Per- and polyfluoroalkyl substance profiles and associations with thyroid hormones in a coal mining population from Shanxi Province, China

Liangpo Liu; Yufan Cheng; Zhipeng Sun; Yu Gao; Lu He; Yingxiao Yue; Shuqi Xu; Yalin Liu; Dan Wang; Hongying Gao; Wei Yan; Huan Song; Xiujuan Yang; Jianquan Guo; Ben Li; Qiansheng Huang; Qian Gao; Jinzhu Yin; Tong Wang

doi:10.1016/j.envint.2026.110247

Per- and polyfluoroalkyl substance profiles and associations with thyroid hormones in a coal mining population from Shanxi Province, China

Environ Int. 2026 Apr:210:110247. doi: 10.1016/j.envint.2026.110247. Epub 2026 Apr 8.

Authors

Liangpo Liu¹, Yufan Cheng¹, Zhipeng Sun¹, Yu Gao¹, Lu He¹, Yingxiao Yue², Shuqi Xu¹, Yalin Liu¹, Dan Wang¹, Hongying Gao¹, Wei Yan¹, Huan Song¹, Xiujuan Yang¹, Jianquan Guo¹, Ben Li³, Qiansheng Huang⁴, Qian Gao⁵, Jinzhu Yin⁶, Tong Wang⁷

Affiliations

¹ Department of Public Health Laboratory Sciences, School of Public Health, Shanxi Medical University, Taiyuan 030001, PR China; Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Ministry of Education, Taiyuan 030001, PR China.
² Department of Public Health Laboratory Sciences, School of Public Health, Shanxi Medical University, Taiyuan 030001, PR China; Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Ministry of Education, Taiyuan 030001, PR China; Department of Nutrition and Food Hygiene, School of Public Health, Key Laboratory of Precision nutrition and health, Ministry of Education, Harbin Medical University, Heilongjiang 150081, PR China.
³ Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Ministry of Education, Taiyuan 030001, PR China; Department of Toxicology, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
⁴ Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China.
⁵ Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Ministry of Education, Taiyuan 030001, PR China; Department of Health Statistics, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
⁶ Department of Neurosurgery, Sinopharm Tongmei General Hospital, Datong, Shanxi 037003, PR China.
⁷ Key Laboratory of Coal Environmental Pathogenicity and Prevention, Shanxi Medical University, Ministry of Education, Taiyuan 030001, PR China; Department of Health Statistics, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China. Electronic address: tongwang@sxmu.edu.cn.

PMID: 41966766
DOI: 10.1016/j.envint.2026.110247

Abstract

Background: Per- and polyfluoroalkyl substances (PFASs) exposure may cause endocrine disruption. However, PFAS exposure and their potential associations with thyroid hormones remain unclear in coal mining areas.

Objectives: To characterize PFAS exposure profile and their associations among this population.

Methods: Serum levels of PFASs and thyroid hormones were measured in 760 participants. Multiple linear regression and restricted cubic spline models assessed individual PFAS associations with thyroid hormones, while Bayesian kernel machine regression and quantile-based g-computation evaluated joint effects. Stratification and sensitivity analyses were conducted to verify the validity and robustness of results.

Results: PFOA was extraordinarily high (median: 1623 μg/L), reaching 10-fold those of fluorochemical plant workers, and showed a positive correlation with a 0.057 increase in FT4 per ln-unit (95% CI: 0.006, 0.107). Emerging PFAS substitutes showed stronger, non-linear dose-response associations with thyroid hormones than legacy compounds. PFAS mixture exposure was inversely associated with FT3, TT4, TT4/FT3 and TT4/FT4 (β: -4.816 to -0.071, 95% CI: -6.708 to -0.121, -2.923 to -0.021), but positively with FT4/FT3 (β: 0.074, 95% CI: 0.021, 0.126). Age and BMI were important effect modifiers for associations between PFASs and thyroid hormones, with underweight and obese individuals being more susceptible.

Conclusions: PFAS exposure levels were extraordinarily high and significantly associated with thyroid hormones. Emerging substitutes showed stronger effects and complex bidirectional influences, and mixture exposure exerted the same effects. Age and BMI served as important effect modifiers. Notably high PFAS exposure and their strong links to thyroid hormone homeostasis in coal mining population warranted further validation.

Keywords: Coal mining population; Mixture exposure; Non-linear effect; Per- and polyfluoroalkylsubstances; Thyroid hormones.

MeSH terms

Adult
Caprylates
China
Coal Mining*
Environmental Pollutants* / blood
Female
Fluorocarbons* / blood
Humans
Male
Middle Aged
Occupational Exposure* / analysis
Occupational Exposure* / statistics & numerical data
Thyroid Hormones* / blood

Substances

Thyroid Hormones
Fluorocarbons
perfluorooctanoic acid
Environmental Pollutants
Caprylates