scholarly journals Multi-compartment chemical characterization and risk assessment of chemicals of emerging concern in freshwater systems of western Kenya

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Faith Jebiwot Kandie ◽  
Martin Krauss ◽  
Riccardo Massei ◽  
Akbar Ganatra ◽  
Ulrike Fillinger ◽  
...  

Abstract Background Within the last decades, there has been increasing research on the occurrence of chemicals of emerging 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 previously 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 anthropogenic 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 contamination 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 ◽  
Author(s):  
Faith Jebiwot Kandie ◽  
Martin Krauss ◽  
Riccardo Massei ◽  
Akbar Ganatra ◽  
Ulrike Fillinger ◽  
...  

Abstract Background Within the last decades, there has been increasing research on the occurrence of chemicals of emerging 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 previously 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 anthropogenic 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 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 contamination of sediments and aquatic biota, our study reveals that CECs pose a substantial risk on environmental health in Kenya demanding for monitoring and mitigation.


2020 ◽  
Author(s):  
Faith Jebiwot Kandie ◽  
Martin Krauss ◽  
Riccardo Massei ◽  
Akbar Ganatra ◽  
Ulrike Fillinger ◽  
...  

Abstract Background: Within the last decades, there has been increasing research on the occurrence of chemicals of emerging 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 previously 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 anthropogenic 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 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 contamination of sediments and aquatic biota, our study reveals that CECs pose a substantial risk on environmental health in Kenya demanding for monitoring and mitigation.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Charles Kakilla ◽  
Alphaxard Manjurano ◽  
Karen Nelwin ◽  
Jackline Martin ◽  
Fabian Mashauri ◽  
...  

Abstract Background Vector control through long-lasting insecticidal nets (LLINs) and focal indoor residual spraying (IRS) is a major component of the Tanzania national malaria control strategy. In mainland Tanzania, IRS has been conducted annually around Lake Victoria basin since 2007. Due to pyrethroid resistance in malaria vectors, use of pyrethroids for IRS was phased out and from 2014 to 2017 pirimiphos-methyl (Actellic® 300CS) was sprayed in regions of Kagera, Geita, Mwanza, and Mara. Entomological surveillance was conducted in 10 sprayed and 4 unsprayed sites to determine the impact of IRS on entomological indices related to malaria transmission risk. Methods WHO cone bioassays were conducted monthly on interior house walls to determine residual efficacy of pirimiphos-methyl CS. Indoor CDC light traps with or without bottle rotator were hung next to protected sleepers indoors and also set outdoors (unbaited) as a proxy measure for indoor and outdoor biting rate and time of biting. Prokopack aspirators were used indoors to capture resting malaria vectors. A sub-sample of Anopheles was tested by PCR to determine species identity and ELISA for sporozoite rate. Results Annual IRS with Actellic® 300CS from 2015 to 2017 was effective on sprayed walls for a mean of 7 months in cone bioassay. PCR of 2016 and 2017 samples showed vector populations were predominantly Anopheles arabiensis (58.1%, n = 4,403 IRS sites, 58%, n = 2,441 unsprayed sites). There was a greater proportion of Anopheles funestus sensu stricto in unsprayed sites (20.4%, n = 858) than in sprayed sites (7.9%, n = 595) and fewer Anopheles parensis (2%, n = 85 unsprayed, 7.8%, n = 591 sprayed). Biting peaks of Anopheles gambiae sensu lato (s.l.) followed periods of rainfall occurring between October and April, but were generally lower in sprayed sites than unsprayed. In most sprayed sites, An. gambiae s.l. indoor densities increased between January and February, i.e., 10–12 months after IRS. The predominant species An. arabiensis had a sporozoite rate in 2017 of 2.0% (95% CI 1.4–2.9) in unsprayed sites compared to 0.8% (95% CI 0.5–1.3) in sprayed sites (p = 0.003). Sporozoite rates were also lower for An. funestus collected in sprayed sites. Conclusion This study contributes to the understanding of malaria vector species composition, behaviour and transmission risk following IRS around Lake Victoria and can be used to guide malaria vector control strategies in Tanzania.


2018 ◽  
Vol 374 (1764) ◽  
pp. 20180004 ◽  
Author(s):  
Trong Dieu Hien Le ◽  
Mira Kattwinkel ◽  
Klaus Schützenmeister ◽  
John R. Olson ◽  
Charles P. Hawkins ◽  
...  

Salinization of surface waters is a global environmental issue that can pose a regional risk to freshwater organisms, potentially leading to high environmental and economic costs. Global environmental change including climate and land use change can increase the transport of ions into surface waters. We fit both multiple linear regression (LR) and random forest (RF) models on a large spatial dataset to predict Ca 2+ (266 sites), Mg 2+ (266 sites), and (357 sites) ion concentrations as well as electrical conductivity (EC—a proxy for total dissolved solids with 410 sites) in German running water bodies. Predictions in both types of models were driven by the major factors controlling salinity including geologic and soil properties, climate, vegetation and topography. The predictive power of the two types of models was very similar, with RF explaining 71–76% of the spatial variation in ion concentrations and LR explaining 70–75% of the variance. Mean squared errors for predictions were all smaller than 0.06. The factors most strongly associated with stream ion concentrations varied among models but rock chemistry and climate were the most dominant. The RF model was subsequently used to forecast the changes in EC that were likely to occur for the period of 2070 to 2100 in response to just climate change—i.e. no additional effects of other anthropogenic activities. The future forecasting shows approximately 10% and 15% increases in mean EC for representative concentration pathways 2.6 and 8.5 (RCP2.6 and RCP8.5) scenarios, respectively. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.


2018 ◽  
Vol 6 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Ouma George ◽  
Odhiambo G. Duncan ◽  
Musyimi David ◽  
Kwach Johnson

Avocado (Persia americana) is an important world crop. In Kenya, it has become a very important crop but its production is limited by several factors. Studies were conducted in the Lake Victoria Basin counties of Bunyala in Busia, Kisumu, Muhoroni, Nyando and Rachuonyo in western Kenya to investigate the socioeconomic factors affecting Avocado production.  Information were collected from focus group discussions, key informants, individual interviews and secondary sources. Statistical Package for Social Scientist was used to analyze data collected interpreted and reported.  The objectives were to assess how Avocado growers in western Kenya using Agricultural extension services affects the Livelihood of farmers considering their level of education and extension services and the implication it has on their decisions making to invest in Avocado production. There was positive relationship within the participating farmers as relates their level of education, income and availability of extension services that led to high adoption of inputs, choice of rootstocks to grow the crop, varieties chosen, planting, cultural practices harvesting, storage and marketing.


Author(s):  
Orech FO ◽  
◽  
Treza Akenga ◽  
J Ochora ◽  
H Friis ◽  
...  

Traditional leafy vegetables are those plants leaves or aerial parts have been integrated in a community’s culture for use as food over a long span of time. These vegetables are highly recommended due to their relatively high nutritional value compared to the introduced varieties, and are also important in food security. Qualitative phytochemical screening, using standard laboratory procedure, was carried out for alkaloids, saponins, cardenolides, flavonoids and polyphenols on traditional leafy vegetables consumed amongst the Luo, an agro-pastoral community living along the shores of lake Victoria, Western Kenya. The vegetables included: Amaranthus hybridus L. (subsp.hybridus), Asystasia mysorensis T. Anderson, Coccinia grandis (L) Voigt, Crotalaria ochroleuca (Kotschy) Polhill, Cucurbita maxima Duchesne ex Lam, Portulaca quadrifida L., Sesamum calycimum Welw. var. angustifolium (Oliv.) Ihlenf. and Siedenst., Senna occidentalis L. and Sida acuta Burm. F. All the vegetables were found to contain polyphenols and flavanoids while other classes of phytochemicals varied from species to species. Brine shrimp lethality tests revealed that S. calycimum var. angustifolium (LC50 84.8 g/ml), S. occidentalis (LC50 99.5 g/ml), S. acuta (LC50 99.4 g/ml), C. grandis (LC50 100.6 g/ml) and A. mysorensis (LC50 207.7 g/ml) exhibited marked levels of toxicity. C. ochroleuca (Sunnhemp) contained all the five classes of phytochemicals, but proved less toxic (LC50 4511.3 g/ml). This vegetable is highly utilized in Nyang’oma, and seventy per cent of the respondents consume this species. Though A. hybridus (African spinach, or Amaranth) was found to be the least toxic (LC50 6233.6 g/ml) and this vegetable is recommended for consumption. From the results, five vegetables contain possible agents that can cause acute or chronic toxicities when consumed in large quantities or over a long period of time. Hence some vegetables should be consumed with great care. Further studies are recommended to determine which of the phytochemicals are lethal to mammals, especially human beings.


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