Browsing by Author "Gyamfi, Opoku"

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    Changes in Water Quality from Source to Point-of-Use: A case study of the Owabi Headworks
    (2012-9-19) Gyamfi, Opoku
    Water supports all forms of life and is a key natural resource that is inevitable for sustaining human health. Poor quality water is a vehicle for the spread of diseases. This study was conducted to ascertain the change in quality of drinking water from source to point-of-use from the Owabi Headworks supplies to some parts of Kumasi and its environs...
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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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    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.