对长江三角洲地区某典型污染区农田生态系统和部分农产品中多氯代二苯并二嘿英(PCDDs)/呋喃(PCDFs)的污染特征、生物富集及潜在健康风险进行了初步研究。结果表明,该地区局部农田土壤中PCDD/Fs含量及毒性当量平均达556 pg g^-1dw和TEQ 20.2 pg g^-1dw,已在不同农产品中明显积累,其中稻米中PCDD/Fs含量及毒性当量为50.7 pg g^-1dw和TEQ6.4 pg g^-1dw,蔬菜茎叶中为35.2 pg g^-1dw和TEQ6.7 pg g^-1dw;当地家禽鸡肉中PCDD/Fs含量及毒性当量为30.9 pg g^-1ww和TEQ5.7 pg g^-1ww。日允许摄入量(TDI)计算结果表明,经稻米-蔬菜、稻米-蔬菜-鱼腥草、稻米-蔬菜-鱼腥草-鸡肉三种暴露途径至人体的PCDD/Fs日摄入量分别为TEQ67.4、72.1、83.5Pg kg^-1d^-1,均远远超过世界卫生组织(WHO)制定的TDI标准(TEQ 1-4pg ks^-1d^-1)。该地区局部农田生态系统及部分农产品中存在二嘿英类(PCDD/Fs)污染,已构成较大的人体健康风险。
Pollution characteristics, bioaccumulation and potential health risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were preliminarily studied in typical farmland soil-ecosystems of Yangtze River Delta region. The resuits showed that averaged concentration and TEQ of total PCDD/Fs in the farmland soil were 556 pg g^-1dw and TEQ 20.2 Pg g^-1 dw. The bioaccumulation of PCDD/Fs was clearly observed in different biological tissues. The concentration and TEQ of PCDD/Fs were 50.7 pg g^-1 dw and TEQ 6.4 pg g^-1 dw in the rice, 35.2 pg g^-1 dw and TEQ 6.7 pg g^-1 dw in the stems and leaves of vegetables, 30.9 pg g^-1 ww and TEQ 5.7 pg g^-1 ww in the chicken meat. The tolerable daily intake (TDI) values estimated based on the following exposure ways of rice-vegetable, rice-vegetable-Houttuynla cordata Thunb, rice-vegetable-Houttuynla cordata Thunb-chicken meat were TEQ 67.4, 72.1, 83.5 pg kg^-1 d^-1, respectively, which all were higher than the tolerable daily intake (TDI) (TEQ 1 - 4 pg kg^-1 d^-1) for PCDD/Fs recommended by the World Health Organization (WHO). It is concluded that bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from the farmland ecosystems has posed potential risks to agro-product safety and human health in the typical contaminated area.