Browsing by Author "Kato, Charles Drago"

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    Electronic wastes in sub-Saharan Africa : a critical review of environmental and health impacts, regulatory responses, and future perspectives.
    (Elsevier Inc., 2025) Ssebugere, Patrick; Miiro, Ashirafu; Matovu, Henry; Odongo, Silver; Kato, Charles Drago; Babirye, Prudence Mary; Nabuuma, Josephine; Sillanpaa¨, Mika; Sifuna, Douglas; Nyakairu, George William
    Recent technological advancements coupled with lax policy regulations have caused increased electronic waste (e-waste) burden in the Sub-Saharan Africa (SSA), thereby exacerbating the environmental signatures of hazardous substances including contaminants of emerging concern (CECs), endocrine-disrupting chemicals (EDCs), persistent organic pollutants (POPs), and toxic metals such as lead (Pb), mercury (Hg), and cadmium (Cd), among others. This review synthesized 62 studies published between 2008 and 2025 to assess the environmental and health risks associated with e-waste disposal in SSA. Pb, Hg, Cd, and brominated flame retardants were the most detected hazardous substances. Near e-waste sites, Pb levels in soil ranged from 120 to 14,000 mg/kg, while Cd reached 6.8 mg/kg in topsoil. Water contamination by Hg near informal processing sites ranged from 0.3 to 2.8 µg/L, exceeding the U.S Centers for Disease Control and Prevention (CDC) safety thresholds. Air pollution from open burning releases polycyclic aromatic hydrocarbons (400–1800 ng/m3), dioxins (3.5–19.2 ng/m3), and volatile metals, worsening the environmental health crisis. Informal recycling practices were the primary source of these pollutants, exposing workers and nearby communities to these toxic substances. This review highlighted significantly elevated health risks, with widespread exceedance of safety thresholds (e.g., blood Pb levels up to 309 µg/dL, compared to CDC reference: 5 µg/dL; Cd up to 8.5 µg/L), leading to cognitive deficits, neurological damage, cancer, and respiratory and reproductive disorders, particularly for the vulnerable populations. Observed trends, gaps in recycling infrastructure and policy underscore the urgent need for improved legislation, formal recycling systems, and public awareness to mitigate health risks in the SSA. Keywords: E-waste, Sub-Saharan Africa, EDCs, Heavy metals, Recycling, Exposure
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    Legacy and emerging organic pollutants in indoor and outdoor environments in Africa : contamination levels, health risks, and analytical techniques.
    (Elsevier B.V., 2025) Muhwezi, Godfrey; Kyarimpa, Christine; Gumula, Ivan; Nagawa, Christine Betty; Omwoma, Solomon; Matovu, Henry; Matsiko, Julius; Odongo, Silver; Sifuna, Douglas; Spanik, Ivan; Kato, Charles Drago; Ssebugere, Patrick
    The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic pollutants (EOPs) are among the biggest contributors to this burden. Herein we reviewed literature published for the period 2000e2023 on selected LOPs and EOPs in indoor dust and outdoor air in Africa to understand the occurrence, associated human health risks and common analytical techniques used to identify and quantify these contaminants. The findings revealed generally lower contamination levels for most pollutants than that in most regions outside Africa except for PCBs in outdoor air and OCPs in indoor settled dust. Apart from a few studies for polychlorinated biphenyls (PCBs), most studies reported hazard index (HI) values less than 1 for outdoor air and indoor dust exposure, which suggested negligible non-carcinogenic risks in children and adults. Gas Chromatography and mass spectrometry were the most frequently used analytical techniques for both air and dust probably due to their sensitivity and selectivity in detecting chemical traces at the pg m 3 and ng g 1 levels. Although the current contamination levels are generally low, their synergistic and cumulative effects may in the long run affect the environment and human health. There is also a paucity of data on most contaminants, especially for PCNs, and PFASs in both outdoor air and dust. Coordinated efforts are needed to limit the trade, importation, and disposal of products containing LOPs and EOPs in Africa.
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    Novel and legacy per- and poly-fluoroalkyl substances in major wastewater treatment plants within the Lake Victoria basin, East Africa.
    (Elsevier B.V., 2025) Miiro, Ashirafu; Mubiru, Edward; Odume, Oghenekaro Nelson; Odongo, Silver; Nyakairu, George William; Matovu, Henry; Kato, Charles Drago; Spanik, Ivan; Sillanpää, Mika; Sifuna, Douglas; Khvalbota, Liudmyla; Ssebugere, Patrick
    Over the past two decades, rapid urbanization and industrialization in Uganda have generated wastewater containing emerging contaminants including per- and poly-fluoroalkyl substances (PFASs). This study assessed PFASs contamination of wastewater from Bugolobi (Kampala) and Kirinya (Jinja) wastewater treatment plants (WWTPs) by analyzing 80 influent and effluent samples for 15 PFASs using LC-MS/MS. We quantified 10 PFASs, with levels ranging from non-detectable (n.d) up to 372.4 ng/L (mean: 20.94 ± 0.42 ng/L). At Bugolobi WWTP, influent levels ranged from n.d to 190.01 ng/L (60.85 ± 1.03 ng/L) while effluents varied from n.d to 372.4 ng/L (237.91 ± 7.06 ng/L). At Kirinya WWTP, influent levels ranged from n.d to 29.37 ng/L (17.58 ± 3.54 ng/L) and effluents up to 30.21 ng/L (7.79 ± 0.85 ng/L). Short-chain PFASs (PFBS, PFBA) were more predominant, suggesting their possible use or degradation of the long-chain PFASs. Total mass loadings were higher at Bugolobi WWTP (5353.56 mg/day), serving the more densely populated Kampala, than at Kirinya WWTP (93.62 mg/day). PFSAs exhibited higher removal (72.45 % Bugolobi; 36.45 % Kirinya) than PFCAs (− 127.38 % Bugolobi; − 20.50 % Kirinya), which could be attributed to their stronger hydrophobic adsorption and partial biodegradation. Bugolobi, with ⁓82.59 % total removal, outperformed Kirinya (~25.19 %) due to its advanced conventional treatment. Ecological risk assessment revealed higher risks at lower trophic levels at Bugolobi compared to Kirinya, likely due to lower influx and partial mitigation by its pond-based system. These findings highlight the role of WWTPs as critical point sources of PFASs, posing ecological risks to aquatic ecosystems. Keywords: Per- and poly-fluoroalkyl substances, Wastewater treatment plants, Mass loadings, Ecological risks, Lake victoria
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    Organochlorine pesticides in placenta, blood and breast milk of mothers in Uganda : concentrations and health risks to breast fed infants.
    (Elsevier Ltd., 2026) Omoding, Daniel; Nantume, Teddy; Wasswa, John; Odongo, Silver; Kyarimpa, Christine; Karume, Ibrahim; Matovu, Henry; Sillanpa¨a¨, Mika; Kato, Charles Drago; Nabuuma, Josephine; Miiro, Ashirafu; Ssebugere, Patrick
    Exposure to organochlorine pesticides (OCPs) remains a major public health concern in low-income countries, where historical usage and poor regulation continue to result in maternal and early-life exposures. This study assessed concentration profiles of selected OCPs, namely; p,p′-DDT, p,p′-DDE, o,p′-DDE, p,p′-DDD, o,p′-DDD, aldrin, dieldrin, lindane, α-endosulfan, β-endosulfan, and endosulfan-sulfate in maternal blood, breast milk, and placenta samples collected from 52 healthy mothers residing in the rural Kanungu District and urban Kampala District in Uganda. Analytical quantification was performed using gas chromatography-electron capture detection (GC-ECD), and compound identity was confirmed by gas chromatography–mass spectrometry (GC-MS). Concentrations of total DDTs (∑DDTs) were 63.0, 27.1, and 35.0 ng g-1 lipid weight (l.w) in blood, breast milk, and placenta, respectively. o,p′-DDE was the predominant metabolite in blood (67% of ∑DDTs), while p,p′-DDE dominated in placenta and milk (34% and 70%, respectively), possibly due to degradation of technical DDT applied in past decades. Other OCPs were generally low (
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    Sub-Acute toxicity effects of methanolic stem bark extract of entada abyssinica on biochemical, haematological and histopathological parameters in wistar albino rats
    (Frontiers in pharmacology, 2021) Obakiro, Samuel Baker; Kiprop, Ambrose; Kigondu, Elizabeth; K’owino, Isaac; Kiyimba, Kenedy; Kato, Charles Drago; Gavamukulya, Yahaya
    Background: Whereas the efficacy of Entada abyssinica (fabaceae) extracts against various ailments has been scientifically validated, its safety has not been established. This study was undertaken to evaluate the toxicity effects of methanolic stem bark extract of E. abyssinica on biochemical, haematological and histological parameters of Wistar albino rats following repeated oral administration. Methods: Wistar albino rats of both sexes were randomized into groups and orally administered daily with determined doses (150, 300 and 600 mg/kg) of E. abyssinica methanolic extract using 1% tween 80 in distilled water as a control for 28 days. On the 29th day, all the animals were sacrificed and dissected to collect blood and selected organs. The serum and whole blood were assayed for biochemical and haematological parameters respectively while selected organs were examined for histopathological lesions. Numerical data was analyzed using graph pad prism and expressed as mean ± standard error of mean. The differences between the treatment and control groups were tested for statistical significance using one-way analysis of variance and/or Student’s t-test. Results: In repeated daily oral doses (150, 300 and 600 mg/kg), the methanolic stem bark extract of E. abyssinica did not cause significant alteration in majority of the biochemical and hematological indices. However, the extract significantly elevated the level of uric acid (all doses), aspartate aminotransferase (300 and 600 mg/kg), low density lipoproteins (150 mg/kg) and mean corpuscular heamoglobin concentration (all doses). On the other hand, the extracts reduced high density lipoproteins (150 and 300 mg/kg), mean corpuscular volume (all doses), haematocrit (150 and 600 mg/kg), mean platelet volume (150 and 600 mg/kg) and procalcitonin (150 mg/kg). In the vital organs, therewere no significant lesions observed except at the highest dose (600 mg/kg) where there was mild evidence of lymphocyte infiltration in the liver and focal interstitial nephritis. Conclusion: The methanolic stem bark extract of E. abyssinica is relatively safe in Wistar albino rats when repetitively administered orally in small doses for a prolonged period of time. We recommend more chronic toxicity studies and clinical trials on herbal remedies containing this plant to ensure that its use is free of potential toxicity to humans. Keywords: toxicity, fabaceae, traditional medicine, Entada abyssinica, biochemical, haematological, histopathalogical, wistar albina rats