Chlorinated Polyfluorinated Ether Sulfonates and Thyroid Hormone Levels in Adults: Isomers of C8 Health Project in China

• Published in: Environmental science & technology Vol. 56; no. 10; pp. 6152 - 6161
• Main Authors: Li, Qing-Qing, Liu, Jiao-Jiao, Su, Fan, Zhang, Yun-Ting, Wu, Lu-Yin, Chu, Chu, Zhou, Yuanzhong, Shen, Xubo, Xiong, Shimin, Geiger, Sarah Dee, Qian, Zhengmin Min, McMillin, Stephen Edward, Dong, Guang-Hui, Zeng, Xiao-Wen
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17.05.2022
• Subjects: Animal models; Bayesian analysis; Ecotoxicology and Public Health; Epidemiology; Hormones; Isomers; Mathematical models; Mixtures; Perfluoro compounds; Perfluoroalkyl & polyfluoroalkyl substances; Perfluorooctane sulfonic acid; Perfluorooctanoic acid; Population studies; Regression analysis; Regression models; Sulfonates; Thyroid; Thyroid gland; Thyroid hormones; Thyroid-stimulating hormone; Thyroxine; Triiodothyronine; China; perfluoroalkyl substances (PFAS); perfluorooctanoic acid (PFOA); perfluorooctanesulfonate (PFOS); Isomers of C8 Health Project; chlorinated polyfluorinated ether sulfonates (Cl-PFESAs); thyroid hormones
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.1c03757

Chlorinated polyfluorinated ether sulfonates (Cl-PFESAs) are one kind of replacement chemistry for perfluorooctanesulfonate (PFOS). Recent studies have shown that Cl-PFESAs could interfere with thyroid function in animal models. However, epidemiological evidence on the link between Cl-PFESAs and thyroid function remains scarce. In this study, we focused on two representative legacy perfluoroalkyl substances (PFAS), including PFOS and perfluorooctanoic acid (PFOA), and two PFOS alternatives (6:2 and 8:2 Cl-PFESAs) in the general adult population from a cross-sectional study, the “Isomers of C8 Health Project in China”. Three serum thyroid hormones (THs), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), were measured. We fitted generalized linear regression, restricted cubic spline regression, and Bayesian kernel machine regression models to assess associations of individual Cl-PFESAs, legacy PFAS, and PFAS mixtures with THs, respectively. We found individual PFAS and their mixtures were nonlinearly associated with THs. The estimated changes of the TSH level (μIU/mL) at the 95th percentile of 6:2 Cl-PFESA and PFOS against the 5th percentile were −0.74 (95% CI: −0.94, −0.54) and −1.18 (95% CI: −1.37, −0.98), respectively. The present study provided epidemiological evidence for the association of 6:2 Cl-PFESA with thyroid hormone levels in the general adult population.