Occurrence of rare earth elements in umbilical cord serum and association with thyroid hormones and birth outcomes in newborns

Xin Liu; Qian Xiang; Lei Zhang; Jingguang Li; Yongning Wu

doi:10.1016/j.chemosphere.2024.142321

Occurrence of rare earth elements in umbilical cord serum and association with thyroid hormones and birth outcomes in newborns

Chemosphere. 2024 May 14:359:142321. doi: 10.1016/j.chemosphere.2024.142321. Online ahead of print.

Authors

Xin Liu¹, Qian Xiang², Lei Zhang³, Jingguang Li⁴, Yongning Wu⁵

Affiliations

¹ College of Food Science and Engineering, Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, Wuhan Polytechnic University, Wuhan, 430023, China.
² Healthcare-associated Infection Control Center, Sichuan Academy of Medical Sciences, Sichuan People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China.
³ Department of Nutrition and Food Safety, Peking Union Medical College, Research Unit of Food Safety, Chinese Academy of Medical Sciences, Beijing, 100021, China; NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing, 100021, China. Electronic address: zhanglei1@cfsa.net.cn.
⁴ Department of Nutrition and Food Safety, Peking Union Medical College, Research Unit of Food Safety, Chinese Academy of Medical Sciences, Beijing, 100021, China; NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing, 100021, China.
⁵ College of Food Science and Engineering, Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, Wuhan Polytechnic University, Wuhan, 430023, China; Department of Nutrition and Food Safety, Peking Union Medical College, Research Unit of Food Safety, Chinese Academy of Medical Sciences, Beijing, 100021, China; NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing, 100021, China.

PMID: 38754495
DOI: 10.1016/j.chemosphere.2024.142321

Abstract

Rare earth elements (REEs) are emerging contaminants that are increasingly used in high technology products. However, limited information is available regarding exposure to REEs and associated health effects in neonates. This study aimed to investigate the association between REE concentrations and thyroid hormone levels, as well as birth outcomes in 109 newborns in Beijing, China. We measured the concentrations of 16 REEs and thyroid hormones in umbilical cord serum. To assess the impact of exposure to individual REEs and REE mixtures on thyroid hormone levels and birth outcomes, we employed univariate linear regression, least absolute shrinkage and selection operator (LASSO), and weighted quantile sum (WQS) models. We detected 14 REEs at high rates (92.6%-100%), with yttrium exhibiting the highest median (interquartile range) concentration [43.94 (0.33-172.55) ng/mL], followed by scandium [3.64 (0.46-11.15) ng/mL]. Univariate analyses showed that per logarithmic (ln)-unit change of neodymium (Nd) and samarium (Sm) was associated with 0.039 [95% confidence interval (CI): 0.001, 0.007] and 0.031 (95% CI: 0.003, 0.060) increases in free thyroxine (FT4) levels, respectively. Moreover, 14 REEs exhibited significant associations with triiodothyronine (T3) levels, resulting in increases ranging from 0.066 to 0.307. Elevated concentrations of terbium (Tb) [per ln-unit change: -0.021 (95% CI: -0.041, -0.01)] and lutetium (Lu) [-0.023 (95% CI: -0.043, -0.002)] were inversely correlated with birth length in newborns. A further multiple exposure analysis employing the LASSO model identified Sm, Nd, Y, Sc, and Lu as critical factors influencing FT4 and T3 levels. Additionally, WQS analyses showed positive associations between exposure to a mixture of 14 REEs and FT4 (P = 0.046), T3 (P < 0.001), and birth length (P = 0.049). These findings suggest that in utero exposure to REEs might disrupt thyroid hormone homeostasis and impact intrauterine growth. Further studies are warranted to validate these findings and elucidate the underlying mechanisms.

Keywords: Birth outcome; Newborn; Rare earth element; Thyroid hormone; Umbilical cord serum.