Bioaccumulation Of Trace Metals Research Articles

Metal bioaccumulation and effects of olivine sand exposure on benthic marine invertebrates

Due to the anthropogenic increase of atmospheric CO2 emissions, humanity is facing the negative effects of rapid global climate change. Both active emission reduction and carbon dioxide removal (CDR) technologies are needed to meet the Paris Agreement and limit global warming to 1.5 °C by 2050. One promising CDR approach is coastal enhanced weathering (CEW), which involves the placement of sand composed of (ultra)mafic minerals like olivine in coastal zones. Although the large-scale placement of olivine sand could beneficially impact the planet through the consumption of atmospheric CO2 and reduction in ocean acidification, it may also have physical and geochemical impacts on benthic communities. The dissolution of olivine can release dissolved constituents such as trace metals that may affect marine organisms. Here we tested acute and chronic responses of marine invertebrates to olivine sand exposure, as well as examined metal accumulation in invertebrate tissue resulting from olivine dissolution. Two different ecotoxicological experiments were performed on a range of benthic marine invertebrates (amphipod, polychaete, bivalve). The first experiment included acute and chronic survival and growth tests (10 and 20 days, respectively) of olivine exposure while the second had longer (28 day) exposures to measure chronic survival and bioaccumulation of trace metals (e.g. Ni, Cr, Co) released during olivine sand dissolution. Across all fauna we observed no negative effects on acute survival or chronic growth resulting solely from olivine exposure. However, over 28 days of exposure, the bent-nosed clam Macoma nasuta experienced reduced burrowing and accumulated 4.2 ± 0.7 μg g ww−1 of Ni while the polychaete Alitta virens accumulated 3.5 ± 0.9 μg g ww−1 of Ni. No significant accumulation of any other metals was observed. Future work should include longer-term laboratory studies as well as CEW field studies to validate these findings under real-world scenarios.

Biomarkers of oxidative stress and bioaccumulation of trace metals in waterbirds from different rice fields systems

AbstractWe compared trace metal concentrations (Pb, Zn, Cd, Cu) in feathers and biomarkers in muscle and liver tissue of waterbirds from organic and conventional irrigated rice farms in South Brazil. Cu and Pb concentrations were higher in waterbirds from conventional farms, whereas Cd and Zn levels were elevated in organic farms. Birds foraging in organic farms exhibited lower CAT and SOD activity and higher NPSH, LPO, and PC concentrations compared to those in conventional farms. Higher Cu and Pb concentrations were associated with elevated SOD and CAT activity, more prevalent in birds frequenting conventional farms. Conversely, birds with higher Cd and Zn concentrations showed increased NPSH, LPO, and PC levels and were more common in organic farms. Our study underscores complex differences in trace metal accumulation and oxidative stress biomarkers among waterbirds in organic and conventional rice crops.

Bioaccumulation of trace metals in the plastisphere: Awareness of environmental risk from a European perspective

The term "Plastisphere" refers to the biofilm layer naturally formed by microorganisms attaching to plastic surfaces. This layer possesses the capability to adsorb persistent organic and inorganic pollutants, particularly trace metals, which are the focus of this research study. Immersion experiments were concurrently conducted in five locations spanning four European countries (France, Ireland, Spain, and Italy) utilising eight distinct polymers. These immersions, repeated every three months over a one-year period, aimed to evaluate the baseline bioaccumulation of 12 trace metals. The study underscores the intricate nature of metal bioaccumulation, influenced by both micro-scale factors (such as polymer composition) and macro-scale factors (including geographical site and seasonal variations). Villefranche Bay in France exhibited the lowest metals bioaccumulation, whereas Naples in Italy emerged as the site where bioaccumulation was often the highest for the considered metals. Environmental risk assessment was also conducted in the study.The lightweight nature of certain plastics allows them to be transported across significant distances in the ocean. Consequently, evaluating trace metal concentrations in the plastisphere is imperative for assessing potential environmental repercussions that plastics, along with their associated biota, may exert even in locations distant from their point of emission.

Enrichment, Bioaccumulation and Health Risks of Trace Metals in Soils and Leafy Vegetables Grown on the Banks of the Ugandan Lifeline River, River Rwizi

Urban vegetable farming in wetlands and riverbanks are common features of Ugandan cities. However, urbanization has led to various anthropogenic activities that can lead to the pollution of water resources, enrichment of pollutants in soils and, consequently, pollutant bioaccumulation in edible tissues of plants cultivated on such soils. In this study, we report on the levels of six trace metals (TMTs) in 75 samples of leafy vegetables (Brassica oleracea L., Spinacia oleracea L., Amaranthus hybridus L., Cucurbita pepo L. and Solanum nigrum L.) and soils (n = 75) grown on the banks of River Rwizi, the second longest river in Uganda only after the Nile River. The concentrations of TMTs (Mn, Zn, Cd, Pb, Cr and Cu) in edible vegetable tissues and soils were quantified using flame atomic absorption spectrometry. The mean concentrations (in mg kg−1) of the TMTs in the soil samples were 205–373.84 (Mn), 12.72–65.04 (Zn), 0.26–0.42 (Cd), 3.36–16.80 (Pb), 5.96–25.06 (Cr) and 2.83–35.27 (Cu). In vegetable samples, the concentrations ranged from 43.25 to 110.00 (Mn), 1.08 to 1.83 (Cd), 41.06 to 71.20 (Zn), 4.31 to 6.16 (Pb), 0.65 to 0.81 (Cr) and 5.70 to 14.35 (Cu). With the exception of Mn and Cr, the rest of the TMTs were bioaccumulated in the edible vegetable tissues (bioconcentration factors = 1.03 to 10.71). Considering chronic daily intake through ingestion, dermal contact and inhalation of the TMTs in soils from the banks of River Rwizi, there are no potential non-cancer and carcinogenic health effects that could be experienced in both adults and children. Consumption of leafy vegetables could pose both non-cancer health risks (from ingestion of Zn, Pb, Cr, Mn and Cd) and cancer health risks (due to intake of Cd) in both children and adults. There is therefore a need to enforce regulations to mitigate the pollution of River Rwizi for a more sustainable economic development.

Induction of Oxidative Stress by Waterborne Copper and Arsenic in Larvae of European Seabass (Dicentrarchus labrax L.): A Comparison with Their Effects as Nanoparticles.

The aim of this work was to compare the potential induction of oxidative stress and the antioxidant enzymatic response after a short-term waterborne exposure to copper (Cu) and arsenic (As) with that of the nanoparticles (NPs) of these elements (Cu-NPs and As-NPs) in fish larvae of the species Dicentrarchus labrax. Larvae were grouped in several tanks and exposed to different concentrations of contaminants (0 to 10 mg/L) for 24 or 96 h under laboratory conditions. Copper and arsenic concentrations were analysed in larval tissues using ICP-MS. A set of oxidative stress biomarkers, including the levels of hydroperoxides (HPs), and superoxide dismutase (SOD) and catalase (CAT) activities were assessed. The trace element concentrations (mg/kg d.w.) in larvae ranged as follows: 3.28-6.67 (Cu at 24 h) and 2.76-3.42 (Cu at 96 h); 3.03-8.31 (Cu-NPs at 24 h) and 2.50-4.86 (Cu-NPs at 96 h); 1.92-3.45 (As at 24 h) and 2.22-4.71 (As at 96 h); and 2.19-8.56 (As-NPs at 24 h) and 1.75-9.90 (As-NPs at 96 h). In Cu tests, the oxidative damage (ROOH levels) was induced from 0.1 mg/L at both exposure times, while for Cu-NPs, this damage was not observed until 1 mg/L, which was paralleled by concomitant increases in SOD activity. The CAT activity was also increased but at lower metal concentrations (0.01 mg/L and 0.1 mg/L for both chemical forms). No oxidative damage was observed for As or As-NPs after 24 h, but it was observed for As after 96 h of treatment with 0.01 mg/L. A decrease in SOD activity was observed for As after 24 h, but it turned out to be increased after 96 h. However, As-NPs did not alter SOD activity. The CAT activity was stimulated only at 96 h by As and at 24 h by As-NPs. Therefore, the two chemical forms of Cu exhibited a higher bioaccumulation and toxicity potential as compared to those of As. Importantly, the association of both Cu and As in NPs reduced the respective trace metal bioaccumulation, resulting also in a reduction in the toxic effects (mortality and biochemical). Furthermore, the assessment of oxidative stress-related biomarkers in seabass larvae appears to be a useful tool for biomonitoring environmental-occurring trace elements.

Bioaccumulation of Trace Metals in Fish from Issiet River, Uruan, Nigeria

Bioaccumulation of Trace Metals in Fish from Issiet River, Uruan, Nigeria

Bioaccumulation, biomagnification, and ecological risk of trace metals in the ecosystem around oilfield production area: A case study in Shengli Oilfield.

The production for crude oil usually leads to contamination of the soil with trace metals and organic contaminants from spilled petroleum. Organic contaminants were generally paid more attention than trace metals in the oilfield pollution. Many studies have investigated the impacts of some petroleum hydrocarbon pollutants, however, the impacts and risk assessment of trace metals remain largely unexplored. Moreover, under some circumstances, the risks associated with trace metals are not necessarily lower than those associated with organic contaminants. This study aimed to investigate methods to evaluate the possible risks associated with 11 trace metals (Ti, Ba, Sr, Rb, V, Li, Mo, Co, Cs, Bi, and Tl) in soil and biota samples from the Shengli Oilfield using ICP-MS. The results showed that 11 trace metals in the surface soils exceeded the local background levels. The geo-accumulation index (Igeo) indicated that the soils had light-moderate to moderate contamination levels, with higher Igeo value of Ba, V, Li, Mo, Co, and Cs. The individual potential ecological risk indices ([Formula: see text]) demonstrated moderate Bi and Tl pollution in soils. Comparatively, the [Formula: see text] is recommended for the risk assessment of trace metals on the ecosystem around the oilfield area. Mo, Bi, and Sr easily accumulate in plants, as reflected by their bioaccumulation factor. Ti, Ba, V, Li, Co, Cs, Bi, and Tl exhibited considerable biomagnification, particularly in birds. In this study, trace metals showed considerable bioaccumulation and biomagnification, and the risks of these trace metals on the ecosystem around oilfield production area need more attention.

Response of Propsilocerus akamusi (Diptera: Chironomidae) to the leachates from AMD-contaminated sediments: Implications for metal bioremediation of AMD-polluted areas

Acid mine water (AMD) is a global environmental problem caused by coal mining with the characteristics of low pH and high concentrations of metals and sulfates. It is a pertinent topic to seek both economical and environmentally friendly approaches to minimize the harmful effects of AMD on the environment. Insect larvae are considered a promising solution for pollution treatment. Chironomidae is the most tolerant family to contaminants in pools and its larvae have a strong capacity for metal accumulation from sediment. This paper aimed to evaluate the larvae of Propsilocerus akamusi, a dominant species in the chironomid community, as a new species for entomoremediation in AMD-polluted areas. We detected the toxic effects of AMD on P. akamusi larvae based on their survival and the trace metals bioaccumulation capabilities of P. akamusi larvae. Moreover, we analyzed the expression patterns of four stress-response genes, HSP70, Eno1, HbV, and Hb VII in P. akamusi larvae. Our results revealed that AMD exposure did not significantly affect the survival of the P. akamusi larvae and individuals exposed to some AMD gradients even exhibited higher survival. We also observed the significantly accumulated concentrations of Fe, Ni, and Zn as well as higher bioaccumulation factors (BAFs) for Ni and Zn in the P. akamusi larvae exposure to AMD. Induced expression of Eno1 and Hb VII may play important roles in the AMD tolerance of P. akamusi larvae. This study indicated the potential application of P. akamusi larvae in the metal bioremediation of AMD-polluted areas. Statement of environmental implicationAcid mine drainage (AMD) is a global environmental problem related to coal mining activities. AMD pollution has become a long-term, worldwide issue for its interactive and complex stress factors. Bioremediation is an effective method to remove the metals of AMD from wastewater to prevent downstream pollution. However, the disadvantages of the slow growth rate, susceptibility to seasonal changes, difficult post-harvest management, and small biomass of hyperaccumulating plants greatly limit the usefulness of phytoremediation. Insect larvae may be useful candidate organisms to overcome these shortcomings and have been considered a promising pollution solution. Propsilocerus akamusi is a dominant species in the chironomid community and is distributed widely in many lakes of eastern Asia. This species has extraordinary abilities to resist various stresses. This research is the first time to our knowledge to evaluate the application of P. akamusi as a new species in entomoremediation in AMD-contaminated areas.

Trace elements assessment in Cerastoderma glaucum from port areas in the Tunisian Mediterranean coast: The influence of parasites on bioaccumulation

In the present study, the seasonal concentration of seven trace elements was investigated in sediment and the cockle Cerastoderma glaucum tissues from two port areas in the North-East and South of Tunisia comparing cockles non-parasitized (NP) and parasitized (P) with digenean parasites. Elements concentration in sediments analyzed in both sites revealed that Zinc (Zn), Chromium (Cr), and Lead (Pb) were the most abundant ones, while Cadmium (Cd) and Mercury (Hg) were less abundant. The bioaccumulation of trace metals and Arsenic (As) in the tissues of cockles seems to be modulated by both the infection state and the parasite species. The relationship between bioaccumulation of metals and As, trematode species and abiotic parameters showed that the availability of certain metals for uptake by P cockles of both sites was influenced by the salinity and temperature of the water. Our results corroborate the possibility of using digenean infecting bivalves in biomonitoring aquatic ecosystems.

Assessment of trace metal bioaccumulation in Mytilus galloprovincialis of the central Atlantic ocean after installation of treatment sewage facilities

Mussels (Mytilus galloprovincialis) are vital to Morocco's artisanal fishermen both nutritionally and economically. This study probed the bioaccumulation of trace metals zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb) in mussels from three sites north of Agadir: Anza, Aourir, and Imouran. Analyzed using atomic absorption techniques across different seasons, findings indicated variable metal concentrations, with Imouran notably presenting the highest, potentially due to influences from the new wastewater plants of Anza and Aourir. While lead was not detected, cadmium, albeit in lower concentrations, posed potential health concerns upon regular consumption. Individual Mean Bioaccumulation Index (IMBI) demonstrated fluctuations, majorly influenced by Zn, Cd, and Cu levels. These trends in IMBI between 2017 and 2018 for Aourir and Imouran hinted at similar environmental impacts or exposure levels. Despite site differences, Metal Pollution Index (MPI) values consistently pointing to analogous potential toxicity due to metal combinations. Intricate relationships between trace metals and their environmental parameters were evident, with multiple linear regression analysis (MLRA) showcasing differing correlations between variables. These results highlight the nuanced interactions between trace metals and bioaccumulation indices, such as MPI and IMBI. In conclusion, the findings accentuate the imperative of regular coastal water quality checks and effective management strategies to curtail pollutant discharges.

Determination of physicochemical parameters and assessment of trace metals bioaccumulation in the Lagos lagoon and edible tissues of the southern pink shrimp (Farfantepenaeus notialis - Pérez-Farfante, 1967)

Abstract. Bio-inorganic chemistry is found as an endearing aspect to research in today’s epoch. It deals with chemical reactions between the metals with natural resources, such as air, soil, water and byproducts (foods). To assess the decline in the quality of southern pink shrimps and water quality on samples from the Lagos lagoon, the morphometric assessment of the crustacean (Farfantepenaeus notialis – F. notialis), physicochemical parameters (pH, temperature, salinity, conductivity, total hardness, total dissolved solids, total suspended solids, biological oxygen demand, chemical oxygen demand, dissolved oxygen, sulphates, nitrate and phosphate) and levels of six (6) trace metals (Cadmium, Chromium, Zinc, Iron, Manganese and Copper) were collected from three sampling points with renowned anthropogenic activities along the stretch of the Lagos Lagoon using standard analytical procedures and the results were compared with standard acceptable limits. The crustaceans used had total length (4.0 – 14.4 cm), carapace length (1.6 – 6.4 cm), total weight (1.1 – 20.8 g) and carapace weight (0.9 – 11.5 g). The results obtained in the physicochemical analysis revealed that a few parameters such as biochemical oxygen demand and total suspended solids were beyond acceptable limits, while the trace metals were present in the samples at different levels but still within the maximum residual levels in the edible tissues of the pink shrimps. The obtained results showed that the crustacean and water from the lagoon contained metals but did not exceed both local and international standards of limit and thus, they are still safe for consumption and domestic uses.

A first study on the bioaccumulation of trace metals in Rhyssoplax olivacea (Mediterranean Polyplacophora)

This study investigates, for the first time, the bioaccumulation of trace metals in the chiton Rhyssoplax olivacea. Fe, Cu, Co, Cr and Cd were measured in the shell and soft tissue of R. olivacea sampled in five sites along the Algerian west coast during the cold and hot seasons. Physiological and contamination indices were calculated. The condition index provides information on habitat quality and on R. olivacea reproductive performance and physiological status. The metal/shell-weight index informs on the bioavailability of trace metals. The trace element pollution index is used to assign a global contamination status to the studied sites. The trace element spatial variation index ranks Cd and Cr as trace metals of primary environmental concern based on the overall variability of their levels. An exhaustive review compiling data on trace element bioaccumulation in chitons is performed. The potential use of R. olivacea as bioindicator species is discussed.

Acute bioaccumulation and chronic toxicity of olivine in the marine amphipod Gammarus locusta

Active atmospheric carbon dioxide removal (CDR) is needed at a gigaton scale in the next decades to keep global warming below 1.5 °C. Coastal enhanced silicate weathering (CESW) aims to increase natural ocean carbon sequestration via chemical weathering of finely ground olivine (MgxFe(1−x)SiO4) rich rock dispersed in dynamic coastal environments. However, the environmental safety of the technique remains in question due to the high Ni and Cr content of olivine. Therefore, we investigated the short term bioaccumulation and chronic toxicity of olivine in the marine amphipod Gammarus locusta. Acute 24-h olivine exposure resulted in significant grain size dependent olivine ingestion and subsequent Ni and Cr accumulation in tissues. Thousands of small (mainly ≤ 10 µm) olivine grains were ingested by G. locusta, but their importance for trace metal bioaccumulation requires additional research. Most olivine grains were egested within 24 h. Chronic 35-day olivine (3–99 µm) exposure reduced amphipod survival, growth, and reproduction, likely as a result of metal induced oxidative stress and disturbance of major cation homeostasis. Amphipod reproduction was significantly reduced at olivine concentrations of 10% w/w and higher. In the context of ecological risk assessment, application of an arbitrary assessment factor of 100 to the highest no observed effect concentration of 1% w/w olivine yields a very low predicted no-effect concentration (PNEC) of 0.01% w/w olivine. This low PNEC value highlights the urgent need for additional marine olivine toxicity data to accurately assess the environmentally safe scale of coastal enhanced weathering for climate change mitigation.

Distribution, toxicity and bioaccumulation of trace metals in environmental matrices of an estuary in a protected area

Mangroves are productive ecosystems that are highly threatened by anthropogenic activities. We investigated the environmental quality of the Serinhaém river estuary located in a legally protected area. Through chemical analysis of sediments and tissues of Cardisoma guanhumi, in addition to bioassays with elutriate involving Nitokra sp. and Thalassiosira pseudonana, we determined the contamination status and risk factors related to trace metals in the estuary. For the sediment, the concentrations of Cr and Ni were above the limit established by CONAMA n° 454/2012 in the “City” site, and Cr above the TEL in all sampling sites. Ecotoxicological tests showed high toxicity in samples from “City” and “Tributary”. The elements Cr, Mn, Ni and Zn were also higher in crabs from these sites. Cr levels exceeded the Brazilian limit for food consumption. The bioaccumulation factor was not significant. However, the overall analysis proved that this estuary is increasingly impacted by anthropogenic pressure.

Assessment of trace metal bioaccumulation on the shells of edible gastropod Chicoreus ramosus and Hemifusus pugilinus

The current study aimed to examine how some gastropods absorbed trace metals (Chicoreus ramosus and Hemifusus pugilinus). The existence of 17 elements, including aluminium, arsenic, boron, calcium, cadmium, cobalt, chromium, copper, iron, potassium, lithium, manganese, sodium, nickel, phosphorus, lead, and zinc (Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mn, Na, Ni, P, Pb, and Zn), was confirmed by inductively coupled plasma-mass spectroscopy (ICP-MS) analysis of trace metals. According to the ICP-MS results, C. ramosus (Al: 1.97 ± 0.2µg/g, Fe: 1.93 ± 0.2µg/g, and As: 1.52 ± 0.4µg/g) and H. pugilinus (Al: 1.85 ± 0.7µg/g, Fe: 1.68 ± 0.6µg/g, and As: 1.37 ± 0.6µg/g) both had significant amounts of aluminium, iron, and arsenic, respectively. Zinc concentrations of 0.58 to 0.7μg/g (C. ramosus) and 0.67 to 0.2μg/g were recorded (H. pugilinus). The elemental composition of the surface of the sample was confirmed by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) micrographs, which also showed the degree of trace metal absorption in the chosen gastropod species.

Assessment of Edaphic pollution indices and bioaccumulation of trace metals in Solanum lycopersicum, Spinacia oleracea and Triticum aestivum: an associated health risk evaluation

The present study investigates bioaccumulation factor (Bfc), Edaphic pollution indices and associated health risk assessment of trace metals (TMs) i.e., Cu, Fe, Zn, Mn and Co in the crops, agricultural soil (AgS), and irrigation water (IgW) collected from various peri-urban area of metropolitan city of India, Lucknow. Though the level of these TMs was within the permissible limits (PL) (FAO/WHO, 2011) in AgS and IgW however it was higher than PL in tomato, spinach and wheat cultivated in the fields. The bioaccumulation factor of Cu, Fe and Mn in edible parts of tomato, spinach and wheat was 8 to 25 times higher through the AgS and 10 to 300 times higher through the IgW in the tomato, spinach and wheat samples. The enrichment factor (Efc), contamination factor (Cfc), contamination degree (Cdg) and modified contamination degree (mCdg) values of Co, Cu, Mn, Fe and Zn ranged from low to high levels of contamination, whereas the geo-accumulation index reflected low contamination in agricultural soil. on the other hand, the metal pollution load index (Mpi) was found strongly contaminated in most of the study areas. Due to the consumption of these contaminated vegetables and cereal (VCs) by human consumers, the hazard quotient (HQ), total hazard quotient (THQ) and hazard index (HI) were found to be more than the requisite value of 1, which indicates a far-long health risk in this crowded city and its surrounding regions.

Bioaccumulation and health risks of multiple trace metals in fish species from the heavily sediment-laden Yellow River

The health risk caused by metal pollution is a global concern due to potential metal bioaccumulation, toxicity, and carcinogenicity with multiple sources and pathways. Here, the factors influencing metal bioaccumulation in more than a thousand fish individuals were investigated along a 5464 km continuum of the heavily sediment-laden Yellow River and the health risks to humans were evaluated. The average concentrations of Cr, Zn, As, Cu, Cd, and Pb were below the permissible limits established by domestic and foreign organizations. The fish showed biomagnification of Se and Sn through trophic transfer and a growth dilution effect for V, Mn, Co, Ni, Cu, Zn, As, Cd, and Ba. The concentrations and distributions of most metals in fish were mainly influenced by the trophic levels (δ15N) of fish and the content of the metals in the aquatic environment. The consumption of fish from the Yellow River does not pose a noncarcinogenic risk to the health of adults and juveniles. Cr and As could cause carcinogenic risks, and Cd and Pb also have carcinogenic risks, but these were within an acceptable range. The carcinogenic risks of fish consumption were relatively low in regions with low levels of metal pollution, such as the source region, while the risks were high in regions with heavy pollution and carnivorous fish at high trophic levels. In response to this threat, people can minimize these risks by adjusting their diet and appropriately reducing their consumption of aquatic products from the Yellow River.

Analysis of Trace Metal Bioaccumulation in Fish and Man; Health Risk Impact

Trace metals occur during natural processes and are also obtained during anthropogenic activities. Streams, lakes and rivers surrounded by farmlands engaged in the use of Trace metal-enriched fertilizers have shown a possible and positive correlation to the rise of Trace metals in the use of chemical, organic and water-soluble fertilizers for a long period. there is a tendency for high correlations of trace metals in source waters. Furthermore, the increasing level of trace metals in fish is alarming and has spurred scientists to make research on the dangers caused by the trace metals resulting in trace metal accumulation and bioaccumulation of life cells. This study aims at assessing the possible sources of trace metals in the aquatic environment, the impact of Trace metals in the aquatic environment, their bioaccumulation in fish and human health risk impact, negative effects in fish have been attributed to the accumulation of trace metals such as irritation of the gastrointestinal mucosa, nephritis, necrosis, neurological and behavioural disorders and death amongst others). The ingestion, absorption and uptake of trace metals in fish are usually toxic and result in harmful damage to the fish and fish life. Since most of the metals taken up are non-biodegradable, such metals can bioaccumulate and bio-magnify. Over time, the accumulated metals affect the growth and development stages of fish from the production of viable eggs, hatchability laval, fingerlings and juvenile life stages. This is so because the early life stages are more sensitive than during maturing and adulthood. In conclusion, negative results of the presence of trace metals and the effect of bioaccumulation and bio-magnification have been reviewed in this paper. This study recommends that the proper assessment and treatment of all forms of wastewater, agricultural waste, sewage, and industrial effluents be carried out before their discharge into the environment.

Bioaccumulation and human health implications of trace metals in oysters from coastal areas of China

This study recompiled a national dataset to characterize the pollution level and health risk of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in oysters along the coastal areas of China. Results showed that the median concentrations of Cd, Cu, Pb and Zn in nationwide oysters were 5.5, 335, 1.3 and 1280 mg/kg dry weight, respectively. Generally, oysters from the north coasts presented lower metal pollution and higher quality than those from the south. The regional characteristics of trace metals in oysters might be contributed by the interspecific differences. Nationally, the noncarcinogenic risk posed by these four metals in oysters was relatively low, with the risk only occurring in a few hotspots such as the Pearl River Estuary and the Jiulong River Estuary. However, more attention should be paid to the carcinogenic risk of Cd, and priority should be given to formulating control measures to mitigate Cd pollution.

Bioaccumulation of trace metals in Neoechinorhynchus buttnerae and in its fish host tambaqui (Colossoma macropomum) from fish farms.

Fish parasites are excellent bioindicators of environmental contamination because they respond quickly to water pollutant chemicals, and they can accumulate high concentrations of trace metals compared to their hosts. Here, we investigated the bioaccumulation pattern of the following: Cd, Ca, K, Na, Mg, Fe, Al, Zn, Ba, Mn, Cu, Pb, Cr, Ni, and Co. We investigated the presence of trace metals in the acanthocephalan parasite Neoechinorhynchus buttnerae, and the bioaccumulation factors (BAFs) of metals were tested in the food, muscle, and liver of its host fish Colossoma macropomum (tambaqui). We used samples from four commercial fish farms that also conduct other agribusiness activities. Tissues of the fish along with their parasites were subjected a trace metal concentration analysis by inductively coupled plasma optical emission spectrometry. Most of metals showed significantly higher presence in N. buttnerae than in tambaqui (p < 0.05), with increased level of Na, Pb, Ca, Mn, Zn, Al, and Fe in fish muscle and that of Cr, Ni, Zn, Al, Ca, and Ba in fish liver. Considering all the fish farms, the highest values of BAF were observed for Fe, Al, Zn, and Mn with concentrations up to 35.63, 26.88, 14.12, and 6.66 times higher in acanthocephalan tissues than in the fish muscle, respectively. Moreover, Ba, Ca, and Al showed concentrations up to 18.11, 12.18, and 11.77 times higher in acanthocephalan than in the liver of tambaqui. Our results indicate that the higher the levels of these metals in the parasite, the lower their concentrations in the muscular and hepatic tissues of the fish. Therefore, we suggest that N. buttnerae can directly influence the concentrations of trace metals in the fish tissues and accumulate both essential trace (Fe, Zn, Mn, and Ca) and toxic elements (Al, Pb, and Ba) in the host.