Outdoor light at night and autism spectrum disorder in Shanghai, China: A matched case-control study

Yinyu Xie; Zhijuan Jin; Hong Huang; Shanshan Li; Guanghui Dong; Yuewei Liu; Gongbo Chen; Yuming Guo

doi:10.1016/j.scitotenv.2021.152340

Outdoor light at night and autism spectrum disorder in Shanghai, China: A matched case-control study

Sci Total Environ. 2022 Mar 10:811:152340. doi: 10.1016/j.scitotenv.2021.152340. Epub 2021 Dec 14.

Authors

Yinyu Xie¹, Zhijuan Jin², Hong Huang³, Shanshan Li⁴, Guanghui Dong⁵, Yuewei Liu⁶, Gongbo Chen⁷, Yuming Guo⁴

Affiliations

¹ Guangdong Provincial Engineering Technology Research Center of Environmental and Health Risk Assessment; Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, Guangdong, China; Department of Global Health, School of Public Health, Wuhan University, Wuhan 430071, Hubei, China.
² Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
³ Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
⁴ Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
⁵ Guangdong Provincial Engineering Technology Research Center of Environmental and Health Risk Assessment; Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, Guangdong, China.
⁶ Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, Guangdong, China.
⁷ Guangdong Provincial Engineering Technology Research Center of Environmental and Health Risk Assessment; Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, Guangdong, China. Electronic address: chengb36@mail.sysu.edu.cn.

PMID: 34914994
DOI: 10.1016/j.scitotenv.2021.152340

Abstract

Background: Several environmental factors have been identified to be associated with autism spectrum disorder (ASD) over the past decades. However, evidence is limited for the effect of exposure to outdoor light at night (LAN) on ASD in China and even elsewhere in the world.

Methods: Participants in this study were from a multi-stage sampling survey on ASD conducted between June 2014 and October 2014 among children aged 3-12 years in Shanghai, China. All participants underwent a two-stage screening of ASD via questionnaire, and then, suspected cases were finally diagnosed by clinical examination. For data analyses, each ASD case was randomly matched with 10 healthy controls by age and sex. The LAN data were extracted from the stable lights product of the US Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) according to geolocation information of residential addresses. Mean levels of exposure to LAN during the 3 years after birth and 1 year before birth were calculated. We used conditional logistic regression models to examine the association between LAN and ASD.

Results: We investigated 84,934 children from 96 kindergartens, 55 primary schools, and 28 special education schools, and 203 children were diagnosed as ASD cases. A total of 1727 children (157 ASD cases and 1570 healthy controls) were included in the final analyses. Brighter LAN exposures after and before birth were significantly associated with higher risk of ASD. After adjusting for potential covariates, adjusted odd ratios and 95% confidence intervals associated with per unit increase in LAN were 1.066 (1.027, 1.107) during the 3 years after birth and 1.046 (1.018, 1.075) during the 1 year before birth.

Conclusions: Results of our study concluded brighter LAN exposure was significantly associated with higher risk of ASD among Chinese children, which suggested that outdoor LAN could be a potential risk factor of ASD.

Keywords: A matched case-control study; Autism spectrum disorder; Light at night.

MeSH terms

Autism Spectrum Disorder* / epidemiology
Autism Spectrum Disorder* / etiology
Case-Control Studies
China / epidemiology
Humans
Odds Ratio
Risk Factors