Potential risk assessment of trace metals accumulation in food, water and edible tissue of rainbow trout (Oncorhynchus mykiss) farmed in Haraz River, northern Iran

Health risk assessment of heavy metals (Zn, Pb, Cd, and Hg) in water and muscle tissue of farmed carp species in North Iran

This cross-sectional study was conducted to determine and compare the concentrations of heavy metals (Zn, Pb, Cd, and Hg) in carp-farming water and muscle of various carp species including common carp (Cyprinus carpio), bighead carp (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), and grass carp (Ctenopharyngodon idella) collected from three major warm-water fish farms in Mazandaran Province (Iran) during March 2018 to March 2019. In addition, bioaccumulation of heavy metals (BCFs) and carcinogenic and non-carcinogenic risk assessments of consumers exposed to heavy metals through fish consumption were estimated. The water concentration of all metals in this study was lower than permissible limits. The concentration of Zn in the water (10.21-17.11 μg L^-1) was higher than that of other metals in all sites, followed by Pb > Cd > Hg. In fish muscle, Zn concentration in silver carp was the highest, and the lowest concentrations were related to Hg and Cd in common carp and grass carp, respectively. The target hazard quotients (THQ) indicated that the non-carcinogenic health risk to humans was relatively low by consuming four farmed carp species products. The carcinogenic risk of inorganic Pb was 1.24E-04 (common carp) to 2.11E-04 (grass carp) for adults, which is within the acceptable range. The values of BCFs for all metals demonstrated that farmed carp muscle could not be considered a bioaccumulative tissue for heavy metals. The results indicated that the concentrations of heavy metals in the farmed carp species in North Iran were relatively low and did not cause considerable human health risks.

Probabilistic chronic dietary exposure assessment adjusted for bioaccessible fraction to metals by consumption of seaweed and derived foods

The chronic exposure to heavy elements, i.e. Ni, As, Cd, Hg and Pb the evaluation of toxicological risk through intake of raw or seaweed based foods for Belgian consumers is presented in this study. The bioaccessible fraction, obtained for different metals, were used to refine the exposure values to avoid overestimation in the reported exposures. The decrease in the exposure values was higher for As with average bioaccessible fraction of 56.8% followed by Pb, Cd, Ni and Hg. The pure seaweeds show more approximation or exceeding of toxicological limits compared to the composite foodstuffs. For all elements (except Hg), toxicological limits are approached at the maximum exposure situation due to consumption of certain seaweed-based foods. Further, the study demonstrates that the introduction of innovative foods on an emerging market may result in potential health issues due to the shift in consumption patterns as the increased consumption of seaweed and their derivatives in Europe.

Ecological and human health risk assessment of potentially toxic element contamination in waters of a former asbestos mine (Canari, Mediterranean Sea): implications for management

Between 1948 and 1965, the Canari asbestos mine (Corsica, France) discharged 11 million tonnes of serpentinite rubble into the sea. This study, therefore, aims to assess the environmental and health risks associated with contamination of potentially toxic elements using bioindicators (seagrass and fish) in the areas bordering the former mine within the perimeter of the Cap Corse and Agriate Marine Natural Park. The results and multivariate statistical analyses of the potentially toxic elements, made it possible to identify a concentration gradient, a model of bioaccumulation, and the occurrence of different groups, thus reflecting a spatial variation of the contamination. These results indicate that the former asbestos mine can still be considered, 55 years after its closure, as a major source of Co, Cr, and Ni for marine ecosystems and still influences the quality of the coastal area today. Our study, therefore, indicates that the two most polluted sites (Albo and Negru) are the closest stations to the south of the old Canary asbestos mine. According to the Trace Elements Pollution Index (TEPI) values, 6 species were classified as having a high contamination level: Scorpaena notata (1.37), Scorpaena porcus (1.36), Sepia officinalis (1.27), Diplodus vulgaris (1.02), Spicara maena (0.95), and Mullus surmuletus (0.94). Regarding the potentially toxic elements measured in the edible tissues of fish, the concentrations were all below the regulatory thresholds and did not reveal any potential risk to human health (Cd, Cu, Fe, Pb, Se, Sn, Zn). This work provides new and useful information to improve the monitoring of the environmental quality of a region characterized by previous mining activity and to assess the potential risk to human health due to the consumption of fish. Beyond the purely scientific aspects, these results could serve as decision support at the regional level for the definition of long-term public policies.

Heavy Metal Pollution in Aquaculture: Sources, Impacts and Mitigation Techniques

Aquaculture is one of the fastest growing agro-industries as it presently accounts for nearly 50% of all fish for direct human consumption and 43% of total seafood supply. Fish provide about 20% average daily intake of animal protein for about 3.2 billion people globally. The treatment of aquaculture in recent years for the mitigation of heavy metals and other contaminants has been gaining traction due to the benefits of aquaculture to both man and the environment. This paper provides a review of the sources, impacts, and the various methods that have been deployed in recent years by various researchers for the treatment of heavy metal contaminated aquaculture. Related works of literature were obtained and compiled from academic search databases and were carefully analysed in this study. The dangers these metals pose to the sustainability of aquaculture were studied in this review. Studies indicate that some heavy metals, such as mercury, lead, and cadmium, due to their long-term persistence in the environment, allow them to accumulate in the food chain. Mitigation techniques such as adsorption, bio-sorption, and phytoremediation have been deployed for the treatment of heavy metal contaminated aquaculture. Some research gaps were also highlighted which could form the basis for future research, such as research centred on the effects of these metals on the embryonic development of aquaculture organisms and the alterations the metals caused in their stages of development.

Possible health risk assessment for heavy metal concentrations in water, sediment, and fish species and Turkmen pregnant women's biomonitoring in Miankaleh Peninsula, Iran

This study investigated the human biomonitoring of heavy metals in the water, sediments, and tissues of mostly consumed fish species using Turkmen pregnant women's biomarkers in winter 2019, at the Miankaleh Peninsula, north of Iran. Metal concentrations were measured in various fish organs as well as pregnant women's blood, hair, and nail as biological indicators. For this purpose, a total of 20 water and sediment, 14 fish, and 16 human samples were collected. Inductively coupled plasma mass spectrometry (ICP-MS) was used to evaluate the concentration of Cr, Co, Cu, As, Hg, and Pb. Results showed metals with the highest concentrations as Cu and Cr in water (93.35 and 80.91 µg/l, respectively), Hg and Pb in sediment (7.40 µg/g for both), Cu and Pb in the liver (27.00 and 18.9 µg/g for C. carpio; 1414 and 31.7 µg/g for L. auratus), muscle (10.00 and 18.80 for C. carpio; 37.20 and 8.27 µg/g for L. auratus), and skin (26.40 and 9.90 for C. carpio; 10.80 and 11.74 µg/g for L. auratus). In addition, Cu, in pregnant women samples, had the highest values at 2.53 mg/l, 8.87, 36.46, and 29.04 µg/g for blood, hair, fingernail, and toenail, respectively. However, Co showed the lowest concentration in all studied samples. Fish liver and fingernail of pregnant women did reveal the highest heavy metal accumulation, whereas fish muscle and blood of pregnant women had the lowest accumulated heavy metals. The concentration of Hg in water, sediment, fish muscle, and women's blood and hair exceeded the limits suggested by various organizations. Therefore, this study highlighted that heavy metal concentration, in particular Hg, in water, sediments, and fish is a serious risk to the health of local inhabitants who rely on fisheries products and recommended that necessary information should be provided to warn Turkmen pregnant women in consumption of Hg-contaminated fish in this area.

Phycoremediation of contaminated water by cadmium (Cd) using two cyanobacterial strains (Trichormus variabilis and Nostoc muscorum)

Background

Water pollution with heavy metals is a severe dilemma that concerns the whole world related to its risk to natural ecosystems and human health. The main objective was to evaluate the removal efficiency of Cd of various concentrations from contaminated aqueous solution by use of two cyanobacterial strains (Nostoc muscorum and Trichormus variabilis). For this purpose, a specially designed laboratory pilot-scale experiment was conducted using these two cyanobacterial strains on four different initial concentrations of Cd (0, 0.5, 1.0 and 2.0 mg L−1) for 21 days.

Results

N. muscorum was more efficient than T. variabilis for removing Cd (II), with the optimum value of residual Cd of 0.033 mg L−1 achieved by N. muscorum after 21 days with initial concentration of 0.5 mg L−1, translating to removal efficiency of 93.4%, while the residual Cd (II) achieved by T. variabilis under the same conditions was 0.054 mg L−1 (89.13% removal efficiency). Algal growth parameters and photosynthetic pigments were estimated for both cyanobacterial strains throughout the incubation period.

Conclusions

High Cd concentration had a more toxic impact on algal growth. The outcomes of this study will help to produce treated water that could be reused in agrarian activities.

The concentration of potentially hazardous elements (PHEs) in drinking water and non-carcinogenic risk assessment: A case study in Bandar Abbas, Iran

In this study, concentration of potentially hazardous elements (PHEs) including slice (Si), strontium (Sr), aluminum (Al), Fluoride (F), Iron (Fe), Zinc (Zn), Barium (Ba), Lead (Pb), Lithium (Li), Vanadium (V), selenium (Se), Chrome (Cr), Arsenic (As) and Uranium (U) in tap drinking water (n = 40) and filtration plant (n = 22) in Bandar Abbas city between March to July 2020 were analyzed. Analysis of PHEs ions was conducted by inductively coupled plasma mass spectrometry (ICP-MS). Also, concentration of F was measured by SPADNS Method. The non-carcinogenic risk in the exposed population (adult and children) were estimated. Concentration of PHEs between tap drinking water and filtration plant was compared using T statistical test. In addition, association among PHEs in tap drinking water and water filtration plant using Pearson correlation coefficient. The rank order of PHEs in tap drinking water was Si (6356.25 μg/l) > Sr (3980 μg/l) > Al (115.42 μg/l) > Fe (30.00 μg/l) > Zn (14.59 μg/l) > Ba (13.91 μg/l) > Pb (13.01 μg/l) > Li (11.60 μg/l) > V (4.43 μg/l) > Se (4.17 μg/l) > Cr (2.51 μg/l) > As (2.00 μg/l) > U (0.65 μg/l) > F (0.31 μg/l) and also in filtration plant was Si (1825.00 μg/l) > Sr (539.00 μg/l) > Fe (45.00 μg/l) > Al (26.00 μg/l) > Zn (8.08 μg/l) > Ba (2.24 μg/l) > Se (1.36 μg/l)> Pb(1.28 μg/l) > Li (1.26 μg/l) > Cr (1.17 μg/l) > F (0.66 μg/l) > V (0.61 μg/l) > As (LOD < ) ~ U (LOD <). The most of PHEs in tap drinking water was considerable different with filtration plant (p value < 0.05) therefore the chemical quality of tap drinking water should be more attention. The results of non-carcinogenic risk assessment revealed that TTHQ in the adults and children due to drinking tap water content of PHEs was 2.59E-3 and 6.05E-3 and filtration plant was 8.88E-04 and 2.07E-03, respectively. Therefore, TTHQ in adults and children was lower than 1; therefore, consumers are in the safe range due to drinking tap water and water filtration plant content of PHEs.

Bioaccumulation of heavy metals in fish species of Iran: a review

Accumulation of heavy metals (HMs) in fish tissues is an important factor in monitoring the health and safety of aquatic ecosystems. Furthermore, fish are important parts of aquatic food chains and play a significant role in human health. Considering the significant role of fish in the diet of humans and their ability to transfer and biomagnify HMs, it is necessary to determine and study these contaminants in fish tissues, especially in the edible parts of the fish. In addition to the other ecological and economic services of aquatic ecosystems, water bodies, especially the Persian Gulf in the south and the Caspian Sea in the north of Iran, are the main sources of seafood for people in nearby areas, as well as people living farther away who have gained access to seafood due to the extensive trade of aquatic organisms. This study provides an overview of the health conditions of the aquatic ecosystems in Iran by monitoring HM bioaccumulation in fish species. For this purpose, we reviewed, summarized, and evaluated papers published on HM concentrations in fish species from different aquatic ecosystems, including the Persian Gulf, the Caspian Sea, wetlands, rivers, qanats, water reservoirs, lakes, and dams, with emphasis on species habitats, feeding habits, and target organs in accumulation of HMs. Generally, the highest concentrations of HMs were observed in fishes collected from the Persian Gulf, followed by species from the Caspian Sea. Species inhabiting the lower zone of the water column and carnivorous and/or omnivorous species showed the highest levels of HMs. Moreover, liver was the main accumulator organ for HMs.

Health risk assessment of trace metals in selected food crops at Abuakwa South Municipal, Ghana

Trace metals contamination has recently been a major issue due to its damaging effects on public health and environmental receptors. This study focussed on the health risk assessment of trace metals (As, Pb, Cr, and Ni) associated with the direct intake of some selected food crops (namely cocoyam and plantain) at Abuakwa South Municipal, Ghana. The food crops and soil samples were selected randomly from three reclaimed mined sites and one non-mining site in the study area. Results from the trace metal concentration analyses in the soil samples showed that As, Cr, and Ni were above the control. The daily intake of metals (DIM), target hazard quotient (THQ), and carcinogenic risk (CR) assessments of health risks accompanied by the continuous ingestion of the selected food crops polluted through these trace metals were evaluated. 0.23 mg/kg and 0.05 mg/kg, 0.11 mg/kg and 0.02 mg/kg, 0.78 mg/kg and 0.65 mg/kg, and 0.23 mg/kg and 0.09 mg/kg were recorded for As, Cr, Ni, and Pb in that order in the cocoyam and plantain, respectively. The As and Pb concentrations in the food crops were above the WHO recommended limits. This implies that individuals within the vicinity are exposed to high levels of As and Pb through food intake which could result in varying health implications. The DIM and THQ for the studied trace metals were below their permissible limits suggesting that there is a tolerable non-carcinogenic adverse health risk level for adults and children within the studied area. In addition, the lifetime probability of contracting cancer by ingesting Ni, Pb, and Cr in plantain grown in the study area is high. It is recommended that regular monitoring of these trace metals in food crops be carried out in preventing their excessive accumulation.

Concentration of Potentially Harmful Elements (PHEs) in Trout Fillet (Rainbow and Brown) Fish: a Global Systematic Review and Meta-analysis and Health Risk Assessment

In this work, articles regarding the concentration on potentially harmful elements (PHEs) in fillet trout (rainbow and brown) fishes were retrieved from Cochrane, Scopus, and PubMed databases between 1 January 1983 and 30 April 2020. The pooled concentration of PHEs in fillet trout fishes was meta-analyzed using a random-effect model (REM) and following the non-carcinogenic and carcinogenic risks was calculated using the Monte Carlo simulation (MCS) method. The meta-analysis of 42 articles (43 data report) revealed that a sort of PHEs in fillet trout was 19,996.64 μg/kg ww for Fe; 1834.75 μg/kg ww for Co; 772.21 μg/kg ww for Cu; 335.78 μg/kg ww for Ni; 290.46 μg/kg ww for Se; 226.20for Cr; 178.11 μg/kg ww for Pb; 77.40 μg/kg ww for Hg; 19.40 μg/kg ww for Cd; and 3.66 μg/kg ww for inorganic As. The non-carcinogenic risk assessment indicated that the lowest and highest hazard index (HI) in the adults was Pakistan (0.0012) and Turkey (0.2388), respectively, and in children was Pakistan (0.0057) and Turkey (1.114), respectively. The non-carcinogenic risk was acceptable for adult consumers in all countries (HI > 1 value) but non-carcinogenic risk for children was not acceptable in Turkey. The sort of countries based on carcinogenic risk in the adults due to inorganic As was China (1.44E-06) > Iran (9.14E-08) > Turkey (4.45E-08) > Portugal (9.04E-10). The carcinogenic risk was threshold for adult consumers in China (CR < 10^-6). Consumption of fillet trout (rainbow and brown) content of PHEs in many countries cannot endanger the health of consumers.

Protection of Siganus oramin, rabbitfish, from heavy metal toxicity by the selenium-enriched seaweed Gracilaria lemaneiformis

Seaweed is an inherently important entity in marine ecosystems. It is not only consumed by aquatic animals but also improves environmental quality in the mariculture. Seaweed is also part of the diet of human beings. The purpose of the present study was to evaluate the antagonism of selenium (Se)-enriched Gracilaria lemaneiformis against heavy metals, specifically, the potential of dietary Se-enriched Gracilaria to protect against heavy metal toxicity in rabbitfish (Siganus oramin). Growth rate, heavy metal (Se, Cd, Pb, Cu, Zn and Cr) concentrations, malondialdehyde (MDA), metallothionein (MT), and the activity of the antioxidants, glutathione peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) were all assessed. The results showed that the total organic and inorganic Se concentration for the 250 mg L^-1 Se-enriched Gracilaria was significantly higher than those of the 50 and 10 mg L^-1 treatments after 3 days of enrichment. The mean total Se concentrations in Gracilaria were 42.5 μg g^-1 in the 250 mg L^-1 treatment, 13.5 μg g^-1 in the 50 mg L^-1 treatment and 2.5 μg g^-1 in the 10 mg L^-1 treatment, respectively. Organic Se accounts for 80-82% of total Se in Se-enriched Gracilaria. The Se concentration of rabbitfish fed Se-enriched Gracilaria was significantly higher than control. Furthermore, Se increased Cu and Zn absorption, and enhanced MT generation, and improved GPX, CAT, and SOD antioxidant activity, and decreased MDA concentrations and lipid peroxidation levels, all antagonistic to Cd, Pb and Cr. The effects of Se-enriched Gracilaria on waterborne Cd, Pb and Cr-induced toxicity occurred via both enzymatic and non-enzymatic antioxidative mechanisms in rabbitfish. Selenium had synergistic effects on Zn and Cu in rabbitfish. For the 50 mg L^-1 Se-enriched Gracilaria treatment, the Se, Cu, Zn, and antagonistic Cd, Pb, Cr, and the antioxidant enzymes CAT, SOD, GPX activities, and MT concentrations in rabbitfish were higher than that with the 250 mg L^-1 and 10 mg L^-1 Se-enriched Gracilaria treatments. The 50 mg L^-1 Se treatment of Gracilaria was deemed to be the optimum concentration to promote growth of rabbitfish. Therefore, the obtained results suggest Se-enriched Gracilaria can antagonize heavy metal toxicity, and is an advisable Se supplement to improve the edible safety of cultured animals.

High-Fat Diet Affects Heavy Metal Accumulation and Toxicity to Mice Liver and Kidney Probably via Gut Microbiota

Previous studies proved that heavy metals could increase the risk of disease by acting on the gut microbiota. Meanwhile, gut microbiota played important roles in detoxifying heavy metals. However, the response of gut microbiota to heavy metals and which microbes dominated this detoxification processes are still unclear. This study investigated the difference of high-fat-diet (HFD) and normal-diet (ND) gut microbiota and their response to and detoxification effects on arsenic (As), cadmium (Cd), and lead (Pb) exposure. Results showed that gut microbiota of ND and HFD was significantly different and responded to As, Pb, and Cd exposure differently, too. When exposed to 100 ppm As, Cd, or Pb, HFD-fed mice accumulated more heavy metals in the liver and kidney along with more severe functional damage than ND-fed mice, indicated by a more dramatic increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and urinary total protein (TPU), urinary uric acid (UUA), and urinary creatinine (Ucrea) content. Among ND gut microbiota, relative abundance of Bacteroides, Lactobacillus, Butyricimonas, and Dorea was significantly increased by arsenic (As) exposure; relative abundance of Faecoccus and Lactobacillus was significantly increased by Cd exposure; relative abundance of Desulfovibrio, Plasmodium, and Roseburia were significantly increased by Pb exposure. However, among HFD gut microbiota, those microbes were not significantly changed. Bivariate association analysis found weak positive correlations between content of fecal excreted heavy metals and richness of total fecal microbiota as well as abundance of some of the heavy metal-enriched microbes. Our study concluded that HFD increased disease risk of heavy metal exposure probably via its gut microbiota which excreted less heavy metal through feces.

Phytoremediation potential of Arundo donax (Giant Reed) in contaminated soil by heavy metals

Soil pollution from heavy metals poses a serious risk for environment and public health. Phytoremediation is an eco-friendly and cheaper alternative compared to chemical-physical techniques. We carried out in vitro tests where three microorganisms Trichoderma harzianum, Saccharomyces cerevisiae and Wickerhamomyces anomalus were exposed to eight different heavy metals (one metal at a time) in order to evaluate resistance, growth and bioaccumulation capability for each metal (Ni, Cd, Cu, V, Zn, As, Pb, Hg). Taking into account the natural characteristics of T. harzianum, (resistance to environmental stress, resistance to pathogenic fungi, ability to establish symbiotic relationships with superior green plants) and the good bioaccumulation capacity for V, As, Cd, Hg, Pb shown after in vitro tests, it was chosen as a microorganism to be used in greenhouse tests. Controlled exposure tests were performed in greenhouse, where Arundo donax and mycorrhized Arundo donax with T. harzianum were exposed for 7 months at two different doses (L1 and L2) of a heavy metal mix, so as to assess whether the symbiotic association could improve the bioaccumulation capability of the superior green plant A. donax. Heavy metals were determined with ICP-MS. The average bioaccumulation percentage values of A. donax for L1 and L2 were, respectively: Ni (31%, 26%); Cd (35%, 50%); Cu (30%, 35%); As (19%, 27%); Pb (18%, 14%); Hg (42%, 45%); V (39%, 26%); Zn (23%, 9%). The average bioaccumulation percentage values of mycorrhized A. donax with T. harzianum for L1 and L2 were, respectively: Ni (27%, 38%); Cd (44%, 42%); Cu (36%, 29%); As (17%, 23%); Pb (37%, 54%); Hg (44%, 60%); V (16%, 20%); Zn (14%, 7%). A. donax showed the highest BAF (bioaccumulation factor) for Cd (0.50), Cu (0.35), As (0.27) and Hg (0.45) after exposure to L2; mycorrhized A. donax with T. harzianum showed the highest BAF for Ni (0.38), Cd (0.42), Pb (0.54) and Hg (0.60) after exposure to L2. A. donax showed the highest TF (translocation factor) values for Cd (0.28) and Hg (0.26) after exposition at L1 and L2 respectively; A. donax mycorrhized with T. harzianum showed the highest TF values for Cd (0.70), As (0.56), V (0.24), Pb (0.18) after exposition at L2, and Zn (0.30) after exposition at L1. Our study showed a good growth capability in contaminated soils and a good bioaccumulation capability of heavy metals, both for A. donax and mycorrhized A. donax with T. harzianum. Furthermore, for three metals (Ni, Pb and Hg) the bioaccumulation capability was improved by the symbiosis of T. harzianum with A. donax. So, these results proved the suitability both for A. donax and mycorrhized A. donax with T. harzianum for phytoremediation processes.

Macroelements and toxic trace elements in muscle and liver of fish species from the largest three reservoirs in Turkey and human risk assessment based on the worst-case scenarios

Macroelement (Na, K, Ca, Mg and P) and toxic trace element (As, Cd and Pb) contents were investigated in muscle and liver of the two fish species (common carp and trout barb) from the largest three reservoirs (Atatürk, Keban and Karakaya) in Turkey. Also, human health risks for consumers using the worst-case scenarios were assessed. Potassium was the most abundant macroelement in muscle of both fish species in all reservoirs, whereas phosphorus was the most abundant in liver. Toxic trace element contents in the liver of the two fish species from the three reservoirs were higher than those in muscle. The mean levels of As and Pb in muscle and liver of fish species from the Karakaya Reservoir were higher than those from the other two reservoirs. Three-way ANOVA showed that the interaction between fish species, reservoir and fish tissue was significant for only Cd (p < 0.01). The maximum levels of As, Cd and Pb in muscle and liver of fish species from the three reservoirs were below permissible limits. The estimated daily intakes of toxic trace elements in fish species were much lower than their corresponding tolerable daily intakes. The target hazard quotient (THQ) and total THQ values in fish species were below 1, which indicated that non-carcinogenic health effects are not expected. The carcinogenic risk values for inorganic arsenic were within acceptable range. The results revealed that toxic trace elements in common carp and trout barb from the Atatürk, Keban and Karakaya reservoirs do not pose a significant health risk to consumers.

Bioaccumulation of trace metals in freshwater prawn, Macrobrachium rosenbergii from farmed and wild sources and human health risk assessment in Bangladesh

The giant freshwater prawn, Macrobrachium rosenbergii, is an important species for Bangladesh's national economy, aquatic biodiversity, and employment opportunities; furthermore, human health risk associated to consumption of this species has become a crucial issue. Eight trace metals (Pb, Cr, Ni, Cd, Fe, Cu, Zn, and Mn) in different body parts of M. rosenbergii (U/10 as large and U/12 and U/15 as medium size), and water collected from farm and wild sources along with the human health risks were assessed in this study. Except Cd, all trace metals exceeded the maximum permissible limits proposed by different authorities. Elevated levels of Pb, Cr, Fe, Cu, Zn, and Mn were found in the wild-caught prawn, whereas Ni and Cd were higher in farmed prawn. A higher trace metal contamination was recorded from the cephalothorax part than the abdomen of both sized prawns. However, trace metal concentrations between two sizes of prawns were not statistically significant (p > 0.05). The estimated daily intakes (EDI) values were higher than the recommended and/or tolerable daily intake for Pb and Cr. Moreover, the target hazard quotient (THQ) values were > 1 for Pb, Cd, Cu, and Zn, elucidating non-carcinogenic risks to the consumers. In addition, the target cancer risk (TR) values of Pb and Ni were high and exceeded the acceptable guideline of 10^-6, explicating the possibility of carcinogenic risks. Therefore, the study concludes that the consumption of the studied prawn species contaminated with elevated levels of toxic metals is associated with higher degree of potential health risks.

The influence of processing and clarifier agents on the concentrations of potentially toxic elements (PTEs) in pekmez (a grape molasses-like syrup)

The changes in some potentially toxic elements (PTEs) including lead (Pb), cadmium (Cd), arsenic (As), iron (Fe), zinc (Zn), and copper (Cu) during pekmez (grape molasses-like syrup) processing and the utilization of various types of clarifiers (white soil, bentonite, and gelatin) in two levels (1.5 and 3% w/w) were analyzed. The average concentrations of Pb, Cd, As, Fe, Zn, and Cu in grape samples were measured as 0.055 ± 0.005, 0.030 ± 0.002, 0.044 ± 0.002, 2.882 ± 0.013, 2.372 ± 0.088, and 1.194 ± 0.01 μg g^-1. During pekmez production, the range of changes in Pb, Cd, As, Fe, Zn, and Cu was -43.38% to 40.25%, -55.49% to 0.23%, -76.15% to 1.80%, -74.15% to 58.47%, -40.55% to -18.12%, and -83.16% to -21.39%, respectively. The effect of the clarification process on the PTEs depended on the type and concentration of both PTE and clarifier agent used while the incorporation of gelatin resulted in a significant reduction in all of PT. Graphical abstract.

Application of algae for heavy metal adsorption: A 20-year meta-analysis

The use of algae to adsorb heavy metals is an efficient and environmentally friendly treatment for contaminated water and has attracted widespread research attention. In this study, a meta-analysis of the heavy metal adsorption capacity of algae from five different phyla and the factors influencing these capacities was conducted. Phaeophyta was found to have a high heavy metal adsorption capacity, whereas Bacillariophyta had a relatively low adsorption capacity; Chlorophyta, Rhodophyta, and Cyanophyta had moderate adsorption capacities. Non-living algae were more effective in practical applications than living algae were. Algal biomass had a relatively high adsorption efficiency of 1-10 g/L, which did not increase significantly when algal concentration increased. The algal adsorption efficiency for initial heavy metal concentrations of 10-100 mg/L was higher than for concentrations of greater than 100 mg/L. The results further show that algal adsorption of heavy metals reached a maximum capacity of 80-90% within 20 min. Heavy metal adsorption by algae was not temperature-dependent, and it was more effective in moderately to weakly acidic environments (pH = 4-7.5). Considering these aspects for practical applications, algae from some phyla can effectively be used for heavy metal biosorption in contaminated water.

Bioconcentration and depuration of cadmium in the selected tissues of rare minnow (Gobiocypris rarus) and the effect of dietary mulberry leaf supplementation on depuration

A 56-day trial was conducted to elucidate the bioconcentration and depuration of Cd in the liver and muscle of rare minnow (Gobiocypris rarus) and determine the effect of dietary mulberry leaf supplementation on depuration. Juvenile rare minnow were exposed to environmentally relevant doses of Cd (1 and 10 μg/L) for 28 days of uptake and then allowed 28 days of depuration. The bioaccumulation factors of the treated rare minnow in the liver and muscle were calculated to be between 4.13-4.675 and 1.76-1.94, respectively. This results suggested that Cd had high potential for bioconcentration in rare minnow. To investigate the effect of dietary mulberry leaf supplementation on depuration, the remaining fish of each group were allowed to depurate with different ratios (0%, 10%, and 30% dry weight) of dietary mulberry leaf supplementation for an additional 28 days. Fish weights did not differ significantly (p >  0.05) between the control and mulberry leaf treated groups. Mulberry leaf powder did not significantly affect Cd depuration in the 10 μg/L group or in the muscle of the 1 μg/L group, but caused a significant decrease in Cd content in the liver of the 1 μg/L group (p <  0.05). This work was the first to model the bioconcentration of Cd in rare minnow and showed that mulberry leaf supplementation decreased Cd residues in the liver of the 1μg/L group. Such a finding may promote the development of new approaches to mitigate the potential hazards of heavy metals to human health.

Reply for comment on "Exposure to microplastics (<10 μm) associated to plastic bottles mineral water consumption: The first quantitative study by Zuccarello et al. [Water Research 157 (2019) 365-371]"

Microplastics (MPs) are a threat to both the environment and human health. In the absence of an official method that would allow the analysis of all MPs with diameters less than 10 μm, it was not possible to estimate the exact exposure to these contaminants, yet. In the last years, few studies are available in literature with the first data concerning the concentrations of MPs on bottle mineral waters. Zuccarello et al. (2019) carried out an exposure assessment study where a high value of EDI (Estimated Daily Intake) has been reported. This rebuttal letter aims to reply to the comments of Oßmann et al. (2018) on the article of Zuccarello et al. (2019) about the new analytical method and both the use and the interpretation of Principal Component Analysis.

Evaluation of health risks from exposure to arsenic and heavy metals through consumption of ten fish species

In this study, the levels of 11 heavy metal(loid)s (HMs) were determined in ten different fish species (wild, farmed, freshwater, and marine) frequently consumed in Turkey and compared with the maximum permissible limits (MPLs) established by international standards. Also, human health risks for the consumers were assessed. Among 11 HMs, only Al and Cr levels did not show significant differences among fish species. The highest concentrations of As were found in red mullet, which is a demersal fish. The average concentrations of Cd, Cr, Cu, and Pb in all fish species were below the MPLs, whereas those of Zn in European anchovy and Mediterranean horse mackerel, and that of inorganic As in red mullet exceeded the MPLs. The highest and lowest toxic metal contents (Al, As, Cd, and Pb) were recorded in red mullet and farmed rainbow trout, respectively. The estimated daily intakes of HMs in each fish species were very lower than their corresponding tolerable daily intakes, suggesting the daily intake of HMs through fish consumption would not pose health risks for the consumers. The target hazard quotient for individual HMs and hazard index for combined HMs in fish species were below 1, which indicated that non-carcinogenic health effects are not expected. The carcinogenic risk results revealed that there was a carcinogenic risk from exposure to inorganic As via the consumption of red mullet. Among all investigated fish species, rainbow trout and common carp were safer in terms of both non-carcinogenic and carcinogenic risks from exposure to HMs.

The concentration of potentially toxic elements (PTEs) in muscle tissue of farmed Iranian rainbow trout (Oncorhynchus mykiss), feed, and water samples collected from the west of Iran: a risk assessment study

The pollution of the environment by potentially toxic elements (PTEs) is one of the most important raised concerns. Therefore, the current investigation was devoted to measuring the concentration of lead (Pb), cadmium (Cd), elemental mercury (Hg), nickel (Ni), iron (Fe), zinc (Zn), and copper (Cu) in muscle tissue of farmed rainbow trout (n = 30) as well as their feed (n = 15) and water (n = 15) samples collected from farms (Hamadan Province, Iran) by the aid of an inductively coupled plasma atomic emission spectrometer (ICP-OES). Also, the associated risk for human and biomagnification factor (BMF) and bioconcentration factor (BCF) for PTEs in the fish muscle through feed and water were calculated. The mean concentration of Pb, Cd, Hg, Ni, Fe, Zn, and Cu in rainbow trout muscle was reported as 0.056 ± 0.040 μg g^-1 wet weight, <LOD, 0.014 ± 0.016 μg g^-1 wet weight, 0.140 ± 0.188 μg g^-1 wet weight, 1.051 ± 0.909 μg g^-1 wet weight, 0.635 ± 0.725 μg g^-1 wet weight, and 0.275 ± 0.325 μg g^-1 wet weight, respectively, while all of the samples were contaminated in the concentrations below the permitted limits by regulatory bodies such as EC, Food and Agriculture Organization (FAO), and WHO/FAO. No significant difference between the amounts of PTEs among the collected feed and water samples was noted, while the corresponded values for PTE concentrations also were lower than the allowable limits. The values of BMF and BCF for all analyzed PTEs through water and feed were lower than 1000, demonstrating that the rainbow trout muscle could not be considered as a bioaccumulative tissue for PTEs. Additionally, no health risk due to ingestions of investigated PTEs via consumption of this rainbow trout fish was noted.

Carcinogenic and Non-carcinogenic Risk Assessment of Heavy Metals in Groundwater Wells in Neyshabur Plain, Iran

The present work reports the As, Cr, Cu, Pb, Zn, and Fe concentrations of drinking water samples in Neyshabur Plain, Iran. This study aimed also to ascertain the potential consumers' health risk of heavy metal intake. Heavy metal concentrations were analyzed by inductively coupled plasma optical emission spectrometry. The highest and lowest average values in the analyzed water samples were observed for Fe (9.78 ± 5.61 μg/L) and As (1.30 ± 2.99 μg/L), respectively. These values were well below the limits recommended by the World Health Organization and the Iranian national standard. Heavy metal pollution index and heavy metal evaluation index were used to evaluate drinking water quality. The risk index was calculated by chronic daily intake and hazard quotient according to the United States Environmental Protection Agency approach. Heavy metal pollution index in all the samples was less than 100, indicating that it is a low-level heavy metal. The total risk of all heavy metals in the urban environment varied from 40.164 × 10^-7 to 174.8 × 10^-7. In this research, the maximum average of risk belonged to lead and copper with the respective values of 60.10 × 10^-7and 33.99 × 10^-7 from the selected wells. However, considering the toxic effect of some elements, including Pb and As, in the chronic exposure of consumers, we suggest a continuous evaluation and monitoring of drinking water resources.

Copper and zinc levels in soil, water, wheat, and hair of inhabitants of three areas of the Orenburg region, Russia

The objective of the present study was to assess the level of zinc and copper in soil, water, wheat and hair of inhabitants of the western, central, and eastern areas of the Orenburg region. A total of 525 water, soil, and wheat samples, as well as 420 hair samples were assessed using atomic absorption spectrometry (water, soil, wheat) and inductively-coupled plasma mass spectrometry (hair). The highest levels of Zn and Cu in water (4.9(4.2-5.1) and 1.0(0.9-1.1) mg/l), soil (23.8(20.7-27.0) and 2.6(1.9-3.1) mg/kg), and wheat (24.7(20.5-31.0) and 4.8(4.2-5.5) mg/kg) were observed in the eastern area (p < 0.001). Hair zinc levels in inhabitants of the western (184(165-198) µg/g) and eastern (224(211-253) µg/g) areas of the region exceeded the respective values from the central area by 32% and 61% (p < 0.001). In turn, hair Cu levels in the central (16.4(14.3-17.8) µg/g) and eastern (17.9(16.4-19.0) µg/g) areas exceeded the values from the western area by 10% and 20%, respectively. Correlation analysis demonstrated that hair Zn levels were positively correlated with water and soil content, whereas wheat Zn levels were associated with soil and water content. For copper significant direct correlation was observed only between soil and water Cu content. In multiple regression models, only water zinc level was significantly associated with hair Zn content, although the general model accounted for 55% of variability of hair Zn content. Higher zinc and copper exposure in the eastern area is presumably associated with higher activity of metal-processing industry.

Comparison of elemental composition in two wild and cultured marine fish and potential risks to human health

Among all available species, fish are a powerful model for risk-benefit assessments to study the effects of contaminants on human health. Gilthead seabream (Sparus aurata, Linnaeus 1758) and european seabass (Dicentrarchus labrax, Linnaeus 1758) are two species of great economic importance, representing very large production volumes in the Mediterranean. The objective of this study is (1) to analyze the concentrations of Trace Elements (TE) between wild and cultured seabream and seabass specimens, (2) to compare the determined concentrations with other studies, and (3) to increase the data about the potential risks to human health. Our results point to significant intra- and interspecies-specific differences between wild and cultured fish for several trace elements. Several strong and moderate inter-elemental correlations in fish muscle were observed through correlation analysis. In our study, the mean levels of trace elements were still below the standard safety values for fish intended for human consumption. The same results were reached for all the parameters analyzed (international legal limits, estimated weekly intake, provisional tolerable weekly intake, target hazard quotient, target cancer risk), with trace element levels in fish below those that could pose a risk to human health. Consequently, these fish can be considered safe for human consumption. A better understanding of the levels of trace elements in fish would also better inform consumers about the potential risks of exposure to contaminants.

Metal concentrations in fillet and gill of parrotfish (Scarus ghobban) from the Persian Gulf and implications for human health

Despite the benefits of seafood's consumption, the bioaccumulation of metals in fish can endanger consumers' health. This study analyzed lead (Pb), mercury (Hg), Arsenic (As), and Cadmium (Cd) concentrations in fillet and gill of parrotfish (Scarus ghobban) using flame atomic adsorption spectroscopy (FAAS). The potential non-carcinogenic and carcinogenic health risks due to consumption of Scarus ghobban fillet were assessed by estimating average target hazard quotient (THQ) and total target hazard quotient (TTHQ) and Incremental Lifetime Cancer Risk cancer risk (ILCR) of the analyzed metals. This study indicated that Cd, Pb, As and Hg concentrations were significantly (p < 0.05) lower than Food and Agriculture Organization (FAO) and national standard limits. The meal concentrations (μg/kg dry weight) in both fillet and gill were ranked as follows Pb > Cd > As > Hg. THQ and TTHQ were lower than 1 for adults and children, indicating that consumers were not at considerable non-carcinogenic risk. However, ILCR value for As was greater than 10^-4, indicating that consumers are at carcinogenic risk. Overall, this research highlighted that although the consumption of parrotfish from the Persian Gulf does not pose non-carcinogenic health risks, carcinogenic risks derived from toxic As can be detrimental for local consumers.

Carcinogenic and non-carcinogenic health risks of metal(oid)s in tap water from Ilam city, Iran

One of the most important pathways for exposure to metals is drinking water ingestion. Chronic or acute exposure to metals can endanger the health of the exposed population, and hence, estimation of human health risks is crucial. In the current study for the first time, the concentrations of Mercury (Hg), Arsenic (As), Zinc (Zn), Lead (Pb) and Cobalt (Co) in 120 collected tap water samples (2015, July-November) from Ilam city, Iran were investigated using flame atomic absorption spectrophotometer. Also, the metal-induced carcinogenic and non-carcinogenic risks for consumers exposed to tap drinking water were calculated. The average (range) concentrations of Hg, Zn, As, Pb and Co were defined as 0.40 ± 0.10 μg/L (ND-0.9 μg/L), 5014 ± 5707 μg/L (2900.00-5668.33 μg/L), 21.008 ± 2.876 μg/L (3.5-62 μg/L), 30.38 ± 5.56 μg/L (6-87 μg/L), and 11.34 ± 1.61 μg/L (0.1-50 μg/L), respectively. Average concentrations of all examined metals were significantly higher than WHO and national standard recommended limits. The ranking order of metals concentrations in the tap drinking water was Zn > Pb > As > Co > Hg. Except for Hg and Co, at least one age group consumers were at considerable non-carcinogenic risks induced by Zn, As and Pb [Target Hazard Quotient (THQ > 1)]. The rank order of age groups consumers based on THQ and Incremental lifetime cancer risk (ILCR) was <1 years >1-9 years > 20 + years > 10-19 years. The calculated ILCR for As in all age groups were higher than 10^-3 value. All age groups of consumers in Ilam city, especially infants (<1 years) and children (1-10 years), are at considerable non-carcinogenic and carcinogenesis risk.

Trace elements in seafood from the Mediterranean sea: An exposure risk assessment

Fish and shellfish belonging to five different species among pelagic, benthonic and molluscs, were collected from the Gulf of Catania in 2017 to evaluate arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se) vanadium (V) and zinc (Zn). Risk of developing chronic systemic effects derived from seafood consumption was evaluated with the Target Hazard Quotient (THQ) and compared with the results obtained from the same area and the species, collected in 2012. Hg, Cd and Pb concentrations were found below the limits set by European Community for human consumption in all the analysed species. The total risk is reduced from 1.1 to 0.49, and this result is strongly associated with the lower bioaccumulations levels found for Hg, Mn, Se and V. Others metals such as As, Pb, Ni and Zn bioaccumulation levels remain approximately the same, conversely, it is revealed a slight increase of Cd and Cr. Overall, the present study show a positive picture of the studied area, the Gulf of Catania, highlighting not only a decreased metal availability of the study area, but, above all, a decreased risk to develop chronic systemic effects derived from consumption of local seafood.

Bioaccumulation of metals in juvenile rainbow trout (oncorhynchus mykiss) via dietary exposure to blue mussels

The potential for metals to bioaccumulate in aquatic species, such as fish, via trophic level transfer was investigated. An in vivo experiment was set up in a flow-through system in which juvenile rainbow trout were fed blue mussels collected from a Class A pristine site and an effluent-impacted river estuary, over a period of 28 days. Selected elements (As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Mo, Ni, Se, Sn, V, Zn) were determined in the mussels and fish tissues (muscle and skin) collected at 0, 14 and 28 days. This study reveals the occurrence of metals in mussels sampled in the Irish marine environment and highlights the bioaccumulation potential of metals in fish tissues via trophic transfer. All 14 monitored metals were determined in the mussels collected from both sites and mussels collected from the effluent-impacted site contained three times more Co, Mo, Sn and V than the mussels collected from the Class A site. Following a 28-day dietary exposure, concentrations of As and Se (fish muscle), and Pb, Se and Zn (fish skin), were significantly greater in fish feeding on contaminated mussels compared to those with a regular fish feed diet. The significance of metal detection and bioaccumulation in the mussel and fish tissues, highlights the potential for metal exposure to humans through the food chain. As fish are recommended as a healthy and nutritious food source, it is important to fully understand metal bioaccumulation in commercially important aquatic species and ensure the safety of human consumers.

Bioaccumulation of metals and biomarkers of environmental stress in Parablennius sanguinolentus (Pallas, 1814) sampled along the Italian coast

Heavy metal pollution is one of the greatest threats to the ecosystems because it degrades the habitat and is potentially toxic to wildlife and human populations. In the last few decades, bioaccumulation studies performed with a multimarker approach have been a valuable tool for the investigation of environmental and animal safety. We perform an analysis of a benthic teleost fish species - Parablennius sanguinolentus - sampled at several Italian coastal sites with different degrees of anthropogenic pressure. Our integrative analysis encompasses bioaccumulation of 10 metals, biomarkers of environmental stress (micronuclei and nuclear abnormalities) and neutral genetic variation (using sequences of the mtDNA control region). We find a clear and significant correlation of metal bioaccumulation with micronuclei and nuclear abnormalities, especially with undisputed genotoxic metals, such as Cd, Cr, Hg and Pb. Furthermore, the molecular genetic analysis revealed a decrease of genetic variability in the populations more subjected to anthropic pressure.

Trace element concentrations in the apex predator swordfish (Xiphias gladius) from a Mediterranean fishery and risk assessment for consumers

Swordfish (Xiphias gladius L., 1758) is an apex predator, highly migratory meso-pelagic fish widely distributed in the Atlantic Ocean and Mediterranean. As top predators, this fish may be the end reservoir of the bioaccumulation of trace elements in a food chain because they occupy higher trophic levels and are an important food source, causing them to be potentially hazardous to consume. This study aims to investigate the concentration of 18 trace elements of Swordfish, caught in the Mediterranean Sea and to discuss human exposure risks. The mean element levels in the fish muscles were clearly below the maximum allowable concentrations established by International food safety regulations. The data suggested that the risk is minor and acceptable for human health. The findings of this study amplify the scarce database on contaminants available, especially new data on "emerging elements", for this species from the Mediterranean Sea.

Dietary exposure to toxic and essential trace elements by consumption of wild and farmed carp (Cyprinus carpio) and Caspian kutum (Rutilus frisii kutum) in Iran

This study was conducted to determine and compare the concentrations of mercury (Hg), cadmium (Cd), arsenic (As), lead (Pb), nickel (Ni), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), cobalt (Co), and selenium (Se) in the muscle of wild and farmed carp (Cyprinus carpio) and wild and farmed Caspian kutum (Rutilus frisii kutum) collected from south-western Caspian Sea areas of Iran between December 2014 and March 2015. In addition, risk assessment of consumers to exposure to metals through fish consumption was estimated. In all the samples, the arsenic concentration was lower than the detection limit. The Pb, Cd, Hg and Mn concentrations were significantly higher in the wild fish samples compared to the farmed fish samples. There was no significant difference in the Fe, Zn, Cu, Co, Ni and Se concentrations of the wild and farmed carp and the wild and farmed Caspian kutum. Iron displayed the highest concentration of all the analysed metals in both the wild and farmed fish, followed by Zn and Cu. The highest Hg, Cd, Pb, Ni, Fe, Zn, Cu, Mn, Co and Se concentrations were 0.056, 0.011, 0.065, 0.120, 4.151, 3.792, 2.948, 2.690, 0.037 and 0.162 μg g^-1, respectively. The estimated daily intake of all metals was acceptable, and the hazard quotient values showed that consumption of the analysed fish posed no health risk to consumers.

Heavy metal content and molecular species identification in canned tuna: Insights into human food safety

Canned tuna in olive oil and in brine of the most popular brands sold in Italian markets were analyzed to verify the authentication of transformed products, with the aim to unveil commercial frauds due to the substitutions of high value species with species of low commercial value, and to assess the health risk of consumers related to cadmium (Cd), lead (Pb) and mercury (Hg) contents. Species authentication was evaluated with amplification of COI DNA barcode and confirmed the declared species. Among tested metals, Hg had the highest concentrations, followed by Cd and Pb. None of the tested samples surpassed the European regulatory limits no. 1881/2006 fixed for Hg and Pb, whereas one batch of canned tuna in olive oil exceeded standard for Cd. Risk for human health was evaluated by the metals daily intake and target hazard quotient (THQ). As a result, Cd and Pb did not exceed the toxicological reference values established by World Health Organization (WHO) and the Environmental Protection Agency (EPA). Conversely, Hg content suggests a consumption no more than once a week and a continuous surveillance of this fishery products for consumer protection.

Heavy metal concentrations in edible muscle of whitecheek shark, Carcharhinus dussumieri (elasmobranchii, chondrichthyes) from the Persian Gulf: A food safety issue

Together with several health benefits, fish meat could lead to heavy metal intoxication of consumers. In this study, we discuss Zn, Cu, Pb, Hg and Cd concentrations in fillets of forty specimens of Carcharhinus dussumieri, analyzed with atomic adsorption spectroscopy (AAS). The potential human health risks due to consumption of C. dussumieri was assessed by estimating average daily intake (EDI) and target hazard quotient (THQ) of metals. The average concentrations of metals measured in this study were (ppm dry weight): Cu 7.49 ± 0.25; Zn 3.47 ± 0.26; Pb 0.12 ± 0.03; Hg 0.028 ± 0.02; Cd 0.11 ± 0.03. Our results showed that no metal exceeded the EC and FAO limits. Cu and Cd accumulate in muscles with a body length (age)-dependent manner. The exposure daily intake of all toxic metals analyzed was found lower than the PTDI provided by WHO and the THQ resulted lower than 1, suggesting no risk for human health derived from consumption.