Levels, sources, and potential human health risks of PCNs, PCDD/Fs, and PCBs in an industrial area of Shandong Province, China.

Polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) are of public concern worldwide because of their persistence and toxicity. To address the human health risks of these pollutants and identify possible sources, soil samples were collected from an industrial area and surrounding residential area in Shandong Province, China. The PCN, PCDD/F, and PCB levels in these samples were determined. Extremely high concentrations of PCNs were detected in two soil samples, and their congener distributions were similar to those of a PCN industrial technical product. The levels of combustion-related PCNs and PCDD/Fs were high in samples collected near a secondary copper smelter. The distribution of total PCB concentrations was similar to that of PCNs. Both historical residues from industrial technical products and emissions from the secondary copper smelter were likely sources of PCNs and PCBs, whereas emissions from the smelter were the main source of PCDD/Fs. A soil sample from near the smelter had a high ΣTEQ concentration (PCDD/Fs + PCBs + PCNs = 18.33 pg TEQ/g) and carcinogenic risk (0.85 × 10) to workers. For all the other samples, the levels of PCDD/Fs, PCBs and PCNs exhibited low carcinogenic and noncarcinogenic risks to workers and residents.