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Marco, J.A.M. and Kishimba, M.A., 2007. Organochlorine pesticides and metabolites in young leaves of Mangifera indica from sites near a point source in Coast region, Tanzania. Chemosphere, 68(5), pp.832-837. |
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Young leaves of Mangifera indica (mango tree) from nine sites were used as bioindicators of local atmospheric contamination by organochlorine pesticides and metabolites from a point source, an old storage site at Vikuge farm in Tanzania. Sample extracts were analyzed by GC-ECD and GC-MS. The concentrations ranged 2.7–649 ng g-1 p,p’-DDT, below detection limit (bdl)–290 ng g-1 o,p’-DDT, 0.4–13 ng g-1 p,p’-DDE, bdl to 4 ng g-1 o,p’-DDE, 1–231 ng g-1 p,p’-DDD and 0.5–55 ng g-1 o,p’-DDD. The concentrations of other compounds were up to 3.9 ng g-1 pentachloroanisole, 1.3 ng g-1 a-HCH, 12 ng g-1 b-HCH and 2 ng g-1 g-HCH, on fresh weight basis. The compounds p,p’-DDT, p,p’-DDE, p,p’-DDD and o,p’-DDD were found in 100% of the samples, while pentachloroanisole, o,p’-DDT and o,p’-DDE were detected in 78%, 56% and 67% of the samples, respectively. The low DDE/DDT ratios (0.01–0.20) in all samples indicate recent input of significantly non-degraded DDT from the point source. The low a-/g-HCH ratios (<0.3–0.7) in most samples indicate recent input of lindane (99% g-HCH). The slightly high a-/g-HCH ratios in some samples might be due to photochemical or bacterial transformation of g-HCH to a-HCH, or could reflect input of technical HCH. The very strong positive correlations in the concentrations of p,p’-DDT, p,p’-DDE, p,p’-DDD, o,p’-DDT, o,p’-DDE and o,p’-DDD (r = 0.91–0.98, n = 18, p < 0.01) indicate that they have a common source. The results suggest that young mango leaves are suitable bioindicators of recent inputs of organochlorine contaminants from a point source. |
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