Association between outdoor artificial light at night and low birth weight in California

Artificial light at night (ALAN) is a growing environmental issue associated with adverse health consequences, but the association with low birth weight remains unknown. We aim to explore associations between outdoor ALAN and low birth weight across 7,808 census tracts in California. We use data from the California Communities Environmental Health Screening Tool (CalEnviroScreen) at the census tract level. VIIRS Nighttime Day/Night Band Composites Version 1 dataset within the Google Earth Engine platform was used to assess outdoor ALAN. Multivariable linear regression was used to analyze the data. Our findings showed that an interquartile range increase in outdoor ALAN resulted in an increase of 0.42% (95% CI: 0.37, 0.46) in low birth weight rate on average, after adjusting for all potential covariates. The results demonstrate a significant association between outdoor ALAN and low birth weight. These associations remained consistent in sensitivity analyses.