Potentially toxic elements in commonly consumed fish species from the western Mediterranean Sea (Almería Bay): Bioaccumulation in liver and muscle tissues in relation to biometric parameters

Assessment of metal and organic pollutants in combination with stable isotope analysis in tunas from the Gulf of Cadiz (east Atlantic)

Bioaccumulation patterns of heavy metals (Pb, Cd, Cr, Ni, Fe and Cu) and organic (priority and emerging) pollutants, in combination with stable isotope analysis (SIA), were assessed in muscle and liver of three tuna species from the Gulf of Cadiz (Atlantic bluefin tuna, Thunnus thynnus; Atlantic bonito, Sarda sarda, and skipjack tuna, Katsuwonus pelamis). SIA and contaminant (heavy metal and organic) profiles separately discriminated between species. There was no significant overlap between the trophic niches estimated from isotopic data, suggesting that there are diet differences which may determine differential bioaccumulation patterns. The levels of heavy metals and persistent organic pollutants in muscle of all the individuals analyzed were below the allowable limits established by the current legislation. Concentrations of most contaminants were higher in liver than in muscle, underlining the powerful detoxifying capacity of the liver in tunas. In addition to diet, other factors such as size and age (exposure time to environmental chemicals) explain differences in pollutant accumulation patterns in tissues between species, each with varying degrees of involvement depending on the pollutant class. Our results show that combining contaminant profile data with trophic features based on SIA may help understand pollutant bioaccumulation patterns in upper levels of marine food webs.

Determination of potentially toxic elements bioaccumulated in the commercially important pelagic fish narrow-barred Spanish mackerel (Scomberomorus commerson)

Anthropogenic activities have increased the discharge of marine contaminants threatening marine life. Small gulfs, such as the Arabian Gulf, are vulnerable to accumulating potentially toxic elements in marine species due to slow water exchange. The concentration of 21 elements was determined in the tissues of Scomberomorus commerson from Umm Al Quwain (United Arab Emirates) and Bandar Abbas (Iran). Chromium, Copper, and Iron exceeded internationally established maximum permissible limits. Sites could not be distinguished based on Principle Component Analyses of elements. Elevated Cu and Cr in muscle are of concern to marine species as well as humans. Metal Pollution Index showed a significant difference between sites, with 20.34 % and 100 % of individuals suffering high metal toxicity and poor body conditions, respectively. The Arabian Gulf is experiencing an increase in discharge of industrial wastes. Implementation of strict policies to reduce discharge of toxic substances is required to protect marine organisms and humans.

A Comparative Analysis of Sparisoma cretense in Island Environments: Unraveling Metal Accumulation Differences in the Canary Islands (Spain, NW African Waters)

This study investigates the impact of varying environmental conditions on the metal composition within the tissues of Sparisoma cretense, contributing to the understanding necessary to offer scientifically sound advice regarding the health status of this species. This knowledge extends beyond fishery production, encompassing implications for food security. The data span the years 2022 and 2023, encompassing both cold and warm climatic seasons. The concentrations of various metals, such as Al, Zn, Cd, Pb, Fe, and Cu, exhibited noteworthy variations across the islands, with significant increases recorded in 2023, particularly during the warm season. The intricate interplay between multiple factors shaped the availability of the analyzed elements in S. cretense. Factors such as rising temperatures during the warm season increased biological activity in marine ecosystems, seasonal fluctuations in weather conditions, water quality, and anthropogenic influences, all contributing to the observed variations in metal concentrations. Additionally, the geological composition of each island and the patterns of marine currents and sediment transport play pivotal roles in these differences. Comprehensive scientific research, monitoring, and environmental surveillance are essential for a holistic understanding of this variability and providing valuable insights for the conservation and management of marine ecosystems in the Canary archipelago.

Potentially toxic element bioaccumulation in consumed indoor shrimp farming associated with diet, water and sediment levels

Shrimp production is an important industry for many countries and shrimp consumption is increasing worldwide. Shrimps are a highly nutritional food, but can pose a risk for human health if subject to high levels of environmental contaminants. This work studies the presence of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in shrimps from Ecuador and compares them to such contents noted in other shrimp-production areas in the world to evaluate the possible risks associated with these elements for consumer health, and to relate them to potentially toxic element (PTE) contents in water, sediments and diets, and also to animal biometric parameters. The PTE levels (mg kg-1 DM) obtained are as follows: in the head-As (3.52-6.11), Cd (0.02-0.10), Co (0.14-0.49) Cr (0.23-4.89), Cu (99.9--233.0), Ni (0.52-1.86), Pb (0.24-1.09), Zn (51.8-100.5) and Hg (μg kg-1 DM) (10.00-66.81); in the tail-(0.91-3.21), Cd (0.01-0.02), Co (0.01-0.43) Cr (0.01-6.52), Cu (20.0-72.44), Ni (0.15-2.03), Pb (0.01-0.69), Zn (31.2-66.1) and Hg (μg kg-1 DM) (10.00-67.18). The concentration of all the PTEs is generally lower than the limits set for seafood by European regulations, except for As in the cephalothorax (4.63 mg kg-1). Different behaviours for PTE accumulation in shrimps were found, which preferentially tend to accumulate in the cephalothorax, except for Hg (40.13 μg kg-1 DM), which accumulates in muscle (body) and is associated with contents of proteins, lipids and total shrimp weight. Nonetheless, the target hazard quotient (THQ) values for PTEs indicate that the consumption of shrimp muscles from Ecuador does not pose a human health risk because the values of these indices are below 1 in all cases.

Assessment of health risks due to toxic metals in demersal fish captured from Saros and Edremit Bays, Northern Aegean Sea

Bays are vulnerable ecosystems generally located near densely populated areas where toxic metals tend to accumulate and stay longer, affecting marine life. This study aimed to investigate the age-based health risks arising from Hg, Cd, Pb, and As in demersal fish captured from two major bays in the Aegean Sea. For this purpose, red mullet, whiting, piper gurnard, and tub gurnard, frequently consumed species, were caught from Saros and Edremit Bays. Toxic metal concentrations were determined from the muscle tissue of fish. Health risk assessments were conducted by the estimation of weekly intake (EWI), provisional tolerable weekly intake (PTWI), target hazard quotient (THQ), total THQ (TTHQ), and target carcinogenic risk (TR). Red mullet from Edremit Bay was the species with the highest toxic metal levels, which were 1.597 mg/kg, 0.041 mg/kg, 0.070 mg/kg, and 19.351 mg/kg for Hg, Cd, Pb, and As, respectively. Whiting from Edremit Bay had higher mean concentrations of Hg and As than those from Saros Bay. The levels of Hg, Pb, and As (0.328, 0.043, and 0.574 mg/kg) in the tub gurnard were higher in comparison with the piper gurnard (0.252, 0.020, and 0.382 mg/kg) caught in the same station in Saros. TTHQs of red mullet and whiting from the same bay were found to be > 1, indicating potential health risks for all nine age categories studied. On the other hand, TTHQs of all species from Saros Bay were determined to be > 1 for the first four age categories, which might trigger health risks for children and adolescents. According to the TR index for Pb, no risk was determined for the fish from both bays. However, TR calculations for inorganic As indicated high cancer risk in most of the age categories for red mullet and whiting from Edremit Bay. To sum up, the results revealed that the fish captured from Edremit Bay posed serious health risks in terms of Hg and As concentrations for all nine age categories. Surveillance and monitoring of toxic metal levels in demersal fish and population-based health risk evaluation are vital in heavily populated bays.

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.

Exposure status, spatial variation, and health risk assessment of selected heavy metal(loid)s in common commercial fish species of the Beibu Gulf

Fishes are considered as biological indicators of heavy metal(loid)s pollution. In this study, contents of seven heavy metal(loid)s, including Cu, Cr, Cd, Pb, Zn, As, and Hg, in the muscles of ten common fish species in the Beibu Gulf were analyzed to figure out the pollutants status and their health risk. Results showed all species were largely contaminated by arsenic. Under conservative estimation scenario, target hazard quotient and health index revealed no health risk of species except Alepes kleinii. Under pessimistic estimation scenario, target cancer risk and estimated daily intake showed that, except Saurida undosquamis, Saurida tumbil, and Trachinotus ovatus, the remaining species were at risk of causing cancer for their consumers. Daily intake of arsenic and mercury in most species by residents in the Beibu Gulf exceeded provisional maximum tolerable amount recommended by FAO, suggesting the need of moderate consumption of these species.

Trace elements in Foodstuffs from the Mediterranean Basin-Occurrence, Risk Assessment, Regulations, and Prevention strategies: A review

Trace elements (TEs) are chemical compounds that naturally occur in the earth's crust and in living organisms at low concentrations. Anthropogenic activities can significantly increase the level of TEs in the environment and finally enter the food chain. Toxic TEs like cadmium, lead, arsenic, and mercury have no positive role in a biological system and can cause harmful effects on human health. Ingestion of contaminated food is a typical route of TEs intake by humans. Recent data about the occurrence of TEs in food available in the Mediterranean countries are considered in this review. Analytical methods are also discussed. Furthermore, a discussion of existing international agency regulations will be given. The risk associated with the dietary intake of TEs was estimated by considering consumer exposure and threshold values such as Benchmark dose lower confidence limit and provisional tolerable weekly intake established by the European Food Safety Authority and the Joint FAO/WHO Expert Committee on Food Additives, respectively. Finally, several remediation approaches to minimize TE contamination in foodstuffs were discussed including chemical, biological, biotechnological, and nanotechnological methods. The results of this study proved the occurrence of TEs contamination at high levels in vegetables and fish from some Mediterranean countries. Lead and cadmium are more abundant in foodstuffs than other toxic trace elements. Geographical variations in TE contamination of food crops clearly appear, with a greater risk in developing countries. There is still a need for the regular monitoring of these toxic element levels in food items to ensure consumer protection.

Contamination, sources and health risks of potentially toxic elements in the coastal multimedia environment of South China

Coastal ecosystems are vulnerable to the accumulation of potentially toxic elements (PTEs), which pose a threat to marine ecosystems and human health. In this study, the concentrations of eight PTEs in a typical area of South China were analysed, and their distributions, seasonal variations, pollution degrees, potential health risks and sources in seawater, sediment and organisms were evaluated. The comprehensive pollution index (CPI), pollution load index (PLI), potential ecological risk index (PERI) and target hazard quotient (THQ) were applied to assess seawater, sediment and organism quality, respectively. The annual mean concentrations of Zn, Hg, Cr and As in the bottom seawater were higher than those in the surface water while those of Pb, Mn and Cu were higher in the surface seawater. The mean content of Hg was higher than the corresponding background value of that in China Shelf Sea sediment. Marine organisms have a high enrichment capacity for Cu, Zn, Cr, Hg, As and Mn in seawater. Based on CPI, the seawater was generally not polluted by PTEs. The PLI and PERI results demonstrated that Hg was the main contamination element in surface sediment. The total target hazard quotient (TTHQ) analysis illustrated that long-term consumption of some fish by children poses a noncarcinogenic health risk, while that risk to adults is negligible. Natural sources, agricultural activity sources, coal burning and industrial emission sources were the main sources of the PTEs in surface sediments according to positive matrix factorization (PMF) model.

Tissue dynamics of potential toxic elements in the Pacific hake (Merluccius productus): distribution and the public health risk assessment

This study aimed to establish the distribution of As, Cd, Pb, Cu, and Zn in the main tissues (muscle, liver, gonads, and gills) of the Pacific hake (Merluccius productus) from the northern Gulf of California to establish baseline bioavailability levels in the northern stock. The results for Pb and Cd were the lowest in the studied tissues (Pb < 0.005 mg kg^-1 in the liver and gonads and 1.43 mg kg^-1 for Cd in the liver), followed by levels of Cu and As (muscle > liver > gonads > gills) and Zn with the most abundant levels in all the tissues. The sex of the organisms was not a factor that influenced the bioaccumulation and distribution of the potential toxic elements (PTEs) nor total length, except for As in gills and Cd in muscle and the liver. Important interactions among Zn and non-essential elements were established. The Pacific hake intake of PTEs was probably through the diet via bioaccumulation of the elements in their prey and less by pollution of the water column. In the muscle, a major distribution and storage of As, Zn, and Pb were observed, but in the liver, higher loads were from Cd and Cu. The maximum tolerable weekly intake must be very high to be at health risk for the essential elements and Cd. However, the population might be at risk for Pb and As consumption if more than 124 g of M. productus in adults and 35 g in children are consumed per week. Further investigations are required to understand the dynamics of PTEs in M. productus as it could be proposed as a biomonitor species.

Determination of heavy metals from Aloe vera by- product in golden mullet (Liza aurata); A consumer health risk assessment

Heavy metals have become subject of concern in the recent years because of its potency to cause cardiovascular diseases and other toxic health effects. Therefore, this research was assumed to investigate the level of toxicity in terms of heavy metals accumulation in the fish samples and its benefits and risk for human consumers health and also evaluate the partial replacement of plant sources by canarian Aloe vera diets as a pure product or like a by-product on toxicological effects on the golden mullet (Liza aurata) fillet and whole body. In this study risks arising from fish metal content has been measured using various parameters as Estimated Daily Intake (EDI), Maximum Safe Consumption (MSC_A), Target Hazard quotient (THQ), Hazard Index (HI) Carcinogenic risk of As (As- CR), the Value Selenium Health Benefit (Se HBV) and also the Nutritional Values has been evaluated. The results showed that all heavy metal levels in the fish tissue and diets were below the confirmed safe limits for consumption. In case of diets, it is obvious that with the exception of As, Hg, and Se, the presence of heavy or essential metals in both whole fish and raw fillet in golden grey mullet given experimental diets revealed that the whole fish had the highest concentration. Thus, it can be concluded that Aloe vera product and byproduct were in safety limits for fish and also for humans through food chain. Various risk and benefit assessment measures established by national and international authorities concluded that Liza aurata use was mostly safe.

Bioaccumulation of selected trace elements in some aquatic organisms from the proximity of Qeshm Island ecosystems: Human health perspective

In this study selected marine species from north Persian Gulf ecosystems were collected to investigate the concentration of 15 trace elements (Al, As, Co, Cr, Cu, Fe, Li, Mo, Ni, Pb, Se, Sr, V, Zn and Hg) in muscle and liver tissues for the purpose of evaluating potential health risks for human consumers. The results indicated that Fe, Zn, Sr, Cu and As are the most abundant TEs in the tissues of the species. The concentration of Cu in P. semisulcatus and As in most investigated species pose the highest risk of exposure. The carcinogenic risk values indicate that As and Ni concentrations in the species are above the acceptable lifetime risk for adults and children in most of the species. The margin of exposure risk approach indicated that the risk of detrimental effects due to dietary Pb intake for age groups is low, except for consumers of T. tonggol.

Residual Levels of Mercury, Cadmium, Lead and Arsenic in Some Commercially Key Species from Italian Coasts (Adriatic Sea): Focus on Human Health

This study provides information on the potential human health risk of Hg, Cd, Pb and As exposure from consumption of two fish species (Umbrina cirrosa and Sciaena umbra) in the general population and in high-level fish consumers. The concentrations did not show significant differences between the two species, and no fish length element level–body-length relationship was observed, except for Hg. The average metal(loid) levels, irrespective of species, varied in the following ranges: Hg = 0.18–0.19, Cd = 0.07–0.10, Pb = 0.10–0.12, As = 0.59–0.69 μg g⁻¹ w.w. The concentrations remained below the maximum permissible limits (MPLs) for human consumption, except for Cd. The estimated intakes of Hg, Cd and Pb in both consumption scenarios were lower than the respective PTWI/PTMIs, as well as those of inorganic As, which were even lower than the BMDL₀₁. The non-carcinogenic risk (THQ) did not reveal any concerns, except for Hg. The lifetime health cancer risk (ILCR) suggested hazard exclusively from Cd, although for high-level fish consumers, even the ILCR of inorganic As was, in some cases, above the acceptable range. Continuous monitoring of metal(loid) levels in these fish is strongly recommended because the results demonstrate the occurrence of potential health risks, especially in high-level fish consumers, due to the presence of Hg and Cd.

Potentially toxic elements and microplastics in muscle tissues of different marine species from the Persian Gulf: Levels, associated risks, and trophic transfer

Selected potentially toxic elements (PTEs), including As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, and Zn, along with microplastic particles (MPs) were characterized in the muscle of seafood species in order to study potential health risk and also investigate biomagnification of the contaminants. The results revealed high levels of the analyzed PTEs and MPs in crustaceans. The cancer risk among the consumer population (adult and children) posed by As is higher than the acceptable lifetime risk of 10^-4. Portunus plagicus and Platycephalus indicus had the highest and lowest amount of MP particles in their muscles, respectively, among investigated species. Finally, PTEs (except Hg) and MPs are not biomagnified in the collected species. The results of this research emphasize the importance of accounting for health risks posed by potential pollutants via consumption of contaminated seafood.

Metal Bioaccumulation and Potential Health Risk Assessment in Different Tissues of Three Commercial Fish Species (Merluccius merluccius, Mullus barbatus, and Pagellus erythrinus) from Edremit Bay (Aegean Sea), Turkey

Metal levels and potential health risk assessment in muscle, liver, and gills of three fish species (Merluccius merluccius, Mullus barbatus, and Pagellus erythrinus) from the Edremit Bay were investigated in spring and autumn 2015. Metal concentrations (Hg, Cd, Pb, Cr, Cu, Zn, Mn, and Fe), metal pollution index, and bioaccumulation factors in P. erythrinus were observed to be generally higher than those in M. barbatus and M. merluccius. Tissue was the main factor that might be responsible from the variations of metals in fish species according to ANOVA and PCA. Hg concentrations in M. barbatus and P. erythrinus were greater than threshold limits defined by international authorities; however, no carcinogenic risks were found for Cd and Pb levels. According to the results, the bay has been negatively influenced by human activities, and further research on monitoring of the biota and sediments is recommended for Edremit Bay and similar coastal areas under human pressure.

Arsenic contamination in widely consumed Caribbean sharpnose sharks in southeastern Brazil: Baseline data and concerns regarding fisheries resources

Although shark meat is consumed worldwide, elevated arsenic (As) concentrations have been increasingly reported. The Caribbean sharpnose shark (Rhizoprionodon porosus) is a widely consumed fishing resource in Brazil, with scarce information on As burdens to date. Herein, commercial-sized juvenile Caribbean sharpnose sharks from Rio de Janeiro (Brazil) were assessed in this regard, presenting significantly higher hepatic As concentrations in males (8.24 ± 1.20 mg kg^-1 wet weight; n = 12) compared to females (6.59 ± 1.87 mg kg^-1 w.w.; n = 8), and a positive correlation (r = 0.74) was noted between female muscle and liver As concentrations, indicating systemic inter-tissue transport not evidenced in males. Arsenic concentrations were over the maximum permissible As limit established in Brazilian legislation for seafood and calculated Target Hazard Quotients suggest consumption risks, although cancer risks were not evidenced. Therefore, Public Health concerns with regard to Caribbean sharpnose shark As burdens deserve careful attention.

Influence of Biometric and Seasonal Parameters on the Metal Content of Scomber colias in Northwestern African Waters

Studies of the content of heavy metals and trace elements in fish and other marine organisms are of great importance to know the state of the marine ecosystem. This study has been carried out in northwestern African waters, Scomber colias being the target species, sampling a total of 345 specimens over 2 years. For the determination of metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V, and Zn) in the muscle, the ICP-OES (inductively coupled plasma optical emission spectrometry) was used. In the statistical study, the factors (oceanographic and maturity in the seasons, size of the specimens) were used. The samples sampled in the cold season that had high concentrations of metals may be due to the influence that African upwelling has on the Canary Islands. The metallic contents of our samples are lower than those found in the studies in Mauritania and Morocco due to the greater influence that upwelling has in these areas.

Polycyclic aromatic hydrocarbons (PAHs), arsenic, chromium and lead in warty crab (Eriphia verrucosa): occurrence and risk assessment

This study assesses the PAH and heavy metal levels in muscle of warty crabs (Eriphia verrucosa), from the northern coast of the Campania region improving the data on toxic contaminants in this crustacean. The results showed a minimal PAH contamination; the mean concentrations were as follows: 0.2, 1.6 and 1.7 μg kg-1 wet weight (ww) for BaP, PAH4 and PAH6, respectively. Regarding the levels of the two PAHs not included in the European regulations, the BkF mean concentration was 0.1 μg kg-1 ww, while DahA was detected only in 10.7% of samples. Pb and Cr were also detected at low levels with mean values of 0.068 and 0.468 mg kg-1 ww, respectively; instead, high As levels, with a mean value of 5.021 mg kg-1 ww, were found. Considering the EWIs and the ILCRs calculated in this study, the PAH, Pb and Cr contamination levels found in the edible part of the crabs resulted safe for human consumption. Contrariwise, the ILCR calculated for the As exceeded the acceptable level of cancer risk, although the calculation did not refer to the inorganic form which is the only one recognized as carcinogenic. Hence, this study shows that warty crabs can accumulate environmental contaminants in their muscle tissue representing an important route of exposure to these toxics for the local population that regularly consumes them. This finding highlights the importance of monitoring the presence of these pollutants in crabs and in general in all fish and seafood in order to ensure food safety for consumers.

Trace and Major Elements Concentration in Fish and Associated Sediment-Seawater, Northern Shores of the Persian Gulf

The concentration of 19 metal and non-metal elements in two fishes (Liza subviridis and Sphyraena jello) and associated sediment-seawater from the northern part of the Persian Gulf was measured. The samples were gathered from two industrial ports, one commercial port, and one residential port. The metal accumulation in the muscle and liver of fishes was evaluated. Nickel (mean 362.07-712.83 μg/g) and chromium (mean 470.00-691.47 μg/g) in sediment and zinc (mean 9.01-31.15 μg/L) and arsenic (mean 18.22-22.14 μg/L) in seawater had the most abundancy among studied elements. The accumulation of elements in S. jello (a pelagic species) was higher than L. subviridis (a demersal species). For both species, major elements of S and Mg and trace elements of Fe, Al, Si, Zn, and Cu showed highest accumulation. Also, fish samples from Emam Hassan Port were more contaminated than other stations. Ecological indexes values have revealed a low to moderate elemental pollution of sediment and fish samples in the north part of the Persian Gulf.

Heavy metal pollution and stable isotope ratios (δ13C and δ15N) in marine organisms from the Northern Beibu Gulf, South China Sea

Twenty biota species were collected from the Northern Beibu Gulf to understand the heavy metal pollution status and biomagnification characteristics. Mean concentrations (μg/g) of Mn, Zn, Pb, Cr, Ni, As, Cu, and Cd in the biota species were 0.99, 38.33, 0.14, 0.079, 0.085, 51.10, 7.92, and 0.21, respectively. As levels in most biota species exceeded the corresponding guidelines. Crabs were detected with high metal accumulation ability for each heavy metal except Pb. The ranges of δ¹⁵N and δ¹³C in organisms were from 8.0‰ to 15.6‰ and from -21.4‰ to -15.6‰, respectively. Cr, Mn, Ni, and As showed potential biomagnification trends in the food webs. The EDI values of these elements decreased by the sequence of As > Zn > Cu > Mn > Cd > Pb > Ni > Cr. High THQ and CR values for As indicated a potential health risk by consumption of these aquatic products.

Possible human health risk of some heavy metals from consumption of tilapia fish from Lake Mariut, Egypt

Lake Mariut Main Basin (MB) is not only one of the three basins composing Lake Mariut (LM) but is also the main source of the popular tilapia fish to Alexandrian people. Unfortunately, this basin was consistently for about 50 successive years receiving a continuous discharge of agricultural, sewage, and industrial effluents. This has led to contamination of the flesh of its tilapia fish living there particularly with some toxic heavy metals like Cd and Pb. Lately, in 2010, a rehabilitation program was adopted and carried out to save this vital MB from such intensive pollution. This had been achieved by diverting all those polluting sources. The present work is made after elapsing about 7 years from the diversion process date, to assess and evaluate the levels of those two metals (in addition to the other four one's Fe, Cu, Cr, and Zn) in the edible flesh part besides the liver and gills of this fish (Nile tilapia spec., Oreochromis niloticus), and in ambient water of this restored basin to measure the efficiency of the rehabilitation program on quality of endogenous fish. A simultaneous parallel sampling program was also commenced for the other two basins of LM. The obtained results revealed that the concentration level of the studied metals in each of the muscles of the fish and the ambient water of the restored MB becomes now not only almost alike the metal levels of the corresponding compartments of the other two basins of LM, but also they became at concentration levels lay below those of their counterpart permissible limits in fish and water recommended by national and international standards. Health risk assessment indices: bioaccumulation factor (BAF), metal pollution index (MPI), estimated daily intake (EDI), hazardous index (HI), and relative risk (RR) for the present case were estimated, assessed, and subsequently evaluated. All are referring to a fact that MB is currently in good environmental condition and producing safe fish for human consumption.

Bioaccumulation of Toxic Metals in Children Exposed to Urban Pollution and to Cement Plant Emissions

Cement plants located in urban areas can increase health risk. Although children are particularly vulnerable, biomonitoring studies are lacking. Toenail concentration of 24 metals was measured in 366 children (6-10 years), who live and attend school in a city hosting a cement plant. Living addresses and schools were geocoded and attributed to exposed or control areas, according to modeled ground concentrations of PM₁₀ generated by the cement plant. Air levels of PM₁₀ and NO₂ were monitored. PM₁₀ levels were higher in the exposed, than in the control area. The highest mean PM₁₀ concentration was recorded close to the cement plant. Conversely, the highest NO₂ concentration was in the control area, where vehicular traffic and home heating were the prevalent sources of pollutants. Exposed children had higher concentrations of Nickel (Ni), Cadmium (Cd), Mercury (Hg), and Arsenic (As) than controls. These concentrations correlated each other, indicating a common source. Toenail Barium (Ba) concentration was higher in the control- than in the exposed area. The location of the attended school was a predictor of Cd, Hg, Ni, Ba concentrations, after adjusting for confounders. In conclusion, children living and attending school in an urban area exposed to cement plant emissions show a chronic bioaccumulation of toxic metals, and a significant exposure to PM₁₀ pollution. Cement plants located in populous urban areas seem therefore harmful, and primary prevention policies to protect children health are needed.

Bioaccumulation of trace elements in tissues of Indian oil sardine (Sardinella longiceps) from the northern United Arab Emirates

Small, partially enclosed gulfs are especially vulnerable to coastal pollution. The Arabian Gulf is a shallow, hypersaline, warm gulf with rising levels of pollution caused by rapid development and industrialization. We measured 19 trace elements in the gastrointestinal tract, liver and muscle of Indian oil sardines (Sardinella longiceps) from three sites from the United Arab Emirates in the southern Arabian Gulf. Concentrations of cadmium, chromium, copper and zinc exceeded international maximum permissible limits (MPL) in all three tissues in most sites. High concentrations in muscle raises concerns about the risk to humans, as muscles are widely consumed by humans. Discriminant Function Analysis showed that the three study sites (Sharjah, Ajman and Umm Al Quwain) could be discriminated based on a combination of elements. Improved monitoring of pollutants is needed to ascertain the concentration of pollutants in species at different trophic levels. We recommend better control measures to reduce the discharge of pollutants into this fragile marine ecosystem.

Bioaccumulation of metal in liver tissue of fish in response to water toxicity of the Araguari-Amazon River, Brazil

This study aimed to determine the concentration of metals in the water and in the liver tissue of fish (Anodus orinocensis, Hemiodus unimaculatus, Curimata vittata, and Plagioscion squamosissimus) in the lower Araguari River. Steps were also taken to estimate any difference in metal bioaccumulation in the liver of fish species at different trophic levels, determine any correlations between metals found in hepatic tissue of fish species relative to that found in river water, and evaluate the bioaccumulation factor. The metals analyzed in the water in the lower Araguari River (Cd, Pb, Fe, Hg, Cu, and Zn) exceeded the limits considered safe for aquatic life. We found a significant difference only in the bioaccumulation of Pb between A. orinocensis and C. vittata (F = 4.65, p = 0.005) and Cr between A. orinocensis and H. unimaculatus (F = 3.12, p = 0.03). Species of distinct trophic levels showed differences in metal concentration in liver. Cd and Cu showed bioaccumulation factor above 100, especially Cu with a relatively high value, for all fish species. The bioaccumulation of metals in the liver of fish species showed a positive correlation with the metals detected in the water of the Araguari River. In this sense, the lower course of the Araguari River is undergoing some type of environmental stress, making this study of additional valuable in diagnosing environmental quality pursuant to the development of environmental monitoring projects in order to guarantee the safety and maintenance of aquatic life.

Toxic and essential trace element concentrations in fish species in the Lower Amazon, Brazil

The Lower Amazon region (Western Pará, northern Brazil) is greatly affected by mining exploitations (particularly artisanal gold mines) and other industrial and intensive agricultural activities with potentially strong impacts on aquatic ecosystems. Although such impacts include contamination with various toxic elements, to date only the effects of Hg have been considered. In this study, toxic and trace element concentrations were determined in the flesh of 351 fish specimens, including detritivores (Acarí, Pterygoplichthys pardalis), omnivores (Piranha, Pygocentrus nattereri; Pirarucu, Arapaima sp.) and carnivores (Caparari, Pseudoplatystoma fasciatum; Tucunaré, Cichla ocellaris), during the dry and wet seasons in 2015 and 2016. The range of concentrations of toxic element residues were 2-238 μg/kg fresh weight for As, 1-77 μg/kg for Cd, 4-1922 μg/kg for Hg and 1-30 μg/kg for Pb. Only the maximum concentrations of Hg established in the Brazilian legislation for fish destined for human consumption (0.5 mg/kg) were exceeded (in 16% of carnivorous species). The large between-species and seasonal differences observed for all these toxic elements are probably related to the seasonal behaviour and dietary habits of the different fish species. By contrast, essential trace element concentrations were low and not related to seasonal or dietary factors, and the observed differences may be at least partly related to the metabolism of each species. The associations between Hg and the essential trace elements Se, Fe, Co and Mn deserve special attention, as these trace elements may play a role in Hg cycling and methylation and merit further evaluation with the aim of reducing Hg toxicity in aquatic environments.

Polycyclic aromatic hydrocarbons in bays of the Rio de Janeiro state coast, SE - Brazil: Effects on catfishes

The Brazilian coast of the Rio de Janeiro State has bays of great economic, ecological and social importance. However, these ecosystems have been suffering intense anthropogenic influence, mainly due to the contamination by polycyclic aromatic hydrocarbons (PAHs) from urban-industrial activities. Moreover, PAHs are organic pollutants of high toxicity and carcinogenicity causing global concern to human and environmental health. This study evaluated on catfish (Genidens genidens) a set of key parameters (sex, morphometric traits, condition factor (K), PAH metabolites in gallbladder, frequency of micronucleus (MN) and erythrocytic nuclear abnormalities (ENA) in blood. In addition we also evaluated histopathological hepatic effects, Ethoxyresorufin-O-deethylase (EROD) activity and Benzo(a)pyrene diol epoxide (BPDE)-DNA adducts) in liver samples, in order to indicate the fish health status and environmental pollution levels of three main Bays (Guanabara, Sepetiba and Ilha Grande) of the Rio de Janeiro State, in the Southeast of Brazil. In general, the worst physical and metabolic conditions in catfishes were evidenced in Guanabara Bay, possibly indicating the highest level of contamination by PAHs. Contrary evidence was observed in Ilha Grande Bay, showing lower biological changes in G. genidens. However in Sepetiba Bay, the influence of PAHs contamination showed the highest hepatic lesions in catfishes, prevailing foci of cellular alterations, megalocytic hepatosis and hydropic vacuolations. The employability of a set of biomarkers on catfish was efficient for screening pollution for PAHs in tropical environments. This reinforces the need for effective actions of monitoring and conservation strategies of bays of the Rio de Janeiro State (Brazil), in order to ensure quality and health to both human and environment.

Comparison of Carcass Traits, Meat Quality, and Chemical Composition of Tissues from Progeny Derived from Cloned and Noncloned Pigs

Systematic studies of progeny derived from somatic cell nuclear transferred animals in their biophysical and biochemical characters are critical in assessing the safety of this kind of food. In this study, we compared the carcass traits and meat quality of 12 cloned and noncloned pigs, respectively, and chemical composition of tissues of 6 cloned and noncloned pigs, respectively. The carcass trait parameters, including body weight, carcass straight length, loin-eye area, backfat thickness at 10th and 11th interface, and rib number, were tested, and carcass yield was calculated. Meat quality parameters, such as meat color, marbling, temperatures, conductivity, and drip loss, were also tested. Finally, the gross chemical properties and the constitutions of fat acids, amino acids, and minerals in loin-eye muscle, omental fat, and liver from the two groups were tested. The results showed that the value for most parameters of these two groups was equivalent. In conclusion, these data indicated that the progeny of cloned pig were not different in the carcass traits, meat composition, and biochemical composition of tissues compared to the conventionally bred pigs, which further indicated the safety of products from cloned pigs.