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

ABSTRACT 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.

66 Reads
  • Source
    • "[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. "
    [Show abstract] [Hide abstract]
    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
  • Source
    • "Across its range, the African White-backed Vulture has suffered myriad threats such as inter alia indirect poisoning, habitat loss, collisions, drowning and electrocution by power lines (Anderson 2000, Herholdt and Anderson 2006). Throughout Kenya, there is a growing threat from the misuse of the highly toxic Carbamate-based pesticide Furadan™ which has already caused large-scale vulture mortalities (Maina 2007, Mijele 2009, Otieno et al. 2010, ST pers. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Vulture populations have declined globally as well as regionally within Africa. Little is known about the status of the African White-backed Vulture Gyps africanus in Kenya, but ongoing studies indicate that its population has declined over the last two decades. A total of 32 African White-backed Vulture nests were monitored in the Masai Mara National Reserve over a five-year period between 2003 and 2007. Mean nesting success was 59%, which is comparable to that of populations from southern Africa. Nearest neighbour distances were significantly closer in wooded habitats (‘trees and shrubs savanna’) than in more open grassland habitats (‘open low shrubs’). Based on nearest neighbour distances, the estimated total breeding population within the Masai Mara National Reserve is 1 106 pairs, a figure that may be an overestimate and requires ground-truthing. Collecting baseline data on numbers of breeding pairs and regular nest monitoring are essential in order to assess the impact of various threats to vultures in Kenya, which include growing threats (elephant-mediated habitat disturbance and fire) as well as emerging threats (such as poisoning with the carbamate-based pesticide Furadan™).
    Ostrich - Journal of African Ornithology 11/2010; 81(3):205-209. DOI:10.2989/00306525.2010.519894 · 0.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We solve eight partial-differential, two-dimensional, nonlinear mean field equations, which describe the dynamics of large populations of cortical neurons. Linearized versions of these equations have been used to generate the strong resonances observed in the human EEG, in particular the α-rhythm (8–), with physiologically plausible parameters. We extend these results here by numerically solving the full equations on a cortex of realistic size, which receives appropriately “colored” noise as extra-cortical input. A brief summary of the numerical methods is provided. As an outlook to future applications, we explain how the effects of GABA-enhancing general anaesthetics can be simulated and present first results.
    Neurocomputing 06/2004; 58-60:1197-1202. DOI:10.1016/j.neucom.2004.01.185 · 2.08 Impact Factor
Show more