Concentrations of heavy metals in two Ghanaian Lagoons (original) (raw)
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Correlation between Heavy Metals in Fish and Sediment in Sakumo and Kpeshie Lagoons, Ghana
Journal of Environmental Protection, 2012
Concentrations of heavy metals (Cd, Pb, Mn, Zn, and Cu) were measured in bottom sediment and the black-chin tilapia (Sarotherodon melanotheron) from the Sakumo and Kpeshie lagoons using Atomic Absorption Spectrometry (AAS). Results for the levels of these metals in the sediments and fish were compared with WHO guideline values. It was observed that heavy metal concentrations in sediments of Sakumo lagoon were higher than those of Kpeshie lagoon. Among the metals, Cu and Zn were found to be highly concentrated in the fish but lower than the World Health Organization (WHO) recommended values. Spearman correlation coefficient study showed significant correlation coefficients between Pb and Zn (0.937) and between Cu and Mn (0.613) at 0.05 levels.
ASSESSMENT OF HEAVY METAL LEVELS IN FISH TISSUES, WATER AND SEDIMENT FROM EPE LAGOON, LAGOS, NIGERIA
SCIENCE WORLD JOURNAL, 2021
Pollution of heavy metal in water bodies is a threat to public water supplies and also to consumer of fishery sources. This study aimed at investigating the distribution of heavy metals in some fish species, water column and sediment of Epe Lagoon. Water samples, sediments and ten fish species (Synodontis schall, Chrysichthys nigrodigitatus, Megalaspis cordyla, Ulua mentalis, Caranx hippos, Tilapia guineensis, Marcusenius cyprinoides, Xenomystus nigri, Oreochromic niloticus, Clarias gariepinus) were sampled in 2019. Heavy metals (Zinc, Copper, Manganese, Iron, Lead and Cadmium) were detected in three matrices including fish tissues, water and sediment using Atomic Absorption Spectrophotometer (AAS). The heavy metal level ranges of the metals detected were: Zn: 1.128 to 4.875 mg/kg; Cu: ND to 0.488 mg/kg; Mn: 0.5 to 7.480 mg/kg; Fe: 0.125 to 9.125 mg/kg; Pb: ND to 0.875 mg/kg; and Cd: 1.750 to 2.750 mg/kg. The highest mean concentration of the heavy metal in all fish species is Zn, followed by Mn, Cd, Fe, Cu and Pb. The mean concentration of metals determined in the water samples ranged from 0.020-0.635 mg/L and for sediments the range was 0.669-17.453 mg/kg. The results obtained show high levels of Mn, Fe and Cd in some fish species which can pose danger to consumers of foods and water from this Lagoon. There is therefore the need for continual assessment of the level of pollution of this Lagoon with a view to reducing this level via sensitization and education.
The proximate composition and heavy metal content of the mangrove oyster Crassostrea gasar from the Andoni River was investigated. Samples were categorized into three class sizes: small (< 25 mm), medium (25-50 mm), and large (> 50 mm) each with 10 sampling units for each class size. Differences across class size were significant for carbohydrate, lipid, and fiber content with their highest mean values recorded as 58.39 ± 0.21%, 6.70 ± 0.10% and 18.22 ± 0.28% respectively. Size-specific differences were detected only for concentrations of lead and zinc which showed maximum concentrations of 0.53 ± 0.02μg/g and 42.69 ± 1.81μg/g respectively. The proximate composition and heavy metal content recorded were generally higher in large-sized oysters and the variations observed were attributed to obvious differences in their class sizes. The remarkably low moisture content recorded in C. gasar was attributed to higher drying temperatures (105°C). Food quality and uptake of heavy metals in tissues of C. gasar generally varied along size gradients, with peak values in large-sized individuals. However, the levels of heavy metals recorded in soft tissues of C. gasar in this study were generally very low and fall within levels expected in tissues of aquatic biota.
Heavy Metals Concentrations in Shellfish and Sediments of Andoni River, Rivers State, Nigeria
The concentrations of seven heavy metals Fe, Zn, Mn, Cu, Pb, Cd and As were investigated in two aquatic organisms oyster (Saccostrea cululata) and cockle (Andra granosa) of Andoni Rivers system. Similar sizes of each species of the organisms were collected from five stations. The aquatic organisms were prepared and digested with a mixture of mineral acids, HNO3 and HCl, while sediments by mixture of HClO4 and H2SO4. They were analyzed with Atomic Absorption Spectrophotometer model 205. The results obtained showed that of the essential elements, Fe had the highest concentration of 2896.48± 2083.11mg/Kg in sediment and the least concentration of 0.61 ± 0.302mg/Kg occurred in cockle. Of the non-essential elements Pb, Cd and As, As had the highest mean concentration of 0.7950 ±0.19mg/Kg, while Pb had the lowest concentration of 0.0680 ± 0.082mg/Kg in cockle. The results of ANOVA and Post Hoc Test (PHT) revealed significance difference at p<0.05 in the mean concentrations of some of the heavy metals. On the other hand, high pollution load index (PLI), were obtained at the stations. The consumer of shellfish in the area is at risk of being poisoned by heavy metals, as the values obtained were above standard set by WHO.
Determination of Heavy Metals in the Black-Chin Tilapia from the Sakumo Lagoon, Ghana
Samples of the Black-chin Tilapia were analyzed for the concentration of heavy metals (Arsenic, cadmium, chromium, copper, iron, mercury, nickel and zinc) using atomic absorption spectrophotometry and instrumental neutron activation analysis. The sequence of order of the heavy metals measured in the fish samples observed from the Sakumo lagoon was as follows: Fe > Cu > Mn> V> Hg > Cd, respectively. The results showed elevated levels of iron, copper and managanese in all the fish samples although mercury and cadmium were available in relatively low concentration in the most of the fish samples. Fe, Mn, and Zn concentration in fish were greater than WHO/FAO certified values. Hazard index < 1 suggests unlikely adverse health effects whereas HI $ 1 suggests the probability of adverse health effects. Although the heavy metals analysed in Blackchin Tilapia did not pose any immediate health risk to humans but due to the bioaccumulation and magnification of these heavy met...
Nigerian Journal of Animal Production, 2020
The concentration of heavy metals(Zn, Ni, Pb, Cd and Cu) in the muscle of three fishery organisms (Chrysicththysnigrodigitatus, Sarotherodongalilaeus and Peneausmonodon)and in environmental samples of waterand sediment were tested in Yewa Lagoon, Nigeria. Five fishing villages along the lagoon were selected as the sample sites where these metals were tested. The heavy metal content in the muscle of the fishery organisms was Zn > Ni >Pb> Cu > Cd;Zn > Ni >Pb> Cd > Cu and Zn > Ni >Pb> Cd > Cu inC.nigrodigitatus, S.galilaeus and P.monodon respectively. The heavy metal concentrations in the sediment was Zn >Pb> Cu > Ni > Cd. However, nickel and cadmium were not present in the water at two sampling sitesof Yewa Lagoon.The water of Yewa Lagoon is polluted with all the five heavy metals which were all higher than the WHO standard. The concentration of Zinc in the fishery organisms were below the WHO standard. However, the high concentration of zinc in the water (which is well above the WHO standard) could be associated with the fact that zinc is naturally abundant in Nigeria soils.
World Environment, 2015
The level of some Potential toxic metals PTM (Zn, Fe, Mn, Cu, Pb and Cd) in Synodontis membrane (Catfish), Tilapia zilli (Tilapia), Callinectes amnicola (Crab) and Macrobrachium macrobachion (Prawn), from Lagos Island and Epe lagoon were investigated using Atomic Absorption Spectrophotometer (AAS), model Buick Scientific 210 GVP, the analysis on all the samples were done in triplicates. The analysis of PTM in Synodontis membrane and Tilapia zillii was conducted on head, gills and trunk, and the results indicated the accumulation of metals differently in various parts of the fishes. Lead (Pb) and Cadmium (Cd) were not detected (ND) from all the samples, this may be due to the existence of few or no industrial activities around the locations. The orders of accumulation in Catfish were Head>Gill>Trunk and the pattern of distribution is Zn>Fe>Mn>Cu in all the organs. In Tilapia, the accumulation follows the order; Gills (Fe>Zn>Mn>Cu)>Head (Zn>Fe>Mn>Cu)>Trunk (Fe>Zn>Mn>Cu). The mean values of the Crab obtained fell in the ranges: Fe (19.7±1.7-24.7±7.7); Zn (8.0±2.5-11.6±1.3); Cu (9.0±3.3-10.3±1.9); Mn (5.0±2.9-7.3±3.7). While that of the Prawn falls in the ranges: Fe (6.3±1.9-4.0±1.6); Zn (6.3±2.9-8.0±2.5); Cu (2.0±1.0-2.7.±0.9); and Mn (1.7±0.5-3.0±0.8) for Lagos Island and Epe Lagoon respectively. The high concentrations of iron and zinc in the fish parts could be associated with the fact that these metals are naturally abundant in Nigerian soils and since the source of metal depositories are the aquatic systems. The general trend of accumulations in all the organisms were Chrysichthys nigrodigitatus>Tilapia zillii>Callinectes, amnicola>Macrobrachium macrobrachion. The analysis of the Crab and Prawn shows that concentrations of Zn and Fe in the samples are lower than the permissible limits set by WHO and FEPA, while Mn and Cu concentrations in the fish samples were above the standard set limits hence consumption of the fish from the analysed lagoon may be dangerous to health, therefore it is pertinent to regularly monitor the activities of both the lagoons.
The concentration of heavy metals; Lead, Nickel, Zinc and Iron in surface waters and sediment as well as in liver of catfish species; Malapterurus (=Erpetoichthys) electricus, Chrysichthys nigrodigitatus and Synodontis clarias collected from Lekki Lagoon were investigated. Heavy metal concentrations were determined in water, sediment, liver of fish species using Atomic Absorption Spectrophotometer. Higher concentrations of heavy metals were detected in sediment as compared to concentrations detected in surface water. The trend of metal concentrations in surface water was; Zn > Ni > Fe < Pb, and sediment was; Ni > Zn > Fe > Pb. M. electricus had the highest concentrations of hepatic lead, iron and nickel; Pb (0.98±0.79 mg kg-1), Fe (24.54±55.07 mg kg-1), Zn (6.83±8.20 mg kg-1), Ni (3.42±6.26 mg kg-1) as compared to the other species; S. clarias which had, Pb (0.02±0.04 mg kg-1), Fe (0.61±0.21 mg kg-1), Zn (0.38 ± 0.20 mg kg-1), Ni (0.04±0.01 mg kg-1) and C. nigrodigitatus which had the Pb (0.01±0.04 mg kg-1), Fe (5.58±5.38 mg kg-1), Zn (29.81±25.10 mg kg-1), Ni (0.68±0.75). S. clarias showed the lowest accumulation efficiency of heavy metals form surface water and sediment as compared to bio-accumulation factors recorded for M. electricus and C. nigrodigitatus. M. electricus and S. clarias had similar trend in hepatic metal concentrations; Fe > Zn > Ni > Pb while C. nigrodigitatus had; Zn > Fe > Ni > Pb. The difference in trend could be attributed to bioavailability, intrinsic fish processes, and trophic structure variation. Concentrations of the heavy metals analyzed in the edible fish species were above the safe limits recommended by FEPA and WHO (Pb, 0.01 mg kg-1 , Ni, 0.02 mg kg-1 , Fe, 0.2 mg kg-1 , Zn, 3.0 mg kg-1). Therefore measures should be taken to monitor the Lekki lagoon for heavy metals pollution. Use of multiple indicator species in bio-monitoring should be encouraged and M. electricus which has shown better bio-indicator capability according to results obtained from this study should be considered a preferred fish model in bio-monitoring program.