Browsing by Author "Akoto, Osei"

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    Antimicrobial and Phytochemical Properties of Alstonia Boonei Extracts
    (OMICS Publishing Group, 2015-01-01) Opoku, Francis; Akoto, Osei
    Alstonia boonei De wild is a major spice crop grown abundantly in Ghana and other tropical countries. In this study we have carried out phytochemical analysis and antimicrobial investigation of ethanol and aqueous extracts of the root of Alstonia boonei against a panel of clinically significant bacterial and fungal strains. Four Gram positive and Gram negative bacteria namely Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus were subjected to test the antimicrobial activity along with one fungi namely, Candida albicans. The ethanol and aqueous extracts of root of Alstonia boonei were subjected to microbial susceptibility assays using agar well diffusion method. Phytochemical screening was done to test the presence of phytochemicals responsible for the antimicrobial potential of roots of Alstonia boonei. The results of the phytochemical studies revealed the presence alkaloids, cyanogenetic glycosides, flavonoids, terpenoids and steroids and saponins. Susceptibility testing by disc diffusion assay revealed significant antimicrobial activity of methanol and aqueous extracts of the roots against the pathogens tested. The minimum inhibitory concentrations (MIC) of the various extracts by Agar Dilution method ranged from 3.0 to 10.0 mg/ml. The ethanol extracts exhibited better antimicrobial activity than aqueous extract. The study findings provide supportive evidence for the use of Alstonia boonei in traditional medicines.
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    Carcinogenic and non-carcinogenic risk of organochlorine pesticide residues in processed cereal-based complementary foods for infants and young children in Ghana
    (Pergamon, 2015-08-01) Akoto, Osei; Oppong-Otoo, John; Osei-Fosu, Paul
    Fourteen organochlorine pesticides (OCPs) residues were analyzed in 10 brands of processed cereal-based complementary foods with the aim of assessing the health risk to infants and young children. The QuEChERS method was used for extraction and clean-up of pesticide residues. Subsequent detection and quantification were done using GC with ECD and PFPD. Levels of p,p0-DDE, dieldrin, b-endosulfan, b-HCH, and c-HCH detected in the processed cereal-based complementary food were higher than their respective MRL. The mean estimated daily intakes of OCPs in infants were significantly higher than that of young children. Exposure levels of heptachlor and dieldrin were higher than their respective ADI’s. Their HIs recorded were greater than 1 indicating the possibility of adverse health effect on consumers. Hazard ratio for carcinogenic risk posed by b-HCH, dieldrin, heptachlor, c-HCH and c-chlordane were greater than 1. This result raises concerns of possible carcinogenicity for infants and young children.
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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, Spatial Variation and Risk Assessment of Heavy Metals and a Metalloid in Surface Soils in Obuasi, Ghana
    (Black Smith Institute, 2018-08) Akoto, Osei; Bortey-Sam, Nesta; Nakayama, Shouta M.M.; Ikenaka, Yoshinori; Baidoo, Elvis; et. al
    Soil contamination with heavy metals and metalloids has become an increasingly important issue in recent years. Objectives. The present study examines possible contamination of the environment with metals from gold mining activities in Obuasi, Ghana. Methods. Soil samples were collected from commercial and residential areas and tailing dams in Obuasi in order to investigate the extent of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu), zinc (Zn), cobalt (Co), chromium (Cr), nickel (Ni) and arsenic (As) pollution, create thematic maps showing the extent of heavy metals pollution, identify the sources of pollution, and to assess risks to humans and the surrounding ecological system. Results. Mean concentrations of metals from the study were found in the order of As > Cu > Zn > Cr > Ni > Pb > Co > Hg > Cd. The results showed that all communities were severely polluted with As, and distribution maps highlighted two hot spots at the sulfite treatment plant and Pompura treatment plant tailings dams. Additionally, the levels of Pb, Cu and Zn were elevated around the city center where vehicular traffic is very dense. Principal component analysis indicated that mining activities may have significantly contributed to metal levels in Obuasi soils. The potential ecological risk (RI) indicated that soils in 41% of the communities pose very high risks to the surrounding ecological system, 50% pose considerable risk, and 9% pose a moderate risk. Arsenic and Hg contributed 73 and 15% of the RI, respectively. The average hazard quotient due to soil As exposure was 2.51 ± 1.23 and ingestion of soils in 95% of the communities in the study area could pose non-carcinogenic health risks to children. Moreover, the average cancer risk for children from the communities was 1.13 × 10-3. Based on the United States Environmental Protection Agency (USEPA) recommendation for cancer risk of 10-6 to 10-4, the cancer risk for children (> 10-3) was higher in 45% of the studied communities. Conclusions. The central part of the study area is polluted with Pb, Zn and Cu, and As pollution is severe in all of the studied communities. The RI from all study sites revealed very high risk to the ecological system, including mammals. There could be non-cancer and cancer risks to Obuasi residents due to ingestion of As-contaminated soils, and children are particularly vulnerable. Competing Interests. The author declares no competing financial interests
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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 characteristics and health hazards of heavy metals in shallow groundwater: case study Anloga community, Volta Region, Ghana
    (Springer International Publishing, 2019-03-01) Akoto, Osei; Agbeshie Teku, Justice; Gasinu, Diane
    Five water samples each were collected from six shallow wells which serve as source of drinking water at different locations within the Anloga community of the Volta Region in Ghana. Samples were analyzed for physicochemical characteristics, and human health risk associated with the consumption of heavy metals in the samples was also assessed. The results showed that pH, EC, water hardness, fluoride and sulfate levels were below the maximum permissible levels recommended by the WHO for drinking but chloride and nitrate levels in well A6 were above their respective WHO limits. Concentration of heavy metals showed Cd and Pd toxicities in some of the wells since their concentrations were higher than the WHO accepted limit for drinking water. Estimated non-carcinogenic health risks of the metals through ingestion were less than 1 in some of the wells, indicating small to no health hazard; however, high non-carcinogenic risk was recorded in well 2, 3 and 5 indicating a potential health hazard to the local residents. Health risk through dermal injection of the metals was found to be less than 1, indicating no health risk associated with water samples via dermal absorption. Cancer risk computed for Cd ranged from 1.82E−02 in well A5 to 9.09E−02 in well A1 and A6, indicating that consumption of water from these wells could result in an excess of 2–9 cancer cases per 100 people. The risk of developing cancer from Pb as a result of consuming water from wells A1, A2 and A5 was estimated to be 3.69E−06
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    Contamination Levels and Sources of Heavy Metals and a Metalloid in Surface Soils in the Kumasi Metropolis, Ghana
    (Black Smith Institute, 2017-09) Akoto, Osei; Bortey-Sam, Nesta; Ikenaka, Yoshinori; Nakayama, Shouta M.M.; Baidoo, Elvis; et. al
    Environmental contamination with heavy metals and metalloids due to industrial, smelting and mining activities have become common in large and growing cities. Kumasi is one of the most industrialized cities in Ghana and experiences metal pollution due to recent and past activities. Although metals are naturally abundant in the area, their accumulation in soils could potentially lead to adverse effects on local ecosystems. Objectives. The aims of this study were to determine the distribution, enrichment, geo-accumulation and sources of metals in Kumasi soils and to estimate the contamination factor (CF) and pollution load index (PLI) of these metals in soils. Methods. Concentrations of eight heavy metals and a metalloid were determined in 112 soil samples randomly collected from 31 sampling sites in the area. In addition, 5 soil samples were collected from a pristine site (Kwame Nkrumah University of Science and Technology Botanical Gardens) for data comparison, to determine the local background values for metal concentrations and to evaluate the extent of metal pollution in the study area. Results. Heavy metals such as zinc (Zn), lead (Pb), cadmium (Cd) and chromium (Cr) were enriched in 65, 32, 58 and 93% of the sampling sites, respectively, and geo-accumulation indexes for Cr, Zn, Cd, mercury (Hg) and Pb showed moderate to extreme contamination in 100, 97, 77, 65 and 45% of the sampling sites, respectively. Principal component and cluster analyses revealed that industrial activities including mining were the major sources of metals in Kumasi soils with high metal input in the community of Suame. Distribution maps revealed hotspots of Cd, nickel (Ni), arsenic (As), cobalt (Co), copper (Cu) and Pb in Suame. The highest CFs for Cu, Cd, Ni, As, Co and Pb highlighted anthropogenic inputs in Suame, while Hg was highest in Mbrom, Zn in Suntreso, and Cr in Aboabo. Conclusions. The PLI of metals revealed Suame as the most polluted study site, while Anomangye and Bomso were the least polluted. Competing Interests. The authors declare no competing financial interests.
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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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    Dissolved nitrogen in drinking water resources of farming communities in Ghana
    (Academic Journals, 2008) Akoto, Osei; Adiyiah, Jackson
    A water quality study was carried out on streams and boreholes which serve as drinking water sources in farming communities in the Brong Ahafo region of the Republic of Ghana. The objective of this research was to determine concentrations of different forms of nitrogen in drinking water samples. Water samples were collected from these sources every three months (from January – December 2005) and analyzed for ammonia, nitrate and nitrite using the Palintest Photometer Method. Results indicated the annual mean concentration of nitrate, nitrite and ammonia varied from 0.09 - 1.06 mg/l, 0.006 - 0.36 mg/l and 0.008 - 0.179 mg/l respectively. An important observation is that, in general, higher nitrate and nitrite concentrations were found during the rainy season compared to the dry season. Concentrations of these potentially toxic substances were below WHO acceptable limits for surface and groundwaters, indicating these water resources appear safe for drinking from a dissolved nitrogen perspective.
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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 Organs of Sheep and Goat Reared in Obuasi: A Gold Mining Town in Ghana
    (International Journal of Environmental Science and Toxicology, 2014) Akoto, Osei; Bortey-Sam, Nesta; Nakayama, Shouta M.M.; Ikenaka, Yoshinori; Elvis Baidoo; et. al
    The aim of this study was to determine the concentration of metals in some organs of goat and sheep and assess the distribution of these metals in the sample tissues. Samples were digested with 60% nitric acid and concentrations of the heavy metals measured using atomic absorption spectrophotometer while the concentrations of Hg were measured with mercury analyzer. Concentrations of Zn, Cu were very high in the organs followed by Cr, Ni, Co, Pb, Cd, As and Hg. Total rank score assessment showed that liver, kidney and lung had accumulated high levels of metals while brain accumulated lowest. Mean Zn concentrations in all organs ranged between 24.88±11.22 in goat brain and 97.06±19.66 mg/kg in liver of goat. Mean Cu concentrations ranged between 7.96±1.20 (small intestine of sheep) and 106.63±111.24 mg/kg in liver of sheep. Cd concentration in liver and kidney in both species were above the EU set limit of 0.05 mg/kg. Concentrations of Co in liver, kidney and lungs of the two different animals did not vary significantly. As and Hg concentration were homogenous in all the organs of both animals and did not show any significant variation. Prolonged consumption of kidney, liver and lungs of goats and sheep having high concentrations of Zn Cu and Cd may lead to accumulation of these metals in humans and cause metal toxicity.
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    Effects of Per-household treatments on chlorpyrifos residues in Lettuce (Lactuce sativa)
    (BioMed Central, 2016-12) Akoto, Osei; Addai-Mensah, Fredrick
    The study was organized to evaluate the extent of accumulation of chlorpyrifos on Lactuca sativa during cultivation and also examine the effect some pre-household treatment procedure on residue levels. Concentrations of Chlorpyrifos applied at different stages of growth of lettuce were examined using GC equipped with LCD. at different time intervals of 1 h 24 h and 7 days after pesticide application. The results showed that residue levels detected at 1 h and 24 h after application were all above the MRL of 0.05 mgkg-1 and can pose health risk to consumers while that recorded 7 days after application were far below the MRL. Accumulation of chlorpyrifos on crop during cultivation was not observed since no significant differences were observed 7 days after application at all the different stages. There is therefore the need for farmers to allowed 7 days’ re-entry intervals before harvesting. All the pre-household treatment procedures caused significant reduction in residues levels. Treatment T3 was most effective in removing residues. Hence to reduce the risk associated with intake of chlorpyrifos through lettuce, T3 procedure should be followed before consumption.
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    Excretion of polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in cattle urine in Ghana
    (Elsevier, 2016-11-01) Bortey-Sam, Nesta; Ikenaka, Yoshinori; Akoto, Osei; Nakayama, Shouta M.M.; Marfo, Jemima; et. al
    Previous studies of polycyclic aromatic hydrocarbons (PAHs) in particulate matter, soils and livers of wild rats indicated that the city centre of Kumasi, Ghana has been severely polluted with high cancer potency. Cattle urine were therefore collected from Kumasi (urban) and Offinso (rural), Ghana: to determine concentrations of urinary PAH metabolites (OH-PAHs); and find their association with sex; and to estimate exposure of cattle to PAHs from the different sites. From the results, geometric mean concentrations (adjusted by specific gravity), GMSG, showed that 2-OHNaphthalene (2-OHNap) was the most abundant OH-PAH in cattle urine from all study sites, and naphthalene-containing-mothballs might have contributed significantly to the levels. There was no significant difference between urinary OH-PAHs concentrations in cattle from urban and rural sites except for 2-OHPhe and 4-OHPhe, and similar to urban areas, rural sites could also be polluted with PAHs. GMSG of 2-OHNap in cattle urine in Kokote (21.9 ± 6.51 ng/mL; a rural area), was significantly higher compared to the other sites followed by Oforikrom (4.15 ± 4.37 ng/mL; urban). The GMSG concentration (ng/mL) of the sum of OH-PAHs decreased in the order, Kokote (44.7) > Oforikrom (7.87) > Saboa (6.98) > Santasi (6.68) > and Twumasen Estate (5.23). The high concentrations of urinary 2-OHNap, 2-3-OHFlu, 2-OHPhe, 3-OHPhe and 4-OHPhe in Kokote indicated high PAHs exposure to cattle in this area or different/specific source of PAHs exposure. GMSG of 2-OHNap was significantly higher in male cattle compared to females while 1-9-OHPhe was significantly higher in females. Capsule: 3 PAH metabolites were measured in cattle urine in urban and rural areas in Ghana; 2- OHNaphthalene (2-OHNap) was the most abundant PAH metabolites.
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    Exposure levels of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in wild rats in Kumasi, Ghana
    (Peer reviewed and revised papers, 2015-08-31) Bortey-Sam, Nesta; Ikenaka, Yoshinori; Akoto, Osei; Nakayama, Shouta M.M.; Yohannes, Yared Beyene; et. al
    Wild rats were trapped from communities in Kumasi, Ghana, to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and heavy metals. The results of the study showed that phenanthrene (0.51 ± 0.08 ng/g dw) was the most abundant individual PAH in the liver of wild rats. The ΣPAH concentrations in liver ranged from 0.05 to 1.64 ng/g dw in Bomso (a community) and city centre, respectively. Abundance of individual PAHs in the liver of wild rats decreased in the order: phenanthrene > pyrene > acenaphthene > naphthalene > fluoranthene and > anthracene. Levels of phenanthrene and pyrene detected were significantly higher than other PAHs. Naphthalene and fluoranthene were detected in 80% and 78% of the samples collected respectively. Heavy metals in the liver of wild rats in Kumasi decreased in the order Zn > Cu > As > Ni > Pb > Co > Cd > Cr.
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    Heavy metal contamination assessment of groundwater quality: a case study of Oti landfill site, Kumasi
    (Springer International Publishing, 2019-03-04) Boateng, Thomas Kwame; Opoku, Francis; Akoto, Osei
    Environmentally friendly municipal solid waste management is the biggest problem facing several developing countries, including Ghana. Heavy metals pollution generated by landfill leachate has become increasingly concerned due to its potential impact on human health. This study assessed the pollution level and sources of heavy metal levels in groundwater, as well as evaluated the human health risk effect. The sampling technique and sample treatment were done based on the Standard Methods for the Examination of Water and Wastewater. The results suggested that the mean concentration of Pb, Fe, Cd, and Cr was above the acceptable limits of the World Health Organization for drinking water except for Zn and Cu. The heavy pollution index indicates contamination, while hazard index values at sites BH1 and W4 were greater than one, suggesting adverse health effects. However, the heavy metal pollution index values were less than the critical limit of 100 for drinking water. Multivariate analysis predicted that lithogenic and anthropogenic factors were the possible sources of water pollution of heavy metal in the Oti community. Thus, multivariate statistical techniques could be a beneficial tool for the evaluation of possible sources of heavy metal contamination. The high levels of heavy metals found in the Oti community suggested a considerable pollution of water by leachate percolation from the landfill site. The findings of the study, which can be used in areas under similar environmental conditions, can offer a valuable benchmark for the design of suitable approaches to manage groundwater resources by both local and national policymakers
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    Heavy Metals Pollution in Surface Soils in the Vicinity of Abundant Railway Servicing Workshop in Kumasi, Ghana
    (Int. J. Environ. Res., 2008) Akoto, Osei; Ephraim, J. H.; Darko, Godfred; 0000-0001-7157-646X
    Heavy metals in soils are of great environmental concern, in order to determine heavy metal content in the surface soil from the vicinity of an abundant railway servicing workshop and evaluate the contamination levels, 40 surface soil samples were collected and analyzed for Cu, Zn, Cd, Pb, Fe and Ni contents using atomic absorption spectroscopy. Soil texture, conductivity, pH, total organic content and cation exchange capacity were also measured. Heavy metals concentrations were determined after digestion of samples with aqua regia. In the investigated soils, the mean recorded concentrations of the heavy metals were 7.21 mg/kg f ff or Cu, 0.033 mg/kg for Ni, 0.087 mg/ kg for Cd, 48.52 mg/kg for Fe, 7.33 mg/kg for Zn and 26.66 mg/kg for Pb. The reported results indicate that the enrichment factors of the measured heavy metals were 2.26, >0.1, 0.39 and 3.47 for copper, nickel, zinc and lead respectively. I-geo (geoaccumulation index) values of the metals in the soils under study indicate that they are uncontaminated to slightly contaminate with nickel and iron but highly contaminated with copper and lead.
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    Human health risks from metals and metalloid via consumption of food animals near Gold Mines in Tarkwa, Ghana: Estimation of the daily intakes and target hazard quotients (THQs)
    (Academic Press, 2015-01-01) Bortey-Sam, Nesta; Nakayama, Shouta M.M.; Ikenaka, Yoshinori; Akoto, Osei; Baidoo, Elvis; et. al
    Heavy metal and metalloid contamination in food resulting from mining is of major concern due to the potential risk involved. Food consumption is the most likely route for human exposure to metals. This study was therefore to estimate the daily intake and health risk (based on target hazard quotients, THQ) from metals via consumption of free-range chicken, goat and sheep near gold mines in Tarkwa, Ghana. The concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb were measured with an inductively coupled plasma33 mass spectrometer and Hg analysis was done using the mercury analyzer. The mean concentrations of metals ranged from nd–542 mg/kg wet weight. Principal component analysis of the results showed a clear separation between chicken, grouped on one side, and the ruminants clustered on another side in both offal and muscle. Interestingly, As, Cd, Hg, Mn and Pb made one cluster in the offal of chicken. Chicken muscle also showed similar distribution with As, Hg and Pb clustered together. The daily intake of As (μg/kg body weight/day) were in the following ranges; [0.002 (kidneys of goat and sheep)–0.19 (chicken gizzard)], Cd [0.003 (chicken muscle)–0.55 (chicken liver)], Hg [0.002 (goat muscle)–0.29 (chicken liver)], Pb [0.01 (muscles and kidneys of goat and sheep)–0.96 (chicken gizzard)] and Mn [0.13 (goat kidney)–8.92 (sheep liver)]. From the results, daily intake of As, Cd, Hg, Pb and Mn in these food animals were low compared to the provisional tolerable daily intake guidelines. The THQs although less than one, indicated that contributions of chicken gizzard and liver to toxic metal exposure in adults and especially children could be significant.
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    Pesticide residues in water, sediment and fish from Tono Reservoir and their health risk implications
    (Springer International Publishing, 2016-12-01) Akoto, Osei; Azuure, Augustine Asore; Adotey, K. D.
    Levels of organochlorine (OC) and organophosphorus (OP) pesticide residues in fish, sediments and water and their health risk associated with the consumption of the fish from the Tono Reservoir, Ghana were evaluated. The analytical methods included solvent extraction of the pesticide residues using ultrasound sonication and soxhlet extraction and their subsequent quantification using GC equipped with electron capture detector and pulse flame photometric detector after clean-up on activated silica gel/anhydrous sodium sulphate. A total of 29 pesticides comprising 16 OCs and 13 OPs were analyzed, out of which aldrin, p,p′-DDE and p,p′-DDD were detected in fish and sediment samples. The results showed that all the residues in water had their concentrations below the detection limit. Mean concentrations of organochlorine pesticide (OCP) residues in fish ranged from 0.017 to 0.17, 0.043 to 0.30, 0.027 to 0.243 and 0.097 to 0.263 μg/g in Sarotherodon galilaeus, Clarias anguillaris, Schilbe intermedius and Marcusenius senegalensis respectively. Mean concentrations of organophosphates pesticides ranged from 0.080 to 0.090, 0.080 to 0.087 and 0.050 to 0.063 μg/g in C. anguillaris, S. intermedius and M. senegalensis respectively. The level of chlorpyrifos in S. galilaeus was 0.160 μg/g. Mean concentrations of OCP residue in sediments ranged from 0.047 to 0.090 μg/g. Aldrin recorded the highest level while p,p′-DDD recorded the lowest level. The mean concentrations for all the detected residues were below the WHO/FAO maximum residue limits. Health risk estimation revealed that aldrin in M. senegalensis had great potential for systemic toxicity to consumers.
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    Potentials of Synedrella nodiflora and Sida fallax growing naturally around an abandoned railway station for phytoextraction of heavy metals
    (Academic Journals, 2012-07-31) Akoto, Osei; Lawson, Belinda Akokor; Marfo, Jemima Tiwaa
    Phytoextraction is a non-destructive, cost-effective and safe alternative to conventional cleanup techniques of contaminated soils. In this study, the ability of two plants species Synedrella nodiflora and Sida fallax growing naturally around the abandoned Asafo Railway Station in Kumasi for selective extraction and accumulation of four heavy metals (Pb, Cu, Fe and Zn) were studied using Atomic Absorption Spectroscope. The degree of translocation of these metals by the plants was also calculated. High translocation indices greater than one in the case of Fe and Zn were recorded in S. nodiflora and S. fallax, respectively. However Cu and Pb examined in this study were not effectively extracted nor transported within the plants, hence these plants are excluders of Cu and Pb. The soil plant transfer coefficient for both plant species were calculated for each metal. The highest translocation coefficient value in this study for both plants was recorded for Zn. The translocation coefficient values for Pb and Cu were not significant in both plants, hence these plants can be described as Pb and Cu extruders but potential candidates for Fe bioaccumulation using phytoextraction.
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    Preliminary Studies on the Use of Sawdust and Peanut Shell Powder as Adsorbents for Phosphorus Removal from Water
    (Emerging Science Journal, 2019-02-25) Nkansah, Marian Asantewah; Donkoh, Moses; Akoto, Osei; Ephraim, James Hawkins
    Phosphorus is one of the key nutrients that contribute to eutrophication and excess algal growth in rivers and lakes and other surface water bodies. Such algal blooms affect the life of aquatic organisms, especially fishes, and block sunlight from reaching bottom dwelling plants thus inhibiting photosynthesis and stunting growth. In this study, sawdust and peanut shell powder were explored as adsorbents for the removal of phosphorus from aqueous solutions. A series of batch experiments were conducted to determine the effects of adsorbent dosage, initial phosphorus concentration and contact time on the rate of phosphorus removal. The results showed that 78% and 39% of phosphorus was removed by sawdust and peanut shell powder respectively at adsorbate concentrations of 10 mg/l (total P) for a period of 180 min at an adsorbent dosage of 0.4 g. It was also found that the highest phosphorus removal occurred at adsorbent mass of 0.4 g of sawdust and 0.6 for peanut shell powder. Adsorption data were fitted to the linearised forms of the Freundlich and Langmuir isotherm models to determine the water - adsorbent partitioning coefficient. Sawdust proved to be a better adsorbent than peanut shell powder.