长江三角洲地区土壤环境质量与修复研究I·典型污染区农田土壤中多氯代二苯并二噁英/呋喃(PCDD/Fs)组成和污染的初步研究

SOIL ENVIRONMENTAL QUALITY AND REMEDIATION IN YANGTZE RIVER DELTA REGION I. COMPOSITION AND POLLUTION OF POLYCHLORINATED DIBENZO-p-DIOXINS AND DIBENZOFURANS (PCDD/Fs) IN A TYPICAL FARMLAND

通过同位素稀释高分辨率气相色谱．质谱方法(HRGC／HRMS)对长江三角洲地区某典型污染区农田土壤中多氯代二苯并二噁英(PCDDs)／呋喃(PCDFs)组成、含量及毒性当量进行了初步研究。结果表明，该地区农田土壤中PCDD／Fs总含量的平均值达2639．1pgg^-1dw，并检测出PCDD／Fs的四氯～八氯多种异构体。根据世界卫生组织毒性当量(TEQ，哺乳动物)计算结果显示，农田土壤中PCDD／Fs的毒性当量为TEQ20．8～21．3pgg^-1dw，超过加拿大国家居住环境土壤二噁英含量控制标准的5倍多，其中2，3，4，7，8-PCDF和1，2，3，7，8．PCDD对P(2DD／Fs的TEQ值贡献最大。该地区农田土壤中已经出现一定程度的二噁英／呋喃污染。

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in a typical farmland soil from Yangtze River Delta region were detected by high resolution gas chromatography coupled with high resolution mass spectrometry (HRGC/HRMS). The results showed that averaged total PCDD/Fs concentration in the farmland soil was 2 639 pg g~ -1 dw. The isomers of PCDD/Fs covered Cl_4～Cl_8. WHO-TEQ calculation indicated that PCDD/Fs TEQ in the soils ranged from 20. 82 to 21. 32 pg g-1 dw, among which 2,3,4,7,8-PCDF and 1,2,3,7,8-PCDD were the two important isomers contributing largely to the total PCDD/Fs TEQ. It is concluded that the farmland soil had been contaminated to some extent with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) that were likely released from dismantlement, dissolution and cineration of capacitors in transformer and/or electronic wastes.