Environmental exposure to perchlorate, nitrate and thiocyanate, and thyroid function in Chinese adults: A community-based cross-sectional study

Lei King; Qiang Wang; Lili Xia; Pei Wang; Guanhua Jiang; Wanyi Li; Yue Huang; Xiaoling Liang; Xiaolin Peng; Yonggang Li; Liangkai Chen; Liegang Liu

doi:10.1016/j.envint.2022.107713

Environmental exposure to perchlorate, nitrate and thiocyanate, and thyroid function in Chinese adults: A community-based cross-sectional study

Environ Int. 2023 Jan:171:107713. doi: 10.1016/j.envint.2022.107713. Epub 2022 Dec 21.

Authors

Lei King¹, Qiang Wang¹, Lili Xia¹, Pei Wang¹, Guanhua Jiang¹, Wanyi Li¹, Yue Huang¹, Xiaoling Liang¹, Xiaolin Peng², Yonggang Li³, Liangkai Chen⁴, Liegang Liu⁵

Affiliations

¹ Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
² Department of Non-communicable Disease Prevention and Control, Shenzhen Nanshan Center for Chronic Disease Control, Shenzhen, China.
³ Hubei Provincial Key Laboratory for Applied Toxicology, Hubei Provincial Center for Disease Control and Prevention, Wuhan, China.
⁴ Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address: clk@hust.edu.cn.
⁵ Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Ministry of Education Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address: lgliu@mails.tjmu.edu.cn.

PMID: 36565572
DOI: 10.1016/j.envint.2022.107713

Abstract

Background: Evidence on environmental exposure to perchlorate, nitrate, and thiocyanate, three thyroidal sodium iodine symporter (NIS) inhibitors, and thyroid function in the Chinese population remains limited.

Objective: To investigate the associations of environmental exposure to perchlorate, nitrate, and thiocyanate with markers of thyroid function in Chinese adults.

Methods: A total of 2441 non-pregnant adults (mean age 50.4 years and 39.1% male) with a median urinary iodine of 180.1 μg/L from four communities in Shenzhen were included in this cross-sectional study. Urinary perchlorate, nitrate, thiocyanate, and thyroid profiles, including serum free thyroxine (FT4), total thyroxine (TT4), free triiodothyronine (FT3), total triiodothyronine (TT3), and thyroid stimulating hormone (TSH), were measured. Generalized linear model was applied to investigate the single-analyte associations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were used to examine the association between the co-occurrence of three anions and thyroid profile.

Results: The median levels of urinary perchlorate, nitrate, and thiocyanate were 5.8 μg/g, 76.4 mg/g, and 274.1 μg/g, respectively. After adjusting for confounders, higher urinary perchlorate was associated with lower serum FT4, TT4, and TT3, and higher serum FT3 and TSH (all P < 0.05). Comparing extreme tertiles, subjects in the highest nitrate tertile had marginally elevated TT3 (β: 0.02, 95% CI: 0.00-0.04). Each 1-unit increase in log-transformed urinary thiocyanate was associated with a 0.04 (95% CI: 0.02-0.06) pmol/L decrease in serum FT3. The WQS indices were inversely associated with serum FT4, TT4, and FT3 (all P < 0.05). In the BKMR model, the mixture of three anions was inversely associated with serum FT4, TT4, and FT3.

Conclusions: Our study provides evidence that individual and combined environmental exposure to perchlorate, nitrate, and thiocyanate are associated with significant changes in thyroid function markers in the Chinese population with adequate iodine intake.

Keywords: Cross-sectional study; Nitrate; Perchlorate; Thiocyanate; Thyroid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bayes Theorem
China
Cross-Sectional Studies
East Asian People
Environmental Exposure / adverse effects
Female
Humans
Iodine* / urine
Male
Middle Aged
Nitrates
Perchlorates / adverse effects
Perchlorates / urine
Thiocyanates / urine
Thyroid Gland*
Thyrotropin
Thyroxine
Triiodothyronine

Substances

Iodine
Nitrates
perchlorate
Perchlorates
thiocyanate
Thiocyanates
Thyrotropin
Thyroxine
Triiodothyronine