Abstract
BackgroundEvidence of associations between prenatal exposure to perfluoroalkyl substances (PFASs) and fetal thyroid hormones (THs) is controversial, and few studies have estimated the associations, while addressing the high correlations among multiple PFASs. We aimed to examine the associations between prenatal PFAS exposure and thyroid hormone concentrations in cord blood.MethodsA total of 300 mother-infant pairs from the Shanghai-Minhang Birth Cohort Study were included. We measured the concentrations of eight PFASs in maternal plasma samples collected at 12–16 gestational weeks, as well as those of total thyroxine (T4), free T4 (FT4), total triiodothyronine (T3), free T3 (FT3), and thyroid stimulating hormone (TSH) in cord plasma. We estimated the associations between maternal PFAS concentrations and TH concentrations using linear regression and Bayesian kernel machine regression (BKMR) models.ResultsIn BKMR models, higher PFAS mixture concentrations were associated with increased T3 concentrations, and there were suggestive associations with increased FT3 concentrations. For single-exposure effects in BKMR models, a change in PFDA, PFUdA, and PFOA concentrations from the 25th to 75th percentile was associated with a 0.04 (95%CrI: − 0.01, 0.09), 0.02 (95%CrI: − 0.03, 0.07), and 0.03 (95%CrI: − 0.001, 0.06) nmol/L increase in T3 concentrations, respectively. PFOA, PFNA, and PFDA were the predominant compounds in PFASs-FT3 associations, and the corresponding estimates were 0.11 (95% CrI: 0.02, 0.19), − 0.17 (95% CrI: − 0.28, − 0.07), and 0.12 (95% CrI: − 0.004, 0.24) pmol/L, respectively. A change in PFNA and PFOA concentrations from the 25th to 75th percentile was associated with a − 1.69 (95% CrI: − 2.98, − 0.41) μIU/mL decrease and a 1.51 (95% CrI: 0.48, 2.55) μIU/mL increase in TSH concentrations. The associations of PFOA and PFNA with T3/FT3 were more pronounced in boys, while those with TSH were more pronounced in girls.ConclusionOur results suggest that prenatal exposure to multiple PFASs was associated with thyroid hormones in cord blood. However, individual PFAS had varied effects—differing in magnitude and direction—on fetal thyroid hormones.
Highlights
Perfluoroalkyl substances (PFASs) are synthetic fluorinecontaining chemicals that have been extensively used in a range of industrial and commercial products during the past 60 years [1]
In Bayesian kernel machine regression (BKMR) models, the perfluoroalkyl substances (PFASs) mixture was associated with increased Total triiodothyronine (T3) and free T3 (FT3) concentrations
For individual PFAS-hormone associations, maternal perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA) exposure was associated with increased T3 and FT3 concentrations, and maternal perfluorononanoic acid (PFNA) exposure was associated with decreased thyroid stimulating hormone (TSH) concentrations in both BKMR and linear regression models
Summary
Perfluoroalkyl substances (PFASs) are synthetic fluorinecontaining chemicals that have been extensively used in a range of industrial and commercial products during the past 60 years [1]. Since PFOS and PFOA were added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in 2009, PFAS production has been restricted in many European countries and the US. PFASs are persistent in the environment due to their high resistance to degradation and long half-lives [1, 10]. The adverse effects of PFAS exposure continue to pose a public health concern. Since PFASs can cross the placental barrier and expose the fetus [11, 12], there is significant concern regarding the adverse effects of in utero PFAS exposure. We aimed to examine the associations between prenatal PFAS exposure and thyroid hormone concentrations in cord blood
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.