Source identification of PCDD/Fs and PCBs in pine (Cedrus deodara) needles: A case study in Dalian, China

Factor analysis model with nonnegative constraints (FA-NNC) and positive matrix factorization (PMF) were successful in source identification of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in pine (Cedrus deodara) needle samples collected from Dalian, China. The source profiles and source contributions derived from the two receptor models were comparable. The results suggested that the main sources of PCDD/Fs were various combustion processes (58–74%), pentachlorophenol contamination (15–17%), secondary aluminum smelters (9–12%), and traffic emissions (2–13%). As for PCBs, two sources were identified as PCB3 and PCB5, two typical Chinese technical PCB products. The overall source contributions of PCB3 are 72–80% and PCB5 20–28%, which is qualitatively consistent with the proportions of technical PCB products produced in China. This can be the first attempt to semi-quantitatively apportion PCDD/Fs and PCBs in vegetation samples using different receptor models.