Abstract
This study uses the approach of selective studies of individual foods to investigate the dietary intake of dioxin-like compounds by Taiwanese from 2000 to 2003. The concentrations of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are measured in a total of 380 compound samples, assembled from 3477 individual food samples of animal origin and high fat, are measured. Furthermore, twelve dioxin-like PCBs in some beef, milk and fish samples are also measured to evaluate their contributions of toxicity equivalency quantity (TEQ) between terrestrial and aquatic animal foods. The upper bound average concentrations of PCDD/DFs in 22 classes of foods investigated in this study range from 0.020 to 0.255 pg WHO-TEQPCDD/F /g on fresh weight basis, or from 0.179 to 3.74 pg WHO-TEQPCDD/F /g on lipid basis. The estimated TEQ contributions from dioxin-like PCBs are 35% and 65% of total TEQ in terrestrial and aquatic animal foods, respectively. The upper bound dietary intakes of DLCs among the general population (50th percentile) of Taiwanese adults are calculated in the range of 0.6~0.8 pg WHO-TEQPCDD/F+PCB/kg bw/day, and 2.2~3.0 pg WHO-TEQPCDD/F+PCB/kg bw/day for the 95th percentile population. Fish meats are regarded as the principal dietary source of DLCs intake, approximately contributing to half of dietary intake of DLCs. Terrestrial meats are the secondary TEQ contributors and estimate to have 35% contribution. Dairy products, eggs and oil/fat foods contribute only ca. 5% of dietary intake of DLCs each. The average daily intake of DLCs from foods of animal origin and high fat for the general population of Taiwanese adults is within the tolerable daily intake (TDI), i.e., 1-4 pg WHO-TEQ/kg bw/day, recommended by World Health Organization in 1998. If the TEQ contributions from foods of plant origin are also taken into consideration, the human health risks of cancer and non-cancer effects by the current dietary intake of DLCs by Taiwanese adults are still acceptable.