滨海城市大气中多氯联苯的污染特征

Pollution Characteristics of Atmospheric Polychlorinated Biphenyls in Coastal City

选取滨海城市厦门的城区、郊区、工业区和背景区为研究对象,于2008年10月至2009年9月对厦门市大气进行了为期四个季节的采样工作,用GC-MS对气相和颗粒相中的28种多氯联苯（PCBs）同系物进行测定。研究结果表明,厦门市PCBs具有明显的时空分布特征,PCBs的含量在66.94689.59 pg/m^3之间,平均值为220.56 pg/m^3。除工业区PCBs含量以外,厦门市城区、郊区和背景区大气PCBs的含量低于国内外其他地方。春季和夏季PCBs中主要以3、4和5氯代PCBs为主,它们的含量占Σ28 PCBs的75%以上,与国外高氯代PCBs有所不同。秋季PCBs中主要以2、3、5和6氯代PCB为主,而冬季样品中8氯代PCBs组分相对较高,占了Σ28 PCBs的34.0%52.6%,这可能与外来源有关。5个采样点Σ28 PCBs含量的分布表明该污染物排放源主要来自工业区。

Choosing urban,suburban,industrial area and background in the southeast coastal city,Xiamen,Fujian Province as study sites,atmospheric samples were collected using an active sampler from October 2008 to September 2009 and analyzed for 28 homologues of polychlorinated biphenyls（PCBs）in the particulate and gaseous samples with gas chromatography mass spectrometry（GC-MS）.Results indicated that there were obvious characteristics of spatial and temporal distribution for PCBs in Xiamen.Concentration of PCBs ranged from 66.94 to 689.59 pg/m^3 with mean of 220.56 pg/m^3. Except samples from industrial areas,the concentration of PCBs in urban,suburban and background atmospheric samples was lower than those data for other places in the world.PCBs were dominated by tri-,tetra-and penta-PCBs,which accounted for more than 75%of PCBs in spring and summer,which were different from high chloro-PCBs that reported by other researches in the world.Bi-,tri-,penta-and hex-PCBs were main component in PCBs in autumn,whereas there was higher level of octa-PCBs in winter samples,and which ranged from 34.0%to 52.6%in PCBs,which may be due to relative to other sources. Distributions of PCBs concentrations in 5 sampling sites suggested that the contaminants mainly came from industrial areas.