Bioconcentration and trophic transfer of polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and dibenzofurans in aquatic animals from an e-waste dismantling area in East China

Abstract

Eight aquatic biota species were collected from an e-waste dismantling area in East China to investigate bioconcentration and trophic transfer of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The mean concentrations of PCBs varied widely from 6.01 × 10⁴ to 2.27 × 10⁶ pg per g dry weight (dw). The ∑₂₅PCB concentrations in eels were significantly higher than those in other species. The levels of PCDD/Fs changed from 8.13 pg per g dw in toads to 617 pg per g dw in stone snails. World Health Organization-toxic equivalents (WHO₂₀₀₅-TEQs) ranged from 2.57 to 2352 pg WHO-TEQ per g dw with a geometric mean value of 64.7 pg WHO-TEQ per g dw, which greatly exceeded the maximum levels of 4 pg per g ww set by the European Commission. The log-transferred bioconcentration factors (BCFs) of 25 PCB congeners ranged from 1.0 to 6.6, with the highest value for CB-205 in crucian carp and the lowest value for CB-11 in frog. A parabolic correlation was observed between log BCF and log K_ow (R² = 0.53, p < 0.001), where the maximum value occurred at a log K_ow of approximately 7. A similar correlation was also found in the plot of log BCF against the number of chlorine atoms of PCBs (R² = 0.57, p < 0.001), indicating that medium-halogenated congeners of PCBs are more easily accumulated by aquatic biota species. There were no significant correlations between the log-transferred concentrations and trophic levels of aquatic species, suggesting that trophic magnification for PCBs and PCDD/Fs was not observed in this study.