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In the present work, the concentrations of toxic heavy metals in mangrove sediments, mangrove leaves, and seeds collected from five stations in the Vattanam mangrove of Palk Bay, southeastern India, as well as the effects of the monsoon season on toxic heavy metals concentrations were determined. The concentrations were 17.5 μg/g for zinc (Zn), 9.11 μg/g for copper (Cu), and 6.03 μg/g for lead (Pb) in sediments; 10.71 μg/g (Zn) and 8.94 μg/g (Cu) in mangrove leaves; and 26.24 μg/g (Zn) and 17.01 μg/g (Cu) in mangrove seeds. At all sampling stations, the Cd concentration was below the limit of detection. These mangroves seem to have adapted successfully to their environment given their selective intake of only essential metals (Cu and Zn) and the restricted movement of non-essential metals (Cd and Pb). The concentrations of metals were below the maximum residual limits regulated by national and international standard limits., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study presents an environmentally sustainable method for minimizing sludge production in the textile effluent sector through the combined application of electrokinetic (EK) and electrooxidation (EO) processes. AAS and XRF analyses reveal that utilizing acidic electrolytes in the EK method successfully eliminates heavy metals (Cu, Mn, Zn, and Cr) from sludge, demonstrating superior efficiency compared to alkaline conditions. In addition, the total removal efficiency of COD contents was calculated following the order of EK-3 (60%), EK-1 (51%) and EK-2 (34%). Notably, EK-3, leveraging pH gradient fluctuations induced by anolyte in the catholyte reservoir, outperforms other EK systems in removing COD from sludge. The EK process is complemented by the EO process, leading to further degradation of dye and other organic components through the electrochemical generation of hypochlorite (940 ppm). At an alkaline pH of 10.0, the color and COD removal were effectively achieved at 98 and 70% in EO treatment, compared to other mediums. In addition, GC-MS identified N-derivative residues at the end of the EO. This study demonstrates an integrated approach that effectively eliminates heavy metals and COD from textile sludge, combining EK with EO techniques., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Ocean acidification (OA) and heavy metal pollution in marine environments are potentially threatening marine life. The interactive effect of OA and heavy metals could be more vulnerable to marine organisms than individual exposures. In the current study, the effect of OA on the toxicity of cadmium (Cd) in the crab Scylla serrata was evaluated. Crab instars (0.07 cm length and 0.1 g weight) were subjected to pH 8.2, 7.8, 7.6, 7.4, 7.2, and 7.0 with and without 0.01 mg l -1 of Cd for 60 days. We noticed a significant decrease in growth, molting, protein, carbohydrate, amino acid, lipid, alkaline phosphatase, and haemocytes of crabs under OA + Cd compared to OA treatment. In contrast, the growth, protein, amino acid, and haemocyte levels were significantly affected by OA, Cd, and its interactions (OA + Cd). However, superoxide dismutase, catalase, lipid peroxidation, glutamic oxaloacetate transaminase, glutamic pyruvate transaminase, and accumulation of Cd in crabs were considerably elevated in OA + Cd treatments compared to OA alone treatments. The present investigation showed that the effect of Cd toxicity might be raised under OA on S. serrata. Our study demonstrated that OA significantly affects the biological indices and oxidative stress responses of S. serrata exposed to Cd toxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Human hair and nail samples from Cuddalore fisherfolk populations were used as biomarkers for assessing metal concentrations in humans. Hair samples from 80 participants (47 men and 33 women) and nail samples from 40 participants (21 men and 19 women) were collected, and the concentrations of Cd, Cu, Pb, and Zn were assessed using an atomic absorption spectrophotometer (AAS). Metal data from AAS were compared with the survey questionnaire's personal and dietary parameters. Results indicate that both personal and dietary parameters may influence metal exposure; however, majority of the sources may have originated from metal-contaminated seafood. Higher metal accumulation in communities, especially those which consume seafood on a daily basis, may increase the possibility for them to get affected by metal-related diseases. Based on environmental parameters, people who live ≤500 m from industrial zones accumulate more metals. Further extensive studies with more individuals and more questionnaire parameters are needed to identify the metal accumulation pathway in humans., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The spatiotemporal variations of five heavy metals (Cd, Cu, Cr, Pb, and Zn) in the beach sediments along the Tamil Nadu coast sourced from various anthropogenic activities were assessed using atomic absorption spectrophotometry (AAS). Various pollution monitoring indices were computed to clearly understand the metal pollution status along the Tamil Nadu coastline. The metal concentrations in sediments were typically higher in the summer season than in the monsoon season. In the monsoon season, metal concentration followed a decreasing order of Zn > Cr > Cu > Pb > Cd, and in the summer season, the order was Cr > Zn > Cu > Pb > Cd. During the monsoon season, freshwater runoff from the rainfall dilutes the sediments and their trace element load. However, due to a lack of freshwater influx during the summer season, the heavy metals in the sediments get concentrated and showed elevated levels. Geo-accumulation index, ecological risk index, pollution load index, and contamination degree clearly depict that Cd and Pb have higher accumulation and pose greater hazard when compared with other metals. The rivers flowing in the region also transport the heavy metals from the mainland to the estuaries and coastal environments. Metal levels along the Tamil Nadu coast are influenced by various anthropogenic activities persistent along the coastline. Some of the activities that cause metal contamination are mining, milling, electroplating, furnishing, pharmaceutical industries, fishing, harbor activities, urban runoff, and agricultural runoff, which release a variety of toxic metals into the coastal environment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The concentrations of five heavy metals (Cd, Cr, Cu, Pb, and Zn) in the sediments, water, phytoplankton, zooplankton, and macroalgae from Kongsfjorden Fjord and the freshwater lakes of Ny-Ålesund in the Svalbard archipelago were determined in order to describe the anthropogenic impacts related to the Ny-Ålesund town. Water samples from nine stations, sediment samples from 23 stations, plankton samples from five stations, and six species of macroalgae were collected and subjected to heavy metal analysis using atomic absorption spectrophotometry (AAS). Only Cu and Zn were detected in the water samples. The plankton samples had only Zn, Cu, and Cr. The average metal concentrations in macroalgae fell in the decreasing order of Cu > Zn > Cr > Cd > Pb. In sediment samples, the metal order was as follows: Zn > Cu > Cr > Pb > Cd. Multivariate statistical analyses including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to identify the source of the metal contamination. The metals were found to originate from a blend of both anthropogenic and geogenic sources. Pollution monitoring indices including geoaccumulation index (I geo ), contamination factor, contamination degree (C deg ), pollution load index (PLI), and potential ecological risk (PER) were calculated using the metal data. In the study area, I geo values of the metals showed pollution grades from 0 (uncontaminated) to 6 (extremely contaminated). C deg fell in classes from 1 (low contamination) to 4 (very high contamination). PLI values ranged between 0 and 5.68. PER values expressed that except for a few stations located at higher elevations in the glacial outwash plains, all other sites were highly polluted. The high level of pollution indices in the sites can be attributed to the anthropogenic activities persistent in the study area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Distribution of five heavy metals (Cd, Cr, Cu, Pb, and Zn) in molluscan and echinoderm species collected from Kerala and Gulf of Mannar in Southern India is presented. Atomic absorption spectrometry was used to determine metal concentrations. Concentrations of metals showed a descending order of Zn > Cu > Pb > Cd > Cr. Zn and Cu might have originated from both natural and man-made sources. However, Cd, Cr, and Pb could have strong anthropogenic influences such as harbour activities and untreated industrial and agricultural runoff. Bioaccumulation factor (BAF) value of Cd in two edible bivalves from Munambam is slightly greater than one. Regular consumption of Cd-loaded shellfish can cause serious health hazards and concerns to humans. BAF results showed that Zn, Cu, Pb, and Cd were more bioaccumulated and beyond the threshold limits in certain species. It is evident that consumption of shellfish from the Kerala coastal waters may have adverse health impacts to the consumers., Competing Interests: Declaration of competing interest All the authors agree with the contents and to the submission and disclose that, there is no conflict of interest including financial, personal or other relationships with other people or organizations., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Seasonal distribution of four metals (Cd, Cu, Pb, and Zn) in eight shellfish species collected from the heavily contaminated Cuddalore coast in Tamil Nadu, Southern India, were analyzed. Metal concentrations in all shellfish species were determined using atomic absorption spectrometry. All metals were present in all seasons in most of the species, however, with a few exceptions. Overall, the metal concentration was in the descending order: Zn > Cu > Pb > Cd. Metals might have emerged from both natural and anthropogenic sources as per multivariate statistical analysis. Bioaccumulation factor results showed that cadmium was more bioaccumulated and beyond the threshold limit. Hazard index (HI) values revealed that consuming shellfish from Cuddalore coast can pose hazards to human health, with all HI values beyond threshold limit across all seasons - premonsoon (1.33), monsoon (1.73), postmonsoon (2.55), and summer (2.64). It is evident that consumption of shellfish across all seasons may have adverse health impacts to the people., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

We present seasonal variation of four metals (Cd, Cu, Pb, and Zn) in nine pelagic and three benthic fish species from the highly polluted Cuddalore coast in Tamil Nadu, India. Metals were assessed using atomic absorption spectrometry and detected in all fish species, in at least one season, except Iniistius cyanifrons where cadmium was not detected throughout. In both benthic and pelagic fish, order of metal concentration was Zn > Cu > Pb > Cd. Multivariate statistical analysis revealed that metals may have originated from both natural and anthropogenic sources. Health risk assessment revealed that consumption of fish from Cuddalore coast does not pose health risk for now; however, hazard index values (pelagic = 0.97; benthic = 0.90) are in borderline. Even a slight increase in metal concentration in fish can prove hazardous for human consumption. Sooner or later, eating fish from Cuddalore coast may pose a considerable health risk to humans if metal pollution is not held at Bay., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Togo's phosphate processing plant at Kpeme discharges waste, containing Cd, Pb, and fluoride, into the sea and on the soil. Heavy metals toxicity on kidneys and the liver has been studied. However, fluoride toxicity on these organs remains to be investigated. The present study deals with the variation in renal and hepatic functioning parameters due to fluoride, Cd and Pb. Totally, 350 volunteers were recruited from five different localities around this phosphate processing plant for sample collection. Cd and Pb contents in blood samples were determined by spectrophotometry and fluoride by the titanium chloride method. Biochemical parameters were measured using Biolab kits. The pollutant contents were elevated in polluted areas where ASAT, ALAT, creatinine, and urea increased, and total protein decreased. Correlation and multivariate tests showed that fluoride is related to the various pathologies mentioned. PCA revealed that phosphate processing in Togo is a source of renal and hepatic toxicity., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

In this study, we have assessed the concentrations of four heavy metals (Cu, Zn, Cd, and Pb) in the feathers of 11 species of birds from the Point Calimere Wildlife and Bird Sanctuary, a protected environment. Concentrations of copper and zinc were detected in all the bird species, cadmium was observed only in two bird species, and lead was below the detection limits for all birds. The order of concentration of metals in the feathers is Zn > Cu > Cd > Pb. Using the multivariate statistical analysis, principal component analysis (PCA), the metal origins were traced to natural, dietary, and manmade sources. In addition, sediment samples were also collected from the sanctuary, to assess the bioaccumulation factor (BAF). The BAF values follow the order Cd < Cu < Zn < Pb. In comparison with worldwide heavy metal reports in bird feathers, lower concentrations of metals are observed in our study area. The tropical marine ecosystem at Point Calimere Wildlife and Bird Sanctuary can be considered as pristine regarding heavy metal pollution. Continuous monitoring of the ecosystem is crucial to sustain the pristine nature of the sanctuary and to attract many more birds., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present study aimed to determine metal accumulation levels in tissue and biomineralisation in shells of 20 species of molluscs (13 gastropods and 7 bivalves) from Palk Bay, India. In most cases, metal concentrations in the tissues were higher than in the shells of the same species collected from same location, meaning that in many cases biomineralisation factors of metal ratios were <1. The highest biomineralisation factor for Cd was detected in Melampus sincaporensis (3.72 ± 0.1) from the Thondi mangrove, for Pb in Cerithidea cingulata (2.51 ± 0.17) from the Vattanam mangrove, for Cu in Melampus sincaporensis (0.88 ± 0.2) from the Thondi mangrove, and for Zn in Cerithidea cingulata (0.93 ± 0.3) from the Devipattinam mangrove. In most cases, metal concentrations were higher than reported in previous studies but were within the maximum limits stated by national and international regulatory agencies. Variations in the biomineralisation factor of metal ratios among the molluscan species likely stems from variations in bioaccumulation efficiency, selectivity of individual organisms, and availability of metals in the mangrove and coastal environments., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In the present study, we have assessed the degree of contamination of heavy metals (Cd, Cu, Pb, and Zn) in ten species of red and brown seaweeds, the seasonal variations in the concentration of metals, and the health risk due to the seaweeds. Overall metal concentrations for red and brown seaweeds followed the order Pb > Zn > Cu > Cd and Pb > Cu > Zn > Cd, respectively. Cd and Pb levels were found to be elevated in both the red and brown seaweeds. Multivariate statistical analysis revealed that the sources of Cd and Pb are mainly anthropogenic. Despite the high concentrations of the non-essential metals (Cd and Pb) in the seaweeds, the health risk assessment revealed that they have a lower hazard index. Hence, consumption of edible red and brown seaweeds from the Tuticorin coast may not pose health hazards in humans for the time being., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This study aims to estimate anthropogenic sources of pollutants such as heavy metals that pollute or poison the commercial marine finfish and shellfish present around the Ennore coastal area and to identify, quantify and manage the associated risks for the betterment of society. The levels of toxic heavy metal concentrations from monitoring and surveillance of copper, chromium, cadmium, mercury, lead and zinc heavy metals were estimated from water, sediment and commercial marine finfish and shellfish samples that were collected for study. The individual mean bioaccumulation index (IMBI) and Metal Pollution Index (MPI) values varied between finfish and shellfish. Target hazard quotient (THQ) index values were calculated, and copper and zinc were found to be elevated at levels affecting children in particular. Thus, efforts are urgently needed to resolve the current and potential risks associated with the negative impact of heavy metal intake from seafood on human health. This study attempts to identify levels of metal contamination and corresponding risk factors with regard to human health.

In this study, the production and compositional analysis of exopolysaccharides produced by Bacillus cereus KMS3-1 grown in metal amended conditions were investigated. In addition, the metal adsorption efficacy of exopolysaccharides (EPS) produced by KMS3-1 strain was evaluated in a batch mode. Increased production of exopolysaccharides by KMS3-1 strain was observed while growing under metal amended conditions (100 mg/L) and also, the yield was in the order of Pb(II)>Cu(II)>Cd(II)>Control. Characterization of EPS using FT-IR, XRD, and SEM analysis revealed that the EPS can interact with metal ions through their functional groups (O‒H, CH, C˭O, C‒O, and C‒C˭O) and assist the detoxification process. Further, equilibrium results were fitted with the Langmuir model and notably, the maximum adsorption capacity (Q max ) of EPS for Cd(II), Cu(II), and Pb(II) found to be 54.05, 71.42, and 78.74 mg/g, respectively. To the best of our knowledge, EPS demonstrating proficient metal adsorption was substantiated by XRD analysis in this study. Owing to good adsorbing nature, the exopolysaccharides could be used as chelating substances for wastewater treatment., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Three species of mangroves and six species of salt marshes were collected from various locations along the Tuticorin coast for the estimation of metals like Cu, Cd, Pb, and Zn. The bioaccumulation of metals in mangroves is in the order of Cu > Pb > Zn > Cd, and the season-wise accumulation was higher in monsoon followed by summer, post-monsoon, and pre-monsoon seasons. The accumulation of metals in mangroves showed higher in Rhizophoraapiculata followed by Avicenniamarina, and Rhizophoramucronata. The concentration of metals in salt marshes is in the order of Pb > Zn > Cu > Cd, and the species-wise accumulation showed in the order of Suaeda maritime > Ipomoea sp. > Suaeda sp. > Spinifix littoreous > Sesuvium portacastrum > Ipomoea pes-capras. BAF in salt marhes and mangroves is as Cd < Pb < Cu < Zn and Cd < Cu < Pb < Zn, respectively., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In the present study, heavy metals (Cd, Cu, Pb, and Zn) level in the water, sediment, and crabs were analyzed from Noyyal and Chinnar Rivers of the Western Ghats in Tamil Nadu, India. Based on our results, Noyyal River is considered as polluted environment due to the discharge of contaminants by various anthropogenic activities, whereas, Chinnar River maintained as unpolluted one due to its tributary nature of Noyyal River located in Western Ghats hills. The results showed that the heavy metals in water and sediments were higher in Noyyal River. Also, the level of bioaccumulation of studied metals and biochemical constituents were higher in the crab Spiralothelphusa hydrodroma sampled from Noyyal River than Barytelphusa cunicularis collected from Chinnar River. The present findings revealed that the crab sampled from Noyyal River had elevated heavy metals which lead to a significant increase in biochemical constituents to overcome the stress.

The present study was mainly focused on the distribution of metals (Cd, Cu, Pb, and Zn) in commercially important marine finfish and shellfish resources collected from the Tuticorin coast of the Gulf of Mannar, Southeastern India. Sixty-six species were collected in all four seasons for the analysis of metals. The order of bioaccumulation of metals in fishes is (Zn > Pb > Cu > Cd), in Crustaceans is (Zn > Pb > Cu > Cd), and in mollusks is (Pb > Zn > Cu > Cd). The human health risk assessment factors such as BCF, THQ, and HI were higher in most of the tested animals. The outcome of the present study will sound the alarm to the community about heavy metal contamination of sea foods. We conclude that continuous monitoring of the ecosystem is essential to the maintenance of the pristine ecosystem and quality of the seafood., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The present study was performed to analyze the bioaccumulation of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes in the crab Scylla serrata from different regions of Tuticorin, Southeast Coast of India. The study area consists of Threspuram and Harbour Beach which were polluted environments due to the discharge of industrial effluents and domestic sewage into them. Punnakayal, which is a low-polluted environment where the in-situ culture of S. serrata is carried out by local fish farmers, was selected as well. The results revealed that the level of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes were significantly high in the crabs collected from Threspuram and Harbour Beach compared to the crabs collected from Punnakayal. This study indicates that crabs from polluted environments have significant heavy metals bioaccumulation which leads to elevated antioxidants and metabolic enzyme levels. This implies that the crabs are under oxidative and metabolic stress., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Metals such as Cd, Pb, Cu and Zn were analysed in five seagrass species from five locations of the Palk Bay coast of south-eastern India. The maximum Cd concentration (2.83 ± 0.08 μg g -1 ) was recorded in Syringodium isoetifolium on the Mallipattinam coast in the post-monsoon season, and the Cu (29.54 ± 1.03 μg g -1 ) in Enhalus acoroides of the Thondi coast during monsoon season. The maximum concentrations of Pb (3.12 ± 0.14 μg g -1 ) and Zn (52.66 ± 0.88 μg g -1 ) were observed in S. isoetifolium and Cymodoceae rotundata on the Devipattinam and Karangadu coasts, respectively, during the monsoon season. The metal concentrations obtained in different seagrass species varied significantly among species, and no clear monsoon season had a clear effect on the accumulation of heavy metals in the investigated seagrass species. S. isoetifolium has higher capacity for Cd and Pb accumulation than other tested seagrass species., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Bioaccumulation of metals in ten species of green seaweeds collected along the Palk Bay was assessed in the present study. The accumulation of metals in all the ten species were in the order of Pb > Cu > Zn > Cd. Cd was recorded above the permissible level, and Pb, Cu and Zn were below the permissible level of CEQG. The metal concentration in seaweeds was above the WHO standards. The permissible levels of metals were compared with the standards of human health risk assessment, which shows that the exposure of metals from seaweeds has moderate hazard risk to humans. The result of trace element accumulation in four seasons was in the order of summer >monsoon>pre-monsoon>post monsoon. One-way ANOVA revealed that Cd and Pb show significant differences (p˂0.01) in all the species. Cu showed significant variation (p˂0.01) in all the four seasons. Zn also showed significant difference (p˂0.01) during pre-monsoon season., Competing Interests: Declaration of competing interest All the authors agree with the contents and to the submission and disclose that, there is no conflict of interest including financial, personal or other relationships with other people or organizations., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The concentration of nine trace elements were analyzed in the different tissue organs of commonly available crabs (Portunus sanguinolentus, Portunus pelagicus and Scylla serrate) and bivalve (Polymesoda erosa) species collected from the Miri coast, Borneo in order to evaluate the potential health risk by consumption of these aquatic organisms. Among the analyzed organs, metal accumulation was higher in the gill tissues. The essential (Cu and Zn) and non-essential (Pb and Cd) elements showed the highest (i.e. Zn) and lowest concentrations (i.e. Cd) in their tissue organs, respectively. The estimated daily intake and hazard indices of all metals in the muscle indicate that the measured values were below the provisional tolerable daily intake suggested by the joint FAO/WHO Expert Committee on Food Additives. Compared to Malaysian and international seafood guideline values the results obtained from the present study are lower than the permissible limits and safe for consumption., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study aimed to monitor the concentrations of metals including Cd, Pb, Cu and Zn in commercially important and commonly edible brown, red and green algal species collected from Thondi coast, southeast India. Green seaweed Chaetomorpha linum contained higher (Cd 8.51 mg kg -1 , Pb 5.24  mg kg -1 , Cu 15.38 mg kg -1 , and Zn 22.34  mg kg -1 ) concentrations of metals than other tested seaweed samples. The concentrations of metals significantly varied within and between the investigated species of seaweed samples (P < 0.05). It was revealed that Cd, Pb, Cu and Zn metals were present in the species of seaweeds at different concentration. The residual levels of metals were less than the maximum allowable levels specified for human consumption compared to PTWIs, JECFA, FAO/WHO, FSSAI and EC. This study suggested that exposure to the analysed metals (Cd, Pb, Cu and Zn) through seaweeds consumption does not raise serious health effects to consumers and it is safe for human consumption., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Toxic heavy metals are an important group of emerging chemical contaminants in seafood. Heavy metal concentrations in commercially important and most commonly eaten 10 fish species from Thondi fish landing, southeast coast of India, were determined by atomic absorption spectrometry. The concentrations of heavy metals significantly varied within and between the investigated fish species (P<0.05). The results of this study showed best significant correlations among the toxic heavy metals in the fish samples. It was revealed that Cd, Pb, Cu, and Zn metals were present in the fish samples at various levels. The residual levels of toxic heavy metals were less than the permissible levels specified for human consumption by the European Union, Food and Agriculture Organization and World Health Organization guidelines. Therefore, the fish species found in the Thondi fish landing and their fishery products can be considered safe for human consumption and can be exported worldwide., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The heavy metal concentrations in water and sediment samples were investigated in the tropical Muthupet mangrove ecosystem, southeast coast of India. The results demonstrated that, ranges of metals in water comprise of Cd-0.05 to 3.72; Cu-0.5 to 4.43; Pb-6.31 to 17.87; Zn-0.0 to12.91 ppm and sediment comprises of Cd-0.06 to 0.57; Cu-4.46 to 20.59; Pb-2.90 to 21.35; Zn-4.41 to 39.18 ppm. In all the three sites, heavy metals in sediment exhibited significant higher concentrations compared to water, except Cd. The spatial distribution of metals in water and sediment samples followed a similar pattern except Cd with the preponderance of Zn (75% of total metals) followed by Cu and Pb. Muller's Geoaccumulation indexes (Igeo) showed Cd is a potent pollutant in the ecosystem and moderately contaminated the study area. The aquaculture and agricultural culture practices follow improper disposal of municipal wastages, and idol immersion activities are the potent metallic sources for heavy metal pollution were identified by performing principle component analysis. In order to protect the ecosystem from further contamination, regular monitoring is needed to in order to control the anthropogenic discharges. Graphical abstract.