Study On Organohalogens In Atmosphere In Beijing

Due to their carcinogenicity, mutagenicity and teratogenicity some organohalogens have gained utmost attention as contaminants of potential threat to human health. In this study, neutron activation analysis (NAA) and gas chromatography (GC) have been used to study organohalogens in atmosphere in Beijing, in order to get the distribution and sources of oganohalogens in the atmosphere, and support data to establish the related controlling steps and rules and to set up organohalogens models for further developments.It is the analysis of organohalogens in Beijing atmosphere by NAA combined with GC during 2005.08-2006.09, which detemined the extractable organohalogens bulk and species. Effects by related climate factor are discussed. It first discovered clear correlations between EOX in precipitation in Beijing.The method of NAA and GC for determination of EOX and EPOX in air has been proved credible by experiments. The analysis results show that major fractions of EOBr(EOI) in air is an acid-liable or acid-soluble fraction during the sampling period; EOBr is prond to volatilizate, C(EOBr) in gaseous phase is higher than it in particulate phase.However,EOI is prone to be adsorbed by air partical.And the main source of EOBr(EOI) is the burning of heating fluel in winter . The results might indicate that there are new inputs of γ-HCH, DDT and DDE in air in Beijing.This implied that there are the additional usage of lindane and dicofol in recent years. The mean concentrations of PCBs in gaseous phase are higher than it in particulate phase. Gas phase accounts for about 17% of it in gaseous phase.Cl_3-5-CBS are the most abundant isomers in polluted air.Because the products of PCBs in our country are mainly Cl₃-CBs.Cl₅-CBs, and most of them are used as transformer oil.It suggests that PCBs in air mainly originate from the leakage of transformer oil.