Carbofuran and its Toxic Metabolites Provide Forensic Evidence for Furadan Exposure in Vultures (Gyps africanus) in Kenya

Department of Chemistry, Maseno University, P.O. Box 333, 40105 Maseno, Kenya.
Bulletin of Environmental Contamination and Toxicology (Impact Factor: 1.26). 04/2010; 84(5):536-44. DOI: 10.1007/s00128-010-9956-5
Source: PubMed


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.

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    • "Furthermore, carbofuran is known to be more persistent than other carbamate or organophosphate insecticides and thus often detected in water (Salman and Hameed, 2010). Low concentrations of carbofuran and its metabolites have been recorded in water samples from Kenya (0.005e0.495 mg L À1 ) in the farmlands (Otieno et al., 2010) whereas highest concentrations reported from Bangladesh paddy land water were 0.198 mg L À1 (Chowdhury et al., 2012). The World Health Organization specified the permissible limit of 0.007 mg L À1 for carbofuran (Stewart et al., 2002) in drinking water. "
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    ABSTRACT: This study reports the thermodynamic application and non-linear kinetic models in order to postulate the mechanisms and compare the carbofuran adsorption behavior onto rice husk and tea waste derived biochars. Locally available rice husk and infused tea waste biochars were produced at 700 °C. Biochars were characterized by using proximate, ultimate and surface characterization methods. Batch experiments were conducted at 25, 35, and 45 °C for a series of carbofuran solutions ranging from 5 to 100 mg L(-1) with a biochar dose of 1 g L(-1) at pH 5.0 with acetate buffer. Molar O/C ratios indicated that rice husk biochar (RHBC700) is more hydrophilic than tea waste biochar (TWBC700). Negative ΔG (Gibbs free energy change) values indicated the feasibility of carbofuran adsorption on biochar. Increasing ΔG values with the rise in temperature indicated high favorability at higher temperatures for both RHBC and TWBC. Enthalpy values suggested the involvement of physisorption type interactions. Kinetic data modeling exhibited contribution of both physisorption, via pore diffusion, π*-π electron donor-acceptor interaction, H-bonding, and van der Waals dispersion forces and chemisorption via chemical bonding with phenolic, and amine groups. Equilibrium adsorption capacities of RHBC and TWBC determined by pseudo second order kinetic model were 25.2 and 10.2 mg g(-1), respectively.
    Chemosphere 11/2015; DOI:10.1016/j.chemosphere.2015.11.002 · 3.34 Impact Factor
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    • "[1] [3] As in 2010, commercial carbofuran (Furadan Ò ) with 10% active ingredient was allowed for restrictive use by informed users in Kenya. [1] Studies showed that carbofuran was still being imported mainly for use in seed dressing at the rate of 0.5–4 kg a.i. ha ¡1 (active ingredient per hectare) for control of soil-dwelling and foliar-feeding insects. "
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    ABSTRACT: Carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) has been used within the Nzoia River Basin (NRB), especially in Bunyala Rice Irrigation Schemes, in Kenya for the control of pests. In this study, the capacity of native bacteria to degrade carbofuran in soils from NRB was investigated. A gram positive, rod-shaped bacteria capable of degrading carbofuran was isolated through liquid cultures with carbofuran as the only carbon and nitrogen source. The isolate degraded 98% of 100-μg mL(-1) carbofuran within 10 days with the formation of carbofuran phenol as the only detectable metabolite. The degradation of carbofuran was followed by measuring its residues in liquid cultures using high performance liquid chromatography (HPLC). Physical and morphological characteristics as well as molecular characterization confirmed the bacterial isolate to be a member of Bacillus species. The results indicate that this strain of Bacillus sp. could be considered as Bacillus cereus or Bacillus thuringiensis with a bootstrap value of 100% similar to the 16S rRNA gene sequences. The biodegradation capability of the native strains in this study indicates that they have great potential for application in bioremediation of carbofuran-contaminated soil sites.
    Journal of Environmental Science and Health Part B Pesticides Food Contaminants and Agricultural Wastes 06/2015; 50(6):387-397. DOI:10.1080/03601234.2015.1011965 · 1.20 Impact Factor
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    • "Also, several studies have been conducted to evaluate the toxicological effects of these two products. Those done on Carbofuran with several experimental animals showed that it is an inhibitor of acetyl cholinesterase (AChE), (National Research Council of Canada, 1979; FAO/OMS, 1981; Trotter Kent and Wong, 1991; Haubruge, Amichot, 1998; Bretaud Saglio and Toutant, 2001; EPA., 2006; Otieno, Lalah, Virani, Jondiko, and Schramm, 2010; Health Canada, 2013; Salman, 2013; Santé Canada, 2013. On the contrary, the results of the toxicity study on Fluometuron has shown that this product is not toxic, neither by oral ingestion, with a DL50 for the rat included between 6416-8900 mg/kg, (WSSA, 1994; Halladja, 2008), nor by dermal way with a DL50 superior to 200 mg/kg for the rat and superior to 100 mg/kg for the rabbit. "

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