption process. Glutathione, a natural antioxidant known for its metal binding properties, has been successfully grafted to SBA-15 mesoporous silica and the optimum adsorption parameters were determined. This original and multidisciplinary approach combines classical adsorption studies with thermodynamic investigations to understand the adsorption behavior of Cd(II), Cu(II) and Pb(II) on this material. To this end, isothermal titration calorimetry (ITC) has been used to elucidate the mechanisms of single-metal and two-metal adsorption. The results showed affinity in the order Pb(II) > Cu(II) > Cd(II) in single metal systems. Cd(II) adsorption relied mainly on physical contributions while Cu(II) and Pb(II) adsorption was shown to be chemically driven. Two-metal systems highlighted that Cd(II) and Pb(II) are adsorbed on the same coordination sites, whereas Cu(II) and Pb(II) are adsorbed on different sites. The material showed good selectivity and encouraging results were obtained on real effluents.

Assessment of environmental pollution and human health risks of mine tailings in soil: after dam failure of the Córrego do Feijão Mine (in Brumadinho, Brazil)

The dam failure of the Córrego do Feijão Mine (CFM) located in Minas Gerais State, Brazil, killed at least 278 people. In addition, large extensions of aquatic and terrestrial ecosystems were destroyed, directly compromising the environmental and socioeconomic quality of the region. This study assessed the pollution and human health risks of soils impacted by the tailing spill of the CFM dam, along a sample perimeter of approximately 200 km. Based on potential ecological risk and pollution load indices, the enrichments of Cd, As, Hg, Cu, Pb and Ni in soils indicated that the Brumadinho, Mário Campos, Betim and São Joaquim de Bicas municipalities were the most affected areas by the broken dam. Restorative and reparative actions must be urgently carried out in these areas. For all contaminated areas, the children's group indicated an exacerbated propensity to the development of carcinogenic and non-carcinogenic diseases, mainly through the ingestion pathway. Toxicological risk assessments, including acute, chronic and genotoxic effects, on people living and working in mining areas should be a priority for public management and mining companies to ensure effective environmental measures that do not harm human health and well-being over time.

Iron minerals: A frontline barrier against combined toxicity of microplastics and arsenic

The coexistence of microplastics (MPs) and arsenic (As) in terrestrial ecosystems presents challenges to controlling soil pollution and performing environmental risk assessments. In this study, the interactions among As, polystyrene MPs, and goethite in porous media were investigated and the individual and combined toxicities of MPs and As on wheat germination were evaluated. An additional experiment was conducted to assess the mitigating effect of goethite on the toxicity of the two contaminants. The results showed that the presence of MPs reduced As accumulation in wheat and decreased the acute lethal toxicity of As pollutants (the half-lethal concentration of As during wheat germination increased by 68.21%). However, MPs exhibited inhibitory effects on wheat germination and served as carriers to promote the migration of As within the plant body. The addition of goethite mitigated both individual and combined toxicities and further increased the half-lethal concentration for the combined pollution of As and MPs by 39.48%. This was primarily attributed to the adsorption and immobilization of arsenate and MPs on the medium and root surfaces. In our study, goethite reduced soluble As by 48.29% under the combined pollution scenarios and formed iron plaques on wheat roots, effectively obstructing pollutant entry. Thus, iron minerals serve as pioneering barriers to combined toxicity. Our findings contribute to the understanding of the combined toxicity of MPs and As in crops and offer potential strategies for managing combined pollution.

Impacts of long-term irrigation with coalmine effluent contaminated water on trace metal contamination of topsoil and potato tubers in Dinajpur area, Bangladesh

Rapid depletion of groundwater and climate change mediated shifting precipitation pattern is forcing farmers to look for alternative irrigation options like wastewater. However, routine irrigation with trace metal contaminated wastewaters could potentially pollute soil as well as cause health risks through the consumption of food products grown in contaminated soil. Thus, the present study aimed to investigate the trace metals build-up status in topsoil and potato (Solanum tuberosum L.) tubers upon continuous irrigation with coalmine effluent contaminated wastewater compared to irrigation with groundwater and surface water over three consecutive years. Soil pollution status and human health risk associated with consumption of potato tubers grown on wastewater-irrigated soil was also assessed in this study. Three separate experimental sites differing in irrigation source (groundwater, surface water, and coalmine wastewater) were selected near Barapukuria Coal Mining Company Limited located at Parbatipur upazilla of Dinajpur district, Bangladesh. Nine trace metals namely arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) were estimated. Results showed significantly higher trace metal content in both soil and potato tubers due to wastewater irrigation. Wastewater suitability for irrigation regarding Cd, Cr, Cu, Fe, Ni and Pb were off the permissible level although the soil contamination with trace metals and their levels in potato tubers remained within the safety limit. Health risk assessment revealed that, consumption of potato tubers grown in wastewater-irrigated soil remained safe although health risk associated with Cr was almost at the border. The study exclusively highlighted the core massage that, trace metal contamination of both soil and potatoes cultivated in them was increasing alarmingly due to three years of wastewater-irrigation. Although the extent of contamination was below critical limit, it can potentially become hazardous in years to come unless wastewater-irrigation is checked. This study was successful to provide valuable insights regarding the potential environmental and human health threats that might arise due to unmindful irrigation of contaminated coalmine wastewater. Besides, this study should prove useful in strategizing safety measures for cropping under trace metal contaminated soils and for planning industrial effluent disposal to avoid agricultural soil contamination.

Determination of Major and Trace Metals in Date Palm Fruit (Phoenix dactylifera) Samples Using Flame Atomic Absorption Spectrometry and Assessment of the Associated Public Health Risks

This study aimed to assess the concentrations of major and trace metals (Na, Ca, Fe, Zn, Ni, Mn, Cu, Cd, and Pb) in date palm fruit samples collected from diverse regions, including Afar (Ethiopia), Iraq, and Saudi Arabia, utilizing flame atomic absorption spectrometry (FAAS). The wet acid digestion method was employed for sample treatment, with optimization of the key parameters such as reagent volume ratio, oven temperature, and digestion time for analytical applications. Under the optimized parameters, average metal concentrations in date palm fruit samples ranged from 205-299, 134-320, 38.8-115, 25.1-42.2, 9.27-27.9, 7.11-16.3, and 0.002-1.15 mg/kg for Ca, Na, Fe, Ni, Zn, Mn, and Cu, respectively. Cd and Pb levels were below detection limits within the linear range. Generally, date palm samples exhibited higher Ca and Na contents and lower concentrations of Cu and Mn than other metals. Pearson correlation analysis revealed very strong positive correlations between Fe and Na, Na and Zn, Na and Mn, Ca and Zn, Fe and Ni, Fe and Mn, and Mn and Ni. Strong negative correlations were observed for Ni and Na, Fe and Cu, and Cu and Ni. Weak correlations were noted among Na and Cu, Ca and Fe, Ca and Ni, Ca and Mn, Ca and Cu, Fe and Zn, Ni and Zn, Zn and Mn, and Zn and Cu. A recovery study using the spiking method demonstrated acceptable percentage recoveries ranging from 91.6% to 97.8%. Health risk assessment, including chronic daily intake (CDI), hazard quotient (HQ), total exposure hazard index (HI), and carcinogenic risk (CR), indicated CDI, HQ, and HI values below 1.0, except for the HI value for Ni. This suggests that the metals pose no probable public health risk, with the absence of Cd and Pb in date palm samples affirming no carcinogenic threats associated with their consumption.

Country-Wide Ecological Health Assessment Methodology for Air Toxics: Bridging Gaps in Ecosystem Impact Understanding and Policy Foundations

Amid the growing concerns about air toxics from pollution sources, much emphasis has been placed on their impacts on human health. However, there has been limited research conducted to assess the cumulative country-wide impact of air toxics on both terrestrial and aquatic ecosystems, as well as the complex interactions within food webs. Traditional approaches, including those of the United States Environmental Protection Agency (US EPA), lack versatility in addressing diverse emission sources and their distinct ecological repercussions. This study addresses these gaps by introducing the Ecological Health Assessment Methodology (EHAM), a novel approach that transcends traditional methods by enabling both comprehensive country-wide and detailed regional ecological risk assessments across terrestrial and aquatic ecosystems. EHAM also advances the field by developing new food-chain multipliers (magnification factors) for localized ecosystem food web models. Employing traditional ecological multimedia risk assessment of toxics' fate and transport techniques as its foundation, this study extends US EPA methodologies to a broader range of emission sources. The quantification of risk estimation employs the quotient method, which yields an ecological screening quotient (ESQ). Utilizing Kuwait as a case study for the application of this methodology, this study's findings for data from 2017 indicate a substantial ecological risk in Kuwait's coastal zone, with cumulative ESQ values reaching as high as 3.12 × 103 for carnivorous shorebirds, contrasted by negligible risks in the inland and production zones, where ESQ values for all groups are consistently below 1.0. By analyzing the toxicity reference value (TRV) against the expected daily exposure of receptors to air toxics, the proposed methodology provides valuable insights into the potential ecological risks and their subsequent impacts on ecological populations. The present contribution aims to deepen the understanding of the ecological health implications of air toxics and lay the foundation for informed, ecology-driven policymaking, underscoring the need for measures to mitigate these impacts.

The concentration and prevalence of potentially toxic elements (PTEs) in cheese: a global systematic review and meta-analysis

The present study aimed to systematically review the concentration of different PTEs, including Arsenic (As), Mercury (Hg), Lead (Pb), and Cadmium (Cd) in cheese among some databases between 2000 and 2021 (from 57 included studies). Estimated concentrations of 160.78 (95% CI = 119.24-202.28), 15.68 (95% CI = 11.88-19.48), 16.94 (95% CI = 13.29-20.59), and 2.47 (95% CI = 1.70-3.23) µg/kg were calculated for As, Pb, Cd, and Hg, respectively. Most of the studies for PTEs are related to Pb, about 40% of the studies, compared to As, which has fewer studies. The results showed that As and Hg concentrations were lower than the Codex Alimentarius Commission standard limits. Nevertheless, Cd and Pb concentrations were higher than the standard limit values. Results showed that cheese making, the ripening period, fat content, and texture are influential factors in a high level of Pb and Cd in cheese samples.

Ginger mitigated the health risks associated with arsenic-contamination of rats feed via inflammatory and apoptosis regulation

Millions of people around the world are inadvertently exposed to arsenic through drinking water and food. However, food spices possess antioxidants and anti-inflammatory potentials. Therefore, this study evaluated the protective potentials of Zingiber officinale (ginger) against the toxic effects of arsenic in male Wistar rats. Thirty-six Wistar rats were assigned into 6 groups (n = 6); group A1 and A2 (control), group B1 and B2 were fed with arsenic-contaminated feed (3.45x10-3 mg/kg), group C1 and C2 were feed with arsenic-contaminated feed (3.45x10-3 mg) supplemented with ginger respectively for 12 and 24 weeks. The blood, bone marrow, and liver of rats were harvested and prepared for various analyses. Micronucleus and Comet analysis were performed for the genotoxicity assessment every 4 weeks. Activities of AST, ALT, GGT, and SOD, and the concentration of GSH, MDA, protein carbonyl, protein thiol, and total protein, were measured by spectrophotometric methods. Quantification of IL-10, 1 L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguanosine was done by ELISA method while Bax, Bcl2, and Erk 1/2 were quantified by immuno-histochemical staining. mRNA expression of cyclin D1 was quantified using qRT-PCR. Statistical analysis was performed with SPSS and statistical significance was accepted when p<0.05. Result showed significant (p<0.05) decrease in the haemoglobin concentration, red blood cell, lymphocyte counts, tail DNA and MnPCE of rats fed arsenic-contaminated feed compared with control. The supplementation with ginger significantly reduced serum activities of AST and GGT (p<0.05). Ginger supplementation also lowered the arsenic indued increases in liver MDA, protein carbonyl and 8-OXdG levels. Ginger restores to near normal the histological changes due to arsenic exposure. In the arsenic-exposed group, liver IL-10, IL-1β and TNF-α decreased significantly (p<0.05) at week 24 whereas, NF-Ƙβ and TGF-β increased significantly (p 0.05) at weeks 12 and 24 and TNF-α, Bcl2 at week 24. mRNA expression of cyclin D1 was significantly (p<0.05) downregulated in the arsenic and ginger-supplemented groups. This study showed that long-term consumption of arsenic resulted in immunosuppression, anaemia and activated anti-apoptotic process that was mitigated due to ginger supplementation.

Metal and metalloid concentrations in wild mammals from SW Europe: European hedgehog (Erinaceus europaeus) and badger (Meles meles)

In recent years, there have been increasing ecological and global concerns associated to Potentially Toxic Elements (PTEs). Thus, the relevance of wild mammals as biomonitors has been globally recognised. In the present study, Cd, Pb, Hg, Zn and As concentrations were quantified in European hedgehog and badger inhabiting SW Europe, and cumulative trends in relation to age and sex were evaluated. Liver and kidney samples were collected, mineralised and PTE content was determined by ICP-MS. Zn was the most abundant element quantified in both organs (239 and 89.8 mg kg-1 for hedgehogs and 179 and 164 mg kg-1 dw for badgers). In hedgehogs, very high Hg concentration were quantified (4.35 and 15.5 mg kg-1 dw in liver and kidney), and Cd was the most abundant for badgers (4.70 and 7.61 mg kg-1 dw in liver and kidney). Positive correlations were observed for the concentrations of PTE in the organs of both species. Age-dependence increased only Cd concentration, with levels in adult kidneys being significantly higher. In this study, European hedgehog and badger were used as biomonitors for the determination of PTEs to provide current reference values in relatively non-polluted areas of SW Europe, and to enhance the use of these species for future ecotoxicological studies.

High-carbon wood ash biochar for mine tailings restoration: A field assessment of planted tree performance and metals uptake

Unique properties of biochar render it appealing for revegetating and decontaminating historic, barren, and chemically complex mine tailings. Bottom ash from bioenergy facilities can contain high levels of charcoal residue, and thus qualify as a type of biochar; the wide availability of this material at low cost makes it of particular interest in the context of tailings remediation. Nevertheless, bottom ash is variable and often contains residual toxic metal/loids that could be phytoabsorbed into plant tissues. We implemented a replicated field trial on historic contaminated metal mine tailings in Northern Ontario (Canada) over a range of high‑carbon wood ash biochar (HCWAB) dosages (0-30 t/ha) to evaluate tree and substrate responses. Sapling survivorship and aboveground biomass growth were quantified over a 4-year period; substrate chemical parameters were measured using acid-digestion and ICP-MS, as well as ion exchange resin probes. To assess elemental composition of sapling tissues, we used electron probe microanalysis combined with laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) on intact samples across the range of dosages applied. Survival and growth of saplings peaked at mid-range ash dosages of 3-6 t/ha. Similarly, substrate ion availability of P, K, and Zn were stable at lower dosages, but increased above 6 t/ha. The trace amounts of toxic metal/loids of concern measured in wood ash (As, Cd, Cu, and Pb) did not result in significantly increased sapling tissue concentrations at low to moderate dosages, but in some cases tissue contaminant levels were elevated at the highest dosage examined (30 t/ha). Our findings highlight the potential for high‑carbon wood ash biochar to be used for metal mine restoration at low to moderate dosages.

Impact of carbonization conditions and adsorbate nature on the performance of activated carbon in water treatment

The physical and chemical structure of activated carbon (AC) varies with the carbonization temperature, activation process and time. The texture and toughness of the starting raw material also determine the morphology of AC produced. The Brunauer-Emmet-Teller surface area (SBET) is small for AC produced at low temperatures but increases from 500 to 700 °C, and generally drops in activated carbons synthesized > 700 °C. Mild chemical activators and low activator concentrations tend to generate AC with high SBET compared to strong and concentrated oxidizing chemicals, acids and bases. Activated carbon from soft starting materials such as cereals and mushrooms have larger SBET approximately twice that of tough materials such as stem berks, shells and bones. The residual functional groups observed in AC vary widely with the starting material and tend to reduce under extreme carbonization temperatures and the use of highly concentrated chemical activators. Further, the adsorption capacity of AC shows dependency on the size of the adsorbate where large organic molecules such as methylene blue are highly adsorbed compared to relatively small adsorbates such as phenol and metal ions. Adsorption also varies with adsorbate concentration, temperature and other matrix parameters.

Elemental Profile in Chicken Egg Components and Associated Human Health Risk Assessment

Egg is a food product of high nutritional quality, extensively consumed worldwide. The objectives of this study were the determination of the elemental profile in eggs (egg white, yolk, and eggshell), the estimation of the non-carcinogenic health risk associated with the presence of heavy metals in investigated egg samples, and the development of statistical models to identify the best predictors for the differentiation of egg components. The assessments were carried out in a total set of 210 samples, comprising home-produced and commercial eggs, using inductively coupled plasma mass spectrometry. The results suggested measurable differences amongst hen eggs coming from different husbandry systems. The statistical models employed in this study identified several elemental markers that can be used for discriminating between market and local producer samples. The non-carcinogenic risk related to the consumption of the analyzed egg samples was generally in the safe range for the consumers, below the maximum permitted levels set by Romanian and European legislation. Food contamination is a public health problem worldwide, and the risk associated with exposure to trace metals from food products has aroused widespread concern in human health, so assessing the heavy metal content in food products is mandatory to evaluate the health risk.

Remediation of the microecological environment of heavy metal-contaminated soil with fulvic acid, improves the quality and yield of apple

The excessive application of chemical fertilizers and pesticides in apple orchards is responsible for high levels of manganese and copper in soil, and this poses a serious threat to soil health. We conducted a three-year field experiment to study the remediation effect and mechanism of fulvic acid on soil with excess manganese and copper. The exogenous application of fulvic acid significantly reduced the content of manganese and copper in soil and plants; increased the content of calcium; promoted the growth of apple plants; improved the fruit quality and yield of apple; increased the content of chlorophyll; increased the activity of superoxide dismutase, peroxidase, and catalase; and reduced the content of malondialdehyde. The number of soil culturable microorganisms, soil enzyme activity, soil microbial community diversity, and relative abundance of functional bacteria were increased, and the detoxification of the glutathione metabolism function was enhanced. The results of this study provide new insights that will aid the remediation of soil with excess manganese and copper using fulvic acid.

Heavy metal pollution triggers a shift from bacteria-based to fungi-based soil micro-food web: Evidence from an abandoned mining-smelting area

Heavy metals pose significant threats to soil biota, ultimately disrupting soil micro-food web. However, no studies have yet elucidated the impact of heavy metals on soil micro-food web. In this study, we explored the response of bacteria, fungi, nematodes, and soil micro-food web along a gradient of heavy metals in an abandoned smelting-mining area. We found that bacteria responded strongly to heavy metals, whereas fungi showed greater resistance and tolerance. Nematodes responses were less apparent. With the increasing levels of heavy metal pollution, the importance of heavy metal-tolerant organisms in micro-food webs increased significantly. For instance, the keystone bacteria in soil micro-food web shifted from copiotrophic to oligotrophic types, while the keystone nematodes shifted from to bacterial-feeding (e.g., Eucephalobus) to fungal-feeding species (e.g., Ditylenchus). Additionally, elevated heavy metal concentrations increased the proportion of fungi (e.g., Mortierellomycota), intensifying their interactions with bacteria and nematodes and causing a shift from bacteria-based to fungi-based soil micro-food web. Furthermore, heavy metal contamination induced a more complex and stable soil micro-food web. Overall, we highlight the changes in soil micro-food web as a mechanism for coping with heavy metal stress. Our study provides valuable insights into how heavy metal pollution can cause shifts in soil micro-food webs and has critical implications for enhancing our understanding of the ecological consequences of environmental pollution at the ecosystem level.

Receptor model-based source tracing and risk assessment of elements in sediment of a transboundary Himalayan River

This study utilized surface sediments from a potentially less polluted transboundary Himalayan River (Brahmaputra: China-India-Bangladesh) to investigate the abundance of 15 geochemically and ecologically significant elements and to predict their sources and ecological consequences. INAA was applied to determine the elemental concentrations. The average abundances (μg.g-1) of Rb (94.20), Cs (4.49), Th (20.31), & U (2.73) were 1.12-2.26 folds elevated than shale. Environmental indices disclosed a pollution status ranging from "uncontaminated to moderately contaminated," with minimal Rb, U, and Th enrichment in the downstream zone. Consensus-based sediment quality guideline (SQG) threshold values suggested that only Cr (60% samples > TEL) may impose rare biological effects. Ecological risk indices suggested "minor to no" possible eco-toxicological risks for the accounted elements (Cr, Co, Mn, Zn, Sb, & As). The positive matrix factorization (PMF) model predicated the predominance of geogenic or crustal contributions (∼72.69%) for Al, K, Na, Ti, Co, Zn, Ba, Cs, As, Rb, Th, & U derived from elemental fractionations, mineral weathering, and bio-geo-chemical mobilization. The relative contributions of anthropogenic sources (∼27.31%; such as the construction of roads, settlement expansion, litter disposal, municipal waste discharge, mining activities, agricultural encroachment, etc.) on elemental distribution were significantly lower. The abundance of Cr and Mn was mainly influenced by anthropogenic sources. This study demonstrated the effectiveness of utilizing geo-environmental guidelines and receptor models in discriminating the natural & anthropogenic origins of metals in the complex riverine sediments of a less anthropogenically affected river.

Impacts of metal mining on river systems: a global assessment

An estimated 23 million people live on floodplains affected by potentially dangerous concentrations of toxic waste derived from past and present metal mining activity. We analyzed the global dimensions of this hazard, particularly in regard to lead, zinc, copper, and arsenic, using a georeferenced global database detailing all known metal mining sites and intact and failed tailings storage facilities. We then used process-based and empirically tested modeling to produce a global assessment of metal mining contamination in river systems and the numbers of human populations and livestock exposed. Worldwide, metal mines affect 479,200 kilometers of river channels and 164,000 square kilometers of floodplains. The number of people exposed to contamination sourced from long-term discharge of mining waste into rivers is almost 50 times greater than the number directly affected by tailings dam failures.

Co-exposure of polystyrene microplastics influence cadmium trophic transfer along the "lettuce-snail" food chain: Focus on leaf age and the chemical fractionations of Cd in lettuce

Cadmium (Cd) and polystyrene microplastics (PS) co-contamination always occurs in environment; however, the trophic transfer of Cd and PS is still poorly understood. A hydroponic experiment was conducted to investigate the behavior of Cd in lettuce, together with the root or foliar exposure of different sized PS. Accumulation and chemical form distributions of Cd in leaves were distinguished into young and mature leaves. Subsequently, a 14-day snail feeding experiment was performed. Data showed that Cd accumulation in roots, rather than in leaves, are significantly affected by PS coexistence. However, mature leaves had a higher Cd content than young leaves under the root exposure of PS, while a reverse effect was observed in the foliar exposure. There existed a positive correlation between the food-chain transfer associated Cd (CdFi+Fii+Fiii) in mature leaves and Cd content in snail soft tissue (r = 0.705, p < 0.001), but not in young leaves. Though no bio-amplification of Cd in food chain was observed, an increase of Cd transfer factor (TF) from lettuce to snail was noted in the root exposure of 5 μm PS and the foliar exposure of 0.2 μm PS. Moreover, we observed a highest increase rate of 36.8 % in TF values from lettuce to snail viscera, and a chronic inflammatory response in snail stomach tissue. Therefore, more attentions should be paid to study the ecological risks of heavy metals and microplastics co-contamination in environment.

Heavy metal-resistant rhizobacteria fosters to alleviate the cadmium toxicity in Arabidopsis by upregulating the plant physiological responses

This study was designed to investigate the role of Morganella morganii strains in alleviating Cd stress in Arabidopsis seedlings under controlled conditions. Both M. morganii strains ABT3 (ON316873) and ABT9 (ON316874) strains isolated from salt-affected areas showed higher resistance against Cd and possess plant growth-promoting traits such as nitrogen fixation, indole-acetic acid production, ammonia production, phosphate solubilization, and, catalase, gelatinase and protease enzyme production. Plant inoculation assay showed that varying concentration of Cd (1.5 mM and 2.5 mM) significantly reduced Arabidopsis growth, quantum yield (56.70%-66.49%), and chlorophyll content (31.90%-42.70%). Cd toxicity also triggered different associations between lipid peroxidation (43.61%-69.77%) and enzymatic antioxidant mechanisms. However, when both strains were applied to the Arabidopsis seedlings, the shoot and root length and fresh and dry weights were improved in the control and Cd-stressed plants. Moreover, both strains enhanced the resistance against Cd stress by increasing antioxidant enzyme activities [catalase (19.47%-27.39%) and peroxidase (37.50%-48.07%)]that ultimately cause a substantial reduction in lipid peroxidation (27.71%-41.90%). Both strains particularly ABT3 also showed positive results in improving quantum yield (73.84%-98.64%) and chlorophyll content (41.13%-48.63%), thus increasing the growth of Arabidopsis seedlings. The study suggests that PGPR can protect plants from Cd toxicity, and Cd-tolerant rhizobacterial strains can remediate heavy metal polluted sites and improve plant growth.

Butterflies as bioindicators of metal contamination

Anthropogenic trace metal contamination has significantly increased and has caused many hazardous consequences for the ecosystems and human health. The Terni basin valley (Central Italy) shows a heavy load of pollutants from industrial activities, while the characteristic orography structure of the valley favours air stagnation, thus limiting air pollution dispersal. The present study conducted in 2014 aimed to determine the concentration of ten metals in five species of butterflies at nine sites in the Terni valley along a 21-km-long transect, including both relatively pristine and industrial areas. At sites where soil contamination was high for a given metal, such as for chromium as in the case of site 4 (the closest to the steel plant) and for lead as in the case of site 2 (contaminated by a firing range), higher levels of contamination were observed in the tissues of butterflies. We found a correlation between soil contamination and the concentration of Cr, Al and Sr in the tissues of some species of butterflies. The sensitivity to contamination differed among the five species; in particular, Coenonympha pamphilus was generally the species that revealed the highest concentrations of all the ten trace metals at the sites closer to the industrial area. It is known that C. pamphilus is a sedentary species and that its host plants are the Poaceae, capable of accumulating high quantities of metals in their rhizosphere region, thus providing the link with soil contamination. Therefore, monitoring the metal concentration levels in butterflies might be a good indicator and a control tool of environmental quality, specifically in areas affected by high anthropogenic pollution loads linked to a specific source.