Browsing by Author "Schramm, Karl-Werner"

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The bioaccumulation and fate of a branched 14C-p-nonylphenol isomer in Lymnaea stagnalis L.
(2003) Lalah, Joseph O.; Behechti, Akbar; Severin, Gabriele F; Lenoir, Dieter; Günther, Klaus; Kettrup, Antonius; Schramm, Karl-Werner
A single branched isomer of p-nonylphenol, 4(3′,6′-dimethyl-3′-heptyl)-phenol, previously identified by gas chromatography-mass spectrometry as one of the major constituent isomers in p-nonylphenol (constituting approximately 10% of all its isomers), was synthesized and used in studies of its bioaccumulation and excretion in the hermophroditic pond snail Lymnaea stagnalis L. Branched isomers of nonylphenol are perceived to have more estrogenlike toxicity than the straight-chain isomers in addition to being more resistant to biodegradation in the environment. With an average static exposure concentration of 104 μg/L (range: 92–116 μg/L) in water at 19°C for 8 d, the uptake of the compound was found to be fairly rapid, reaching a peak concentration of 23,548 μg/kg of whole tissue wet weight after 5 d and a peak bioaccumulation factor (BAFw) of 242 (5,562, based on lipid weight) after 3 d. The uptake data fitted into a logarithmic expression C(t) = 5,231 ln(t) + 11,956, where C(t) is the amount of residues accumulated in whole tissue in micrograms per kilogram tissue wet weight after a period of time, t, and t is the period of exposure in days. By determination of the excretion of 14C-residues released in water and in feces, an average loss of 96% of the accumulated residues was achieved after 22 d of continuous exposure to clean water. By first-order kinetics analysis of the excretion data, an average half-life of excretion of 4.9 d was obtained. By high-performance liquid chromatography and gas-liquid chromatography-mass spectrometry, a catechol metabolite, 4(3′,6′-dimethyl-3′-heptyl)-catechol, was detected in tissue extracts (after hydrolysis with β-glucuronidase) and in feces, in addition to the parent isomer, suggesting that the isomer may have been metabolized by glucuronic acid conjugation and hydroxylation at the ortho position of its phenolic ring.
Carbofuran and its Toxic Metabolites Provide Forensic Evidence for Furadan Exposure in Vultures (Gyps africanus ) in Kenya
(2010) Otieno, Peter O; Lalah, Joseph O; Virani, Munir; Jondiko, Isaac O; Schramm, Karl-Werner
Forensic analysis of carbofuran residues in weathered tissue samples for evidence of Furadan exposure in vultures (Gps africanus) by HPLC gave concentration (mg/Kg dry tissue weight) ranges of bdl – 0.07 (carbofuran), bdl – 0.499 (3-ketocarbofuran) and 0.013–0.147 (3-hydroxycarbofuran) in beaks, bdl–0.65 (carbofuran), 0.024–0.190 (3-ketocarbofuran) and 0.017–0.098 (3-hydroxycarbofuran) in feet, 0.179–0.219 (3-ketocarbofuran) and 0.081–0.093 (3-hydroxycarbofuran) in crop content, 0.078–0.082 (3-ketocarbofuran) and 0.091–0.101 (3-hydroxycarbofuran) in muscle of a laced carcass and 0.006–0.014 (carbofuran), 0.590–1.010 (3-ketocarbofuran) and 0.095–0.135 (3-hydroxycarbofuran) in soil sampled from a poisoning site. These compounds were confirmed by GC-MS. The results showed that HPLC combined with GC-MS is suitable for forensic analysis of carbofuran residues in bird tissue samples and that forensic investigation should include its two toxic metabolites, 3-hydroxycarbofuran and 3-ketocarbofuran.
Carbofuran use and abuse in Kenya: residues in soils, plants, water courses and the African white-backed vultures (Gyps africanus ) found dead
(2011) Otieno, Peter O; Lalah, Joseph O; Virani, Munir; Jondiko, Isaac O; Schramm, Karl-Werner
The increasing number of incidences of alleged wildlife poisoning with Furadan in Kenya has sparked off a strong lobby fronted by wildlife conservationists against Furadan use in the country and prompted this study. The worst-case scenario was in 2004 in Athi River, where a massive number of 187 African white-backed vultures (Gyps africanus) and hyenas were found dead at a spot where poisoning was suspected to have occurred through a Furadan-laced camel carcass bait. This study was initiated by the Peregrine Fund—Africa Project, and the objective was to provide evidence for Furadan exposure, its misuse and involvement in vulture poisoning and potential impact on areas near two wildlife conservancies in two most affected districts. The study found evidence for ready availability of Furadan 5G in local veterinary retail shops and its illegal misuse by pastoralists and farmers against wildlife to protect their animals and crops. Analysis of soil, water and plants taken from the farms and water sources by high-perfomance liquid chromatography (HPLC) and gas liquid chromatography–mass spectrometry (GC–MS) found residues of carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran, indicating that Furadan was used extensively in farming causing residual environmental distribution and contamination and posing risks to small birds and mammals. Forensic analysis of residues in beaks, feet and crop content of the dead vultures as well as in a laced camel carcass bait and soil samples from one site of poisoning also showed carbofuran and its two metabolites supporting allegations of Furadan involvement in wildlife poisoning and high-mortality cases of African white-backed vultures (Gyps africanus) in Kenya.
Declining commercial fish catches in Lake Victoria's Winam Gulf: The importance of restructuring Kenya's aquaculture programme
(2014) Omwoma, Solomon; Owuor, Philip O; Ongeri, David MK; Umani, Moses; Lalah, Joseph O; Schramm, Karl-Werner
The total weight of commercial fish (metric tons) caught in the Winam Gulf area of Lake Victoria in Kenya declined from 3300 mt to 760 mt between 1995 and 2009. Associated with this decline, and ranked in descending order, the species richness of the commercial fish catch was limited to seven major groups (Rastrineobola argentea; Lates niloticus; Protopterus aethiopicus; Labeo victorianus; Haplochromis species; Clarias gariaepinus; Bagrus domac). Numerous hypotheses ranging from eutrophication, inadequate control of the exotic water hyacinth and overfishing were advanced to explain this decline. The Kenyan government, working in partnership with international organizations, implemented multiple restoration and management programmes in response, including aquaculture. Unfortunately, success for this implemented programme has been very limited because important socio-economic driving factors were overlooked. To provide a better understanding of the issues, 150 members of the Winam Gulf fishing community, ranging in age from 20 to 40 years, were surveyed. The results of this survey identified poverty and inadequate education as two major issues requiring substantial attention. The survey also suggested that if societal changes are to occur, it will rest upon changing the beliefs of the youth in the Winam Gulf area. Restructuring Kenya's aquaculture programme, with a focus on the youth, provides a pathway for increasing the literacy level of the community, as well as for reducing poverty.
Dioxin-like PCBs and PCDD/Fs in surface sediments near the shore of Winam Gulf, Lake Victoria
(Elsevier, 2015) Omwoma, Solomon; Lalah, Joseph O; Virani, Munir; Schramm, Karl-Werner; Henkelmann, Bernhard
Winam Gulf of Lake Victoria is considered to be contaminated with toxic chemicals emanating from anthropogenic activities, especially near large industrial towns such as Kisumu. This has recently caused concerns about its water quality and impact on aquatic organisms and human beings. This study was justified by the need to generate baseline concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in surface sediment from selected sites in the lake and determine the influence of activities on their concentrations and potential risks to fish-eating birds living near the lake. Surface sediments (<30 cm) from three different fish landing beaches, located 200 m from the shore of Winam Gulf of Lake Victoria near Kisumu city, Homa Bay and Mbita (control) towns, were analysed. The total mean concentrations (in pg g−1 dry wt) were found to range from 17.4–812 (Σdl-PCBs), 36.6–813 (ΣPCDDs) and 1.45–46.4 (ΣPCDFs). The calculated Toxic Equivalents (TEQWHO(2005)) ranged from 0.001–0.43 (Σdl-PCBs) and 0.09–31 (ΣPCDD/Fs). The fish landing beaches at Kisumu city were found to be contaminated with respect to dl-PCBs and dioxins, followed by Homa Bay and Mbita. The relatively high levels of octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) influenced the TEQ and the ΣPCDFs/ΣPCDDs ratios indicated chemical processes as partial sources of the dioxins. The levels of contaminants obtained in this study showed potential exposure to aquatic organisms and fish eating birds through food chain transfer
Impact of Agronomic Inputs in Sugarcane Farming on Total Heavy Metal Levels in Aquatic Ecosystems and Soils within Lake Victoria Basin, Kenya.
(Springer, 2014) Omwoma, S; Lalah, JO; Ongeri, DMK; Schramm, Karl-Werner
Sugarcane farming is the most important cash crop cultivation activity in the Lake Victoria basin of Kenya practised in an area covering approximately 114,000 Ha in total. For better yields, various agronomic inputs including fertilizers and herbicides have been used intensively in the farms, causing serious concerns about their potential impacts on the aquatic ecosystems within the lake basin. In this study, the physicochemical features of surface sediment and water including pH, total organic carbon contents and heavy metal (Cd, Cu, Zn, Pb and Cr) loads in River Kuywa and in runoff canals in sugarcane farms in Nzoia nucleus estate within the lake basin were determined to assess the effects of agronomic activities including agronomic inputs in the form of nitrogenous fertilizers [urea and diammonium phosphate (DAP)], herbicides and sewage sludge used in farming on their levels. The results indicated significant differences (p ≤ 0.05) in the heavy metal levels in sediment and water samples taken before and after the farms, respectively, indicating a positive impact on the concentration levels. The canal water and sediment samples’ heavy metal levels were also significantly higher than those of the river samples showing that the influent sugarcane farm canal waters transfer these contaminants into River Kuywa. Although the levels of these parameters were significantly higher in the canals than in the controls obtained from outside the sugarcane farms, the heavy metal levels in soil samples from within the farms with similar agronomic activities did not differ significantly among the various plots. The turbidity, electrical conductivity, temperature, water and soil pH and total organic carbon values in samples obtained within the sugarcane farms showed significant seasonal variations and differed significantly from the values in the controls showing a significant negative impact of agronomic inputs on water quality.
The impact of agronomic inputs on selected physicochemical features and their relationships with heavy metals levels in surface sediment and water in sugarcane farms in Nzoia, Kenya
(Springer, 2014) Omwoma, Solomon; Lalah, Joseph O; Ongeri, David MK; Schramm, Karl-Werner
Sugarcane farming is the most important cash crop cultivation activity in the Lake Victoria basin of Kenya practised in an area covering approximately 114,000 Ha in total. For better yields, various agronomic inputs including fertilizers and herbicides have been used intensively in the farms, causing serious concerns about their potential impacts on the aquatic ecosystems within the lake basin. In this study, the physicochemical features of surface sediment and water including pH, total organic carbon contents and heavy metal (Cd, Cu, Zn, Pb and Cr) loads in River Kuywa and in runoff canals in sugarcane farms in Nzoia nucleus estate within the lake basin were determined to assess the effects of agronomic activities including agronomic inputs in the form of nitrogenous fertilizers [urea and diammonium phosphate (DAP)], herbicides and sewage sludge used in farming on their levels. The results indicated significant differences (p ≤ 0.05) in the heavy metal levels in sediment and water samples taken before and after the farms, respectively, indicating a positive impact on the concentration levels. The canal water and sediment samples’ heavy metal levels were also significantly higher than those of the river samples showing that the influent sugarcane farm canal waters transfer these contaminants into River Kuywa. Although the levels of these parameters were significantly higher in the canals than in the controls obtained from outside the sugarcane farms, the heavy metal levels in soil samples from within the farms with similar agronomic activities did not differ significantly among the various plots. The turbidity, electrical conductivity, temperature, water and soil pH and total organic carbon values in samples obtained within the sugarcane farms showed significant seasonal variations and differed significantly from the values in the controls showing a significant negative impact of agronomic inputs on water quality.
Impacts of climate-induced changes on the distribution of pesticides residues in water and sediment of Lake Naivasha, Kenya
(2013) Otieno, Peter O; Owuor, P. Okinda; Lalah, Joseph O; Pfister, Gerd; Schramm, Karl-Werner
This study reports evidence of increased chlorpyrifos contamination in sediment and water in Lake Naivasha following its intensive application in the horticultural farms in the catchment area. Analytical results show that levels of chlorpyrifos residues were influenced by climate-induced rainfall pattern with higher levels reported during period of heavy precipitation with significant decrease during low rainfall. On average, the levels ranged between 14.8 and 32.8 ng g−1 in sediment during rainy season compared to a range of 8.5–16.6 ng g−1 in the dry season. Additionally, the mean concentration of chlorpyrifos in water ranged between 8.61 and 22.4 μg L−1 during rainy season and below detection limit (bdl) −13.6 μg L−1 in dry season as quantified by enzyme-linked immunosorbent assay. Meanwhile, independent t test analysis indicated that there was significant difference in concentration at p ≤ 0.05 between the seasons with respect to sediment and water samples. This demonstrated that climate-induced variations had considerable influence on contamination. While diazinon and carbofuran were equally applied intensively, their levels were below the detection limit in the all the samples analyzed. ELISA results were validated by the capillary-HPLC photodiode-array detector instrument analysis, and statistical comparison showed no significant difference between them. It was evident that chlorpyrifos residues determination in water and sediment by ELISA can be a useful strategy in environmental management and monitoring program, and a complimentary analytical tool to high performance liquid chromatography. Levels of chlorpyrifos detected in sediment and water were found to exceed recommended criteria for protection of aquatic life and preservation of water quality and may be hazardous if not regularly monitored.
Regioselective Synthesis of a Branched Isomer of Nonylphenol, 4-(3′,6′-Dimethyl-3′-heptyl)phenol, and Determination of its Important Environmental Properties
(2001) Lalah, Joseph O; Schramm, Karl-Werner; Lenoir, Dieter; Henkelmann, Bernhard; Hertkorn, Norbert; Kettrup, Antonius; Günther, Klaus
A method for the synthesis of a pure nonylphenol isomer, 4-(3′,6′-dimethyl-3′-heptyl)phenol, by Friedel–Crafts reaction between anisole and 3-bromo-3,6-dimethylheptane that gives a 47.3 % overall yield is reported. The reactions were followed by GC-MS, and the chemical structures are in agreement with the NMR and IR spectra. The log Kow value for this compound, its water solubility, vapor pressure, and Henry's Law constant were also determined. These physicochemical properties were required for prediction of the compound's behavior in aquatic ecosystems.
Seasonal Variability in Cadmium, Lead, Copper, Zinc and Iron Concentrations in the Three Major Fish Species, Oreochromis niloticus, Lates niloticus and Rastrineobola argentea in Winam Gulf, Lake Victoria: Impact of Wash-Off into the Lake
(Springer, 2012) Ongeri, David MK; Lalah, Joseph O; Wandiga, Shem O; Schramm, Karl-Werner; Michalke, Bernard
Trace metals Cadmium (Cd), Lead (Pb), Copper (Cu), Zinc (Zn) and Iron (Fe) were analyzed in edible portions of three main finfish species namely Lates niloticus, Oreochromis niloticus and Rastrineobola argentea sampled from various beaches of Winam Gulf, Lake Victoria, Kenya, in order to determine any seasonal and site variations and the results showed significantly (p < 0.05) higher mean concentrations of Cd, Cu, Zn and Fe during the wet season compared to the dry season for all the three species indicating the impact of wash-off into the lake during the rainy periods. The overall mean concentrations of the heavy metals (in μg/g dry weight) in all combined samples ranged from 0.17–0.40 (Cd), 0.47–2.53 (Pb), 2.13–8.74 (Cu), 28.9–409.3 (Zn) and 31.4–208.1 (Fe), respectively. It was found that consumption of Rastrineobola argentea can be a significant source of heavy metals especially Zn, to humans, compared with Lates niloticus and Oreochromis niloticus, if only the muscle parts of the latter two are consumed
Soil and water contamination with carbofuran residues in agricultural farmlands in Kenya following the application of the technical formulation Furadan
(2010) Otieno, Peter O; Lalah, Joseph O; Virani, Munir; Jondiko, Isaac O; Schramm, Karl-Werner
Soil and water contamination with carbofuran residues in agricultural farmlands in Kenya following the application of the technical formulation Furadan
(2010) Otieno, Peter O; Lalah, Joseph O; Viranib, Munir; Schramm, Karl-Werner; Jondiko, Isaac O
This study was undertaken to determine the concentrations of carbofuran residues in water, soil and plant samples from selected sites in the farmlands in Kenya and to demonstrate the impact of Furadan use on the local environment. Soil, water and plant samples obtained from agricultural farmlands where the technical formulation Furadan has been used extensively showed high environmental contamination with concentrations of carbofuran and its two toxic metabolites 3-hydroxycarbofuran and 3-ketocarbofuran, separately, ranging from 0.010–1.009 mg/kg of dry surface soil, 0.005–0.495 mg/L in water samples from two rivers flowing through the farms and bdl-2.301 mg/L in water samples from ponds and dams located close to the farms. Maize plant samples contained these residues in concentrations ranging from 0.04–1.328 mg/kg of dry plant tissue. The significantly high concentration levels of carbofuran and its metabolites, 3-ketocarbofuran and 3-hydroxycarbofuran, found in various matrices demonstrate that Furadan was used extensively in the two areas and that there was environmental distribution and exposure of residues in water which posed risks when used for domestic purposes or as drinking water for animals in two wildlife conservancies where the dams and ponds are located. Surface soil contamination was also high and posed risks through run-off into the dams and rivers as well as through secondary exposure to small birds and mammals.
Spatial Distribution and Temporal Trend in Concentration of Carbofuran, Diazinon and Chlorpyrifos Ethyl Residues in Sediment and Water in Lake Naivasha, Kenya
(2012) Otieno, Peter O; Schramm, Karl-Werner; Pfister, Gerd; Lalah, Joseph O; Ojwach, Stephen O; Virani, Munir
Chlorpyrifos ethyl was found to be widely distributed in water and sediment in Lake Naivasha. Higher levels were reported in sediment (11.2–30.0 ng g−1 dry weight (dw) in wet season than in dry season (4.7–17.4 ng g−1 dw). The mean concentration of chlorpyrifos ethyl in water in wet season ranged between 8.8 and 26.6 μg L−1 and decreased to between below detection limit to 14.0 μg L−1 in dry season. On average, higher concentrations of chlorpyrifos ethyl were observed in sediment than water samples. Statistical analysis revealed a significant difference in concentration between the seasons, and a significant interaction between seasons and mean concentrations at p ≤ 0.05. However, levels of diazinon and carbofuran were below the detection limit in all the samples analyzed. Notably, levels of chlorpyrifos ethyl were higher than the maximum allowable limits (0.1 μg L−1) recommended by European Union for drinking water and general water quality criterion for protection of freshwater water organisms (0.083 μg L−1).