Metal Concentrations In Fish Research Articles

Corynosoma caspicum (Acanthocephala, Polymorphidae), as a heavy metal bioindicator in the fish Gasterosteus aculeatus from the Caspian Sea, northern Iran.

Previous marine biology studies found that the concentration of heavy metals in some parasites of fish such as acanthocephalans can be a proper bioindicator. Therefore, we attempted to measure five heavy metal concentrations in the tissues of the fish Gasterosteus aculeatus (G. aculeatus) and its acanthocephalan parasites, Corynosoma caspicum (C. caspicum) from the Southern Caspian Sea, northern Iran. G. aculeatus (three-spined stickleback) was collected from the south of the Caspian Sea, Mazandaran Province, northern Iran. After tissue preparation, the heavy metal concentrations in fishes and acanthocephalans were obtained using the tissue dissolution technique and an atomic absorption spectrophotometer. The concentrations of chromium (Cr), cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) in the skin, liver, muscle, and intestine tissues of the fish and its parasites, C. caspicum, were measured and compared. Eighty (32%) of 250 collected fish were infected by at least one acanthocephalan parasite. The Cr indicated the highest concentration (5.329±3.275) of the heavy metals in acanthocephalan, even more than the skin, liver, and muscle of infected fishes. Cd had the lowest concentration (0.0333±0.0075) of heavy metals in acanthocephalan, but it was still higher than the concentration in the infected fishes' skin, liver, muscle, and intestine tissues. Our findings indicated that C. caspicum parasites can be considered extremely sensitive early-alert bioindicators, particularly in sensitive and under-threat environments with low pollution levels.

Heavy metal profile in smoked Atlantic cutlass fish (Trichiurus lepturus, linnaeus 1758) from some major markets in Benin metropolis, Nigeria

The concentrations of heavy metals (Pb, Cd, Cu and Zn), in smoked Trichiurus lepturus (Trichiuridae) from some major Markets in Benin Metropolis, Nigeria, were determined employing Atomic Absorption Spectrophotometric technique, in order to ascertain their suitability for human consumption against the dearth of data regarding the metal content of such fish. The mean concentrations of metals in fish ranged from 0.118 mg/kg for Cd to 72.738 mg/kg for Zn. The mean concentration of Zn in fish ranged from 51.80 mg/kg at New Benin Market to 89.28 mg/kg at Ramat Market while the mean concentration of Cu ranged from 6.58 mg/kg at Oba Market to 9.29 mg/kg at Ramat Market. The mean concentration of Cd ranged from below detection limits at Oba and New Benin Markets to 0.31 mg/kg at Ramat Market while the mean the mean concentration of Pb ranged from 0.39 mg/kg at New Benin Market to 0.75 mg/kg at Uselu Market. There was no significant difference (P>0.05) in the mean concentrations of metals in fish between Markets. The toxicity quotient for heavy metals ranged from 0.271 for Cu to 2.425 for Zn. The mean concentrations of Zn, Cd and Pb in fish exceeded the Food and Agriculture Organization and Commission Regulation maximum limits for heavy metals in fish indicating that fish must be consumed with caution, to avert heavy metal poisoning.

Heavy Metal Concentrations in Fish from River Tano in Ghana and the Health Risks Posed to Consumers.

Appreciable levels of trace metals have been reported in the Tano basin, but data on the corresponding levels in fish and the risk they pose to consumers are limited. The levels of 7 trace metals in 18 fish muscles were assessed between November 2016 and October 2017 using acid digestion and PerkinElmer (PinAACle 900T) Atomic Absorption Spectrophotometry. Apart from Cu, all the metals studied were detected in all fish samples. The levels of Cr, As, and Hg were higher than the acceptable levels of fish muscles. Cr concentration ranged from 16.10 ± 0.2 mg/kg in Clarias gariepinus to 57.9 ± 4.2 mg/kg in Sarotherodon galilaeus. The levels of As ranged from 1.01 ± 0.08 in Clarias gariepinus to 3.00 ± 0.01 mg/kg in Mormyrus rume. Hg level was 0.58 ± 0.69 mg/kg in Oreochromis niloticus and 2.52 ± 0.70 mg/kg in Ctenopoma kingsleyae. However, Pb, Zn, and Cd concentrations were below the Food and Agriculture Organization limits with low target hazard quotients in all fish samples, suggesting no possible noncarcinogenic risks to adult consumers. Possible noncarcinogenic and carcinogenic health risks were recorded for As, Hg, and Cr in all fish species. Strong associations were observed between Hg, As, Zn, and Cr and between Pb and Cd suggesting a possible common source. Mormyrus rume fish species was under stress in the river, but the remaining species were in good condition. Periodic monitoring of trace metal concentrations in fish and enforcement of the buffer zone policy are recommended.

Monitoring of Environmental Hg Occurrence in Tunisian Coastal Areas.

Total mercury (Hg) was determined in 450 environmental samples (seawater, sediment plant and fish) from five Mahdia coastal areas (Tunisia). Tolerable Weekly Intake% (TWI) values, according to the European Food Safety Authority (EFSA), were calculated based on the average metal concentration in fish and the average weekly fish consumption rate. Hg was accumulated mainly in fish and in Posidonia oceanica leaves. Hg in sediment ranged from 1.88 μg/kg dry weight (d.w.) to 7.48 μg/kg d.w., while it was between 0.32 μg/kg and 0.19 μg/kg in seawaters. Our study showed high concentration in Posidonia oceanica in S3 (plant = 16.76 ± 4.48 μg/kg d.w.) as compared to those in S4 sites (plant = 5.33 ± 0.05 μg/kg d.w.). Concentrations for S. aurata and S. salpa in the Rejiche area exceeded the EC 1881/2006 legislation with values of 1.9 mg/kg and 2.5 mg/kg, respectively, and consumers may be exposed to high concentrations of Hg that exceeds the EFSA. The results showed that the fish species should be constantly monitored due to their TWI% of 154.5% for S. aurata and 209.8% S. salpa respectively.

Assessment of Heavy Metal Concentrations and Public Health Risk in Fish Species of Sakarya River, Turkey

In this study, heavy metal concentrations including cadmium, lead, zinc, copper and arsenic concentrations were determined in five fish species (Capoeta sieboldii, Capoeta tinca, Scardinius erythrophthalmus, Squalius pursakensis and Barbus escherichii) obtained from the Sakarya River. The metal concentrations of fish supplied in four different seasons (winter, spring, summer and autumn) were determined by using atomic absorption spectrophotometry. Although the metal concentrations showed seasonal variations in some fish species and also varied with respect to particular fish species, the concentrations of these metals were found to be within the permissible limits. In addition, it was concluded that the concentration of metal contamination in the evaluated fish species would not pose a risk for human consuming fish species obtained from Sakarya River by considering estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) values.

Bioaccumulation of heavy metals in different trophic levels of aquatic ecosystems with fish as a bioindicator in Visakhapatnam, India

The concentration of 23 metals was analyzed in the tissue of nine fish species, which represents the different habitats, i.e., primary feeder, tertiary feeder, and bottom feeder in fresh and marine waters of Visakhapatnam. Scomberomorus guttatus, Upeneus vittatus, and Penaeus indicus were selected in the coastal waters; Xiphias gladius, Stolephorus indicus, and Penaeus monodon from deep sea; and Channa striata, Puntius chola, and Macrobrachium rosenbergii from freshwater were analyzed. Metals in fish were analyzed by using the Inductive Couple Plasma Mass Spectrometer (ICP-MS). The concentrations of metals in fish were within the permissible limit set by WHO, FAO apart from Chromium, Aluminum, Manganese, and Arsenic. The concentrations were highest in coastal water fish and lowest in freshwater fish. Similarly, higher concentrations were observed in bottom feeders than in other tiers.

Assessment of heavy metal concentrations in the muscles of ten commercial fish species from Lagos lagoon, NigeriaAssessment of heavy metal concentrations in the muscles of ten commercial fish species from Lagos lagoon, Nigeria

The study was undertaken to assess the concentration of five heavy metals (zinc (Zn), lead (Pb), copper (Cu), iron (Fe) and manganese (Mn)) in the muscles of Tilapia zilli, Hydrocynus fiscalis, Parapristipoma humile, Caranx hippo, Cynoglossusa caudatus, Chrysichthys nigrodigitatus, Letjanus sp, Portunus validus, Sardinella maderensis, and Sphyreana sp. The concentrations of heavy metals were measured by atomic absorption spectrophotometry after digestion of the samples. There were significant differences (P<0.05) in the concentration of heavy metals in fish muscles. There was no specific pattern in the levels of heavy metals among the fish species. P. validus had the highest concentration of Zinc in the fish sampled with a mean value of 14.45mg/g while T. zilli had the lowest concentrations of Zn and Mn. Sphyreana sp had the highest concentrations of Lead and Copper and Manganese in the muscles. Iron concentration was highest in the muscle of S. maderensis. In this study, the overall average concentrations of metals in fish muscles were in the order of Zn> Fe > Pb> Cu> Mn. The values of Zn and Cu were within or lower than the acceptable limits FAO/WHO (Food and Agriculture Organization Of the United Nations/World Health Organization) for concentration of heavy metals in fish while levels of Pb, Fe and Mn in the muscles of the various fishes were beyond the safe limit in foods. Close monitoring of heavy metal pollution of Lagos Lagoon is strongly advocated, in view of possible risks to the health of consumers.

Metal concentrations in fresh and salt-dried anchovy, Encrasicholina devisi, and estimation of target hazard quotient for consumers in Kuala Terengganu

Seafood processing methods alter the metal concentrations in fish. Since the concentrations are often quantified for fresh fish, such alteration can under or overestimate the daily intake of metal elements through consumption. This study aimed to determine metal concentrations in fresh and salt-dried anchovies (Encrasicholina devisi) collected from Kuala Terengganu coastal waters. The samples were digested through acid digestion and the concentrations of chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, cadmium, and lead were quantified using inductively coupled plasma-mass spectrometry (Perkin Elmer Elan 9000). Significant concentration variations were not observed in fresh and salt-dried anchovies (p>0.05). The concentration of arsenic exceeded the 1985 Malaysian Food Regulation standards, validating the other reports on local canned anchovies. The values of estimated daily intake and hazard quotient showed that arsenic levels in the salt-dried anchovies might pose health hazards, especially for the age group between 20 and 29 years.

Differences in metal compositions and concentrations of sympatric predatory fish and squid from the South Atlantic Ocean

Metals occur naturally in the environment and in organisms. Organisms at higher trophic levels may contain metals at elevated concentrations, as a result of accumulation from anthropogenic and natural sources, potentially making them more susceptible to detrimental effects, as well as passing them on to consumers. The concentrations of thirty metals were quantified in hake (Merluccius capensis), kingklip (Genypterus capensis), monkfish (Lophius vomerinus) and chokka (Loligo reynaudii) collected from the South Atlantic Ocean of South Africa in February 2017 and February 2019, using inductively coupled plasma mass spectrometry. Metal concentrations and composition in nektobenthic chokka differed significantly from the three demersal fish predators (hake, kingklip, and monkfish). Demersal fish metal concentrations and relative pattern compositions (fingerprints) were similar. Because the samples were collected within an 80 km radius, the differences are likely as a result of a combination of factors, such as diet, habitat (depth), and differences in the physiological regulation of metals between cephalopods and fish, rather than location. Based on South African estimated daily intake, total hazard quotient and European Union limits for mercury, cadmium and lead, these four economically important species from the South Atlantic Ocean are safe for human consumption. Plankton, herbivorous marine species, and larger predators, such as sharks and dolphins, should be studied to obtain further insight into metals as baseline for monitoring possible future pollution and effects from climate change, trophic transfer, toxic effects, and human consumer safety.

Concentrations of Metals in Fishes from the Athabasca and Slave Rivers of Northern Canada.

There is growing concern about possible effects of exploitation of the Alberta Oil Sands on the ambient environment, including possible effects on populations of fishes in the Athabasca River and farther downstream in Lake Athabasca and the Slave River. In the present study, concentrations of metals in dorsal muscle tissue of 5 fish species-goldeye, northern pike, walleye, whitefish, and burbot-from the Slave, Peace, and Athabasca Rivers were quantified. A suite of 25 metals including As, Hg, Se, Tl, and V was analyzed. Most metals exhibited no significant variations in concentration among locations. Concentrations of 5 metals, As, Hg, Se, Tl, and V, revealed significant variations among locations and were of sufficient magnitude to be of interest. Concentrations of Hg did not vary significantly among locations; however, because it was detected at concentrations of concern and the use of the selected fishes was a local source of food for humans and pets, it was of interest. Concentrations of As, Se, Tl, and V in dorsal muscle of certain fishes in the farthest downstream sites on the Slave River were greater than those in the same tissues and species in the farther upstream sites on the Peace and Athabasca Rivers. This phenomenon was most prevalent with Tl and to a lesser extent with As and Se. Nevertheless, concentrations were not of concern for the health of human consumers. Although metals did not appear to be increased in fish in the Alberta Oil Sands region in the present study, further research is needed to understand the potential impacts. Environ Toxicol Chem 2020;39:2180-2195. © 2020 SETAC.

Human health risk assessment of heavy metals in aquatic sediments and freshwater fish caught from Thamirabarani River, the Western Ghats of South Tamil Nadu

Industrialization and advancements in agriculture are increasingly the cause of environmental concerns and need to be addressed. This study was carried out at four sampling sites, viz. Manimuthar (site 1), Tirunelveli (site 2), Srivaikuntam (site 3), and Authoor (site 4), along the Thamirabarani river. The heavy metal concentration in fish and sediments were ranged from 0.001 to 9.505 mg kg−1 and 0.294 to 106.25 mg kg−1. The lifetime cancer risk (LCR) values for children and adults were found to be above the acceptable threshold value (ATV) and children were found to be more susceptible to health risks. For all sites except site 4, the LCR of toxic metals except Cd were within the ATV (10−6–10−4); the value of Cd was above the ATV, and poses a high cancer risk to the downstream inhabitants. This study advises routine heavy metal monitoring on aquatic organisms along these sites to implement regulatory standards.

Impact of Illegal Crude Oil Refining in Jike-ama River of Bille Kingdom, Rivers State, Nigeria

Oil exploration and exploitation is a lucrative business and one of the major sources of revenue in Nigeria. Each year, hundreds of post-impact assessment (PIA) studies are conducted to assess the impact of the hazards generated by the oil industry on social environment and on human health. This hazardous impact is the associated with the activities of illegal refining of crude oil. Thus, this work examined the impact of illegal crude oil refining activities in Jike-Ama river of Jike-Ama community. Shellfish, fish, surface water and sediment samples were randomly collected in triplicates. Physiochemical parameters, heavy metal content, polycyclic aromatic hydrocarbons (PAHs) and total hydrocarbon content of the water in addition to heavy metal content and PAHs in fish, Shellfish and sediment were determined. The results of the physicochemical parameters showed that pH, total suspended solids, biological oxygen demand, turbidity and total hydrocarbon content of water were above FEPA permissible limits while chloride, nitrate and sulphate detected in water were within FEPA permissible limits. Dissolved oxygen was observed to be below FEPA permissible limit. The mean concentration of heavy metals and PAHs in sediment showed significant difference (p<0.05) when compared with values for Shellfish and fish and were above FEPA and WHO permissible limits. Shellfish had higher concentrations of heavy metals and PAHs than fish. PAHs values in shellfish showed significant difference (p<0.05). Heavy metals concentration in fish were above permissible limits except Cr, Zn and Pb. Concentration of PAHs in fish, shellfish, surface water and sediment were generally above FEPA and WHO permissible limits. This findings suggests high concentration of contaminants in Jike-Ama river.

Metal concentrations in fish from nine lakes of Anhui Province and the health risk assessment.

In the present study, to comprehensively investigate the metal contamination in the fish of Anhui Province, four fish species, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, and Hypophthalmichthys nobilis, were collected from nine lakes, and the levels of Zn, Pb, Cr, Cu, Ni, As, Hg, and Cd in the fish muscle were determined. The results showed that the highest concentrations of Zn (7.791mg/kg), Pb (0.522mg/kg), Cr (0.030mg/kg), and Cu (0.767mg/kg) were found in Tiangang Lake, Xifei Lake, Tiangang Lake and Baidang Lake, respectively. However, metals Ni, As, Hg, and Cd were not detected in all fish samples. In the fish species, the metal bioaccumulation ability was decreased with the following order: C. idellus>H. molitrix>H. nobilis>C. carpio. Furthermore, the target hazard quotient (THQ) was used to assess the health risk via fish consumption. The results indicated for co-exposure; C. idellus would pose a health risk to children at high exposure level (95th) as THQ value was higher than 1. It should be pointed out that Pb contributes most to the total THQs (the ratio was 88%); thus, the contamination of Pb should be paid more attention. This field investigation combined with health risk assessment would provide useful information on the heavy metal pollution in Anhui Province.

Levels and human health risk assessments of heavy metals in fish tissue obtained from the agricultural heritage rice-fish-farming system in China

China began to practice Rice-fish-farming system (RFFS) 1700 years ago. Nowadays, the widely spread of metals could be potential threats to the quality of RFFS fish. In this study, Pb, Cd, Hg, As and Cr as the top five most toxic heavy metals were determined in six species of RFFS fish meat obtained from 7 provinces in south China. The mean concentrations of metals in RFFS fish followed Pb (36.89 μg/kg) > As (33.36 μg/kg) > Cr (18.54 μg/kg) > Hg (16.35 μg/kg) > Cd (2.01 μg/kg), which were mostly lower in comparison with fish from traditional aquaculture systems raised by fish feeds. Grass carp obtained lower metal concentrations compared with other fishes, possibly indicating the importance of feeding habits of RFFS fish. Concentrations of metals in fish and RFFS sediment were in good correlations, and benthic fish obtained high pollution levels, suggesting the accumulation of metals through the direct contact with sediment. Risks assessments coupled with Monte Carlo simulation indicated the potential non-carcinogenic risks and carcinogenic risks decreased following As > Hg > Cr ≈ Pb > Cd, and As > Cr > Cd > Pb, respectively. These results suggested RFFS is still a successful mode of green agriculture.

Human risk associated with potential exposure to heavy metals in a gadoid fish species from selected markets in Benin City, Nigeria

The study ascertained the levels of Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) in the Atlantic cod (Gadus morhua) of mean weight 679 ± 16.05 g, from selected markets in Benin city, Nigeria, by Atomic Absorption Spectrometric technique, in order to ascertain their suitability for human consumption. The mean concentrations of heavy metals in G. morhua ranged from 0.03 mg/kg Cd at New Benin market to 52.85 mg/kg for Zn at Ramat market while there was no significant difference (p>0.05) in the mean concentrations of heavy metals in fish between markets. The estimated daily intake (EDI) values for heavy metals ranged from 0.0032 mg/person/day for Cd to 1.70 mg/person/day for Zn while the estimated annual intake (EAI) values for heavy metals ranged from 1.17 mg/person/year for Cd to 620.5 mg/person/year for Zn. The estimated quantity consumed (EQC) values ranged from 0.000064 mg/meal for Cd to 0.034mg/meal for Zn while the theoretical maximum daily intake (TMDI) was 2414 mg/person/day. The margin of exposure (MOE) values for heavy metals ranged from 0.63 for Cd to 4.19 for Cu while the total toxicity of mixtures (TTM) value was 4.82. The toxic/hazard quotient (TQ) values ranged from 0.24 for Cu to 1.60 for Cd while the total heavy metal load in fish by market, ranged from 41.26 mg/kg at New Benin market to 59.27 mg/kg at Ramat market. The mean concentrations of Cd, Pb and Zn in G. morhua exceeded the thresholds established for heavy metals in fish by CODEX Alimentarius, Commission Regulation and Food and Agriculture Organization of the United Nations (FAO), thus making them the metals of critical ecological concern. The implication is that G. morhuamust be consumed with caution in order to avert health problems associated with excess concentrations of Cd, Pb and Zn.Keywords: heavy metals, Gadus morhua, toxic/hazard quotient, markets, Nigeria

Evaluation of heavy metals and radionuclides in fish and seafood products

Despite the existence of a legislation regarding food contaminants, food safety control in Serbia is a matter of great concern. This study investigates the radioactivity levels and heavy metal concentrations in fish and seafood commercially available in Serbian markets. Domestic fish species (caught in the Danube River) and fishery products imported from Europe, Asia and America were analyzed. The content of natural radionuclides and 137Cs were investigated by gamma spectrometry. Activity concentration of 40 K was measured in the range of 44–165 Bq kg−1; low levels of 137Cs were detected in two samples (2.8 and 3.0 Bq kg−1), while concentrations of 226Ra and 232Th were below minimal detectable values. Concentrations of heavy metals (Cd, Hg and Pb) were determined using ICP-OES method. Cd concentration ranged from 0.01 to 0.81 mg kg−1 in sea fish and from 0.01 to 0.03 mg kg−1 in freshwater fish. Hg concentrations were in the range of 0.01–1.47 mg kg−1; the highest value was measured in the predator fish - shark. The highest level of Pb (6.56 mg kg−1) was detected in a blue sea fish (Atlantic mackerel). The health risks associated with the intake of heavy metals and radionuclides via fish consumption were evaluated. The results indicate that fish and seafood consumption do not pose a significant health concern in the case of the usual consumption rate which is typical for the population of Serbia. However, a highly frequent consumption of fishery products can have adverse health effects, especially due to Hg and Pb contamination.

Evaluating Heavy Metals Pollution and Exposure Risk Through the Consumption of Four Commercially Important Fish Species and Water from Cross River Ecosystem, Nigeria.

In order to evaluate heavy metals exposure risk in the mid-Cross River, the concentrations of iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), lead (Pb) and chromium (Cr) in water and four commercially important fishes (Chrysichthys nigrodigitatus, Clarias anguillaris, Tilapia zillii and Mormyrus rume) were studied between February 2015 and August 2016. Iron (2.71 ± 0.5mg/L), Mn (0.49 ± 0.06mg/L), Pb (0.05 ± 0.04mg/L) and Cr (0.06 ± 0.03mg/L) in water were above permissible limits. The pattern of heavy metals concentration in fish was T. zillii > M. rume > C. anguillaris > C. nigrodigitatus except for Pb. The estimated daily intake of most heavy metals was below the tolerable daily intake values except Pb. Although the hazard quotient was below one, the total hazard quotient and the carcinogenic risk value for Cr were above acceptable ranges for all fishes.

Assessment of metallic contamination in sediment and mullet fish (Mugil cephalus Linnaeus, 1758) tissues from the East Algerian coast

AbstractThe present work was designed to assess the contamination level in the coastal of Annaba, following the spectrophotometric determination of the level of some metallic elements (Fe, Cu, Pb, Zn, Ni and Cd) in the sediments along an increasing bathymetric gradient (10 m and 20 m), as well as in the biological indicator grey mullet (Mugil cephalus) muscle. During the winter period (2014), 12 surface sediment samples, and a total of 24 fish were collected. Once the samples are dried, crushed and sieved, 0.5 g dry weight of each sample was added to concentrated acids. The results showed that the levels of some metals are superior to the recommended guideline values, and consequently the sediment of this bay is contaminated by iron, lead and copper. The contamination index (CI) showed a general tendency in the concentration of the studied metals as follows: Fe > Pb > Cu > Zn > Ni > Cd, since the most studied metals occurred at higher concentration in depth (20 m).However, the average concentrations of metals in fishes were found to be as the following order: Fe > Zn > Pb > Cu > Ni > Cd. The consumption of fish from some contaminated sites can be dangerous because concentrations of lead, cadmium and zinc exceed the international standards. Moreover, the strong positive correlation observed between the metallic elements of sediments and fishes confirm that these metals resulted from the similar sources of the anthropic activities, such as domestic, port, industrial and agricultural waste discharges. This is confirmed by the determined of pollution load index (PLI) parameter. Conclusively, a regular monitoring program of heavy metal is recommended for protecting these organisms, and to reduce the environmental risks.

Human exposure to trace elements via farmed and cage aggregated wild Axillary seabream (Pagellus acarne) in a copper alloy cage site in the Northern Aegean Sea

Axillary seabream (Pagellus acarne) farmed in a copper alloy mesh pen and wild individuals of P. acarne aggregated near the copper-alloy cages presented higher concentrations of trace metals in the liver, skin and gills than in fish muscle tissues in two batches of small and large fish sizes. Elevated mean levels of metals (mg kg−1) in muscle tissues in both small and large fish size groups were observed in the rank order of Zn(3.43) > Fe(3.01) > Cu(0.59) > Mn(0.13) and Fe(3.82) > Zn(3.32) > Cu(0.62) > Mn(0.17) for copper cage-farmed fish, relative to ranked mean levels for Zn(2.64) > Fe(1.95) > Cu(0.25) > Mn(0.09) and Fe(5.79) > Zn(3.58) > Cu(0.58) > Mn(0.28) for the copper cage-aggregated wild fish. Nevertheless, trace metal concentrations in fish harvested from the copper cage or those of the cage-aggregated wild individuals in both size groups were far below maximum levels of seafood safety recommended by USEPA and FAO/WHO. Target hazard quotients, calculated to estimate the non-carcinogenic health risks of metals by consuming these fish, were below “1″ (THQ < 1), indicating that there were no potential health risks for humans when consuming copper-caged fish or wild-caught individuals aggregated around the copper mesh pen, with respect to the limits suggested by US Food and Drug Administration and EU Regulations for Seafood Consumption.

Concentration of heavy metals in edible fishes from Atlantic Coast of Muanda, Democratic Republic of the Congo

The present study aims to determine the levels of heavy metals in edible nine different commonly consumed fish species (Pseudotolithus elongatus, Pseudotolithus senegalensis, Cynoglossus senegalensis, Trichiurus lepturus, Galeoides decadactylus, Pentanemus quinquarius, Chrysichthys nigrodigitatus, Mugil curema, and Arius latiscutatus). Fishes were collected during August 2016 from five sites of West Atlantic Ocean Coast of the Democratic Republic of the Congo. Heavy metals (Cr, Cu, Zn, Ni, Sb, Cd, Pb, and Se) levels in fish muscle tissues were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) whereas Hg analysis was carried out using atomic absorption spectrophotometry (AAS). Metal concentrations varied considerably among sampling sites and fish species (P < 0.05), with maximum values (in mg kg−1 wet weight) of 1.00 (Cr), 2.69 (Cu), 29.90 (Zn), 4.25 (Ni), 0.09 (Sb), 0.59 (Cd), 0.09 (Pb), 1.05 (Se) and 1.21 (Hg). Except for Hg, metal concentration in fish was within the permissible levels set by Food and Agriculture Organization, European Union, and World Health Organization for human consumption. However, taking into account the antagonistic effect of Se on Hg, analyzed fishes might have the protection from Hg toxicity. Thus, the results imply that investigated fishes from study area can be considered as safe for human consumption.