Maternal exposure to ambient levels of sulfur dioxide and risk of neural tube defects in 14 cities in Liaoning province, China: a population-based case–control study

• Published in: Journal of exposure science & environmental epidemiology 2021-03, Vol.31 (2), p.266-275
• Main Authors: Zhang, Jia-Yu, Dai, Hui-Xu, Wu, Qi-Jun, Li, Jing, Huang, Yan-Hong, Chen, Zong-Jiao, Li, Li-Li, Chen, Yan-Ling, Liu, Shu, Jiang, Cheng-Zhi
• Format: Article
• Language: English
• Subjects: Abnormalities; Air Pollutants - adverse effects; Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Analysis; Case studies; Case-Control Studies; China - epidemiology; Cities - epidemiology; Confidence intervals; Defects; Dose-response relationship (Biochemistry); Environmental aspects; Epidemiology; Exposure; Female; Health aspects; Humans; Infant; Infants; Maternal Exposure - adverse effects; Medicine; Medicine & Public Health; Neural tube; Neural tube defects; Neural Tube Defects - chemically induced; Neural Tube Defects - epidemiology; Particulate Matter - analysis; Population studies; Population-based studies; Pregnant women; Prenatal influences; Regression analysis; Regression models; Risk; Stations; Statistical analysis; Statistics; Sulfur; Sulfur dioxide; Sulfur Dioxide - adverse effects
• ISSN: 1559-0631; 1559-064X
• DOI: 10.1038/s41370-020-00273-6

Epidemiological studies on the association of sulfur dioxide (SO 2 ) with neural tube defects (NTDs) are lacking. The purpose of this study was to assess the aforementioned association through a population-based case–control study. This study involved 1457 NTDs cases and 7950 randomly selected healthy infants born in 14 cities in Liaoning province between 2010 and 2015. Ambient SO 2 levels were acquired from 75 monitoring stations. The exposure assessment was based on the mean concentration of all stations in mother’s residential city. We used logistic regression models to assess the associations. In multivariable models adjusted for the confounding variables selected based on the 10 percent change-in-estimate method, we found that maternal SO 2 exposure was positively associated with an increased risk of NTDs during the first month after conception (per 10 μg/m 3 increase: adjusted odds ratio [aOR] = 1.02, 95% confidence interval [CI]: 1.00–1.04; highest versus lowest quartile: aOR = 2.55, 95% CI: 1.97–3.31) and the second month after conception (per 10 μg/m 3 increase: aOR = 1.02, 95% CI: 1.00–1.04; highest versus lowest quartile: aOR=2.31, 95% CI: 1.77–3.00). For other exposure windows, positive associations also emerged in high- versus low-exposure analyses, except for the third month before conception; however, we could not further confirm significant findings from the continuous exposure analyses. Our study provides a new evidence that SO 2 exposure may increase the risk of NTDs.