Association of urinary bisphenols with thyroid function in the general population: a cross-sectional study of an industrial park in China

Abstract

Background: Bisphenols (BPs) are potential thyroid disruptors that are widely used in many consumer products, leading to their widespread exposure in the general population. Current studies have found that there is a certain association between exposure to BPs and serum thyroid function measures, albeit with some controversy.Objectives: To describe demographic characteristics, BP exposure levels, and thyroid function measurements in potentially exposed and control districts and to investigate the association of urinary BPs with thyroid function.Methods: Data were collected from a general population aged 3-79 years (N = 281) recruited by the Zhejiang Human Biomonitoring Program (ZJHBP). The concentrations of 10 kinds of BPs in urine and serum free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), total thyroxine (TT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), thyroglobulin antibodies (TgAb), thyroid peroxidase antibodies (TPOAb), and thyrotropin receptor antibody (TRAb) in serum were measured.Results: Bisphenol A (BPA), bisphenol S (BPS), and bisphenol P (BPP) were detected, respectively, in 82.73%, 94.24%, and 55.40% of the population in the exposed area and 81.69%, 61.27%, and 43.66% of the population in the control area. Among adult females, serum TT3 was negatively associated with urinary BPA (β = -0.030, P = 0.047). Among minor females, FT4 and Tg levels were negatively associated with the urinary BPA (β = −0.026, P = 0.032 for FT4; β = −0.129, P = 0.035 for Tg), and TPOAb was positively associated with urinary BPA (β = 0.104 P = 0.039). Conclusion:We found widespread exposure to BPA, BPS, and BPP in the general population of Zhejiang province and found a limited association between BPA and thyroid hormones. This association is gender-and age-dependent and needs to be con rmed in further studies.This study is part of the Zhejiang Human Biomonitoring Program (ZJHBP), a population-based representative and prospective cross-sectional study that has been established to record the degree of human exposure to various environmental chemicals and understand the exposure pro le, degree, and continuous trend of the general population in Zhejiang province, China. District A, where the industrial park was located, was selected as the exposed area, and District B was selected as the control area. Both District A and District B are located in the same city, the living standards and dietary habits of residents in the two regions were similar. Participants recruited in the two districts of Zhejiang gave written consent for the collection blood and urine samples and their participation in the ZJHBP study between September 2021 and October 2021. The exclusion criteria were as follows: history of thyroid disease, history of surgical thyroid interventions, mental disease, cognitive impairment, history of occupational exposure to poisons, and living in the monitoring area for less than 6 months. The participants were also excluded if missing biological samples or lack of information on crit...