Dietary intake of PCDD/Fs and dioxin-like PCBs from the Chinese total diet study in 2007

Concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in 96 food composite samples from eight varieties of food groups from the Chinese total diet study (TDS) in 2007. The concentrations of samples, expressed as WHO toxic equivalents (TEQ), ranged from 0.001 pg TEQ g(-1) to 0.85 pg TEQ g(-1) (fresh weight). Dietary intake of PCDD/Fs and dl-PCBs of 12 age/gender subgroups of the Chinese population subsequently estimated ranges from 15.4 pg TEQ kg(-1) bw month(-1) to 38.7 pg TEQ kg(-1) bw month(-1) for average population and from 68.5 pg TEQ kg(-1) bw month(-1) to 226.1 pg TEQ kg(-1) bw month(-1) for high consumers (the 97.5th percentile). Dietary exposure of children (mean: 32.5 pg TEQ kg(-1) bw month(-1)) is significantly higher than that of the adults (mean: 21.5 pg TEQ kg(-1) bw month(-1)) (p<0.01) presumably due to more food consumed by children relative to their body weight compared to adults. There is no difference of dietary exposure, expressed as pg TEQ kg(-1) bw, found between different genders. Across various regions in China, there are large differences of dietary exposure of adult population and pattern of contribution of food groups to total exposure due to different contamination level and food habits. Dietary exposures of average population of various subgroups were all below the PTMI recommended by JECFA, but those of higher consumers were found exceeding or comparable to the PTMI.