Browsing by Author "Omwoma, Solomon"

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    Comparative exposomics of persistent organic pollutants (PCBs, OCPs, MCCPs and SCCPs) and polycyclic aromatic hydrocarbons (PAHs) in Lake Victoria (Africa) and Three Gorges Reservoir (China)
    (Science of the Total Environment, 2019) Omwoma, Solomon; Muendo Mbithi, Bonface; Pandelova, Marchela; Ssebugere, Patrick; Lalah, Joseph O.; Wang, Yawei; Bi, Yonghong; Henkelmann, Bernhard; Schramm, Karl-Werner
    Exposomics is assessment of organism exposure to high priority environmental pollutants in an ecosystem using OMIC technologies. A virtual organism(VO) is an artificial property-tool (OMIC) reflecting exposomic process in compartments of real organisms. The exposomics of aquatic organisms inhabiting Lake Victoria (L.V.) and Three Gorges Reservoir (TGR) were compared using VOs. The two reservoirs are heavily depended on for food and water both in Africa and China. The target priority pollutants in the reservoirs were polyclic aromatic hydrocarbons (PAHs) and persistent organic pollutants such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), medium chain chlorinated paraffins (MCCPs) and short chain chlorinated paraffins (SCCPs). The VOs showed that in a period of 28 days, aquatic organisms in TGR were exposed to total (Σ) PAHs of 8.71 × 10−6 mg/L, PCBs of 2.81 × 10−6 mg/L, OCPs of 2.80 × 10−6 mg/L, MCCPs of 8.9 × 10−10 mg/L and SCCPs of 1.13 × 10−7 mg/L. While in a period of 48 days, organisms in L. V. were exposed to total (Σ) PAHs of 7.45 × 10−6 mg/L, PCBs of 4.70 × 10−6 mg/L, OCPs of 3.39 × 10−8 mg/L,MCCPs of 4.6 × 10−10 mg/L and SCCPs of 3.6 × 10−9 mg/L. The exposomic levels in TGR after 28 dayswere higher than those in Lake Victoria after 48 days. In both reservoirs, bioaccumulation levels are above set standards for aquatic organisms. The sources of the pollutants into the reservoirswere diagnostically determined to originate fromanthropogenic processes such as petrogenic, diesel emissions, biomass burning, coal combustion, electronic wastes, traffic emissions and historic uses.
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    Environmental levels and human body burdens of per- and polyfluoroalkyl substances in Africa: A critical review
    (Science of the Total Environment, 2020) Ssebugere, Patrick; Sillanpää, Mika; Matovu, Henry; Wang, Zhanyun; Schramm, Karl-Werner; Omwoma, Solomon; Wanasolo, William; Chelangat Ngeno, Emily; Odongo, Silver
    Per- and polyfluoroalkyl substances (PFASs) are known organic pollutants with adverse health effects on humans and the ecosystem. This paper synthesises literature about the status of the pollutants and their precursors, identifies knowledge gaps and discusses future perspectives on the study of PFASs in Africa. Limited data on PFASs prevalence in Africa is available because there is limited capacity to monitor PFASs in African laboratories. The levels of PFASs in Africa are higher in samples from urban and industrialized areas compared to rural areas. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the dominant PFASs in human samples from Africa. Levels of PFOS and PFOA in these samples are lower than or comparable to those from industrialised countries. PFOA and PFOS levels in drinking water in Africa are, in some cases, higher than the EPA drinking water guidelines suggesting potential risk to humans. The levels of PFASs in birds’ eggs from South Africa are higher, while those in other environmental media from Africa are lower or comparable to those from industrialised countries. Diet influences the pollutant levels in fish, while size and sex affect their accumulation in crocodiles. No bioaccumulation of PFASs in aquatic systems in Africa could be confirmed due to small sample sizes. Reported sources of PFASs in Africa include municipal landfills, inefficient wastewater treatment plants, consumer products containing PFASs, industrial wastewater and urban runoff. Relevant stakeholders need to take serious action to identify and deal with the salient sources of PFASs on the African continent.