Organochlorine pesticides and metabolites in young leaves of Mangifera indica from sites near a point source in Coast region, Tanzania.
Marco J. A. M., Kishimba M. A.
Author Affiliation: Department of Chemistry, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania.
Chemosphere 68 : 832-837
Abstract : 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 analysed 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-1o,p?-DDT, 0.4-13 ng g-1p,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 ?-HCH, 12 ng g-1 ?-HCH and 2 ng g-1 ?-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 ?-/?-HCH ratios (0.3-0.7) in most samples indicate recent input of lindane (99% ?-HCH). The slightly high ?-/?-HCH ratios in some samples might be due to photochemical or bacterial transformation of ?-HCH to ?-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.