Levels Of Heavy Metals In Fish Research Articles

Mercury in four common fishes sold in Algeria and associated humans risk

ABSTRACT This study aimed to analyse the concentrations of mercury in fish samples available in the Algerian market and evaluate the potential health risks associated with their consumption. A total of 135 fish samples, representing the species Sardina pilchardus, Merluccius merluccius, Sparus aurata and Auxis rochie, were collected and analysed. Mercury levels were determined using thermal decomposition amalgamation Atomic Absorption Spectrophotometry. Health risks were evaluated by calculating hazard quotients. The overall mean concentration was 0.19 ± 0.11 mg/kg across all species. Individual species concentrations were recorded as 0.17 ± 0.08 mg/kg for Sardina pilchardus, 0.26 ± 0.19 mg/kg for Merluccius merluccius, 0.27 ± 0.18 mg/kg for Sparus aurata and 0.23 ± 0.13 mg/kg for Auxis rochei. Hazard quotients were below 1, indicating low health risk for fish consumers. Nevertheless, it is recommended to conduct periodic monitoring of heavy metal levels in fish, coupled with ongoing risk assessments, to ensure continued consumer protection.

A Review of Chemical Contaminants in Marine and Fresh Water Fish in Nigeria.

Pollutants in aquatic food are a major global concern for food safety and are a challenge to both national and international regulatory bodies. In the present work, we have reviewed available data on the concentrations of polycyclic aromatic hydrocarbons (PAH), persistent organic pollutants, metals, and microplastics in freshwater and marine fish in Nigeria with reference to international maximum levels for contaminants in food and the potential risk to human health. While most of the contaminant levels reported for fish do not imply any health issues, iron and lead may represent potentially toxic levels in fish from specific areas. Studies on PAHs in marine fish are scarce in Nigeria, and the main focus is on the environmental pollution caused by PAHs rather than on their presence in food. The findings suggest that the consumption of smoked Ethmalosa fimbriata poses a higher potential carcinogenic risk than the other fish species that were investigated. Most of the other studies on PAHs in smoked fish are focused on the smoking method, and little information is available on the initial level of PAHs prior to the smoking process. Metal contamination in fish appeared to be affected by mineral deposits in the environment and industrial effluents. In general, heavy metal levels in fish are below the maximum levels, while there is limited data available on POPs of relevance to food safety in fish from Nigeria, particularly in terms of dioxins, brominated flame retardants, and fluorinated compounds. Furthermore, there is currently limited information on the levels of microplastics in fish from Nigerian waters. This work revealed the need for a more systematic sampling strategy for fish in order to identify the most vulnerable species, the hot spots of contaminants, and applicable food safety control measures for fish produced and consumed in Nigeria.

Risk for Indo-Pacific humpback dolphins (Sousa chinensis) and human health related to the heavy metal levels in fish from the Pearl River Estuary, China

Cetaceans and humans shared the same route of exposure to many anthropogenic contaminants via fish consumption. To assess the health risks associated with heavy metal levels in fishes from the Pearl River Estuary (PRE) and the seasonal dynamics, 13 fish species (n = 675) consumed by the Indo-Pacific humpback dolphins (Sousa chinensis) and humans were analyzed for concentrations of nine heavy metals. Heavy metal levels vary significantly by species and by season in the PRE fishes. The two eel goby species were the most contaminated fish species, which had the highest levels of Cu, Pb, Hg, Mn and Se. Levels of non-essential metals (As and Pb) in many different fish species were all found significantly higher in dry season than in wet season, which may reflect the dilution effect on contaminant levels in the PRE waters in rainy season. For essential metals, Cu, Cr and Se in many fish species were significantly higher in dry season compared to wet season, while Se and Mn in the other fish species showed an opposite pattern, since essential metal accumulation could be influenced by several physiological processes in life. Risk assessment for dolphins showed that inorganic-As levels in all fishes exceeded the safe limits, whereas a more conservative approach indicated that the levels of all metals in all fish samples had toxic effects on dolphins, except for Hg. Human health risk analysis showed that inorganic-As levels in tonguesole (all year) and sillago (dry season) and Cr levels in pomfret (dry season) exceeded the acceptable values.

Quantitative Determination of Heavy Metal Contamination in Horse Mackerel and Whiting Caught in the Sea of Marmara.

In this study, the concentrations of lead, cadmium and manganese were determined in horse mackerel (Trachurus mediterraneus) and whiting (Merlangius merlangus euxinus) that were caught in the Sea of Marmara. These are commonly consumed fish species in this region. Fish were provided by a fishermen quarterly between March 2013 and December 2013 and, separated according to size (small, medium and large). Pb(II), Cd(II) and Mn(II) levels were determined using the wet digestion method by Graphite furnace atomic atomic absorption spectrophotometer. According to this study, for horse mackerel, the highest concentration of lead, cadmium, and manganese was 6.69µgkg-1 (September), 5.24µgkg-1 (March) and 9.24µgkg-1 (June), respectively. For whiting, the highest concentration of lead, cadmium, and manganese was 2.25µgkg-1 (June), 0.263µgkg-1 (September) and 10.4µgkg-1 (June), respectively. These heavy metal levels in fish were found to be acceptable for human consumption according to World Health Organization border values.

Heavy Metal Levels in Fish from Heilongjiang River and Potential Health Risk Assessment.

Concentrations of Cu, Zn, Cr, As, Cd, Pb and Hg were determined in 153 samples covering 18 fish species collected from Heilongjiang River, China, and the potential health risks to local residents through fish consumption were estimated. Results revealed that all metals were detected with Cd and Pb having considerably lower detection rate. There were 28.6% of Lethenteron camtschaticum samples exceeding the limit of inorganic As content established by Chinese legislation. Metal bioaccumulation in fish were poorly correlated with fish sizes, and generally tended to increase with trophic levels. The hazard quotient values of all fish species were far below 1 for general population and fishermen. The carcinogenic risk of As in L. camtschaticum for the local fishermen exceeded the acceptable level of 10(-4) rise in cancer rates, but was considered safe given the migratory habits of the fish.

Heavy Metal Levels in Fish from Coastal Waters of Uruguay

Copper, mercury, and zinc levels were determined in muscle and liver (N = 163) of seven fish species caught in coastal waters off Montevideo and Piriapolis (control site): Odontesthes spp., Mugil platanus, Micropogonias furnieri, Urophycis brasiliensis, Cynoscion guatucupa, Menticirrhus americanus, and Mustelus schmitti. The local population commonly uses these species for consumption. Heavy metal concentrations determined in this study were generally below those obtained for fish caught in Argentinean and Brazilian coastal waters, with some exceptions in the case of mercury and zinc. Based on copper, mercury, and zinc levels in muscle tissue, we conclude that the fish studied here are acceptable for human consumption. Nevertheless, it is recommended not to consume the fish liver (up to 466 microg Zn g(-1) dry weight in liver) nor large specimens of the investigated species. Regional programs involving the neighboring countries should be established to assess the fisheries resources and potential risks for human health.

The ecological status of Lake Laguna de Bay, Philippines

This article assesses the ecological status of Laguna de Bay using available published and unpublished information. The declining fishery productivity of the lake is the most glaring evidence of its stressed ecological state. This loss stems from numerous deleterious factors operating throughout the lake and its drainage basin. Phytoplankton community composition has drastically changed over the years and algal biomass has diminished in the presence of ample supplies of nitrogen and phosphorus. Light limitation due to high siltation rates in the perennially turbid lake whose Secchi depth is only 5 cm might be the primary limitation to photosynthesis. The problem of siltation in the lake is the result of deforestation in the watershed that heightened soil erosion rates. Trophic relationships are inadequately examined in Laguna de Bay, the biggest lake in Southeast Asia. High biological oxygen demand and high heavy metal levels in the lake water, sediments, and biota are evidence of excessive pollution. Heavy metal levels in fish are similar to those found in fish from a smaller nearby lake receiving mine tailings. Collectively, these observations show that Laguna de Bay is an extremely stressed ecosystem needing rehabilitation. The article concludes with a set of recommendations on how to deal with the problem of impairment of lake ecology, namely, the improvement of the hydrological regime, control of the internal loading of fertilizing nutrients, toxic and hazardous chemicals, control of the sources of pollution, a systematic implementation of closed and open seasons to fishing, the establishment of a system for the assessment and evaluation of environmental perturbations, and revitalization and support for local community efforts to safeguard the ecology of the lake.

Lead and other metals in dried fish from Nigerian markets.

The Nigerian economy had remarkable industrial growth between 1970 and 1980 and industrialization and urbanization have been sustained albeit at a slower rate. Nevertheless, waste management remains grossly underdeveloped. Environmental concern is only a recent phenomenon, resulting thus far in the launching of a monthly clean-up campaign in 1984 and the establishment of the Federal Environmental Protection Agency (FEPA) in 1988. The level of public awareness has not been encouraging. The indiscriminate discharge of largely untreated factory and urban effluents has continued. Streets and home surroundings become littered soon after clean-up exercises. Inadequate facilities contribute to the unwholesome situation. Refuse collecting centers are mostly without any holding containers, and solid wastes, the focus of the monthly clean-up, are left on the bare ground. Heavy automobile traffic and high lead content of the local automobile fuels have not helped matters. Heavy metals in the human environment are of global concern. In developed countries, limits of concentrations in fish and other foods have been set to safeguard public health, but Nigeria has yet to set any standards because of lack of baseline data. Within the last decade, scientists have been reporting on heavy metal levels in fish from the aquatic environment ofmore » Nigeria. Among the metals, lead was the most prominent, with a mean value comparable to the set limits in Great Britain and New Zealand. The present study was aimed at further establishing the levels of contamination in fish by lead and other metals in the Nigerian aquatic systems. Smoke-dried fish, being the most consumed by the local population, was chosen for the survey on the levels of cadmium, cobalt, copper, chromium, iron, manganese, lead and zinc. Possible surface contamination arising from observed poor handling practices was also investigated. 18 refs., 1 fig., 4 tabs.« less

Anthropogenic impact assessment of heavy metal levels in fish in a eutrophic shallow lake

Anthropogenic impact assessment of heavy metal levels in fish in a eutrophic shallow lake