http://ir.mu.ac.ke:8080/jspui/handle/123456789/61 2026-04-08T12:33:30Z 2026-04-08T12:33:30Z Kandie, Faith Jebiwot K'Oreje, Kenneth Krauss, Martin Kristof, D. D. Torto, Baldwyn Brack, Werner http://ir.mu.ac.ke:8080/jspui/handle/123456789/9987 2025-10-28T13:15:00Z 2022-01-01T00:00:00Z

Occurrence and removal of pharmaceutical residues in water: A case study of the Lake Victoria basin-Kenya Kandie, Faith Jebiwot; K'Oreje, Kenneth; Krauss, Martin; Kristof, D. D.; Torto, Baldwyn; Brack, Werner In the recent years, global concerns have increased on the environmental occurrence of Pharmaceutically Active Compounds (PhACs) due to their pronounced ecotoxicological risk. Several studies have shown their presence in different environmental matrices including water, sediments and biota. Whereas the occurrence of these compounds has been widely studied in the western world, few studies have been done in Africa. Additionally, the fate of PhACs during wastewater treatment by stabilization ponds and trickling filters commonly used in low- income countries, is not well known. To narrow this knowledge gap, this study investigated the occurrence of PhACs in water, snail tissues and sediments in 48 surface water systems and their removal in four selected wastewater treatment plants (WWTPs) within the Lake Victoria Basin, Kenya. Water samples from surface water were directly injected into the Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) for chemical analysis while wastewater samples were first processed using solid-phase extraction before analysis. Extraction of chemicals in snail tissues was done using QuEChERS (quick, easy, cheap, effective, rugged and safe) method while pressurized liquid extraction was applied to sediment samples prior to chemical analysis.

2022-01-01T00:00:00Z Laufer, Nicolai Schaufelberger, Sonja Cardis, Tibaud Tanui, Isaac C. Kandie, Faith Brack, Werner Backhaus, Thomas Inostroza, Pedro A. http://ir.mu.ac.ke:8080/jspui/handle/123456789/9986 2025-10-28T10:01:30Z 2024-01-01T00:00:00Z

Assessing bacterial community responses in four chemically stressed small rivers in Kenya using environmental DNA Laufer, Nicolai; Schaufelberger, Sonja; Cardis, Tibaud; Tanui, Isaac C.; Kandie, Faith; Brack, Werner; Backhaus, Thomas; Inostroza, Pedro A. Microbial communities, in particular bacterial assemblages, are key players in the provision of essential ecosystem services such as the mediation of biogeochemical cycles as well as the degradation of chemical pollutants. The responses of bacterial communities to changing environmental conditions are manifold but can include structural as well as functional alterations depending on the environmental stressors and toxic chemicals they are exposed to (e.g. pharmaceuticals, personal care products, pesticides, and industrial chemicals). In this study, environmental DNA (eDNA) was extracted from surface water samples collected from four small rivers in the Lake Victoria South Basin (Western Kenya) to : i) evaluate whether alpha- and beta-diversity change in dependency of land-use types, ii) identify the environmental variables that explain alterations in community structure, iii) qualitatively and quantitatively assess the consequences of antimicrobial stress on bacterial communities, and iv) evaluate bacterial functional changes related to the degradation of organic chemicals. Our findings suggest that bacterial community composition is a more sensitive indicator to reflect the impact of chemical pollution derived from different types of land-use compared to alpha diversity. Nutrients and stress from chemical pollution were the variables explaining the dissimilarities between bacterial communities in small, forested, urbanised and agricultural rivers. Furthermore, an assessment of potential ecological functions associated with the biodegradation of toxic chemicals unveiled a season-specific decline in bacterial degradation potential in all four rivers. Finally, our results indicate that bacterial communities in small streams in Kenya which run through areas characterised by a low degree of urbanization or subsistence agriculture, respectively, can have a similar potential impact on bacterial communities as rivers exposed to a high degree of urbanization, intensive agricultural activities, or mixed land-use in other areas around the world.

2024-01-01T00:00:00Z Ganatra, Akbar A. Kandie, Faith Jebiwot Fillinger, Ulrike McOdimba, Francis Torto, Baldwyn Brack, Werner Liess, Matthias Hollert, Henner Becker, Jeremias M. http://ir.mu.ac.ke:8080/jspui/handle/123456789/9985 2025-10-28T09:39:12Z 2021-01-01T00:00:00Z

Calibration of theSPEAR pesticides bioindicator for cost-effective pesticide monitoring in East African streams Ganatra, Akbar A.; Kandie, Faith Jebiwot; Fillinger, Ulrike; McOdimba, Francis; Torto, Baldwyn; Brack, Werner; Liess, Matthias; Hollert, Henner; Becker, Jeremias M. Background: Pesticides are washed from agricultural fields into adjacent streams, where even short-term exposure causes long-term ecological damage. Detecting pesticide pollution in streams thus requires the expensive monitor- ing of peak concentrations during run-off events. Alternatively, exposure and ecological effects can be assessed using the SPEAR pesticides bioindicator that quantifies pesticide-related changes in the macroinvertebrate community compo- sition. SPEAR pesticides has been developed in Central Europe and validated in other parts of Europe, Australia and South America; here we investigated its performance in East African streams. Results: With minimal adaptations of the SPEARpesticdes index, we successfully characterized pesticide pollution in 13 streams located in Western Kenya. The East African SPEARpesticides index correlated well with the overall toxicity of 30 pesticides (maximum toxic unit = maximum environmental vs. median lethal concentration) measured in stream water (R2 = 0.53). Similarly, the SPEAR pesticides index correlated with the risk of surface run-off from agricultural fields (as identified based on ground slope in the catchment area and the width of protective riparian strips, R 2 = 0.45). Unlike other bioindicators designed to indicate general water pollution, SPEARpesticides was independent of organic pollution and highly specific to pesticides. In 23% of the streams, pesticides exceeded concentrations considered environmen- tally safe based on European first tiered risk assessment. Conclusions: Increasing contamination was associated with considerable changes in the macroinvertebrate community composition. We conclude that pesticides need to be better regulated also in developing countries. SPEAR pesticides provides a straightforward and cost-efficient tool for the required monitoring of pesticide exposure in small to medium streams.

2021-01-01T00:00:00Z Kandie, Faith Jebiwot Krauss, Martin Massei, Riccardo Ganatra, Akbar Fillinger, Ulrike Becker, Jeremias Liess, Matthias Torto, Baldwyn Brack, Werner http://ir.mu.ac.ke:8080/jspui/handle/123456789/9984 2025-10-28T09:30:37Z 2020-01-01T00:00:00Z

Multi-compartment chemical characterization and risk assessment of chemicals of emerging concern in freshwater systems of western Kenya Kandie, Faith Jebiwot; Krauss, Martin; Massei, Riccardo; Ganatra, Akbar; Fillinger, Ulrike; Becker, Jeremias; Liess, Matthias; Torto, Baldwyn; Brack, Werner Background: Within the last decades, there has been increasing research on the occurrence of chemicals of emerg-ing concern (CECs) in aquatic ecosystems due to their potential adverse effects on freshwater organisms and risk to human health. However, information on CECs in freshwater environments in sub-Saharan countries is very limited. Here, we investigated the occurrence of CECs in snails and sediments collected from 48 sites within the Lake Victoria South Basin, Kenya, which have been previously investigated for water contamination. Samples were analyzed by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) with a target list of 429 compounds. Results: In total, 30 compounds have been detected in snails and 78 in sediment samples, compared to 79 previ- ously identified compounds in water. By extending the monitoring of CECs to snails and sediments, we found 68 compounds that were not previously detected in water. These compounds include the anti-cancer drug anastrozole, detected for the first time in the Kenyan environment. Individual compound concentrations were detected up to 480 ng/g wet weight (N-ethyl-o-toluenesulfonamide) in snails and 110 ng/g organic carbon (pirimiphos-methyl) in sediments. Higher contaminant concentrations were found in agricultural sites than in areas not impacted by anthro-pogenic activities. Crustaceans were the organisms at greatest toxic risk from sediment contamination [toxic unit (TU) up to 0.99] with diazinon and pirimiphos-methyl driving this risk. Acute and chronic risks to algae were driven by diuron (TU up to 0.24), whereas fish were found to be at low-to-no acute risk (TU up to 0.007). Conclusions: The compound classes present at the highest frequencies in all matrices were pesticides and biocides. This study shows substantial contamination of surface water in rural western Kenya. By filling data gaps on contami- nation of sediments and aquatic biota, our study reveals that CECs pose a substantial risk to environmental health in Kenya demanding for monitoring and mitigation.

2020-01-01T00:00:00Z