The Temporal And Spatial Distribution Of Persistent Organic Pollutants In Soils And Atmosphere Of Wolong Area

In order to investigate the mode of emission and the rule of transport of typical persistent organic pollutants, Wolong Nature Reserve, west of Sichuan was selected as the study site. Soil samples were collected in different altitudinal gradient respectively on April and October, 2006; XAD-2 resin based passive air samplers were used to collect atmosphere samples in different altitudinal gradient, gained the spring atmosphere samples(sampling duration: 2005.10 -- 2006.4) and autumn atmosphere samples(sampling duration:2006.4—2006.10). Organochlorine compounds such as HCB, HCHs, DDTs and PCBs were determined using the gas chromatography-high resolution mass spectrometry method. It was revealed that the reproducibility was acceptable; the lower detection limits for OCPs fell in the range of 0.057 to 1.68 ng. The recovery of two surrogate (TMX and PCB209) in soil samples respectively is 78±13% and 77±16%, The recovery, of two surrogate (TMX and PCB209) in atmosphere samples respectively is 92±18% and 89±28%. That of OCPs in Wolong Nature Reserve was relatively low, with HCB at 40.8 ng and PCB52 at 0.122 ng being the highest and the lowest of OCPs. Cluster analysis was used and considered the physical-chemical property data of OCPs, the average levels and chemical compositional characteristics were described and compared with literature data. The results showed: XAD-2 resin based passive air samplers are applicable to long term collection and monitoring for OCPs in atmosphere, which both fits for urban and remote area. The distribution of concentration levels of OCPs among the altitudinal gradient showed the phenomena of "Cold Condense". Because of influence of high temperature in summer and some Of the OCPs was digested, the concentration of OCPs in autumn soil samples was lower than that of in spring, in the contrast, the concentration of OCPs in autumn atmosphere samples was higher than that of in spring. The results of cluster analysis relate to the physical-chemical property data of OCPs, which was indicated that atmospheric transport may be the major source of OCPs in Wolong area.