Comparison of metal concentrations in the organs of two fish species from the Zabol Chahnimeh reservoirs, Iran

Bioaccumulation of Silver Nanoparticles (AgNPs) Co-Exposed with Graphene Oxide Nanosheets (GNs) in the Gill and Intestine Tissues of Guppy (Poecilia reticulata)

Silver nanoparticles (AgNPs) and graphene oxide nanoparticles (GNs) have known health effects on humans and other organisms. Therefore, this study aimed to assess the bioaccumulation and depuration of AgNPs in guppy (Poecilia reticulata) tissues in the presence of GNs. In so doing, two non-lethal concentrations of AgNPs, one non-lethal concentration of GNs, and two concentrations of the combination of AgNPs and GNs were used along with a control group. Based on the results obtained, on day 28, the level of silver in the gill tissue was 0.980 and 1.22 mg/g in the individual groups and 1.34 and 1.23 mg/g in the combined groups, respectively. Conversely, the silver uptake in the intestine tissue on day 28 was 0.377 and 0.267 mg/g in the individual groups and 0.659 and 0.475 mg/g in the combined groups, respectively. Silver uptake in guppy tissues increased with higher concentrations and longer exposure times, and it varied depending on the specific tissues involved. Also, findings show that the depuration rate within 14 days for both tissues is similar across individual and mixture exposure modes, indicating a comparable capacity for the depuration of silver particles. In conclusion, this study demonstrated that the presence of GNs has a synergistic effect on the uptake of silver in guppy tissues.

Relationships of the serum levels of toxic trace elements in pregnant women versus exposure to second-hand smoke

Tobacco smoke contains many toxic heavy metals that cause adverse effects in humans. The association between second-hand smoke (SHS) and the toxic metals accumulated in pregnant women are still unclear. We measured trace element levels in the sera of pregnant women exposed to SHS and compared the data to those of unexposed pregnant women. Moreover, the data were contrasted with the anthropometric measurements (birth weight, birth length, and head circumference) of their newborn babies after delivery. Two groups of pregnant women were voluntarily recruited, and their blood samples were collected. Then, ten trace elements were measured in their sera, and the data were statistically analyzed using R version 4.0.3 software. The serum trace elements in the smoking subjects were higher than those of the non-smokers, but the difference was not statistically significant (p > 0.05). The SHS had adverse effects on some trace elements on the smokers' sera. The concentrations of Cr and Ni in mothers exposed to SHS (32.85-51.25) were significantly higher than those in the mothers unexposed to SHS (28.26-44.80; p < 0.05). The study found that some trace elements significantly affected the anthropometric measurements of infants born to mothers who were exposed to SHS (p < 0.05). Exposure of pregnant women to cigarette smoke had adverse effects on their newborns' body weights. The mothers who smoked had babies with lower weights. Also, the exposure to cigarette smoke might have caused some of the disorders during their pregnancy.

The Concentration of Potentially Toxic Elements in Common Carp (Cyprinus carpio) Fish: Systematic Review and Meta-Analysis and Dietary Health Risk Assessment

Common carp (Cyprinus carpio) is one of the most consumed fish in the world and can be exposed to various forms of pollution, such as potential toxic elements (PTEs). Several studies have been conducted on the concentration of PTEs in common carp fish. The aims of the current study were to meta-analyze the concentration of PTEs in common carp fish and estimate human health risks in consumers. A search was conducted in international databases, including Scopus, PubMed, Science Direct, Web of Science, and Embase to retrieve papers up to January 20, 2024. The non-carcinogenic risk due to PTEs in fish fillets was calculated via the target hazard quotient (THQ), and the carcinogenic risk due to iAs in fish fillets was calculated via cancer risk (CR). The highest concentrations of Cu, methyl-Hg, and Ni were observed in the fillets of common carp fish. The non-carcinogenic risk was lower than 1 in all countries; hence, consuming common carp fish does not pose a non-carcinogenic risk. Adult consumers in Iraq were exposed to an unacceptable carcinogenic due to iAs in common carp fish. Hence, it is recommended that plans be conducted to reduce the concentration of PTEs in common carp fish in Iraq.

Common carp as an ecological indicator of environmental pollution in reservoirs of southern Spain: inferring the environmental risks of anthropogenic activities

Extraction and mineral processing, as well as the waste generated by old abandoned mining sites, are the main sources of contamination of water bodies and lands by potentially toxic elements (PTEs). The common carp (Cyprinus carpio Linnaeus 1758) has been reported to be a good ecological indicator of environmental pollution in water bodies. Hence, we evaluated the concentration of eleven PTEs (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) in different tissues of common carp in two reservoirs of the province of Jaén, southern Spain: El Tranco de Beas (S1) and La Fernandina (S2). We also assessed the concentration of PTEs in water and sediment samples. We used inductively coupled plasma mass spectrometry for all the collected samples. We found high concentrations of As and Fe in water in the S2 reservoir, above the maximum limits allowed by the sanitary criteria in Spain; however, the analysis of sediments indicated low ecological risk in S1 and moderate ecological risk for As in S2. The concentration of PTEs in common carp was higher in the S2 reservoir, exceeding the permissible limits in the case of As, Cd, Pb, and Zn. As and Cd showed higher concentrations in the kidney; Cu, Fe, and Zn showed higher concentrations in the liver; and Pb and Mn presented higher concentrations in the gill and gill bone. There was a good correlation between the concentrations found in water/sediment samples and those in common carp, corroborating its usefulness as a good ecological indicator, allowing the detection of environmental pollution and inferring previous or current anthropogenic activities such as mining.

Mixture effects of trace element levels on cardiovascular diseases and type 2 diabetes risk in adults using G-computation analysis

There is an increasing concern about the health effects of exposure to a mixture of pollutants. This study aimed to evaluate the associations between serum levels of heavy/essential metals ([Arsenic (As), Cadmium (Cd), Mercury (Hg), Lead (Pb), Nickel (Ni), Chromium (Cr), Copper (Cu), Iron (Fe), and Zinc (Zn)]) and the risk of developing cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2D). Data were collected from 450 participants (150 with CVDs, 150 with T2D, and 150 healthy subjects) randomly selected from the Ravansar Non-Communicable Disease (RaNCD) cohort in Western Iran, covering the years 2018-2023. Trace element levels in the serum samples were assayed using ICP-MS. Logistic regression was performed to estimate the adjusted risk of exposure to single and multi-metals and CVD/T2D. Odds ratios were adjusted for age, sex, education, residential areas, hypertension, and BMI. The mixture effect of exposure to multi-metals and CVD/T2D was obtained using Quantile G-computation (QGC). In the logistic regression model, chromium, nickel, and zinc levels were associated with CVD, and significant trends were observed for these chemical quartiles (P < 0.001). Arsenic, chromium, and copper levels were also associated with T2D. The weight quartile sum (WQS) index was significantly associated with both CVD (OR 4.17, 95% CI 2.16-7.69) and T2D (OR 11.96, 95% CI 5.65-18.26). Cd, Pb, and Ni were the most heavily weighed chemicals in these models.The Cd had the highest weight among the metals in the CVD model (weighted at 0.78), followed by Hg weighted at 0.197. For T2D, the serum Pb (weighted at 0.32), Ni (weighted at 0.19), Cr (weighted at 0.17), and Cd (weighted at 0.14) were the most weighted in the G-computation model. The results showed the significant role of toxic and essential elements in CVDs and T2D risk. This association may be driven primarily by cadmium and mercury for CVDs and Pb, Ni, Cr, and Cd for T2D, respectively. Prospective studies with higher sample sizes are necessary to confirm or refute our preliminary results as well as to determine other important elements.

Trace metals in commercial seafood products (canned, pickled and smoked): Comparison, exposure and health risk assessment

This study used inductively coupled plasma and mass spectrometry, followed by microwave digestion, to assess the concentration of six trace metals (Cr, Ni, As, Cd, Hg, and Pb) in three canned products (tuna in oil [TIO], sardine in oil [SIO], and mackerel in oil [MIO]), two pickled products (prawn pickle [PP] and fish pickle [FP]), and one smoked product (masmin) collected from Tuticorin market, southern India. Trace metal (TM) levels in canned, pickled, and smoked fish varied from 0.01 to 1.48, 0.009 to 0.94, and 0.08 to 4.13 mg/kg, respectively. The concentration of TMs in the seafood was observed in the following order: As > Cr > Pb > Ni > Cd > Hg. Regarding their accumulation in the seafood products, masmin showed the highest levels followed by SIO, MIO, TIO, FP, and PP. The results revealed that smoked products showed higher TM concentrations, followed by canned and pickled products. The level of TMs in seafood products was below the maximum residue limit set by the European Commission (EC/1881/2006) and the Food Safety and Standards Authority of India (FSSAI). Risk assessment for consumer health implied that the evaluated target hazard quotient (THQ < 1), hazard index (HI < 1), and target cancer risk (TCR < 1.E-04) values did not exceed their guideline values and did not cause non-carcinogenic and carcinogenic health impacts through seafood product consumption. The pollution index (Pi) values of TMs in seafood products ranged from 0.01 to 0.7, with As and Cd showing the lowest and highest values, which were below 0.7, indicating their safety for consumption. The metal pollution index (MPI) for TMs in seafood ranged from 9.E-05 to 0.007, with the lowest and highest values associated with PP and TIO products. The MPI value for seafood products was below 1, signifying low TMs accumulation, suggesting the safety of seafood for consumption. The maximum seafood meal consumption limit (CRmm) was calculated, showing that adults can safely consume > 16 meals/month without chronic or acute toxicity. The results of this study suggest that the accumulation of TMs in the analyzed seafood product was below the health guidelines and pollution index values, making it suitable for smooth domestic and international export as well as safe consumption.

De-novo exposure assessment of heavy metals in commercially important fresh and dried seafood: Safe for human consumption

The heavy metals (HMs) in seafood are alarming due to their biomagnification in the food chain. The concentrations of As, Cd, Hg, Pb, Cr, and Ni in both fresh and dried fish were quantified, and the potential exposure and safe intake levels for human consumption were assessed by the European Commission (EC) and the Food Safety Standard Authority of India (FSSAI). HMs concentrations ranged from 0.003 mg/kg (Cr) to 2.08 mg/kg for (As) and 0.007 mg/kg (Hg) to 2.76 mg/kg (As). Cd, Hg, and Pb levels in fresh and dried fish were below the maximum residue limits (MRLs) set by the EC and FSSAI, which were 0.1 mg/kg, 0.5 mg/kg, and 0.3 mg/kg, respectively. Cr and As concentrations were also below the MRLs of 12 mg/kg and 76 mg/kg for aquatic products specified by FSSAI. The concentration of HMs in fresh and dried fish was found in the order of As > Cr > Ni > Pb > Cd > Hg and As > Cd > Cr > Ni > Pb > Hg, while the fresh and dried fishes contained HMs in the following order: E. areolatus > S. longiceps > L.lentjen > S. barracuda > E. affinis > S. javus and DA > DS > DR > DB > DSF. The metal pollution index (MPI) validates seafood is HMs free, while the single (Pi) and Nemerow integrated pollution index (Pnw) indicate that concentrations of Cd and As in fresh and dried fish have exceeded the threshold value. The target hazard quotient (THQ<1), hazard index (HI < 1), and target cancer risk (TCR<10-4) indicate that there are no non-carcinogenic and carcinogenic risks through the consumption of seafood and seafood products collected from the Tuticorin coast and marketed at the domestic and international levels. The preliminary findings emphasize the importance of formulating domestic legislation/government initiatives to promote seafood and its consumption. The attainment of this objective shall be facilitated by examining the levels of persistent organic pollutants (POPs) in seafood and evaluating its potential risk to consumers.

Improving robustness of water supply system using a multi-objective robust optimization framework

Due to the uncertainty of rainfall and water demand, the water supply of various participants has been challenged in such a way that this challenge has accelerated the failure of water supply system. Thus, this study proposes a multi-stage Adjustable Robust Optimization integrated to the multi-objective programming framework to drive water supply system to the failure safety zone and thereby improve robustness of system under different scenarios. Indeed, Adjustable Robust Optimization framework is applied to investigate the two uncertain factors of rainfall and water demand. A real arid area of Sistan basin in southeastern Iran is considered to analyze the proposed multi-objective programming model. Next, various comparative feasibilities under different levels of uncertainty are carried out to examine the robustness status in more detail. In the following, due to the deterioration of climatic patterns in the coming years, some managerial insights are highlighted. According to the final outputs, the domestic sector has reached more optimal value compared to that of the agricultural and industrial participants in all objectives due to less water intake, and as a result, it has a significant impact on the robustness of water supply system.

Human health risk assessment of potentially toxic elements in the breast milk consumed by infants in Western Iran

This study aimed to assess the human health risk of some toxic metals/metalloids [lead (Pb), mercury (Hg), cadmium (Cd), nickel (Ni), chromium (Cr), and arsenic (As)] on infants via consumption of the breast milk of women living in urban areas of Kermanshah city, west of Iran. After collecting milk samples, the carcinogenic and non-carcinogenic risk assessment as well as uncertainty analysis of toxic metal levels were carried out. The order of concentration of heavy metals/metalloids in the breast milk samples was Cr (41.07 ± 23.19) > Ni (19.25 ± 11.81) > Pb (11.5 ± 4.48) > As (1.96 ± 2.04) > Cd (.72 ± 0.42) > Hg (0.31 ± 0.26). The results revealed that the levels of Cr and Pb in the breast milk samples were exceeded the World Health Organization (WHO) tolerable daily intake. In the breast milk samples a high levels of one of the trace elements As, Cd, Cr, Pb, and Ni were observed (over 73%) and in 40% of them the levels of Cr, Pb, Cd, As, and Ni were all above WHO tolerable daily intake. Moreover, the As-related point assessment of target risk factor (THQ) was higher than the allowable limit only for 1-month-old male neonates and 2-month-old female neonates (THQ > 1). In addition, Cr-related THQ scores were higher at all age and gender groups (THQ > 1). In conclusion, our findings suggest a potential risk of some metals for infants via the consumption of mothers' breast milk.

Evaluation of some toxic metals in breast milk samples with dietary and sociodemographic characteristics: a case study of Kermanshah, Western Iran

This study aimed to investigate the concentration of some toxic metals (gold (Au), cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb), tin (Sn), and vanadium (V)) and arsenic (As) in breast milk based on demographic characteristics and the diet of mothers. In this cross-sectional study, 100 lactating mothers from Kermanshah, Western Iran, were included. The mean age of the participants was 29.5 (ranging from 16 to 43 years) with a mean BMI of 26.9 (± 3.81) kg (range: 17.0-39.1). The results of the pairwise correlation coefficient of trace elements illustrated that correlation was mostly positive and weak to moderate. A few exceptions of strong correlations were Cr-Ni (r = 0.82), Au-As (r = 0.64), Cr-V (r = 0.64), and Ni-V (r = 0.58). Moreover, results indicated that BMI (p = 0.008), cooking oil (0.042), and potato intake (p = 0.010) affected the trace element levels significantly. The concentrations of V (p = 0.044), Sn (p = 0.036), Au (p < 0.001), and As (p < 0.001) in the breast milk of women was affected by the BMI. The results of univariate linear regression analysis showed that the concentration of Pb in the milk of mothers who use cosmetics was significant (p < 0.05). Since the lifestyle of lactating women, such as cosmetics usage can impact the content of some elements in breast milk, they should be educated in this part.

Risk Assessment of Essential and Toxic Elements in Freshwater Fish Species from Lakes near Black Sea, Bulgaria

The aims of this study were to measure the concentrations of selected toxic and essential elements in the muscle tissue of five common freshwater fish species ((roach (Rutilus rutilus), freshwater bream (Abramis brama), prussian carp (Carassius gibelio), crucian carp (Carassius carassius) and common carp (Cyprinus carpio)) from Lake Burgas and Lake Mandra (Bulgaria). In all samples the levels of Cd, Cr, Cu, Mn, Ni, Pb, Fe and Zn were under the maximum allowed concentrations for safe human consumption in Bulgaria and ranged as follows: Cd 0.02-0.05; Cr 0.03-0.06; Cu 0.11-0.20; Mn 0.05-0.71; Ni 0.06-0.11; Pb 0.15-0.27, Fe 1.68-5.86 and Zn 1.94-9.06 mg/kg wet weight. The concentration of As was under detection limit. An assessment of the human risk by calculation of the target hazard quotients (THQ), hazard index (HI) and target risk (TR) was performed. The target hazard quotient (THQ) for individual elements and HI for combined metals were lower than 1, indicating no health risk for consumers due to the intake of either individual or combined metals. The target risk for iAs, Pb and Ni was below 10^-6, indicating no carcinogenic risk. According to these results, the consumption of these freshwater fish species is safe for human health.

Heavy Metals in the Liver, Kidney, Brain, and Muscle: Health Risk Assessment for the Consumption of Edible Parts of Birds from the Chahnimeh Reservoirs Sistan (Iran)

The concentrations of four heavy metals, zinc (Zn), lead (Pb), nickel (Ni), and cadmium (Cd), were determined in the liver, kidney, muscle, and brain of nine species of birds from the Chahnimeh Sistan from Iran to assess the metal levels and the potential risk to birds and to the people who eat them. Significantly higher levels of all metals were found in the brain than in the other tissues of other birds. There were no significant gender differences in heavy metals in all tissue. The levels of Pb, Cd, Ni, and Zn in the liver and kidney varied as a function of feeding habitats; the median levels were significantly higher in invertebrate predators than they were for fish predators and omnivorous species. Short-distance migrant birds had significantly higher median levels of heavy metals in the liver and kidney than long-distance migrant birds. Ni levels in the liver and kidney tissues in 56% of birds were higher than the critical threshold levels for effects in birds. Our data indicate that environmental exposures to metals were higher in the wintering populations of birds in the Chahnimeh of Sistan from Iran than elsewhere. Concentrations of Zn, Pb, and Cd in a small percentage of birds were above toxicity levels. However, 56% of liver and kidney samples for nickel were above toxicity levels. Determining the exposure frequency and daily intake of birds, the hazard quotient for edible tissues (kidney, liver, and muscle) of these birds showed that their consumption may provide health risk to people consuming them.

Blood lead concentrations in children with iron deficiency anemia: a systematic review and meta-analysis

Iron deficiency is the most common nutritional disorder detrimental to the behavior, cognitive performance, immune system, and physical growth of infants and preschool- and school-age children. Iron deficiency anemia (IDA) increases children's susceptibility to some metals, including the highly toxic lead (Pb), but the character of this relationship is still disputed. Thus, this study aimed to review and meta-analyze the association between the IDA and blood lead levels (BLL) among children, based on papers indexed by international scientific databases and published up to September 2021. A search was performed of the literature in several databases including the ISI Web of Science, PubMed, and Scopus. The final papers were assessed concerning their quality based on the Newcastle-Ottawa Scale (NOS) for cross-sectional studies. Moreover, analyses were performed using R statistical software with the "meta" package. Of the 1528 articles found, only 12 studies met the inclusion criteria and were considered in the meta-analysis. Significantly higher BLL in IDA children (SMD = 2.40; CI 95%, 0.93-3.87 µg/L; p = 0.0014) was seen when compared to non-IDA children. Moreover, the pooled OR is equal to 2.75 (CI 95%, 1.10-6.85 µg/L; p = 0.0303) suggesting a higher risk of IDA development among children with BLL > 10 µg/dL. Thus, we recommend systematic monitoring of Fe and Pb levels among children, especially in countries with limited sources of nutritious food. Since only a few studies were available for this meta-analysis, further studies are necessary to examine the association between IDA and BLL in detail.

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.

Coal mine effluent-induced metal bioaccumulation, biochemical, oxidative stress, metallothionein, and histopathological alterations in vital tissues of the catfish, Clarias batrachus

In the present study, a multi-biomarker approach was used to assess the toxicity of the coal mine effluent (CME) generated at the Rajrappa coal mine on the catfish Clarias batrachus. A core of biomarkers indicative of nutritional value, oxidative stress, and histopathology was selected to illustrate the toxic effects of CME-containing different heavy metals and other toxicants. The results of metal bioaccumulation in CME-exposed fish tissues revealed the highest metal concentration in liver (1.34-297.68 mg/kg) while lowest in muscles (1.47-23.26 mg/kg) as compared to other tissues and so was the metallothionein level. The high value of bioaccumulation observed in liver, kidney, and gills reflects their affinity for metals. In addition, the values of metal pollution index (MPI) of different fish tissues further affirmed that liver followed by kidney and gills are at greater risk than brain, skin, and muscles. Significant alterations in the activity of certain enzymes (aspartate amino transferase, alanine amino transferase, alkaline phosphatase) as well as oxidative stress markers (superoxide dismutase, catalase and lipid peroxidation) were detected in the tissues of CME-exposed fish. The tissue-specific metal accumulation and increased metallothionein levels may be associated with the biochemical and physiological activity of an organ and its constitutive antioxidant defenses. The histopathological changes in the various tissues of the CME-exposed fish justify the high metal accumulation and biochemical alterations. Overall results indicate that the Rajrappa coal mine effluent is very toxic having adverse health impact on the fish and might also affect the human health when consumed.

Environmental Chemistry and Ecotoxicology of Hazardous Heavy Metals: Environmental Persistence, Toxicity, and Bioaccumulation

Heavy metals are well-known environmental pollutants due to their toxicity, persistence in the environment, and bioaccumulative nature. Their natural sources include weathering of metal-bearing rocks and volcanic eruptions, while anthropogenic sources include mining and various industrial and agricultural activities. Mining and industrial processing for extraction of mineral resources and their subsequent applications for industrial, agricultural, and economic development has led to an increase in the mobilization of these elements in the environment and disturbance of their biogeochemical cycles. Contamination of aquatic and terrestrial ecosystems with toxic heavy metals is an environmental problem of public health concern. Being persistent pollutants, heavy metals accumulate in the environment and consequently contaminate the food chains. Accumulation of potentially toxic heavy metals in biota causes a potential health threat to their consumers including humans. This article comprehensively reviews the different aspects of heavy metals as hazardous materials with special focus on their environmental persistence, toxicity for living organisms, and bioaccumulative potential. The bioaccumulation of these elements and its implications for human health are discussed with a special coverage on fish, rice, and tobacco. The article will serve as a valuable educational resource for both undergraduate and graduate students and for researchers in environmental sciences. Environmentally relevant most hazardous heavy metals and metalloids include Cr, Ni, Cu, Zn, Cd, Pb, Hg, and As. The trophic transfer of these elements in aquatic and terrestrial food chains/webs has important implications for wildlife and human health. It is very important to assess and monitor the concentrations of potentially toxic heavy metals and metalloids in different environmental segments and in the resident biota. A comprehensive study of the environmental chemistry and ecotoxicology of hazardous heavy metals and metalloids shows that steps should be taken to minimize the impact of these elements on human health and the environment.

Organochlorine pesticide, antibiotic and heavy metal residues in mussel, crayfish and fish species from a reservoir on the Euphrates River, Turkey

This study investigated the residues of 19 organochlorine pesticides, 37 antibiotics and 5 heavy metals in biota samples (one mussel species, one crayfish species, six wild fish species and one farmed fish species) from the Keban Dam Reservoir on the Euphrates River, Turkey. Among monitored OCPs, only p,p'-DDE was detected in biota samples. It was found only in mussel, fish muscle and fish gill samples. The highest concentration of p,p'-DDE (0.032 mg/kg ww) was determined in the gill of common carp, which was found to be below the maximum residue limit (MRL). Only sulfadimethoxine was detected among antibiotics in biota samples. Its maximum concentration (0.0044 mg/kg ww) did not exceed the MRL of 0.1 mg/kg. Sulfadimethoxine was found only in muscle and gill of common carp collected from site S6, where there are many rainbow trout cage farms. However, no detectable residue of sulfadimethoxine was found in farmed rainbow trout. The highest concentrations of As, Cd and Pb were detected in mussels, while the highest concentrations Cu and Zn were determined in crayfish. Metal concentrations in biota samples did not exceed the maximum permissible levels. According to these results, the consumption of biota samples from the Keban Dam Reservoir is safe for human health.

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.

Assessment of heavy metal pollution risks in Yonki Reservoir environmental matrices affected by gold mining activity

This study reports the heavy metal (Hg, Cd, Cr, Cu, and Pb) contamination risks to and safety of two species of fresh water fish (tilapia, Oreochromis mossambicus and carp, Cyprinus carpio) that are farmed in the Yonki Reservoir in the Eastern Highlands of Papua New Guinea (PNG). The upper reaches of the reservoir are affected by alluvial and large-scale gold mining activities. We also assessed heavy metal levels in the surface waters and sediments and in selected aquatic plant species from the reservoir and streams that intersect the gold mining areas. The water quality was acceptable, except for the Cr concentration, which exceeded the World Health Organization (WHO) standard for water contamination. The sediments were contaminated with Cd and Cu in most of the sampling stations along the upstream waters and the reservoir. The Cd concentration in the sediments exceeded the US Environmental Protection Agency's Sediment Quality Guideline (SQG) values, and the geoaccumulation index (Igeo) values indicated heavy to extreme pollution. In addition, the Cd, Cu, and Pb concentrations in aquatic plants exceeded the WHO guidelines for these contaminants. Between the fish species, tilapia accumulated significantly higher (P < 0.05) Cu in their organ tissues than carp, confirming the bioaccumulation of some metals in the aquatic fauna. The edible muscles of the fish specimens had metal concentrations below the maximum permissible levels established by statutory guidelines. In addition, a human health risk assessment, performed using the estimated weekly intake (EWI) values, indicated that farmed fish from the Yonki Reservoir are safe for human consumption.

Bioaccumulation of metals in common carp (Cyprinus carpio L.) from water bodies of Anatolia (Turkey): a review with implications for fisheries and human food consumption

Although fish is widely consumed by humans for its nutritional properties, accumulation of heavy metals can pose serious health hazards. Widespread common carp Cyprinus carpio is cultured worldwide and represents an economically important species for fisheries in several countries. These include Turkey, where C. carpio often makes for a large part of the sales of the locally marketed fish and also for a traditional dish. This study provides a review of bioaccumulation of metals in tissues of C. carpio from water bodies of Anatolia and also includes reference to worldwide studies. From 42 water bodies across the region, 27 metals in total were studied, of which Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were the most widely analysed, mainly in the muscle, liver and gill tissues. Amongst the potentially toxic metals, Cd, Cr and Pb occurred in several water bodies at concentrations not only above maximum allowed limits but also higher relative to other water bodies worldwide, even though As, Hg and Ni were also sometimes present at potentially hazardous concentrations. The essential metals Cu, Fe, Mn, Se and Zn were detected at various concentrations, with the latter two occasionally above limit. All water bodies flagged as having especially critical (i.e. above limit) concentrations of toxic metals supported C. carpio fisheries from highly populated regions, raising concern about food safety and calling for preventative measures. Given the significantly lower bioaccumulation levels in the muscle relative to the liver and gill tissues, it is suggested that consumption of C. carpio as fillets may be safer than after processing into e.g. meat balls and sausages. The limits of 1.0 μg/g for Cr and 1.15 μg/g for Se, currently lacking from the Turkish food safety legislation, are proposed, and it is suggested that a similar meta-analytical approach as adopted in this study may benefit other countries where C. carpio represents an important fisheries resource.