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

Abstract

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.