Determination of heavy metals in two barbs, Barbus grypus and Barbus xanthopterus in Karoon and Dez Rivers, Khoozestan, Iran

Trace elements in two endemic fish species (Barbus strumicae, Karaman 1955 and Squalius оrpheus, Kottelat & Economidis, 2006) of Nestos River (NE Greece): Levels, organ bioaccumulation and potential health risk

This paper aims to determine the content and bioaccumulation patterns of eight trace elements (Li, Cr, Co, As, Se, Cd, Pb and Hg) and one radioisotope (U) in kidney, liver and muscle tissues of two fish species (Squalius orpheus and Barbus strumicae) from Nestos River (northern Greece), and the potential human health risk due to the fish muscle consumption. Kidney and liver accumulate higher element concentrations, except Hg. The site closer to the river-mouth presents higher concentrations since it receives effluents from agricultural activities. The upstream station shows lower element concentrations, due to obstruction of the free transportation of sediments and suspended matter downstream the irrigation dam. The sediment inhabitant and feeder B. strumicae showed elevated concentrations compared to the water column resident S. orpheus. According to calculated hazard indices, the consumption of the fish edible tissue poses zero health risk in developing chronic undesired effects in humans.

Potentially toxic trace elements in the muscle of coastal South American fish: Implications for human consumption and health risk assessment

Micropogonias furnieri and Urophycis brasiliensis are two coastal demersal fish species distributed in the southwestern Atlantic Ocean. Considering that many coastal areas in the southwestern Atlantic Ocean suffer from anthropogenic pressure, the aim of this study was to assess the level of potentially toxic trace elements (Ag, Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, Sr, V and Zn) in the muscle of coastal species, and evaluated the human health risk related to the consumption of muscle. Mercury, inorganic As (Asi), V, and Se showed a higher contribution to the total THQ. Considering two possible scenarios, Asi represents 1 % or 5 % of the total As, the total THQ was <1 for general population and of some health concerns for fishermen population (Total THQ > 1; 5 % Asi). Consequently these results show the importance of quantifying As species in muscle to generate more reliable risk estimates for human health.

Health risk assessment of heavy metals in Coptodon zillii and Parachanna obscura from a tropical reservoir

In this study, the concentrations of trace metals were examined in commercially important fish, Coptodon zillii and Parachanna obscura from Osu reservoir. These were with a view to providing baseline information on the levels of heavy metals and its associated risks to human health through fish consumption. Fish samples were collected fortnightly for five months using fish traps and gill nets with the assistance of local fisherman. They were brought into the laboratory in an ice chest for identification. The fish samples were dissected and the gills, fillet and liver kept in freezer and later analyzed for heavy metals based on Atomic Absorption Spectrophotometric (AAS) method. The data collected were subjected to appropriate statistical software packages. The results revealed that the concentration of the heavy metals in P. obscura and C. zillii across the tissues were not significantly different (p > 0.05) from each other. Also, the mean concentration of heavy metals in the fish were below the recommended limits of FAO and WHO. The target hazard quotient (THQ) for each heavy metals were below one (1) while the estimated hazard index (HI) for C. zillii and P. obscura showed no threat to human health risk through the consumption of the fish species. However, continuous consumption of the fish could probably cause health risk to the consumers of the fish. According to the study's findings, human consumption of fish species with low concentration of heavy metals at the current accumulating level is safe.

Comparative assessment of human health risk associated with heavy metals bioaccumulation in fish species (Barbus grypus and Tenualosa ilisha) from the Karoon River, Iran: Elucidating the role of habitat and feeding habits

Concentrations of Cd, Ni, and Pb were measured in the liver and muscle tissues of benthic omnivorous (Barbus grypus) and pelagic herbivorous (Tenualosa ilisha) fish collected from two sampling sites along the Karoon River, Khuzestan Province, southwest of Iran. Potential human health risks were evaluated by measuring the estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR). The results highlight the important role of habitat and feeding habits in the uptake of HMs by the two species. The EDI for all HMs exceeded the oral reference doses (RfDo) provided by the USEPA, indicating the two fish species are not entirely safe for human consumption. The THQ values were within the permissible limit (< 1), while HI values (> 1) showed there was non-carcinogenic risk for consumers. The TR values for Pb were within the acceptable range (1.00E-06-1.00E-04) for both species.

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.

Comparison of the Heavy Metals, Copper, Iron, Magnesium, Nickel, and Zinc Between Muscle and Gills of Four Benthic Fish Species from Shif Island (Iran)

Concentrations of copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) in muscle and gills of four Benthic fish species (Brachirus orientalis, Argyrops spinifer, Platycephalus indicus and Sillago sihama) from Shif Island of Iran were analyzed using flame atomic absorption spectrometry. The heavy metal levels observed in tissues varied for Cu: 2.15-820.98, Fe: 24.46-533.26, Mn: 1.80-53.17, Ni: 1.86-65.54 and Zn: 28.77-375.79 mg/kg. Significant differences were found among muscle and gill of the four fish species. Heavy metals concentration were significantly (p < 0.05) higher in the gill than in the muscles of all fish species studied. The metal levels in benthic fish species should be continuously monitored in polluted areas since benthic fish indicated a tendency to bioaccumulate pollutants in their tissues from polluted water. The indices of Estimated Daily Intake, Target Hazard Quotient and Hazard Index suggests no risk while carcinogenic risk for Ni showed unacceptable carcinogenic risk.

Mercury cycling and bioaccumulation in a changing coastal system: From water to aquatic organisms

This study evaluated -for the first time- the occurrence and distribution of total Hg in abiotic (dissolved and particulate water fractions) and biotic (gills and muscle tissues of six commercial fish species) compartments within a South American coastal environment with anthropogenic pressure. This study dealt with environmental issues on developing countries which, as they are in continuous growth, face the highest rate of coastal transformation. Total Hg content was determined by acid digestion and measured using a cold vapor atomic absorption spectrophotometer. Results revealed that dissolved Hg exceeded the recommended levels for superficial saline waters in 67% of the cases. Hg concentrations varied among fish species and its tissues. The results suggested that metal burden in fishes achieved a mean maximum accumulation towards the muscle, with concentrations below the international maximum permitted values. The estimated daily intakes calculated suggest that people would not experience significant health risks through fish consumption.

Heavy metal contamination in two commercial fish species of a trans-Himalayan freshwater ecosystem

Toxic metals have disturbed the quality of freshwater ecosystems worldwide. The concentration of heavy metals was investigated in liver, gills and muscle tissues of Schizothorax niger and Cyprinus carpio captured from river Jhelum of Kashmir Himalaya. The heavy metals displayed a wide range of disparity in studied tissues, seasons, sites and species. Cu²⁺ exhibited the highest concentration (279.6 μg/kg) in the liver tissues of S. niger in autumn at site 2 and the lowest (53.1 μg/kg) in the gill tissues in winter at site 1. In C. carpio, the Cu²⁺ was recorded highest (309.4 μg/kg) in the liver tissues in autumn at site 2. The concentration of Zn²⁺ was found highest (575.7 μg/kg) in the liver tissues at site 2 and the lowest (65.8 μg/kg) was recorded in the muscle tissues in autumn at site 1. Zn²⁺ was recorded highest (416.6 μg/kg) in the liver tissues in autumn at site 3 and lowest (51.5 μg/kg) in the gills of C. carpio during winter at site 1 (control). The concentration of Pb²⁺ (14.42 μg/kg) and Fe²⁺ (323.9 μg/kg) was observed in the liver tissue and gills of S. niger at site 3. Similar levels of Pb²⁺ and Fe²⁺ were recorded in the tissues of C. carpio at different sites. Four-way ANOVA (four way) indicated a statistically significant variation (p ≤ 0.05) in heavy metals with the sites, seasons, species and organs. The study emphasises the utmost need to monitor the level of heavy metals in S. niger on a regular basis as this native fish species is showing a continuous decline in the freshwater ecosystems of Kashmir Valley.

Tracing Cr, Pb, Fe and Mn occurrence in the Bahía Blanca estuary through commercial fish species

Over the last decades the anthropogenic contamination impact has substantially increased in the Bahía Blanca estuarine area, and scarce information exists regarding metals in the biotic compartment of this estuary. Thus, fish tissues were used to evaluate metal accumulation within this aquatic environment. The study focused on the determination of Cr, Pb, Fe and Mn in the gills, liver and muscle tissues of six commercial fish species (Brevoortia aurea, Odontesthes argentinensis, Micropogonias furnieri, Cynoscion guatucupa, Mustelus schmitti and Paralichthys orbignyanus). From the results it can be summarized that C. guatucupa tends to accumulate higher metal levels in the liver tissues, mostly Cr and Fe, than the other studied species. O. argentinensis and P. orbignyanus, both permanent inhabitants of the BBE, achieved the highest metal values in the gill tissues, mostly in comparison to M. schmitti. The gill tissues were found to be the main organ of Mn and Ni accumulation for most species, whereas in general, minimum concentrations were found for all the analyzed metals in the muscle tissues. Nevertheless, and according to the guidelines, all fish species showed at least one sample with concentrations of Mn and/or Cr above the permissible levels for human consumption. Finally, it was highlighted the usefulness of selecting these fish species as bioindicators of metal pollution, since they are either permanent inhabitants of the estuary or, according to the sizes under analyses, spend much of their time in this coastal waters.

Risk assessment of polychlorinated biphenyls (PCBs) and trace metals in River Nile up- and downstream of a densely populated area

Cairo city is the largest populated area along the whole course of River Nile with a wide range of anthropogenic activities. Efforts to restore fish habitat and recreational use of the river have raised concerns about its water, sediment and biota quality. This study provides a baseline data on the levels of PCBs and trace metals in River Nile along Cairo sector and implements the formulation of monitoring activities of the river's pollution status. Water, sediment and Nile tilapia (Oreochromis niloticus) samples were collected during summer season, 2013 from two sites, up- and downstream, for detection and determination of 11 PCB congeners (PCBs 28, 44, 52, 70, 101, 105, 118, 138, 152, 180 and 192) as well as six trace metals (Cu, Zn, Mn, Cd, Pb and Fe). Evidences of long- or short-term exposures to these contaminants as well as its accumulation tendency were assessed by integrating the obtained analytical results of biotic and abiotic components of this aquatic ecosystem. All calculated lifetime cancer risk values for PCBs showed unacceptable risk of cancer for human consumers at both normal and subsistence fish consumption rates. The calculated hazard index for total PCBs indicates that fish are not safe for human consumption except in site 1 at normal consumption rate. Meanwhile, trace metals do not pose unacceptable risks at both consumption rates except for Pb in site 1 at subsistence consumption rate.

Determination of nickel and thallium concentration in Cynoglossus arel fish in Musa estuary, Persian Gulf, Iran

Heavy metals with high bioaccumulation capacity are considered as important contaminants and may be available in high concentrations in environment and biota samples. The main aim of this study was to determine the concentration of nickel and thallium in Cynoglossus arel fish in Musa estuary. Sixty-seven fish samples were collected from Musa estuary during five intervals of 15 days in summer 2013. After biometric measurements, the concentrations of nickel and thallium were measured by graphite furnace atomic absorption spectrophotometer. The mean concentration of nickel and thallium in muscle tissue of fish samples was 2.458 ± 0.910 and 0.781 ± 1.754 mg kg^-1/ww, respectively. The GLM analysis showed a significant negative relationship between nickel concentration and length. In addition, there was a significant positive relationship between thallium concentration and fish length. Nickel concentration exceeded the allowable standards of WHO and FDA in Cynoglossus arel. Therefore, regarding with high consumption of seafood in this region, it is recommended that these fishes should be consumed under a nutritionist counseling.

Mercury concentrations and health risk assessment for two fish species, Barbus grypus and Barbus luteus, from the Maroon River, Khuzestan Province, Iran

The purposes of this study are to investigate the concentration of mercury in edible muscle tissues of two popular edible fish species: the Shirbot (Barbus grypus) and Hemri (Barbus luteus), from the Maroon River, Khuzestan Province, Iran, and to assess the risk of their toxicity on human health. We collected 20 samples of each species from the river, and after biometry and determination of their age and sex, concentration of total mercury (assumed to be about 100% methylmercury) was measured. For B. grypus, mercury averaged 0.16 ± 0.02 μg g(-1) wet weight, and for B. luteus, it averaged 0.08 ± 0.02 μg g(-1) wet weight. Although mercury has been reported to accumulate with age, length, and trophic level in many studies, we did not find a significant correlation among age, sex, length, and mercury content in either of these omnivorous species. Mercury levels (maximum 0.37 μg g(-1) wet weight) were below international standards. Consumption of these fish would not pose a serious health hazard to Iranian consumers at the average national consumption of 17.53 g day(-1). However, high-end consumers eating more than 250 g week(-1) and pregnant women should be attentive in choosing fish low in mercury, for example, B. luteus rather than B. grypus.

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

This study was conducted to measure the Cd, Pb, Cu, Zn, Cr, Co, Ni, and Fe concentrations in organs of Cyprinus carpio and Hypophthalmichthys molitrix, in Zabol Chahnimeh reservoirs, Iran. The highest Pb, Cu, Co, Ni, and Fe concentrations in both fish species were observed in the gill of C. carpio at 0.70, 3.7, 0.7, 0.8 and 31.2 µg/g, respectively; while the highest concentrations of Cd, Zn, and Cr were found in the gill of H. molitrix at 0.13, 22.5, and 0.5 µg/g, respectively. The maximum allowable fish consumption rate for an adult person (71.5 kg body weight) were 10.64, 0.677, 0.558, 1.17, and 0.92 kg/day based on Cd, Cu, Cr, Zn, and Fe levels respectively. Results showed that the Cd, Cu, Zn, and Pb (except of Pb in H. molitrix) concentrations in the muscle of both fish species are below levels of concern for human consumption.

Monitoring of trace metals in tissues of Wallago attu (lanchi) from the Indus River as an indicator of environmental pollution

We aimed to assess the bioaccumulation of selected four trace metals (Cd, Ni, Zn and Co) in four tissues (muscles, skin, gills and liver) of a freshwater fish Wallago attu (lanchi) from three different sites (upstream, middle stream and downstream) of the Indus River in Mianwali district of Pakistan. Heavy metal contents in water samples and from different selected tissues of fish were examined by using flame atomic absorption spectrometry. The data were statistically compared to study the effects of the site and fish organs and their interaction on the bioaccumulation pattern of these metals at P < 0.05. In W. attu the level of cadmium ranged from 0.004 to 0.24; nickel 0.003–0.708; cobalt 0.002–0.768 and zinc 47.4–1147.5 μg/g wet weight. The magnitude of metal bioaccumulation in different organs of fish species had the following order gills > liver > skin > muscle. The order of bioaccumulation of these metals was Ni < Zn < Co < Cd. Heavy metal concentrations were increased during the dry season as compared to the wet season. The results of this study indicate that freshwater fish produced and marketed in Mianwali have concentrations below the standards of FEPA/WHO for these toxic metals.

Human health risk from organ-specific accumulation of toxic metals and response of antioxidants in edible fish species from Chenab River, Pakistan

In the current study, the bioaccumulation of essential and nonessential metals and related antioxidant activity were analyzed in three organs (muscle, gills, and liver) of herbivorous (HF) and carnivorous (CF) edible fish of Chenab River. The comparative analysis revealed a more heterogeneous accumulation of metals in the muscles of HF fish than that of CF fish [chromium (Cr, 3.4 μg g(-1)), cobalt (Co, 1.7 μg g(-1)), copper (Cu, 3 μg g(-1)), and iron (Fe, 45 μg g(-1)) versus Cr (1.3 μg g(-1)), Co (0.1 μg g(-1)), Cu (1.1 μg g(-1)), and Fe (33 μg g(-1)), respectively, P<0.001]. These results implied an organ-specific accumulation of metals at different trophic levels. According to logistic regression analysis, the bioaccumulation of metals had marked differences in HF and CF. The antioxidant activity was significantly related to the tissue type and the metals to which the organs are exposed to. The liver of CF fish had a higher activity of antioxidant superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and lipid peroxidase (LPO) than that of HF (P<0.05). LPO and guaiacol peroxidase (POD) in both groups were associated with a number of metals, but in HF, cadmium (Cd), Cr, Pb, and Zn were more related with the LPO and SOD activities. Moreover, Cd, Co, Fe, Pb, Ni, Cu, and Zn were above the permissible limits set by various agencies. In numerous cases, our results were even higher than those previously reported in the literature. The results provide an insight into the pollution pattern of Chenab River. These results may be helpful in the future to identify biomarkers of exposure in aquatic organisms.

Metals concentrations in Nile tilapia Oreochromis niloticus () from illegal fish farm in Al-Minufiya Province, Egypt, and their effects on some tissues structures

This study clarified the suitability of fishes caught from illegal fish farms to human consumption and their hazards to public health. For this purpose, the concentrations of some metals (Al, Cd, Pb, Hg and Ni) in water and Nile tilapia (Oreochromis niloticus) fish samples collected from an illegal fish farm, in addition to pathological conditions of the fish tissues, were examined. The illegal farm water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in tissues of O. niloticus in concentrations higher than those of farm water. Kidney of O. niloticus contained the highest concentrations of the detected metals, while muscle and skin contained the lowest concentrations. The examination of fish tissues revealed various histopathological lesions which related directly to the pollution of the illegal farm water. Moreover, metals levels in O. niloticus muscle were higher than the maximum permissible levels for human consumption. Consequently, the flesh of fishes from the illegal farms could be considered hazardous to human health. Therefore, warning against eating fish caught from the illegal fish farms should be announced. Moreover, removal of such illegal fish farms is necessary for the public health protection.

Lead bioaccumulation and toxicity in tissues of economically fish species from river and marine water

Bioaccumulation of lead was determined in muscle and liver of Barbus xanthopterus, Liza abu, Barbus grypus, Acanthopagrus latus, Platycephalus indicus, Otolithes ruber exposed to lead contaminated river and marine in Khouzestan. Significant variations in metal values were evaluated using student's t test at p < 0.05. In river fish, liver was polluted in comparison with muscle and high level was in B. xanthopterus (2.80 mg kg(-1) wet weight) except for B. grypus in Karkhe River (1.73 mg kg(-1)wet weight). In marine fish, muscle was contaminated than liver and high level was in O. ruber (47.18 mg kg(-1)wet weight) except for O. ruber in Mahshahr seaport (17.85 mg kg(-1) wet weight).

Determination of lead, mercury and cadmium in wild and farmed Barbus sharpeyi from Shadegan Wetland and Azadegan Aquaculture Site, South of Iran

Lead, mercury and cadmium concentrations were measured in muscle, liver and gill in wild and farmed Barbus sharpeyi from Shadegan Wetland (SW) and Azadegan Aquaculture Site (AAS). Significant variation in metal values were evaluated in Students' tests at p > 0.05. Results showed: In B. sharpeyi high levels of cadmium, lead, and mercury were measured in gill (0.34, 0.68, and 0.06 mg kg(-1) dw). The concentration of metals was not significantly different (p ≥ 0.05) in the muscle between SW (Cd, 0.24; Pb, 0.49 and Hg, 0.04) and AAS (Cd, 0.23; Pb, 0.49 and Hg, 0.04). Lead concentration was higher than cadmium and mercury in different organs (p > 0.05). Cadmium, mercury and lead in different tissues of SW were higher than AAS and there was no significant difference between them (p ≥ 0.05). Metal levels in different tissues were higher than WHO standard.

Mercury concentrations in commercial fish from freshwater and saltwater

Research was performed to investigate the concentration of mercury in muscle and liver of fish species from freshwater (Barbus xanthopterus, Barbus grypus, Liza abu) and saltwater (Cynoglossus arel, Periophthalmus waltoni, Otolithes ruber) in Khouzestan, Iran. In freshwater fish, muscle was polluted in comparison with liver except for Barbus xanthopterus which high levels of mercury were measured in liver. In saltwater fish liver was contaminated than muscle except for Cynoglossus arel which high level of mercury was found in muscle. Significant variations in metal values were evaluated using student's t test at P < 0.05. Mercury concentrations were well above the permissible limits suggested by WHO and FDA guidelines.

Cadmium, iron, lead and mercury bioaccumulation in abu mullet, Liza abu, different tissues from Karoun and Karkheh rivers, Khozestan, Iran

Lead, mercury, cadmium and iron concentration in following tissues: muscle, liver and gill of Liza abu in Karoun and Kharkheh were measured. Karoun and Kharkheh are important rivers in Iran. Significant variation in metal values were evaluated using Student's t test at p < 0.05. Result showed that maximum concentration of metals were recorded in gill tissues. Iron concentration was higher than lead, cadmium and mercury in different organs (p < 0.05). The level of metals Cd, Hg, Fe in different tissues of Karoun river was higher than Karkheh river (p < 0.05). Metals level in different tissue were upper than WHO standard.