Dietary intake of dioxin-related compounds through food in Japan

On the basis of the total diet-market basket method, about one hundred kinds of food were respectively purchased in 1977, 1985 and 1990 in Osaka, Japan, and they were cooked, divided into 13 groups and frozen at -40°C. Dietary intakes of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinaed dibenzofurans (PCDFs) and coplanar PCBs (Co-PCBs) through food in Japan were studied by using these 39 samples. The total dietary intake of PCDDs and PCDFs was 175pg TEQ (2, 3, 7, 8-Tetrachlorinated dibenzo-p-dioxin Toxic Equivalent), i. e., 40pg TEQ/day of PCDDs and 135pg TEQ/day of PCDFs. Co-PCBs, having the same toxic effect as PCDDs and PCDFs, gave an estimated intake of 660pg TEQ/day, which was calculated by using the 2, 3, 7, 8-T4CDD toxicity equivalency factors reported by Hanberg et al. In addition, it was found that Japanese took about 60% of the TEQ of the three chemicals in food through fish & shellifish, daily intakes of which are larger in Japan than in Europe or the USA. It is noteworthy that the dietary intake of Co-PCBs as TEQ was much greater than that of PCDDs or PCDFs.