High Concentrations Of Heavy Metals Research Articles

Heavy Metal Exposure-Mediated Dysregulation of Sphingolipid Metabolism.

Exposure to heavy metals (HMs) is often associated with inflammation and cell death, exacerbating respiratory diseases including asthma. Most inhaled particulate HM exposures result in the deposition of HM-bound fine particulate matter, PM2.5, in pulmonary cell populations. While localized high concentrations of HMs may be a causative factor, existing studies have mostly evaluated the effects of systemic or low-dose chronic HM exposures. This report investigates the impact of local high concentrations of specific HMs (NaAsO2, MnCl2, and CdCl2) on sphingolipid homeostasis and oxidative stress, as both play a role in mediating responses to HM exposure and have been implicated in asthma. Utilizing an in vitro model system and three-dimensional ex vivo human tissue models, we evaluated the expression of enzymatic regulators of the salvage, recycling, and de novo synthesis pathways of sphingolipid metabolism, and observed differential modulation in these enzymes between HM exposures. Sphingolipidomic analyses of specific HM-exposed cells showed increased levels of anti-apoptotic sphingolipids and reduced pro-apoptotic sphingolipids, suggesting activation of the salvage and de novo synthesis pathways. Differential sphingolipid regulation was observed within HM-exposed lung tissues, with CdCl2 exposure and NaAsO2 exposure activating the salvage and de novo synthesis pathway, respectively. Additionally, using spatial transcriptomics and quantitative real-time PCR, we identified HM exposure-induced transcriptomic signatures of oxidative stress in epithelial cells and human lung tissues.

Newly Identified Melanistic and Rostrate form of Monetaria caputdraconis from Easter Island

A newly discovered population of Monetaria caputdraconis has been identified on Easter Island. This new population has a high occurrence of specimens expressing morphologythat appear both melanistic and rostrate, and is named herein Monetaria caputdraconis formdarkini. It is suggested that the geology of the island, which comprises Roiho basalt containing olivine tholeiite with relatively high concentrations of heavy metals, may contribute to this unique morphology

The impact of different types of wastewaters on electrode passivation in electrical coagulation systems

Water is a crucial part of the production process when the company uses reaction or cooling water to create customized goods. It is therefore expected that some of the chemical components from the boats will be present in the water. Ensuring the safety of discharged water into rivers for human consumption is vital, as water supplies are limited and subject to cycles. Industrial wastewater sometimes includes higher concentrations of heavy metals like copper, lead, and other pollutants, whereas domestic wastewater usually has higher amounts of nitrogen and phosphate. Our previous strategy to dealing with these components involved adding chemicals and filtering them, but this method introduced additional compounds into the water sample. Science and technology have advanced alongside sewage treatment techniques. In this paper, we investigated the effects of electrical coagulation on water treatment in a rapidly industrializing environment. The effectiveness of electrical coagulation has been extensively studied, but less is known about how it impacts aquatic habitats and machinery. This work addresses the issue of equipment passivation in a number of potential methods that are related to an improvement in water quality.

Ladle slag–based binder for the solidification/stabilization of heavy-metal-rich industrial waste

Heavy metal pollution from industrial sources is a major environmental and health hazard on a global scale. This study introduces a solidification/stabilization method of industrial waste using a waste-based, ettringite-rich solid binder from ladle slag and gypsum for the immobilization of an industrial waste material with extremely high contents of several heavy metals. The importance of sulfate and water content on the immobilization efficiency and the use of citric acid to increase the processing time of the binder were studied. The leaching of Pb, Hg, Se, As, Cd, Cu, and Ni was measured, and X-ray powder diffraction, field-emission scanning electron microscopy, and field-emission electron probe microanalysis combined with wavelength-dispersive X-ray spectroscopy were used to analyze the structure of the hardened binder and the location of the heavy metals within. The study shows that the ladle slag/gypsum binder is suitable for the solidification/stabilization of heavy-metal-rich solid industrial waste. Hg, As, Cd, Cu, and Ni were fully immobilized in all scenarios covered in the study, whereas Pb and Se showed more complicated behaviors. The main immobilization method was encapsulation, and partial Se incorporation into ettringite was observed. The presence of citric acid increased the processing time of the binder without harming the immobilization, unless combined with low sulfate content.

Glacier mice as a temporary sink for fallout radionuclides and heavy metals on the Norwegian glacier Austerdalsbreen

Glacier mice are peculiar rolling or stationary moss balls found on the surface of some glaciers. They may harbour an ecological habitat for cold-adapted invertebrates and microorganisms, but little is known about their potential to accumulate and disseminate harmful elements and substances. In this study, we investigate the presence of fallout radionuclides (137Cs, 238Pu, 239Pu, 240Pu, 210Pb) and heavy metals (Pb, As, Hg, Cd) in glacier mice and compare the results to bryophytes from adjacent glacier ecosystems. Samples were collected at Austerdalsbreen, a Norwegian outlet glacier from Jostedalsbreen ice cap. Maximum activity concentrations for bryophytes are 552±12Bqkg-1 for 137Cs, 3485±138Bqkg-1 for 210Pb, 0.0223±0.065Bqkg-1 for 238Pu and 4.34±0.43Bqkg-1 for 239+240Pu while maximum heavy metals concentrations are 70.5mgkg-1 for Pb, 1.0mgkg-1 for As, 1.6mgkg-1 for Hg and 0.13mgkg-1 for Cd. Maximum activity concentrations in cryconite are 1973.4±5.0Bqkg-1 for 137Cs, 3632±593Bqkg-1 for 210Pb, 0.51±0.11Bqkg-1 for 238Pu and 13.1±1.4Bqkg-1 for 239+240Pu and maximum heavy metal concentrations are 50.4mgkg-1 for Pb, 3.4mgkg-1 for As, 1.5mgkg-1 for Hg and 0.082mgkg-1 for Cd. We find that glacier mice show lower activity concentrations of radionuclides compared to cryoconite. The major source of plutonium isotopes is related to global fallout, whereas detected radio-cesium may be additionally affected by post-Chernobyl fallout to an unknown extent. Comparison between glacier surface and adjacent glacial habitats shows higher concentrations of heavy metals in glacier mice on the glacier ice surface and medial moraines compared to bryophytes in the glacier forefield. Glacier mice exported from a receding glacier may affect the cycling of radioactive and metal pollutants in developing proglacial ecosystems.

Ecotoxicological and Microbiological Risk Assessment of Groundwater from Dimba Cave, Democratic Republic of the Congo.

Dimba Cave is a large array of natural galleries in limestone mountains of the Democratic Republic of the Congo that contains highly valued pre-historic archaeological artifacts. The cave attracts a high number of tourists every year and is used by local populations as a water supply source. The main objective of the research undertaken in Dimba Cave consisted of assessing the quality of water and sediments from Dimba Cave ponds through evaluating contamination by heavy metals (15 elements analyzed, including As, Cd, Pb, and Hg) and by microbial populations (including Escherichia coli and total coliforms) in order to estimate the ecotoxicological risk to humans and to non-human biota. All water samples collected in the cave ponds showed very high metal concentrations exceeding the internationally recommended limits for drinking water, particularly for Cr, Mn, As, Pb, and Hg. Most sediment samples from cave ponds also displayed high heavy metal concentrations. The calculated pollution parameters, such as the enrichment factor (EF), and ecological risk parameters, such as the ecological risk index (Eri), indicated that the sediment may be toxic to aquatic biota. Furthermore, the microbiological analysis of pond waters indicated a widespread contamination with bacteria such as Escherichia coli, Enterococcus spp., total coliforms, and Pseudomonas spp., probably from anthropogenic and/or animal sources. Therefore, the consumption of Dimba Cave water as a drinking water represents a threat to public health. Urgent management measures should be enforced to protect public health and the cave ecosystem.

Hydrothermal carbonisation of manure-derived digestates: Chemical properties and heavy metals distribution in end-products

Hydrothermal carbonisation of manure-derived digestates: Chemical properties and heavy metals distribution in end-products

Geopolymer Materials from Fly Ash-A Sustainable Approach to Hazardous Waste Management.

This study explores the utilisation challenges of fly ash from municipal waste incineration, specifically focusing on ash from a dry desulphurisation plant (DDS), which is categorised as hazardous due to its high heavy metal content. The ash's low silicon and calcium contents restrict its standalone utility. Laboratory investigations initially revealed that geopolymers derived solely from fly ash after flue gas treatment (FGT), in combination with coal combustion fly ash, exhibited low compressive strength (below 0.6 MPa). However, the study demonstrated significant improvements by modifying the FGT ash through water leaching. This process enhanced its performance when mixed with high-silica and -aluminium fly ash, resulting in geopolymers achieving compressive strengths of up to 18 MPa. Comparable strength outcomes were observed when the modified ash was blended with commercial cement. Leachability tests conducted for heavy metals (HMs) such as copper, zinc, lead, cadmium, and nickel indicated that their concentrations fell below the regulatory limits for landfill disposal: 2, 4, 0.5, 0.04, and 0.4 mg/kg, respectively. These results underscore the effectiveness of water-washing FGT ash in conjunction with other materials for producing geopolymers, contributing to sustainable waste management practices.

Multi-biomarker approach reveals the effects of heavy metal bioaccumulation in the foundation species Prosopis laevigata (Fabaceae).

Mining is a major economic activity in many developing countries. However, it disturbs the environment, producing enormous quantities of waste, known as mine tailings, which can have deleterious environmental impact, due to their high heavy metals (HM) content. Often, foundation species that establish on mine tailings are good candidates to study the effects of HM bioaccumulation at different levels of biological organization. Prosopis laevigata is considered a HM hyperaccumulator which presents attributes of a foundation species (FS) and establishes naturally on mine tailings. We evaluated the bioaccumulation of Cu, Pb, and Zn in P. laevigata foliar tissue, the leaf micro- and macro-morphological characters, DNA damage, and population genetic effects. In total, 80 P. laevigata individuals (20/site) belonging to four populations: The individuals from both sites (exposed and reference) bioaccumulated HMs (Pb > Cu > Zn). However, in the exposed individuals, Pb and Cu bioaccumulation was significantly higher. Also, a significant effect of macro- and micro-morphological characters was registered, showing significantly lower values in individuals from the exposed sites. In addition, we found significant differences in genotoxic damage in P. laevigata individuals, between the exposed and reference sites. In contrast, for the micro-morphological characters, none of the analyzed metals had any influence. P. laevigata did not show significant differences in the genetic structure and diversity between exposed and reference populations. However, four haplotypes and four private alleles were found in the exposed populations. Since P. laevigata is a species that establishes naturally in polluted sites and bioaccumulates HM in its foliar tissues, the resulting genetic, individual and population effects have not been severe enough to show detrimental effects; hence, P. laevigata can be a useful tool in phytoremediation strategies for soils polluted with Pb and Cu, maintaining its important ecological functions.

Determination of Heavy Metals Concentrations in Local and Imported Chicken Meat Found in Hilla Province Markets

This study was carried out in Hilla province, the chicken samples were collected of both local and imported chicken, the concentration of eight heavy metals (iron, copper, zinc, nickel, manganese, cadmium, lead and chromium) were measured in all samples in order to find if the concentrations of these metals were within or exceeded the permissible limit, The samples were analysis by used the Atomic Absorption spectrophotometer. The result show that for iron, copper, Zinc, nickel, manganese, cadmium, lead and chromium the concentrations were ranged from 70.66 - 81.33 ppm, 0.34 - 0.71 ppm, 6.06 - 8.21 ppm , 6.13 - 8.02 ppm, 0.213- 0.51ppm, 0.276 - 0.833 ppm, 0.733 -1.39 ppm and 0.37 - 0.716 ppm respictively . Generally, the highest heavy metal concentration was recorded in Iraqi house breading chicken. While the lowest concentrations of almost all measured heavy metal in Iraqi Farm breed in chickens.

Preparation and Screening of SRB Gel Particles Used for Deep Purification of Acid Mine Drainage.

The progressive decline of the coal industry necessitates the development of effective treatment solutions for acid mine drainage (AMD), which is characterized by high acidity and elevated concentrations of heavy metals. This study proposes an innovative approach leveraging sulfate-reducing bacteria (SRB) acclimated to contaminated anaerobic environments. The research focused on elucidating the physiological characteristics and optimal growth conditions of SRB, particularly in relation to the pH level and temperature. The experimental findings reveal that the SRB exhibited a sulfate removal rate of 88.86% at an optimal temperature of 30 °C. Additionally, SRB gel particles were formulated using sodium alginate (SA) and carboxymethyl cellulose (CMC), and their performance was assessed under specific conditions (pH = 6, C/S = 1.5, T = 30 °C, CMC = 4.5%, BSNa = 0.4 mol/L, and cross-linking time = 9 h). Under these conditions, the SRB gel particles demonstrated an enhanced sulfate removal efficiency of 91.6%. Thermal analysis via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) provided further insights into the stability and properties of the SRB gel spheres. The findings underscore the potential of SRB-based bioremediation as a sustainable and efficient method for AMD treatment, offering a novel and environmentally friendly solution to mitigating the adverse effects of environmental contamination.

The influence of the pre-addition of semi-dry and dry slaked lime during the purification of flue gas on the subsequent chelation and solidification treatment of MSWI fly ash

The influence of the pre-addition of semi-dry and dry slaked lime during the purification of flue gas on the subsequent chelation and solidification treatment of MSWI fly ash

Heavy metal concentrations in fishes from Zakrzówek Reservoir and the Vistula River near Kraków: Human risk assessment

Abstract The aim of this study was to compare tissue concentrations of heavy metals (copper (Cu), manganese (Mn), iron (Fe), nickel (Ni), zinc (Zn)) in roach (Rutilus rutilus (L.)), chub (Squalius cephalus (L.)), and bleak (Alburnus alburnus (L.)) from two locations on the Vistula River upstream from Kraków and Zakrzówek Reservoir, a former limestone quarry flooded over 30 years ago that is located close to the center of Kraków. The findings showed that heavy metal concentrations in fishes from the Vistula River upstream from Kraków were higher compared to those in fishes from Zakrzówek Reservoir. The highest heavy metal concentrations were found in hard tissues, such as bone and scales, and the lowest was in muscle tissue. Metal pollution index (MPI), estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) analyses showed no significant non-carcinogenic risk to human health from the consumption of the muscle meat of the fishes analyzed. Cancer risk (CR) values, calculated based on maximum Ni concentrations in fish muscle tissue, did not exceed the upper limit of the acceptable cancer risk range. The findings show that the assessment of heavy metal contamination of fishes should be continued and extended to include other water bodies used for fishing and other xenobiotics that accumulate in fishes and may pose risks to human health.

Use of Forest Trees in the Treatment of Polluted Soil by Heavy Metals: A Mini Review

Human activities lead to a large accumulation of heavy metals in the soil which comes from industrial activities such as mining smelting refining manufacturing processes and waste resulting from excessive use of chemical fertilizer and vehicle exhausts. So, soil pollutants especially with heavy metals can be treated using different types of plants; such as forest trees and grasses. These plants can tolerate soil pollutants at high concentrations in their biological tissue, and treat pollutants by absorbing and accumulating heavy metals in their living tissues. Therefore, in this article, we reviewed several forest tree species, that showed high resistance in the absorption and accumulation of heavy metals, such as genus Eucalyptus, Acacia, Salix, Populus, Tamarix, Melia, Dalbergia, Leucaena, Acer, Fraxinus, and Thuja. It has been noted that planting forest trees with high biomass that resist high concentrations of heavy metals in soil, works to rid the soil of these pollutants. This is the latest and best technology for treating soil pollution. In particular, it is unique from its counterparts in its environmental friendliness, economic benefits, and other returns resulting from plant cultivation. Therefore, applying phytoremediation techniques that benefit is the best and safest for the environment and living organisms.

Evaluating Technical properties of fired clay Brick production with mosaic sludge: A comprehensive study on heavy metal leachability for sustainable environmental and economic benefits

Evaluating Technical properties of fired clay Brick production with mosaic sludge: A comprehensive study on heavy metal leachability for sustainable environmental and economic benefits

Вміст важких металів у воді, донних відкладах та рибі водних об’єктів різного призначення Дніпропетровської області

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products. Keywords: Dnipropetrovsk region, heavy metals, Dnipro Reservoir, Dnipro-Donbas Canal, ponds, Sholokhivske Reservoir, water, sediment, fish, accumulation of pollutants.

Deciphering the Environmental Code: SEM-EDX Analysis of Lead and Mercury Distribution in Enhalus Acoroides From Kayeli Bay, Indonesia

Background: Illegal gold mining activities around Kayeli Bay have led to increased heavy metal contamination that has the potential to impair water quality and growth of Enhalus acoroides, an important seaweed species. This study aimed to investigate the distribution and concentration of heavy metals Pb and Hg in Enhalus acoroides organs (roots, rhizomes, and leaves) using SEM-EDX techniques and evaluate the impact of mining activities on the surface microstructure of these organs. Methods: Enhalus acoroides samples were collected from ten sampling points in Kayeli Bay, which were selected based on potential heavy metal contamination. SEM-EDX analysis was performed to assess the surface microstructure and distribution of heavy metals in the seaweed samples. Results: Results showed significant differences in Pb and Hg concentrations among samples from different locations, with Hg content consistently higher than Pb. Surface microstructure analysis showed morphological changes in roots, rhizomes, and leaves exposed to heavy metals, indicating environmental stress in Enhalus acoroides. Conclusion: This study confirmed the negative impact of heavy metal contamination on Enhalus acoroides in Kayeli Bay due to illegal gold mining activities. High concentrations of heavy metals, especially Hg, in seaweed organs indicate potential risks to marine ecosystem health and the sustainability of fisheries resources. These findings emphasize the need for stricter environmental monitoring and management to protect this important marine habitat from heavy metal pollution.

Trifolium repens L. recruits root-associated Microbacterium species to adapt to heavy metal stress in an abandoned Pb-Zn mining area

Root-associated microbiota provide great fitness to hosts under environmental stress. However, the underlying microecological mechanisms controlling the interaction between heavy metal-stressed plants and the microbiota are poorly understood. In this study, we screened and isolated representative amplicon sequence variants (strain M4) from rhizosphere soil samples of Trifolium repens L. growing in areas with high concentrations of heavy metals. To investigate the microecological mechanisms by which T. repens adapts to heavy metal stress in abandoned mining areas, we conducted potting experiments, bacterial growth promotion experiments, biofilm formation experiments, and chemotaxis experiments. The results showed that high concentrations of heavy metals significantly altered the rhizosphere bacterial community structure of T. repens and significantly enriched Microbacterium sp. Strain M4 was demonstrated to significantly increased the biomass and root length of T. repens under heavy metal stress. Additionally, L-proline and stigmasterol could promote bacterial growth and biofilm formation and induce chemotaxis for strain M4, suggesting that they are key rhizosphere secretions of T. repens for Microbacterium sp. recruitment. Our results suggested that T. repens adapted the heavy metal stress by reshaping rhizosphere secretions to modify the rhizosphere microbiota.

Ecotoxicological impact of heavy metals on wild mud crabs (Scylla olivacea) in Malaysia: An integrative approach of omics, molecular docking and human risk assessment

Mud crab, one of the aquatic organisms found in estuary areas, has become a significant economic source of seafood for communities due to its delectable taste. However, they face the threat of heavy metal contamination, which may adversely affect their biological traits. This study explored the comparison of the mud crabs collected from Setiu Wetland as a reference site, while Kuala Sepetang is an area that contains a higher concentration of heavy metals than Setiu Wetlands. Heavy metal levels were quantified using inductively coupled plasma mass spectrometry (ICP-MS), while proteomes were assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 1H nuclear magnetic resonance (NMR)-based metabolomics, respectively. Heavy metal contamination affects the proteome, metabolome, and putative molecular targets in mud crabs (Scylla olivacea), leading to oxidative stress. Mud crabs collected from the metal-polluted area of Kuala Sepetang in Perak had considerably elevated concentrations of nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), chromium (Cr), and cadmium (Cd) in comparison to the reference site of Setiu Wetlands in Terengganu. The proteome analysis revealed an upregulation of the stress-response protein Hsp70, which triggered superoxide dismutase (SOD) and increased arginine kinase expression (5.47 fold) in the muscle tissue, results in the alteration of metabolite regulation in the mud crab from Kuala Sepetang. Additionally, in the muscle tissues of mud crabs obtained from Kuala Sepetang, uncharacterized myosin-tail 1 domain proteins and sarcoplasmic calcium-binding proteins were downregulated. The metabolomic investigation identified changes in metabolites associated with energy metabolism and osmoregulation. Exploration of docking analysis suggests potential connections between methylarsonic acid and essential proteins in mud crabs. These findings suggest that the presence of heavy metals disrupts physiological processes and highlights potential molecular targets that warrant further investigation.

Spatial distribution and health risk assessment of heavy metals in drinking water in Nikshahr and Iranshahr cities of Iran

ABSTRACT The presence of high concentrations of certain heavy metals (HMs) in drinking water poses a serious threat to the health of consumers. This work was done to investigate the concentration of heavy metals such as Arsenic (As) cadmium (Cd), chromium (Cr), iron (Fe), mercury (Hg), nickel (Ni), lead (Pb) and cobalt (Co) in the water resources of two cities of Iranshahr and Nikshahr in the south of Sistan and Baluchistan province. For this aim, 24 samples of drinking water sources were collected and the concentration of heavy metals was determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results of samples of these networks showed that the average concentration of Pb (11.25 μg/L), Hg (10.33 μg/L), As (10.62 μg/L) and Cd (3.45 μg/L) far exceeds the standard of the World Health Organisation. The average concentration of heavy metals in the drinking water of Iranshahr and Nikshahr is respectively Fe>Pb>As>Hg>Ni>Cr>Co>Cd and Fe>Pb>As> Ni > Cr >Co>Cd> Hg. Potential sources of pollution in this study are attributed to infiltration of industrial effluents and agricultural runoff, which is a significant threat to groundwater quality. The calculated hazard quotients (HQ(values for non-carcinogenic risk show that this value is less than 1 in most metals, but the hazard index)HI) in children is greater than 1, and non-carcinogenic risk is evident. HI was obtained for children 5.4 and adults 2.6. However, the risk of carcinogenics in children and adults is equal to 2.66 E-05 and1.3E–6, respectively, and the increase in the risk of cancer in children is higher due to the consumption of drinking water. Therefore, it is necessary to protect water sources, water treatment and monitor more water distribution networks based on the water safety plan.