Particle size distributions and health risks of polychlorinated dibenzo-p-dioxin/furans, polychlorinated biphenyls, and polychlorinated naphthalenes in atmospheric particles around two secondary copper smelters in Shandong Province, China

Abstract

Sixteen samples of atmospheric particles in four size fractions (diameter: > 10 μm, 5–10 μm, 2.5–5 μm, and <2.5 μm) were collected around two secondary copper smelters in Shandong Province, China. The levels, particle size distributions, and potential health risks of polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs) in these samples were analyzed. The concentration ranges for the PCDD/Fs, dl-PCBs, and PCNs were 3.13–5.77 pg m−3, 0.43–0.56 pg m−3, and 4.76–9.89 pg m−3, respectively. All of the compounds accumulated strongly in the particles with diameters of <2.5 μm. The congener profiles of PCDD/Fs in particles of various sizes were similar, and were consistent with those in stack gases from local secondary copper smelters. However, the congener profiles of dl-PCBs and PCNs in the particles with diameters of <2.5 μm differed from those for the other particle size fractions. The proportion of highly chlorinated homologs in particles with diameters of <2.5 μm was much higher than that of particles with diameters of >2.5 μm. The results of a risk assessment indicated that the contribution of PCDD/Fs to the total carcinogenic risk (PCDD/Fs + dl-PCBs + PCNs) was >95%. For the PCDD/Fs, dl-PCBs, and PCNs, 78%, 71%, and 86% of the carcinogenic risk was associated with the <2.5 μm fraction, respectively. This study improves our understanding of the particle size distributions and human health risks of exposure to PCDD/Fs, dl-PCBs, and PCNs in the atmosphere around secondary copper smelters.