Browsing by Author "Boakye, Sandra"

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    Distribution and potential risks of heavy metals in fish, water and sediment
    (Environmental Science, An Indian Journal, 2015) Darko, Godfred; Boakye, Sandra; Akoto, Osei; Modise Rammika; Gyamfi, Opoku; 0000-0001-7157-646X
    Heavy metal pollution in aquatic ecosystem impacts negatively on the organisms that depend on the water. Concentrations of some heavy metals in water, fish and sediment samples from Lake Bosomtwi in Ghana were determined to assess the extent of pollution in the lake. Concentrations of Fe, Zn, Cu, Mn and Ni in the lake were within the permissible levels recommended by World Health Organization. However, Cd and Pb exhibited higher concentrations possibly due to pollution events. The accumulation pattern in the study is in the order of Ni>Fe>Cu>Mn>Pb>Zn>Cd. Concentration of heavy metals in tilapia samples were all below the WHO guidelines. The sediment samples registered pollution load index of 3.317 indicating the sediment was polluted. Bioaccumulation in fish relative to the water was less than unity for all the metals except Mn. With respect to the sediments, bio-concentration factor for Cu was the highest (2.40) followed by Mn (1.72). All other metals recorded values < 1 indicating the fish species have not accumulated significantly from the environment. Except for Pb that registered a target hazard quotient of 1.030, all other metals had quotients well below 1. Consumption of tilapia from the lake can therefore be said to constitute no health risks so far as the heavy metals investigated are concerned.
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    Distribution of heavy metals in soils from abandoned dump sites in Kumasi, Ghana
    (Scientific African, 2020-10-23) Akanchise, Thelma; Boakye, Sandra; Borquaye, Lawrence Sheringham; Dodd, Matt; Darko, Godfred; 0000-0002-5037-0777; 0000-0002-7907-6520; 0000-0001-7157-646X
    This study investigated the heavy metal content and the extent of pollution in soils from abandoned dump sites in Kumasi, Ghana. Concentrations of heavy metals in the 70 soil samples were determined using a Niton XL3t GOLD field portable X-ray fluorescence spectrometer and confirmed on an Agilent 7800 inductively coupled plasma-mass spectrometer. Mercury was determined with a Lumex mercury analyzer. Mean concentrations of metals in soils were in the order: Zn (166 mg/kg). Cr (67 mg/kg) > Cu (32 mg/kg), Ni (22 mg/kg) > Pb (11 mg/kg) Cd (8.9 mg/kg) > As (4.2 mg/kg) > Hg (0.04 mg/kg) for Kronum; and Zn (558 mg/kg), Cu (347 mg/kg), Pb (288 mg/kg) > Cr (77 mg/kg) > Ni (35 mg/kg) > As (11 mg/kg) > Cd (3.0 mg/kg) > Hg (0.19 mg/kg) for Amakom. Pollution indices (geo-accumulation, contamination factor, pollution load and potential ecological risk) indicated very high contamination for arsenic, cadmium and lead at Kronum and arsenic, cadmium, copper, lead and zinc at Amakom. Mercury recorded the least level of pollution for both dump sites. Regular monitoring of these abandoned dump sites is required. Remediation programs in these sites should also be instituted.
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    Levels of Selected Pesticide Residues in Cocoa Beans From Ashanti and Brong Ahafo Regions of Ghana
    (2012-05) Boakye, Sandra
    The monitoring of pesticide residues in food has become a priority objective worldwide in order to get an extensive evaluation of food quality and to avoid harm to human health. This study presents results of analysis conducted on twenty one pesticide residues in cocoa beans sampled from the Brong Ahafo and Ashanti regions of Ghana. The pesticides were extracted from cocoa beans using liquid liquid extraction followed by clean up with solid-phase extraction cartridges. Final extracts were dissolved in ethyl acetate and analysis carried out by Gas Chromatography with Electron Capture Detector. Pesticides were identified by their retention times and quantification using an external calibration method. Twenty pesticide residues were detected in the cocoa bean samples. Aldrin was below detection limit in the cocoa beans sampled from the two regions. Chloropyrifos exhibited the highest concentrations of 10.55 mg/kg for samples from Mim in the Brong Ahafo region and 9.81 mg/kg for samples from Offinso in the Ashanti region. The lowest pesticide concentration of 0.01 mg/kg was recorded for Endosulfan I for samples from Sankore in the Ashanti region and Delta HCH which had a value of 0.01 mg/kg for samples from Offinso, Apagya, Juaso and New Edubiase respectively. From the results it could be deduced that 50% of the pesticides residues detected in the Brong Ahafo region were above the EU allowable limit whereas 45% was recorded for Ashanti region.