Atmospheric Deposition Impact of Polychlorinated Dibenzo-p-dioxin and Dibenzofuran on an Aquatic System in Central Taiwan

The content and congener profiles of 17 PCDD/Fs were measured in an aquatic system in central Taiwan that included both aquatic animals and sediment. The total averaged mass content of PCDD/Fs was 0.432, 0.671, 0.244 and 0.727 pg g^(-1), and the corresponding total PCDD/Fs-WHO_(2005)-TEQ were 0.070, 0.015, 0.024 and 0.018 pg WHO_(2005)-TEQ g^(-1) in O. mossambica, M. meretrix, L. calcarifer and O. gigas, respectively. The total PCDD/Fs in the sediment in the coastal area (72.63 ng kg^(-1)) was much higher than that in the fishponds (29.53 ng kg^(-1)), but the corresponding WHO_(2005)-TEQ values in the coastal area (0.545 ng WHO_(2005)-TEQ kg^(-1)) were lower than those in the fishponds (0.655 ng WHO_(2005)-TEQ kg^(-1)). The mass PCDD/F congener profiles of the aquatic animals and sediment samples in the fishponds and coastal area were dominated by more highly chlorinated PCDD/F congeners such as OCDD and OCDF, while the WHO_(2005)-TEQ PCDD/F congener profiles were dominated by the less-chlorinated PCDD/F congeners such as 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF. Over a time periods ranging from 30 and 60 years, the modeled PCDD/F contents in the sediment ranged between 9.27 and 18.53 ng WHO_(2005)-TEQ kg^(-1) in scenario A, and the PCDD/F contents ranged from 6.18-12.36 ng WHO_(2005)-TEQ kg^(-1) in scenario B. Compared with the observed average values of sediment in this study, the ratios of the modeled and observed values ranged from 9.4-34.0.