Study On Chlorine Species Of Air Particles In Shijingshan, Beijing

Organic chlorine compounds were harmful to human for their toxicity,carcinogenicity and teratogenicity. The air particles come from coal, petroleum andnature gas could provide media for chlorine, especially for Beijing, Shanghai andGuangzhou. Therefore, study of the pollution of chlorine compouds can provide notonly supporting data for Beijing atmosphere monitoring, but also further assessmentof climate in Beijing. The main conclusions were summarized as follows.1. A analytical method of X-ray absorption near edge spectrometry （1sXANES）including the quality control for chlorine species in the atmospheric particles wasdeveloped. The inorganic and aromatic and aliphatic chlorine in the standard and≤0.2μm atmospheric particle samples were ananlyzed under the conditions of300-350synchrotron radiation light veam intensity, storage ring energy of1.5GeV and photonenergy of2.82KeV. Compared with fitting standard spectra, the method detectionlimits of inorganic, aliphatic and aromatic chlorine were5.4,8.7and1.7μg/g,respectively. The detectable frequency of atmospheric particle samples was95%. Therelative standard deviation （RSD） of replicate measurements of3-chloro acid standard（n=6） was0.9%. The method was successfully applied to analysis of the urbanatmospheric particles non-destructively. The contents of inorganic chlorine, aromatichydrocarbon substituded organic chlorine in atmospheric ultrafine particles were110ng/m3,12ng/m3, respectively, while the chain hydrocarbon substituted organicchlorine was not detected. The proposed method was applied to the determination ofchlorine species concentration in the atmopheric particles. The results showed that themain chlorine species in one place of Beijing were inorganic chlorine and aromaticchlorine2. The concentrations of ultrafine particles and2.5-1.0μm and1.0-0.2μm sizes particle matters have been detected and the average levels were48.29μg/m3,87.93±45.96μg/m3and114.64±66.96μg/m3, respectively, which were higher than thelimits of atmospheric particles for World Health Organization and Chinese standard,respectively. There was no season tendency for larger size air particles, but content of1.0-0.2μm particle has slightly increased with season. The levels of atmosphericparticles in Beijing were higher than other cities’. The influence of PM_2.5on thevisibility in Beijing was strong, and there is a significant correlation between0.5μmparticles and visibility.3. The concentrations of chlorine species of2.5μm,1.0μm,0.5μm and0.2μmsize particle matters and ultrafine particles from Shijingshan in Beijing were detectedby X-ray absorption near edge spectrometry. Moreover, the sources of chlorinespecies in atmospheric matters were assessed. The atmospheric matters for this areamainly came from vehicle exhaust, however, the source of chlorine was different fromthe source of the atmospheric particulate matters. There are strong correlationsbetween1.0μm,0.5μm and0.2μm size particulate matters and themselves-boundchlorine, respectively, which means that these particulate matters andthemselves-bound chlorine came from the same source. On the other hand, there is nocorrelation between ultrafine particles,2.5μm size particulate matters withthemselves-bound chlorine, which means that the sources of ultrafine particles and2.5μm size particulate matters were very complex.4. The levels of HCH, DDT and HCB in aerosol phase were15.07±17.81ng/m3,760±820pg/m3and280±410pg/m3in Shijingshan of Beijing from July,2009toJuly,2011, respectively. Both in aerosols and in total suspended particles, the ordersof chlorine species concentrations were HCHs> DDTs> HCB> chlordane and thecontents of chlorine species in the aerosols were significantly higher than particles ofchlorine species. In the atmospheric environment, chlordane concentration was closeto the detection limit. Due to its good stability, β-HCH is48%of∑HCHs. Theratio of α-to γ-HCHs was larger than1, which suggested HCHs were used inShijingshan in the past. The ratio of DDTs between aerosol and particle was1. Byanalysis of p,p’-DDT/（p,p’-DDE+p,p’-DDD） and o,p’-DDT/p,p’-DDT, the pollutantsof DDTs stem from industry and usage of chlorfenethol. The concentration of DDTsand HCHs were influenced by strong wind. The content of Chlordane could not bedetected due to the influence of stronger wind and climate.