| Polychlorinated biphenyls(PCBs) and heavy metals are two highly typical pollutants that have extreme biological toxicity, neurotoxicity, endocrine disruptors and carcinogenicity. While solid waste(including industrial solid waste and and electronic waste) that was piled up intensively could lead to extensive pollution caused by PCBs and heavy metals, even after initial treatment, pollutants would remain cause the potential risk to the regional environment and human health. Hence, in this study, we selected an industrial solid waste storage area and the other e-waste storage site in Taizhou, Zhejiang province as our research objects, and roundly investigated the pollution status of PCBs and heavy metals in soils, water, and plants in the study area. Then risk assessment models from USEPA were applied to evaluate the pollution risk caused by PCBs and heavy metals. Meanwhile a dual-luciferase reporter gene assay was used to determine the endocrine disruptor effects of the total PCBs exposure from the soil extracts,preferably evaluating their potential health risk. These data provided effective scientific basis regarding pollution risk management of pollutants in local scope. The research results were as follows:(1) The average contents of the total PCBs in soil, water and plant samples from an industrial solid waste storage area were 6902.9 ng/g, 1637.58 ng/L and 33.95 ng/g, respectively, and the pollution of PCBs in soil showed the most serious. As two important components, the Tri-PCBs and Penta-PCBs accounted for more than 60% of the total PCBs content. PCBs that existed in various media might come from the same or similar sources. According to the toxicity equivalent calculation, the averages of ∑WHO-TEQ were 2.66 ng/g, 5.19 pg/g and 84.64 pg/g, respectively, all putting up certain toxicity. Exposure of PCBs in soil extract would have estrogenic effects on on the CHO cells, and the higher the content of PCBs was, the more potent the effect of estrogen showed.(2) The average contents of Cr,Cu,Cd and Hg in soil samples from an industrial solid waste storage area were 408.28 mg/kg,300.3 mg/kg,1.1 mg/kg and 1.45 mg/kg, respectively, all exceeding the national standard. The range values of P and RI calculated by combined effect of multiple heavy metals were 2.16~5.75 and 141.58~399.60, respectively, belonging to the moderate pollution and medium ecological risk level. Exposure of heavy metals in soil would not generate non-carcinogenic risk on population, except Pb, Hg and Cu for children. The CR value of children exposed to Cd ranged from 4.10×10-6 to 6.25×10-6, which exceeding the acceptable limits(10-6), indicating that Cd pollution in soil would bring carcinogenic on children easily. In the same condition, the non-carcinogenic and carcinogenic of children exposed to heavy metals were both larger than adults.(3) The contents of the total PCBs in soil samples from an e-waste storage site were ranging 71.68~379.77 ng/g, being more serious pollution status. Penta-PCBs and Tetra-PCBs were the largest contributors, accounting for 47.8% and 41.9%, respectively. The source of each component might also be very similar. The ∑WHO-TEQs of DL-PCBs in soil were varying from 0.139 to 1.354 ng/g, which would have rather high risk of toxicity on the regional ecological environment and biocenosis. |
PDF Full Text Request