Levels and profiles of PCDD/Fs, PCBs in mothers' milk in Shenzhen of China: estimation of breast-fed infants' intakes.

Sixty breast milk samples were collected in Shenzhen, China from July to November in 2007. The samples were analyzed of the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The range of upper-bound for ∑TEQ-(PCDD/Fs+PCBs) in the samples was 4.10-35.3 pg TEQ g(-1) lipid (median: 10.6 pg TEQ g(-1) lipid; mean: 11.9 pg TEQ g(-1) lipid). The levels of the measured contaminants in the breast milk had significant correlations with the length of inhabitation period in Shenzhen (r=0.487, p<0.05 for PCDD/Fs, r=0.431, p<0.05 for PCBs and r=0.478, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)), and the consumption rate of fish (r=0.366, p<0.05 for PCDD/Fs, r=0.486, p<0.05 for PCBs and r=0.416, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)), respectively. Moreover, significant positive correlations were also detected between the participant's age (r=0.305, p<0.05 for ∑TEQ-PCBs and r=0.275, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)) and the body burdens of these contaminants respectively. It is estimated that the daily intake (EDI) of the sum of PCDD/Fs and DL-PCBs by the breast-fed infants was 5.60-161 pg TEQ kg(-1) bw per day (mean: 48.2 pg TEQ kg(-1) bw per day; median: 42.2 pg TEQ kg(-1) bw per day). The result showed that both the body burdens of PCDD/Fs and PCBs of the recruit population and the calculated EDI of the breast-fed infants were higher than those in the non-exposed areas in mainland China. This suggests that continuous surveillance on PCDD/Fs and PCBs levels in human milk is critical to more precisely evaluate the human health risk posed by the negative environmental impact in Shenzhen in the future.

Deng B ，Zhang J ，Zhang L ，Jiang Y ，Zhou J ，Fang D ，Zhang H ，Huang H ... -  《-》

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

Li J ，Zhang L ，Wu Y ，Liu Y ，Zhou P ，Wen S ，Liu J ，Zhao Y ，Li X ... -  《-》

Individual breast milk consumption and exposure to PCBs and PCDD/Fs in Hungarian infants: a time-course analysis of the first three months of lactation.

Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are persistent, bioaccumulative and toxic chemicals. These compounds are transferred to breast milk, therefore breastfed infants are at risk of being exposed to considerable amounts of PCBs and PCDD/Fs during this sensitive age. In the present study individual breast milk samples were collected at three time points (days 5, 12 and 84 postpartum) from 22 mothers who delivered their infants during 2007 in Baranya County, Hungary. Breast milk samples were analyzed for 17 PCDD/Fs, 12 dioxin-like (DL) PCBs and 7 non-dioxin-like (NDL) PCBs using high-resolution gas chromatography/high-resolution mass spectrometry. Each infant's daily breast milk consumptions have been measured biweekly over three months. The concentration of several PCB and PCDD congeners in breast milk decreased significantly during lactation, with a main decline between days 5 and 12. The total toxic equivalent (TEQ) concentrations, derived from PCDD/Fs and DL-PCBs, were 3.17±1.72, 2.70±1.57 and 2.41±1.47 pg TEQ/g fat at the three time points, respectively. The corresponding NDL-PCB concentrations were 33.5±29.2, 27.4±20.6 and 26.9±24.8 ng/g fat, respectively. The results highlight the importance of timing of breast milk sampling for consistent exposure assessment estimation. Levels of pollutants in Hungarian breast milk samples were at the lower concentration range when data from Europe are considered. This is the first study in Hungary where each infant's daily intakes of PCBs and PCDD/Fs via breast milk have been measured. The daily intakes of PCDD/Fs and DL-PCBs via breastfeeding per kg body weight were 11.79±6.42, 16.54±13.02 and 11.59±7.70 pg TEQ/kg bw on days 5, 12 and 84, respectively. The exposure was the highest on day 12 but at all three time points each infants' daily exposure to PCDD/Fs and DL-PCBs via breastfeeding exceeded the tolerable daily intake (TDI) of 2 pg TEQ/kg bw per day. These levels are still lower than corresponding levels recently measured in many European countries. Whether the milk-derived POP exposure levels of infants reported here constitute any health risk that may manifest later in life awaits further scrutiny.

Vigh É ，Colombo A ，Benfenati E ，Håkansson H ，Berglund M ，Bódis J ，Garai J ... -  《-》

Breastfed infants' exposure to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, and per- and polyfluoroalkyl substances: A cross-sectional study of a municipal waste incinerator in China.

A municipal waste incinerator (MWI) in Zhejiang, China, operating since 2008 was completely reconstructed from 2016 to 2019. In 2013, we conducted a cross-sectional study of breastfeeding mothers living near the MWI. We evaluated the concentrations of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the mothers' breast milk and their infants' estimated daily intake (EDI). To investigate the temporal variations of these pollutants, we conducted a cross-sectional study of 29 mothers in 2019. We assessed the levels of 18 PCB congeners, 17 PCDD/F congeners, and 21 per- and polyfluoroalkyl substance (PFAS) congeners in breast milk and estimated the EDI. The mean total concentrations of PCDD/Fs (ΣPCDD/Fs) and PCBs (ΣPCBs) were 81.2 and 4.90 ng/g lipid, respectively, while the toxic equivalent quantity (TEQ) levels of ΣPCDD/Fs and dioxin-like PCBs (ΣDL-PCBs) were 2.7 and 1.4 pg WHO-TEQ/g lipid, respectively. Compared to our 2013 measurements, the mass concentrations of ΣPCDD/Fs and ΣPCBs decreased by 13% and 35%, respectively (3.361 vs. 2.915 pg/g wet weight [ww] and 269.1 vs. 175.0 pg/g ww, respectively). The TEQ-ΣPCDD/F levels decreased by 67% (0.241 vs. 0.080 pg/g ww), but the TEQ-ΣDL-PCB levels increased by 11% (0.046 vs. 0.051 pg WHO-TEQ/g ww). The median concentration of PFASs was 0.250 ng/mL, ranging from 0.151 to 0.833 ng/mL. The infants' mean EDI of total PCDD/Fs and DL-PCBs was 17.7 pg TEQ/kg body weight [bw], representing a 20% decline compared to 2013. The average EDI levels of PFOS, PFOA, and PFNA were 5.8, 17.9, and 1.7 ng/kg bw, respectively. A comprehensive comparison of the results with studies from around the world showed that the potential health risks posed by legacy PCDD/F and PCB pollutants were not as grave for mothers and infants living near this MWI, but the emerging PFAS pollutants represented a new cause for concern. MAIN FINDINGS: The potential health risks posed by legacy PCDD/F and PCB pollutants were not particularly serious for mothers and infants living near the MWI, but the emerging PFAS pollutants raised new concerns.

Xu P ，Zheng Y ，Wang X ，Shen H ，Wu L ，Chen Y ，Xu D ，Xiang J ，Cheng P ，Chen Z ，Lou X ... -  《-》

Levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in breast milk in Shanghai, China: A temporal upward trend.

Human milk samples were collected from 150 mothers in 2011 and 2012 in Shanghai, China and analyzed for 17 polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs). The up-bound Toxic Equivalent Quantity (TEQ) ranged from 0.27 to 16.8 pg TEQ/g lipid (mean 5.4 pg TEQ/g lipid) for ∑PCDD/Fs and from 0.75 to 10.2 pg TEQ/g lipid (mean 2.9 pg TEQ/g lipid) for ∑DL-PCBs. TEQs in our study were lower than those in most countries worldwide, and displayed a notable uptrend, in contrast with those in China's national survey in 2007. TEQs in mother milks from urban areas were higher than those from rural areas, and an orderly distribution was found in four geographical regions: Eastern China>Central China≈Southwestern China>Northwestern China. Levels of analytes in Shanghai native mothers' milk ranked the first among those from all provinces and cities investigated. Migrant mothers to Shanghai from other inland provinces could potentially represent the population for exposure and risk assessment in their birth and grown-up places. Both the distribution and the uptrend were associated with release of these pollutants due to rapid industrialization and urbanization in China. Fine correlations were observed between TEQs and age of mothers, and weak correlations between TEQs and consumption of meat & meat products. Participants, who preferred both fresh water and marine fish to freshwater fish only, were prone to be exposed to higher level of PCBs. The estimated daily intake (EDI) doses for breastfed neonates entirely exceeded the tolerable intake dose by WHO.

Lu D ，Lin Y ，Feng C ，Wang D ，She J ，Shen H ，Wang G ，Zhou Z ... -  《-》