Browsing by Author "Odongo, Silver"

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    Anthropogenic footprint and ecological risk assessment of organochlorine pesticides and polychlorinated biphenyls in sediments from Lake Victoria, East Africa
    (Elsevier, 2025-12-15) Kagoya, Afuwa; Arinaitwe, Kenneth; Odongo, Silver; Sifuna, Douglas; Matovu, Henry; Matsiko, Julius; Muhwezi, Godfrey; ˇSp´anik, Ivan; Kato, Charles Drago; Sillanpa, Mika; Ssebugere, Patrick
    Lake Victoria, the world’s second-largest freshwater lake, continues to face pressure from anthropogenic activities in its catchment area, releasing pollutants, which are ultimately trapped in the sediment core, thereby posing threats to aquatic organisms. This study quantified thirteen organochlorine pesticides (OCPs) and ten polychlorinated biphenyls (PCBs) in sediments from the Uganda, Kenya, and Tanzania sides of Lake Victoria using soxhlet method, fractionation column and GC–MS/MS analysis. Total (∑13) OCPs levels were up to 412, 148, and 522 µg kg-1 dry weight (d.w), and 12.1, 8.69 and 9.87 µg kg-1 dw for total (∑10) PCBs for sediments from Uganda, Kenya, and Tanzania, respectively. Diagnostic ratios suggested past and ongoing use of OCPs while principal component analysis confirmed that OCP profiles were mainly due to their application in controlling pests in agriculture and public health programs, and PCB congeners were largely due to volatilization, degradation of higher PCBs into lighter PCBs, improper waste disposal of old transformers, hydraulic fluids, plasticizers, and capacitors. Ecological risk assessment highlighted that the PCB levels in sediments were below threshold effect and probable effect levels, but p,p′-DDD, and lindane were likely to pose adverse effects to sediment-dwelling organisms in Lake Victoria. These results imply persistent pollutant loads in Lake Victoria, and consequently, a need for its enhanced management.
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    Legacy and emerging organic pollutants in indoor and outdoor environments in africa: contamination levels, health risks, and analytical techniques
    (Elsevier, 2025-01-02) Muhwezi, Godfrey; Kyarimpa, Christine; Gumula, Ivan; Nagawa, Christine Betty; Omwoma, Solomon; Matovu, Henry; Matsiko, Julius; Odongo, Silver; Sifuna, Douglas; Špánik, 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 2000-2023 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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    Organochlorine pesticides in placenta, blood and breast milk of mothers in Uganda: Concentrations and health risks to breast fed infants
    (Elsevier, 2025-12-03) Omoding, Daniel; Nantumea, Teddy; Wasswaa, John; Odongo, Silver; Kyarimpa, Christine; Karumea, Ibrahim; Matovu, Henry; Sillanp, Mika; Kato, Charles Drago; Nabuumaa, Josephine; Miiroa, Ashirafu; Ssebugerea, 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 (