Interspecies variability of Dioxin-like PCBs accumulation in five plants from the modern Yellow River delta

To investigate the interspecies variance of Dioxin-like polychlorinated biphenyls (DL-PCBs) in the plants from modern Yellow River delta, the concentrations of 12 DL-PCBs congeners were examined in five plant species and their associated soils. The DL-PCBs concentrations in plants (2.32-287.60 ng/kg dry weight) were low compared to most published literature, and the concentrations and ratios of DL-PCBs congeners in plants varied greatly among species. The properties of plants and PCBs were then studied to explore the factors affecting the interspecies variance of DL-PCBs accumulation. The plants with the smallest variance of morphological and physiological characteristics (Imperata cylindrical var. Major and Phragmites australis (Cav.) Trin. ex Steud) had the most similar accumulation patterns of DL-PCBs among the species tested. As the octanol-air partitioning coefficient (K(oa)) of the DL-PCBs increased, interspecies variance decreased on the whole plant level. Interestingly, the correlation between the DL-PCBs concentrations in plants and log K(oa) of congeners was found to be significant for annual plants, but for perennial plants it was not significant. Thus the patterns of uptake of DL-PCBs are different between annual and perennial plants.