Dietary exposure to dioxins and dioxin-like PCBs of Hong Kong adults: results of the first Hong Kong Total Diet Study.

Dioxins and dioxin-like polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) covered by the Stockholm Convention on POPs. To assess the associated health risk of the Hong Kong population, the dietary exposure of the Hong Kong population and various age-gender subgroups to dioxins and dioxin-like PCBs was estimated in the first Hong Kong Total Diet Study (TDS), where food samples were collected and prepared "as consumed". A total of 142 composite food samples, mainly foods of animal origin and their products and oily food, were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like PCBs by the high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS) system. Dietary exposures were estimated by combining the analytical results with the food consumption data of Hong Kong adults. The mean and 95th percentile exposures to dioxins and dioxin-like PCBs of the Hong Kong population were 21.9 and 59.7 pg toxic equivalent (TEQ) kg⁻¹ body weight (bw) month⁻¹ respectively, which amounted to 31.3% and 85.2% of the provisional tolerable monthly intake (PTMI). The main dietary source of dioxins and dioxin-like PCBs was "Fish and seafood and their products" (61.9% of the total exposure), followed by "Meat, poultry and game and their products" (20.0%) and "Mixed dishes" (6.95%). The study findings suggest that the Hong Kong population is unlikely to experience the major undesirable health effects of dioxins and dioxin-like PCBs.