Background: Thallium (Tl) is a highly toxic heavy metal widely present in the environment. Case reports have suggested that maternal exposure to high levels of Tl during pregnancy is associated with low birth weight (LBW), but epidemiological data are limited.
Objectives: This study was designed to evaluate whether prenatal Tl exposure is associated with an increased risk of LBW.
Methods: This case–control study involving 816 study participants (204 LBW cases and 612 matched controls) was conducted in Hubei Province, China, in 2012–2014. Tl concentrations were measured in maternal urine collected at delivery, and associations with LBW were evaluated using conditional logistic regression.
Results: Higher maternal urinary Tl levels were significantly associated with increased risk of LBW [crude odds ratio (OR) = 1.52; 95% CI: 1.00, 2.30 for the highest vs. lowest tertile], and the association was similarly elevated after adjustment for potential confounders (adjusted OR = 1.90; 95% CI: 1.01, 3.58 for the highest vs. lowest tertile). Stratified analyses showed slightly higher risk estimates for LBW associated with higher Tl levels for mothers < 28 years old and for mothers with lower household income; however, there was no statistical evidence of heterogeneity in risk according to maternal age (p for heterogeneity = 0.18) or household income (p for heterogeneity = 0.28).
Conclusion: To our knowledge, ours is the first case–control study to investigate the association between prenatal Tl exposure and LBW. The results suggest that prenatal exposure to high levels of Tl may be associated with an increased risk of LBW.
1Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People’s Republic of China; 2Zhejiang Provincial Center for Disease Control and Prevention, Zhejiang, People’s Republic of China; 3Department of Epidemiology, Brown University, Providence, Rhode Island, USA; 4Women and Children Medical and Healthcare Center of Wuhan, Wuhan, Hubei, People’s Republic of China; 5Department of Environmental Health Sciences, Yale School of Public Health, New Haven, Connecticut, USA; 6Macheng Maternity and Child Health Care Hospital, Macheng, Hubei, People’s Republic of China; 7Ezhou Maternal and Child Health Hospital, Ezhou, Hubei, People’s Republic of China
Recommended Citation:
Wei Xia,1 Xiaofu Du,1,et al. A Case–Control Study of Prenatal Thallium Exposure and Low Birth Weight in China[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 1):164