Browsing by Author "Darko, Godfred"

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    Antimicrobial and antioxidant properties of the crude peptide extracts of Galatea paradoxa and Patella rustica
    (SpringerPlus, 2015) Borquaye, Lawrence Sheringham; Darko, Godfred; Ocansey, Edward; Ankomah, Emmanuel; 0000-0001-7157-646X
    This study evaluated the antimicrobial and antioxidant activities of crude peptide extracted from Galatea paradoxa (G.paradoxa) and Patella rustica (P. rustica). The extracts were tested against eight strains of bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Salmonella typhi, Enterococcus feacalis, Klebseilla pneumoniae, Streptococcus pneumoniae, Pseudomonas aeruginosa) and one strain of fungi (Candida albicans) using agar well diffusion and broth dilution assays. The extracts from G. paradoxa demonstrated a high degree of activity against the bacteria strains but were inactive towards the fungus. P. rustica, however, showed a markedly higher antifungal activity but little antibacterial effect. The minimum inhibitory concentrations (MIC) of the extracts determined by the broth tube dilution assay were 17 mg/mL of G. paradoxa against the entire spectrum of microorganisms tested except for C. albicans which was 20 mg/mL. The MIC of the extracts of P. rustica was 13 mg/mL against all the strains of microorganisms tested except for E. feacalis (17 mg/mL), K. pneumoniae (17 mg/mL) and C. albicans (13 mg/mL). Antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed scavenging ability on the DPPH radical was 56.77 % at 0.39 mg/ mL for G. paradoxa and 79.77 % at 0.39 mg/mL for P. rustica. The study indicates that the crude peptide extracts from the two molluscs have promising antimicrobial and antioxidant activities that can be harnessed as leads for potential bioactive compounds
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    Assessment of Heavy Metal Contamination and Distribution in Surface Soils and Plants along the West Coast of Ghana
    (West African Journal of Applied Ecology., 2018) Fosu-Menah, B.Y; Ofori, A.; Ofosuhene, M.; Ofori-Attah, E.; Nunoo, F.K.E; Darko, Godfred; Tuffour,I.; Gordon, C.; Arhinful, D,K; Nyarko, A.K.; Appiah-Opong, R; 0000-0001-7157-646X
    Onshore oil drilling activity is ongoing at Jubilee oil fields, Ghana. This activity could lead to heavy metal exposure with consequential adverse effects on public health in nearby coastal communities. Therefore, we assessed heavy metal levels and spatial distribution in soils and plants from the west coast of Ghana to obtain baseline values for monitoring heavy metal exposure. Surface soils were collected from six coastal communities, and analyzed for arsenic, cadmium, copper, mercury, lead, selenium and zinc using atomic absorption spectrophotometer. Mean heavy metal concentrations in soil samples were 2.06, 6.55, 0.016, 21.59, 0.18 and 39.49mg/kg for arsenic, copper, mercury, lead, selenium and zinc, respectively. Mean heavy metal concentrations in plants were 2.70, 17.47, 3.17, 91.74, 1.51 and 9.88mg/kg for arsenic, cadmium, copper, lead, selenium and zinc, respectively. Concentrations of arsenic, cadmium and lead in plants exceeded WHO/FAO permissible limits. Enrichment factor for arsenic was significant and extremely high for selenium, while geoaccumulation index showed moderate pollution for selenium. Soil contamination factors for arsenic, lead, and selenium indicated considerable contamination. In view of these findings remediation methods must be adopted to safeguard the communities. The data will be useful for future monitoring of heavy metal exposure in the communities and to assess the impact of the ongoing crude oil drilling activity on the environment.
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    Assessment of Mercury Levels in Omega-3 Food Supplements Available on the Ghanaian Market
    (Asian Journal of Applied Sciences (ISSN: 2321 – 0893), 2014-10-05) Acheampong, Akwasi; Darko, Godfred; Apau, Joseph; Oti-Boakye, Adolf; 0000-0001-7157-646X
    As a measure to prevent cardiovascular diseases and enhance in-utero development of the foetus, adequate omega-3 intake has been recommended. This has led to the manufacture of omega-3 supplements by various pharmaceutical companies and these products have flooded the market. Coldwater fishes are the primary sources of the omega-3 food supplements but these fishes are known to have high levels of mercury in them. There is therefore the potential of mercury poisoning in the course of people taking the omega-3 food supplements. Mercury levels in ten products of Omega-3 food supplements have been determined in order to ascertain their safety for human consumption. The mean mercury levels determined for the ten brands were 0.0170.003 µg/g, 0.093 0.002 µg/g, 0.0210.003 µg/g, 0.2730.005 µg/g, 0.1230.004 µg/g, 0.06580.001 µg/g, 0.0180.005 µg/g, 0.0260.008 µg/g, 0.4280.002 µg/g, 0.4280.002 µg/g, 0.0290.004 µg/g. All the levels of mercury determined were within the acceptable limits stipulated by Food and Agriculture Organization and World Health Organization, and therefore do not pose any health threat to consumers.
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    Changes in water quality in the Owabi water treatment plant in Ghana
    (Springerlink.com, 2014-09-11) Akoto, Osei; Gyamfi, Opoku; Darko, Godfred; Barnes, Victor Rex
    The study was conducted on the status of the quality of water from the Owabi water treatment plant that supplies drinking water to Kumasi, a major city in Ghana, to ascertain the change in quality of water from source to point-of-use. Physico-chemical, bacteriological water quality parameters and trace metal concentration of water samples from five different treatment points from the Owabi water treatment plant were investigated. The raw water was moderately hard with high turbidity and colour that exceeds the WHO guideline limits. Nutrient concentrations were of the following order: NH3\NO2 -\- NO3 -\PO4 3-\SO4 2- and were all below WHO permissible level for drinking water in all the samples at different stages of treatment. Trace metal concentrations of the reservoir were all below WHO limit except chromium (0.06 mg/L) and copper (0.24 mg/L). The bacteriological study showed that the raw water had total coliform (1,766 cfu/100 mL) and faecal coliform (257 cfu/100 mL) that exceeded the WHO standard limits, rendering it unsafe for domestic purposes without treatment. Colour showed strong positive correlation with turbidity (r = 0.730), TSS (r C 0.922) and alkalinity (0.564) significant at p\0.01. The quality of the treated water indicates that colour, turbidity, Cr and Cu levels reduced and fall within the WHO permissible limit for drinking water. Treatment process at the water treatment plant is adjudged to be good.
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    Characterization of Inhalation Exposure to Gaseous Elemental Mercury During Artisanal Gold
    (Environ. Sci.: Processes Impacts,, 2021) Snow, Melanie A.; Darko, Godfred; Gyamfi, Opoku; Ansah, Eugene; Breivik, Knut; Hoang, Christopher; Lei, Ying Duan; Wania, Frank; 0000-0001-7157-646X
    While occupational inhalation exposure to gaseous elemental mercury (GEM) has decreased in many workplaces as mercury is being removed from many products and processes, it continues to be a concern for those engaged in artisanal and small-scale gold mining or in recycling mercury-containing products. Recently, stationary and personal passive air samplers based on activated carbon sorbents and radial diffusive barriers have been shown to be suitable for measuring GEM concentrations across the range relevant for chronic health effects. Here, we used a combination of stationary and personal passive samplers to characterize the inhalation exposure to gaseous elemental mercury of individuals living and working in two Ghanaian gold mining communities and working at a Norwegian e-waste recycling facility. Exposure concentrations ranging from < 7 ng/m3 to >500 g/m3 were observed, with the higher end of the range occurring in one gold mining community. Large differences in the GEM exposure averaged over the length of a workday between individuals can be rationalized by their activity and proximity to mercury sources. In each of the three settings, the measured exposure of the highest exposed individuals exceeded the highest concentration recorded with a stationary sampler, presumably because those individuals were engaged in an activity that generated or involved GEM vapors. High day-to-day variability in exposure for those who participated on more than one day, suggest the need for sampling over multiple days for reliable exposure characterization. Overall, a combination of personal and stationary passive sampling is a cost- effective approach that cannot only provide information on exposure levels relative to regulatory thresholds, but also can identify emission hotspots and therefore guide mitigation measures.
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    Chemical and biological characteristics of streams in the Owabi watershed
    (Environ Monit Assess, 2010) Osei Akoto; Bruce, Theophilus Nicolas; Darko, Godfred; 0000-0001-7157-646X
    In this investigation, concentrations of physico-chemical and bacteriological qualities of water samples from the major streams within the Owabi watershed in Kumasi, Ghana, were measured at five different locations. The streams were moderately soft and neutral, having a mean pH range of 7.08 ± 0.2 to 7.88 ± 0.6. Total dissolved solids, total suspended solids, grease and oil, alkalinity, and the major ion levels varied significantly at each sampling site. Nutrient levels were however low and did not show any clear variation at sample locations. The bacteriological quality of the water was poor, rendering it unsafe for domestic purposes without treatment. The poor bacteriological quality was due to direct contamination by animal and human wastes. The streams have an appreciable self-purification capacity which is stressed by persistent pollution overloads caused by expanding human activities within the catchment. Cluster analysis performed on the data to determine pollution patterns between the streams depicts that River Owabi was less polluted, Rivers Akyeampomene and Sukobri were moderately polluted, while River Pumpunase was highly polluted.
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    Chemical and biological characteristics of streams in the Owabi watershed
    (Springer Netherlands, 2010-02-01) Akoto, Osei; Bruce, Theophilus Nicolas; Darko, Godfred
    In this investigation, concentrations of physico-chemical and bacteriological qualities of water samples from the major streams within the Owabi watershed in Kumasi, Ghana, were measured at five different locations. The streams were moderately soft and neutral, having a mean pH range of 7.08 ± 0.2 to 7.88 ± 0.6. Total dissolved solids, total suspended solids, grease and oil, alkalinity, and the major ion levels varied significantly at each sampling site. Nutrient levels were however low and did not show any clear variation at sample locations. The bacteriological quality of the water was poor, rendering it unsafe for domestic purposes without treatment. The poor bacteriological quality was due to direct contamination by animal and human wastes. The streams have an appreciable self-purification capacity which is stressed by persistent pollution overloads caused by expanding human activities within the
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    Chemical Composition of Rainwater over a Mining Area in Ghana
    (Int. J. Environ. Res., 2011) Akoto, O.; Darko, Godfred; Nkansah, M. A.; 0000-0001-7157-646X
    A comprehensive study on the chemical composition of rainwater was carried out in Obuasi, a gold mining town in Ghana. Rainwater samples were analyzed for major ions (Ca2+,Mg2+, K+, Na+, NH4+, Cl-,NO3- and SO42-) and trace metals (Fe, Al, Zn, Pb, Cr, and Cd). The rainwater was typically acidic with a mean pH of 4.76±0.47, which ranged from 4.0 to 5.6. The low pH found in the water suggests that the concentration of the alkaline particles in the rainwater were not high enough to neutralize acidic species present. SO42" and Cl”were the main anions, while Ca2+ and K+ were the main cations. Concentrations of trace metals in this study were compared with those of other studies conducted at different sites in the world. The result of this study generally suggests that rainwater chemistry in the area is strongly influenced by local anthropogenic sources (mining). The pollutants in rainwater samples were mainly derived from mining activities. Concentrations of Pb in all the samples were above the WHO permissible limit of 0.01 mg/L for drinking water.
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    Chemical Composition, Antioxidant, and Antimicrobial Activities of the Leaf and Fruit Essential Oils of the West African Plum, Vitex doniana
    (Journal of Chemistry, 2023) Odoom, Jahnissi Frimpomah; Aboagye, Caleb Impraim; Acheampong, Philipina; Asiamah, Isaac; Darko, Godfred; Borquaye, Lawrence Sheringham; 0000-0001-7157-646X
    Vitex doniana (West African plum or black plum) is a plant with varying phytoconstituents and biological activities across different countries. In this study, essential oils extracted from the leaves and fruits of Vitex doniana cultivated in Ghana were investigated for their antimicrobial and antioxidant activities. -e antioxidant actions of the essential oils were determined using hydrogen peroxide (H2O2), phosphomolybdenum, thiobarbituric acid reactive substances (TBARS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. For both essential oils, the total antioxidant capacities ranged from 44 to 68 µg/g AAE, the IC50 values for H2O2 scavenging activity were between 87 and 242 µg/mL, whereas that for DPPH assay were between 322 and 599 µg/mL. -e IC50 for the TBARS assay for both essential oils also ranged from 247 to 414 µg/mL. -e antimicrobial activities of the essential oils were investigated using the broth dilution assay. -e minimum inhibition concentration for the essential oils ranged from 12.5 to 50 mg/mL. BioClm inhibitory activity was also evaluated for both essential oils, and the fruit essential oil showed a half-maximal inhibition of bioClm formation (BIC50) at 44.40±0.6 mg/mL, whereas the BIC50 value of the leaf essential oil was 109.1±0.9 mg/mL. -e fruit essential oil was superior to the leaf essential oil in inhibiting the secretion of pyoverdine. Molecular docking analyses suggested that methyl cinnamate, ethyl cinnamate, p-menth-4-en-3-one, trans-α-ionone, benzyl benzoate, isobutyl cinnamate, and folic acid likely interacted with LasR and algC proteins, and hence, contributed to the inhibition of bioClm formation and pyoverdine secretion. Essential oils from Vitex doniana could, therefore, be exploited as a natural source of radical scavenging and antimicrobial agents and could be useful in the pharmaceutical, food, and cosmetic industries.
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    Chemistry and application of emerging ecofriendly antifouling paints: a review
    (J. Coat. Technol. Res., 2020) Kyei, Sampson Kofi; Darko, Godfred; Akaranta, Onyewuchi; 0000-0001-7157-646X
    There has been a global concern about the use of tributyltin-based coatings in combating biofouling in the marine industry. Although there have been alternatives to tributyltin in preventing biofouling, the emphasis is now on the use of non-toxic and/or eco-friendly natural materials which do not negatively affect the environment upon application. Natural materials are eco-friendly, biodegradable, cost-effective, and can be employed as precursors in the synthesis and formulation of biodegradable antifouling coatings. Consequently, many researchers are investing time into the synthesis and formulation of natural, eco-friendly antifouling coatings, comprised of higher biofiber, which would perform analogous antifouling like other conventional coatings, thus minimizing the more toxic base polymer proportion. A safe environment is surely the signal of a bright future; hence, cost-effective, biodegradable raw materials result in a long-term attainment of sustainability of these products to replace the expensive conventional ones. This review presents an overview of ecologically friendly, cost-effective, and legally acceptable ways of preventing and mitigating the growth of algae and other marine organisms from settling on the hull of a ship and other static constructions in oilfields.
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    Concentrations and Health Risk Assessments of Heavy Metals in Fish from the Fosu Lagoon
    (Int. J. Environ. Res., 2014) Akoto,O; Eshun, Bismark F.; Darko, Godfred; Adei, E.; 0000-0001-7157-646X
    Concentrations of Cu, Pb, Cr, Cd, Mn, Ni, Fe and Zn were determined in the muscle samples of Sarotherodon melanotheron from the Fosu Lagoon in Cape Coast using atomic absorption spectrophotometer. The results showed that, metal concentration in the fish muscle was in the order Mn > Zn > Fe > Pb > Ni > Cd > Cu > Cr. Mean concentrations of Pb and Cd in the fish exceeded the maximum tolerable limit set by the European Union. Although the mean concentrations of some metals exceeded this limit, their estimated daily intakes were below their oral reference dose recommended by the international regulatory bodies. Health risk assessment of consumers from the intake of metal contaminated in the muscle of S. melanotheron from the lagoon was evaluated by using Health Risk Index (HRI) calculations. In this study, the total HRI through consumption of fish calculated by adding the individual HRIs was less than 1, indicating that there is no significant potential health risk associated with the consumption of fish from the Fosu Lagoon.
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    Consumer Characteristics and Consumption Analytics of Frequently Consumed Food Categories in Mining Areas
    (Academic Journal of Life Sciences, 2020) Anyimah-Ackah, Ekpor; Ofosu, Isaac W.; Lutterodt, Herman Erick Lutterodt; Darko, Godfred; 0000-0001-7157-646X
    The WHO/FAO have requested data on food consumption to better understand the increasing toxicological results of foodstuffs. The aim of this study was to determine the food consumption characteristics of the consumers living in smallscale mining areas. Commonly consumed food crops of each category: fruit, cereals, vegetables, legumes and root tubers were selected. In all, 308 consumers were sampled using a one-week dietary recall tool and a stratified sampling method of the consumers. The @Risk Microsoft add-in was used to analyze the data. The results show that the adolescents (10-17 years) consumed cowpea (233.90 g/day) and cassava (666.96g/day) at a relatively higher level compared to children (3-9 years) and adults (18-64 years). Likewise, adults consumed yam (136.65g/day), maize (1739.37g/day), rice (1272.40g/day), pineapple (184.97g/day) and watermelon (656.55g/day) at a relatively higher level compared to children and adolescents. On the contrary, whereas children generally consumed lower quantities of food, they presented higher exposure frequency to cowpea (364 days/year), root tubers (36-364 days/year) and grains (286-364 days/year) compared to adults and adolescents. Both adolescent and adult population subgroups presented higher exposure frequency to vegetables (364 days/year) relative to children (104-364 days/year). The findings further show that, in increasing order rice and maize are the most consumed crops. The adult population subgroup, in the study area may be vulnerable to contaminants in maize grains than other dishes categories due to the high mass consumed and high exposure duration. Children may be vulnerable to contaminants in maize grains because of the high exposure frequency.
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    Contamination and Human Health Risk Due to Toxic Metals in Dust from Transport Stations in the Kumasi Metropolis, Ghana
    (Chemistry Africa, 2020) Rweyemamu, Almachiusi Rwegasira; Nkansah, Marian Asantewah; Darko, Godfred; Dodd, Matt; 0000-0001-7157-646X
    The purpose of this study was to assess the contamination levels and human health risk that heavy metals in the dust from transport stations pose to the inhabitants of the Kumasi metropolis, Ghana. Dust samples were collected from 18 transport stations and analyzed for metals including As, Cd, Cr, Cu, Pb, Fe, Sb, Ni, and Zn using X-ray fluorescence spectrometer prior to confirmation on an inductively coupled plasma-mass spectrometer. Mercury concentrations were determined using Lumex RA-915M Zeeman automatic mercury analyzer. The average concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe, Hg, Sb, and Zn were 6, 10, 130, 54, 30, 22, 16,518, < 1, 15 and 120 mg/kg, respectively. All the measured metal concentrations were higher than their background concentrations and the dust were heavily polluted with the metals. Pollution load indices revealed metal pollution was high in the metropolis. However, hazard indices for all the metals across the three exposure pathways were < 1, indicating no non-carcinogenic risk for both adults and children. Exposure to multiple metals was the main potential non-carcinogenic risk to children. Cadmium showed high carcinogenic risk index exceeding the safe limit of 1E0-4 for children, indicating that children are at risk. The study generally observed a higher health risk to children via ingestion compared to adults.
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    Determination of organochlorine pesticide residues in meat and dairy products in Kumasi
    (2003-11-29) Darko, Godfred
    Cheese samples from three communities in Kumasi (Tafo, Asawasi, and Aboabo), milk and yoghurt from Kumasi Polytechnic and Kwame Nkrumah University of Science and Technology Campuses as well as meat from Kumasi and Buoho abattoirs were analysed for organochlorine pesticide (Lindane, Aldrin, Dieldrin, Endosuffan, DDT and DDE) residues. The organochlorine pesticide residues were extracted from the samples through solvent partitioning, clean-up using C-18 bond elut and residue analysis performed by Capillary Gas Chromatograph equipped with Electron Capture Detector. Organochlorine residues were found in all the samples. The average concentrations of lindane, aldrin, endosulfan, p,p-DDE, dieldrin, and p,p-DDT residues in beef fat from Kumasi were 4.03 μg/kg, 2.06 μg/kg, 21.35 μg/kg, 118.45 μg/kg, 5.23 μg/kg, and 545.22 μg /kg respectively. The levels of these residues in beef fat taken from Buoho were, respectively, 1.79 μg/kg lindane, 4.11 μg/kg aldrin, 2.28 μg/kg endosulfan, 31.89 μg/kg DDE, 6.01 μg/kg dieldrin and 403.82 μg/kg DDT. Lean meat from Kumasi abattoir recorded mean levels of 2.07 μg/kg lindane, 1.43 μg/kg aldrin, 1.88 μg/kg endosulfan, 42.93 μg/kg DDE, 5.92 μg/kg dieldrin and 18.83 μg/kg DDT whilst that from Buoho recorded 0.60 μg/kg Lindane, 0.73 μg/kg aldrin, 0.59 μg/kg Endosulfan, 5.86 μg/kg DDE, 11.48 μg/kg dieldrin and 10.82 μg/kg DDT. DDT and DDE residues were detected in all the yoghurt samples analysed. Yoghurt from the Commercial Area of Kwame Nkrumah University of Science and Technology (KNUST) Campus had an average concentration of 0.03 μg/kg lindane, 0.03 μg/kg aldrin, 0.06 μg/kg endosulfan, 0.55 pg/kg DDE, 0.02 μg/kg dieldrin and 4.09 μg/kg DDT. Yoghurt from Ayeduasi gate, KNUST, recorded a mean of 8.96 pg/kg DDT, 0.14 μg/kg dieldrin, 1.60 μg/kg DDE, 0.05 μg/kg endosulfan, 0.08 μg/kg aldrin. Lindane level in yoghurt from Ayeduasi gate was below detection. The average amounts of residues in yoghurt from Kumasi Polytechnic Campus were 0.01 μg/kg lindane, 0.09 μg/kg aldrin, 0.06 μg/kg endosuifan, 0.49 μg/kg DDE, 0.02 μg/kg dieldrin and 752 μg/kg DDT. The mean levels or organochlorine residues in cheese from Tafo were 4.41 μg/kg lindane, 1.54 μg/kg aldrin, 4.25 μg/kg endosulfan, 140.15 μg/kg DDE, 15.95 μg/kg dieldrin and 298.57 μg/kg DDT. There was an average level of 3.18 μg/kg aldrin, 2.70 μg/kg endosulfan, 31.50 μg/kg DDE, 2.01 μg/kg dieldrin and 42.17 μg/kg DDT in cheese from Asawasi. Cheese from Aboabo recorded the mean levels 2.35 μg/kg aldrin, 3.31 μg/kg endosulfan, 149.07 μg/kg DDE, 4.30 μg/kg dieldrin and 14.02 μg/kg DDT. Lindane was below detection in cheese from Aboabo and Asawasi. Levels of DDT and its metabolite, DDE, in cheese from all the three sampling sites (Aboabo, Asawasi and Tafo) were above the levels recommended by World Health Organisation (WHO). The average levels of DDT residue in beef fat from Buoho and Kumasi abattoirs were also very close to the maximum limits. Although, most of the organochiorine residues detected were below the maximum limits set by the FAQ/WHO, bioaccumulation of these residues is likely to pose health problems in higher organisms like human beings.
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    Dietary intake of organophosphorus pesticide residues through vegetables from Kumasi, Ghana
    (Food and Chemical Toxicology, 2008-09-22) Darko, Godfred; Osei, Akoto; 0000-0001-7157-646X
    Contamination and health risk hazards of organophosphorus pesticides residues in vegetables were studied. Ethyl-chlorpyrifos, observed at an average level of 0.211 ± 0.010 mg kg1 in 42% of tomato, 0.096 ± 0.035 mg kg1 in 10% of eggplant and 0.021 ± 0.013 mg kg1 in 16% of pepper was below the 0.5 mg kg1 MRL. Dichlorvos was the most frequently detected residue in all the samples analyzed. Levels of malathion in tomatoes (0.120 ± 0.101 mg kg1) and pepper (0.143 ± 0.042 mg kg1) exceeded the MRL of 0.1 mg kg1. Health risks were found to be associated with methyl-chlorpyrifos, ethyl-chlorpyrifos, and omethioate in tomatoes and methyl-chlorpyrifos, ethyl-chlorpyrifos, dichlorvos, monocrotophos and omethioate in eggplant. Routine monitoring of these pollutants in food items is required to prevent, control and reduce the pollution and to minimize health risks.
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    Dietary intake of organophosphorus pesticide residues through vegetables from Kumasi, Ghana
    (Pergamon, 2008-12-01) Darko, Godfred; Akoto, Osei
    Contamination and health risk hazards of organophosphorus pesticides residues in vegetables were studied. Ethyl-chlorpyrifos, observed at an average level of 0.211 ± 0.010 mg kg 1 in 42% of tomato, 0.096 ± 0.035 mg kg 1 in 10% of eggplant and 0.021 ± 0.013 mg kg 1 in 16% of pepper was below the 0.5 mg kg 1 MRL. Dichlorvos was the most frequently detected residue in all the samples analyzed. Levels of malathion in tomatoes (0.120 ± 0.101 mg kg 1) and pepper (0.143 ± 0.042 mg kg 1) exceeded the MRL of 0.1 mg kg 1. Health risks were found to be associated with methyl-chlorpyrifos, ethyl-chlorpyrifos, and omethioate in tomatoes and methyl-chlorpyrifos, ethyl-chlorpyrifos, dichlorvos, monocrotophos and omethioate in eggplant. Routine monitoring of these pollutants in food items is required to prevent, control and reduce the pollution and to minimize health risks.
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    Dimethylglyoxime based ion-imprinted polymer for the determination of Ni(II) ions from aqueous samples
    (2011-05-30) Modise Rammika; Darko, Godfred; Tshentu, Zenixole; Sewry, Joyce; Torto, Nelson; 0000-0001-7157-646X
    A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was synthesised by the bulk polymerisation method. The morphology of the Ni(II)-DMG IIP and non-imprinted polymer were observed by scanning electron microscopy and the chemical structures were evaluated by infrared spectroscopy. Selectivity of the Ni(II)-DMG IIP was studied by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. The studies revealed Ni(II) recoveries ranging from 93 to 100% in aqueous solutions with minimal interference from competing ions. Enrichment factors ranged from 2 to 18 with a binding capacity of 120 µg∙g−1. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). Selectivity studies confirmed that the Ni(II)-DMG IIP had very good selectivity, characterised by %RSD of less than 5%. The limits of detection and quantification were 3x10-4 µg∙mℓ−1 and 9x10-4 µg∙mℓ−1, respectively. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3) and the concentration of Ni(II) obtained was in close agreement with the certified one. The Ni(II)-DMG IIP was successfully employed to trap Ni(II) ions from a matrix of sea, river and sewage water. It is believed that the Ni(II)-DMG IIP has potential to be used as sorbent material for pre-concentration of Ni(II) ions from aqueous solutions by solid-phase extraction.
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    Disposal of Unused and Expired Medicines within the Sunyani Municipality of Ghana: A Cross-Sectional Survey
    (Journal of Environmental and Public Health, 2022-05-26) Ivy Anima Amoabeng; Otoo. Bernice Araba; Darko, Godfred; Borquaye, Lawrence Sheringham; 0000-0002-5037-0777; 0000-0001-7157-646X
    The occurrence of pharmaceuticals in the environment is a global challenge. Pharmaceuticals such as antibiotics and analgesics have been reported in various environmental matrices at varying concentrations. ,e major disposal route for unused and expired pharmaceuticals in Ghana is throwing them into dustbins. Although there are laws on the proper disposal patterns of drugs, these laws are poorly implemented. Sunyani is a fast-growing community with several health facilities that dispense medications daily. The purchase and use of medications among households are also high. However, no data exist on the disposal patterns of pharmaceuticals within the Sunyani Municipality. ,is study aims to identify the disposal patterns for unused and expired medications by households and pharmacies within the Sunyani Municipality, Ghana. A descriptive cross-sectional study was conducted among 400 persons in homes and 35 persons from randomly selected pharmacies and over-the-counter medication shops (OTCMs) within the Sunyani Municipality. A face-to-face interview approach using structured questionnaires for each respondent was employed. Household respondents disposed of unused and expired medications mainly through dumping in garbage cans (70.8%), incineration (11.5%), and
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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.