A national survey of polychlorinated dioxins, furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human milk in China.

The study examined the levels of dioxin-like compounds in 24 pooled samples that were comprised of 1237 individual human milk samples from 12 provinces of China. The samples were taken in different regions to evaluate the body burden of these contaminants and assess their health risk to breast-feeding infants of China. The pooled samples were analyzed for 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) congeners. The population of the provinces involved in this study accounts for approximately 50% of the total Chinese population. The range of upper-bound total-TEQ in samples was from 2.59 pg TEQ g(-1) lipid to 9.92 pg TEQ g(-1) lipid with a mean of 5.42 pg TEQ g(-1) lipid and a median of 5.11 pg TEQ g(-1) lipid. PCDD/Fs-TEQ and total-TEQ in human milk from rural areas were lower than those from urban areas. The positive correlations were found between total-TEQ level in human milk and the consumption of aquatic food and meat respectively. The mean estimated daily intake of PCDD/Fs and dl-PCBs by infants was 28.0 pg TEQ kg(-1) bw per day with a range from 14.2 pg TEQ kg(-1) bw per day to 48.6 pg TEQ kg(-1) bw per day. In the study, both the TEQ body burden of the sample population and estimated daily TEQ intake of breast-feeding infants were lower than those of developed countries. Continuous surveillance on PCDD/Fs and dl-PCBs levels in human milk is needed to correctly evaluate both the environmental impact and human health risk in China.