Xu Wang1,2, Cong Liu3, Mingzhi Zhang1,2, Yingying Han1,2, Heidi Aase4, Gro Dehli Villanger4, Oddvar Myhre5, Aaron van Donkelaar6, Randall V Martin6,7, Erica Anne Baines8, Renjie Chen3, Haidong Kan3, Yankai Xia1,2. 1. 1State Key Laboratory of Reproductive Medicine, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China. 2. 2Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China. 3. 3Key Laboratory of Public Health Safety of the Ministry of Education and Key Laboratory of Health Technology Assessment of the Ministry of Health, School of Public Health, Fudan University, Shanghai, China. 4. 4Department of Child Development and Norwegian Institute of Public Health, Oslo, Norway. 5. 5Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway. 6. 6Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada. 7. 7Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts. 8. 8Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
Abstract
Background: Particulate matter (PM) air pollution is an environmental risk to public health. The prevalence of thyroid disease during pregnancy has increased rapidly in recent decades, but the available data on the relationships among air pollution, thyroid function, and birth outcomes in pregnant women, particularly in China, are scarce. We aimed to evaluate the association between maternal exposure to PM2.5 and its components and maternal and neonatal thyroid function and to investigate whether thyroid function acts as a mediator between air pollution and birth weight. Methods: In this prospective birth cohort study, the levels of maternal exposure to PM2.5 and its components during the first trimester were assessed in 433 pregnant women in Nanjing, China, enrolled during 2014-2015. We evaluated the levels of maternal exposure to PM2.5 and its six main constituents-organic matter (OM), black carbon (BC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and soil dust-using the V4.CH.02 product of the Dalhousie University Atmospheric Composition Analysis Group. The maternal serum-free thyroxine (fT4), thyrotropin (TSH), and thyroid peroxidase antibody (TPOAb) levels during the second trimester were measured through electrochemiluminescent microparticle immunoassays. The neonatal TSH levels were detected using an AutoDELFIA Neonatal TSH kit within 72 hours after birth, and the birth weight Z-score of each newborn was estimated. Results: Higher exposure to maternal PM2.5 and some components (BC and NH4+) decreased the maternal fT4 level (p < 0.05), and the birth weight Z-score was decreased (p < 0.05) by higher exposure to maternal PM2.5 and some components (OM, BC, NO3-, and NH4+). A mediation analysis clarified that the maternal fT4 levels explained 15.9%, 18.4%, and 20.9% of the associations of maternal PM2.5, BC, and NH4+ exposure with the birth weight Z-score, respectively (p < 0.05). After additional sensitivity analyses including only nonpreterm participants (n = 418) and non-TPOAb-positive participants (n = 415), the models remained stable. Conclusions: Our results suggest an inverse association between maternal exposure to PM2.5 and its components and the maternal fT4 levels. Maternal fT4 might act as a mediator between exposure to PM2.5 and its components and birth weight.
Background: Particulate matter (PM) air pollution is an environmental risk to public health. The prevalence of thyroid disease during pregnancy has increased rapidly in recent decades, but the available data on the relationships among air pollution, thyroid function, and birth outcomes in pregnant women, particularly in China, are scarce. We aimed to evaluate the association between maternal exposure to PM2.5 and its components and maternal and neonatal thyroid function and to investigate whether thyroid function acts as a mediator between air pollution and birth weight. Methods: In this prospective birth cohort study, the levels of maternal exposure to PM2.5 and its components during the first trimester were assessed in 433 pregnant women in Nanjing, China, enrolled during 2014-2015. We evaluated the levels of maternal exposure to PM2.5 and its six main constituents-organic matter (OM), black carbon (BC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and soil dust-using the V4.CH.02 product of the Dalhousie University Atmospheric Composition Analysis Group. The maternal serum-free thyroxine (fT4), thyrotropin (TSH), and thyroid peroxidase antibody (TPOAb) levels during the second trimester were measured through electrochemiluminescent microparticle immunoassays. The neonatal TSH levels were detected using an AutoDELFIA Neonatal TSH kit within 72 hours after birth, and the birth weight Z-score of each newborn was estimated. Results: Higher exposure to maternal PM2.5 and some components (BC and NH4+) decreased the maternal fT4 level (p < 0.05), and the birth weight Z-score was decreased (p < 0.05) by higher exposure to maternal PM2.5 and some components (OM, BC, NO3-, and NH4+). A mediation analysis clarified that the maternal fT4 levels explained 15.9%, 18.4%, and 20.9% of the associations of maternal PM2.5, BC, and NH4+ exposure with the birth weight Z-score, respectively (p < 0.05). After additional sensitivity analyses including only nonpreterm participants (n = 418) and non-TPOAb-positive participants (n = 415), the models remained stable. Conclusions: Our results suggest an inverse association between maternal exposure to PM2.5 and its components and the maternal fT4 levels. Maternal fT4 might act as a mediator between exposure to PM2.5 and its components and birth weight.
Entities:
Keywords:
PM; birth weight; cohort study; pregnancy; thyroid function
Authors: Eduardo García-Fuentes; Gemma Rojo-Martínez; Sergio Valdés; Viyey Doulatram-Gamgaram; Cristina Maldonado-Araque; Ana Lago-Sampedro; Eva García-Escobar; Sara García-Serrano; Marta García-Vivanco; Luis Garrido Juan; Mark Richard Theobald; Victoria Gil; Fernando Martín-Llorente; Pilar Ocon; Alfonso Calle-Pascual; Luis Castaño; Elías Delgado; Edelmiro Menendez; Josep Franch-Nadal; Sonia Gaztambide; Joan Girbés; F Javier Chaves; José L Galán-García; Gabriel Aguilera-Venegas; Carolina Gutierrez-Repiso; José Carlos Fernández-García; Natalia Colomo; Federico Soriguer Journal: Environ Health Date: 2022-08-17 Impact factor: 7.123