典型再生铜冶炼厂周边土壤中PCDD/Fs、PCBs和PCNs的污染特征及健康风险评估

本研究同时测定了1家典型再生铜冶炼厂周边土壤中PCDD/Fs、PCBs和PCNs的含量，进而分析和评估了该冶炼厂对周边环境的影响和研究区域工人的健康风险.冶炼厂周边土壤中PCDD/Fs、PCBs和PCNs的含量范围分别为17.2~370、1.20~14.2和70.9~950 pg·g^-1.在冶炼厂附近（<300 m）的采样点检出了高含量的PCDD/Fs和PCNs，其含量随距离的增加呈指数型下降.源解析结果表明，再生铜冶炼厂对其周边300 m内土壤中PCDD/Fs和PCNs的含量和单体分布特征影响显著.此外，除再生铜冶炼厂外，周边土壤中PCDD/Fs的污染可能还受到历史使用五氯酚或五氯酚钠的影响.健康风险评估结果表明，工人暴露周边土壤中PCDD/Fs、PCBs和PCNs的非致癌和致癌风险均处于可接受水平范围内，经口摄入是最主要的暴露途径.虽然健康风险评估只考虑工人工作时间内对室外环境中这些污染物的暴露，两份土壤样品的致癌风险值已达到0.47×10^-6和0.15×10^-6（阈值10^-6），值得关注.PCDD/Fs对总致癌风险（PCDD/Fs+PCBs+PCNs）的贡献率最高（96%），是该区域需首要关注和控制的二英类化合物.

Characterization and Health Risks of PCDD/Fs, PCBs, and PCNs in the Soil Around a Typical Secondary Copper Smelter

The concentrations of PCDD/Fs, PCBs, and PCNs in the soil samples around a typical secondary copper smelter were determined simultaneously, and then the impact of the smelter on the surrounding environment and the health risks of workers in the study area were analyzed and evaluated. PCDD/F, PCB, and PCN concentrations were in the range of 17.2-370, 1.20-14.2, and 70.9-950 pg·g^-1 in the soil around the smelter, respectively. High concentrations of PCDD/Fs and PCNs were observed at the sample sites close to the secondary copper smelter (<300 m), and their concentrations exponentially decreased with an increase in distance from the smelter. The results of the source analysis showed that the secondary copper smelter had a significant impact on the PCDD/Fs and PCNs content and congener profiles of the soil within 300 m of its surroundings. In addition, the PCDD/Fs pollution in the surrounding soil may also have been affected by the historical use of pentachlorophenol or sodium pentachlorophenol in addition to the secondary copper smelter. The health risk assessment results showed that the non-carcinogenic and carcinogenic risks of workers exposed to PCDD/Fs, PCBs, and PCNs in the surrounding soil were within acceptable levels, and that oral ingestion was the main exposure route. Although the health risk assessment only considered the exposure of workers to these pollutants in an outdoor environment during working hours, the carcinogenic risk values of the two soil samples had reached 0.47×10^-6 and 0.15×10^-6 (threshold value 10^-6), so they should attract our attention. PCDD/Fs had the highest contribution rate (96%) to the total carcinogenic risk (PCDD/Fs+PCBs+PCNs), and they were the dioxins that need to be the primary concern and control in the study area.