Work

Associations between polycyclic aromatic hydrocarbons exposure and maternal thyroid hormones during pregnancy

Year: 2025

Type: article

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are well-recognized endocrine-disrupting compounds. However, the association between prenatal PAH exposure and maternal thyroid hormones remains contentious. To resolve this uncertainty, we used data from 1165 pregnant women in the Zunyi Birth Cohort, aiming to characterize associations between urinary PAH metabolites and maternal thyroid hormone levels across gestation. We used linear mixed-effects models (LMMs) to examine associations between PAH metabolites and maternal thyroid hormones, restricted cubic spline (RCS) analysis to explore dose-response relationships, and Bayesian kernel-machine regression (BKMR) to assess the collective effects of PAH metabolites on the maternal thyroid system. We found that 2-OHNAP, 9-OHFLU, 4-OHPH, 3-OHPH, 1-OHPH, and 1-OHPYR were associated with thyroid-stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), and free thyroxine (FT4). Additionally, significant dose-response relationships were observed between 9-OHFLU, 2-OHFLU, 3-OHPH, 1-OHPH, 2-OHPH, 1-OHPYR and TSH, TT3, TT4, FT3, FT4. Notably, BKMR analysis revealed an overall non-linear, inverted U-shaped association between PAH metabolite mixtures and TSH, TT3, TT4, FT3, and FT4. Together, these results demonstrate that prenatal PAH exposure is associated with altered maternal thyroid hormone secretion. They further highlight the need to reduce PAH exposure during pregnancy and closely monitor maternal thyroid hormone levels throughout gestation.

Source: Ecotoxicology and Environmental Safety

DOI: 10.1016/j.ecoenv.2025.119128

Authors: Lin Tao, Lulu Dai, Shimin Xiong, Dengqing Liao, Yuan-zhong Zhou, Xubo Shen

Institution: Zunyi Medical University

Language: English

Topic: Effects and risks of endocrine disrupting chemicals

Subfield: Health, Toxicology and Mutagenesis

Field: Environmental Science

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,650