The Impact of Pesticides - Academy Publish

Time Trend Variation of Selected Pesticides Residues inSoil from some Regions in VietnamToan Vu DucABSTRACTThis study was carried out to assess the time trend variation of selectedorganochlorine pesticides (OPCs = p,p’-DDT, p,p’-DDE, p,p’-DDD, α, β, γ and δ-HCH) residues in the soils from some regions of Vietnam. The levels of the selectedOCPs were investigated by means of gas chromatography coupled with massspectrometry. The obtained results show that remarkable residues of selected OPCswere found in most collected soil samples. This highlights the wide contaminationof selected OPCs in the study areas. In general, the distribution of low levelcontamination of ΣHCH and high level contamination of ΣDDT were displayed.Investigation of the ratio of HCH isomers and DDT metabolites in the analysed soilsamples indicates that there is no recent input of these compounds. The decreasingtrends of ΣDDT and ΣHCH levels are observed.INTRODUCTIONOf all the chemical compounds with potential environmental and human healthimpacts, persistent organochlorines pesticides (OCPs) have received the mostattention. They are chemicals of high toxicity. They inflict mutagenic, teratogenicand carcinogenic effects on human beings and have significant impact onenvironmental ecosystems. These substances are transported over long distances,and accumulated in soil, marine environment, plants, and in tissues of livingorganisms. OCPs can be found actually everywhere on the earth even in regionslocated far away from emission sources. Strengthening the ability of developingcountries to identify, reduce and finally eliminate sources of persistent toxicsubstances is a crucial step in reducing ambient levels of such chemicals in the air,water and soil, and so safeguarding public health and the environment everywhere.Viet Nam is located entirely in the tropical zone. A considerable amount of selectedpesticides residues such as Dichlorodiphenyltrichloroethane (DDT) andhexachlorocyclohexane (HCH) have been used in the country. These compoundsseriously affected public health and environmental quality in Viet Nam (Thao et al.,2005). However, to our knowledge, few data are available for the contaminationstatus, composition analysis and the temporal trend of DDT and HCH in the surfacesoils from Vietnam. The present study aims at assessing the residue of DDT andHCH in the surface soil from two typical areas in Vietnam (Hanoi city and Bacninhprovince) to fill this gap.AcademyPublish.org - The Impact of Pesticides286