Organochlorine pesticides and metabolites in young leaves of Mangifera indica from sites near a point source in Coast region, Tanzania.
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(-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) alpha-HCH, 12 ng g(-1) beta-HCH and 2 ng g(-1) gamma-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 alpha-/gamma-HCH ratios (<0.3-0.7) in most samples indicate recent input of lindane (99% gamma-HCH). The slightly high alpha-/gamma-HCH ratios in some samples might be due to photochemical or bacterial transformation of gamma-HCH to alpha-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.
Marco
John A Mahugija
JA
Department of Chemistry, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania.
Kishimba
Michael A
MA
D002849:Chromatography, Gas; D003634:DDT / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D003632:Dichlorodiphenyldichloroethane / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D001556:Hexachlorocyclohexane / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D006843:Hydrocarbons, Chlorinated / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D031022:Mangifera / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry*; D013636:Tanzania
D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D003634:DDT; D003632:Dichlorodiphenyldichloroethane; C023888:beta-hexachlorocyclohexane