Longitudinal increases in PCDD/F and dl-PCB concentrations in human milk in northern China.

There is a dearth of information on the temporal changes in polychlorinated dibenzodioxin/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) contamination, in both environmental and biological specimens, in China. We compared the concentrations of PCDD/Fs and dl-PCBs in human milk collected in Shijiazhuang, Hebei Province, in northern China in 2002 (n=30) and 2007 (n=20). The level of PCDD/Fs and dl-PCBs showed an increasing trend. The mean concentrations of PCDD/Fs plus dl-PCBs were 4.47 TEQ pg g(-1) fat and 6.24 TEQ pg g(-1) fat in human milk from Shijiazhuang in 2002 and in 2007, respectively. Based on statistical analysis of questionnaire data collected by in-person interviews with mothers, we found positive correlations between consumption of sea fish and PCDFs. The PCDDs, PCDFs, PCDD/Fs, and PCDD/Fs plus dl-PCBs levels in individuals consuming greater amounts of sea fish were higher than those consuming less sea fish, both with and without adjustments for potential confounding factors. Among 17 congeners of PCDD/Fs, the 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF congener concentrations in 2007 increased 134%, 55%, 53%, 57%, 65% and 130% when compared to 2002 levels, respectively. The 2007 dl-PCB congener levels were greater than those of the 2002 samples, with the exception of PCB81 and PCB77. Specifically, PCB105, PCB114, PCB118, PCB123 and PCB156 had increased greater than twofold from 2002 to 2007. Continuous surveillance of PCDD/F and dl-PCB levels in human milk is needed to accurately evaluate both environmental contamination and the human health risk to neonates in China.

Levels of dioxins and polybrominated diphenyl ethers in human milk from three regions of northern China and potential dietary risk factors.

Human milk samples were collected from 50 breast-feeding mothers in Shijiazhuang, 60 in Tianjin and 48 in Yantai from November 2006 to April 2007. The three areas are located in northern China. We selected randomly 20 samples from each area for detection of polychlorinated dibenzodioxins/frans (PCDD/Fs), polycholorinated biphenyls (dl-PCBs) and polybrominated diphenyl ethers (PBDEs) by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). Our results show the average concentrations of PCDD/Fs plus dl-PCBs were 6.24 TEQ pg g(-1)fat, 7.54 TEQ pg g(-1)fat and 6.69 TEQ pg g(-1) fat in human milk from Shijiazhuang, Tianjin and Yantai, respectively. The average concentrations of PBDEs were 3.71 ng g(-1) fat, 3.42 ng g(-1) fat and 4.16 ng g(-1) fat in human milk from Shijiazhuang, Tianjin and Yantai, respectively. Among congeners of PBDEs, the high and low brominated congeners BDE209, BDE207, BDE197, BDE153, BDE15, BDE28 and BDE47 were the predominant PBDE congeners, accounting for 91%, 90% and 84% of total PBDEs in samples from Shijiazhuang, Tianjin and Yantai, respectively. Based on the results of an in-person interview of mothers using a questionnaire, freshwater fish consumption was found to correlate with total mono-ortho dl-PCBs (mo-PCBs) and sea fish consumption was found to correlate with total non-ortho dl-PCBs (no-PCBs) of human milk in these areas. However, no correlation was found between concentrations of total PBDEs and total TEQ of PCDD/Fs plus dl-PCBs and food consumption. Continuous surveillance on dioxins and dl-PCBs levels in human milk is needed to correctly evaluate both the environmental impact and human health risk in China.