Perfluoroalkyl substances (PFASs) are a class of widely used chemicals that have been detected in the environment and general population. However, the isomer patterns in human are poorly characterized. Previous studies observed the isomer-specific maternal-fetal transfer of PFASs in human. In our current study, we first examined the profile of PFASs and isomers, including 17 linear PFASs and 10 branched PFOS/PFOA isomers by using isotopic internal standards in umbilical cord serum samples from Guangzhou, China. We collected a total of 321 of cord blood serum samples from July to October in 2013, and analyzed the PFASs concentration with isomer-specific PFASs analysis method. The results showed that 9 out of 17 PFASs (linear PFASs) were detected (>50% detection rate). Perfluorohexane sulfonate (PFHxS, median 3.87 ng/mL) was the predominant, followed by total PFOS (median 2.99 ng/mL) and total PFOA (median 1.23 ng/mL) in cord serum. In addition, 1m-, iso-, ∑3+4+5m-PFOS and iso-PFOA were the branched PFASs detected in the current study. The proportion of linear PFOS (n-PFOS) was 75.16% of ∑PFOS which was similar to the proportion of electrochemical fluorination that produces ca. 70% linear PFOS and 30% branched. On the contrary, linear PFOA (n-PFOA) accounted for 98.69% ∑PFOA in cord serum samples. Our finding indicates distinct PFASs and PFOS/PFOA isomer profile in cord serum, suggesting there might be a different exposure pathway and metabolism of PFASs.
Bibliographical noteFunding Information:
This work was supported by Grants from the National Natural Science Foundation of China (No. 81472936, No. 81172630, and No. 81673127), the Fundamental Research Funds for the Central Universities (No. 16ykzd02), and the Guangdong Province Natural Science Foundation (No. 2014A030313021 and No. 2016A0303342). The views expressed in this article are those of the authors and do not necessarily represent those of the funding source. The funding source had no role in the design or analysis of the study publication.
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Health, Toxicology and Mutagenesis