Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk

Abstract

Chlorinated paraffins (CPs) are complex mixtures of synthetic chemicals found widely in environmental matrices. Short-chain CPs (SCCPs) are candidate persistent organic pollutants under the Stockholm Convention. There should be great concern about human exposure to SCCPs. Data on CP concentrations in human breast milk is scarce. This is the first study in which background SCCP and medium-chain CP (MCCP) body burdens in the general rural population of China have been estimated and health risks posed to nursing infants by CPs in breast milk assessed. The concentrations of 48 SCCP and MCCP formula congeners were determined in 24 pooled human milk samples produced from 1412 individual samples from eight provinces in 2007 and 16 provinces in 2011. The samples were analyzed by comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry. The median SCCP and MCCP concentrations were 303 and 35.7ngg lipid weight, respectively, for the 2007 samples and 360 and 45.4ngg lipid weight, respectively, for the 2011 samples. The C and C homologs were the dominant CP carbon-chain-length groups, contributing 51% and 82% of the total SCCP and MCCP concentrations, respectively. There are probably multiple CP sources to the general Chinese population and numerous exposure pathways. The median estimated daily SCCP and MCCP intakes for nursing infants were 1310 and 152ngkgd, respectively, in 2007 and 1520 and 212ngkgd, respectively, in 2011. SCCPs do not currently pose significant risks to infants in China. However, it is necessary to continuously monitor CP concentrations and health risks because CP concentrations in Chinese human breast milk are increasing.

Environmental Risks of Medium-Chain Chlorinated Paraffins (MCCPs): A Review

“…Also, no significant differences could be observed between rural and urban areas in China. 107,108 The measured MCCP concentrations range between 3.10 and 240 ng/g lipid and are thus one order of magnitude lower than the SCCP concentrations measured in the same samples (with the exception of the concentrations measured in Germany 109 ) (Fig. 9).…”

Chlorinated Paraffin Levels in Relation to Other Persistent Organic Pollutants Found in Pooled Human Milk Samples from Primiparous Mothers in 53 Countries

“…Xia et al. ( 2017a ) reported SCCP and MCCP concentrations in pooled human milk samples from provinces and cities in China that, when summed in the samples with the lowest and highest SCCP and MCCP values, indicate total CP concentrations of lipid ( lipid). In contrast, the range of total CP concentrations in pooled samples from Asian countries in the present study was lipid ( lipid) ( Table 4 ).…”

“…2012 ) indicated a clear dominance of SCCPs (e.g., United Kingdom 2006 median SCCP/MCCP ratio of 7.2). Two studies of samples collected from Chinese donors in 2007 and 2011 indicated a dominance of SCCPs over MCCPs by a factor of 10 ( Xia et al. 2017a , 2017b ).…”

“…2020 )] is in good agreement with our European results, whereas estimations for MCCPs are at least in the same order of magnitude. Notably, the maximum estimated lactational intakes reported for SCCPs in four of five Chinese studies [ BW per day ( Xia et al. 2017a , 2017b ; Yang et al.…”

Risk assessment of chlorinated paraffins in feed and food

“…The same authors reported the concentrations of SCCPs and MCCPs in pooled human milk samples this time from rural areas from 24 Chinese provinces, for the same time frame 2007 and 2011 (Xia et al., 2017b). The levels were lower than those reported in the urban areas, with median SCCP and MCCP concentrations in 2007 of 303 and 35.7 μg/kg fat, respectively, and in 2011 of 360 and 45.4 μg/kg fat.…”