Perinatal Exposures to Ambient Fine Particulate Matter and Outdoor Artificial Light at Night and Risk of Pediatric Papillary Thyroid Cancer

BACKGROUND: Pediatric thyroid cancer incidence has been increasing globally, with environmental exposures being a hypothesized risk factor. OBJECTIVE: ) and outdoor artificial light at night (O-ALAN). Both are considered environmental carcinogens with evidence of thyroid function disruption, reported associations with thyroid cancer in adults, and concerns of distributive inequity. O-ALAN may also serve as a proxy for other outdoor air pollutants or urbanization. METHODS: concentrations from a validated, ensemble-based prediction model and O-ALAN using the New World Atlas of Artificial Night Sky Brightness. We calculated odds ratios (OR) and 95% confidence intervals (CI) using logistic regression adjusting for potential confounders and stratified by age and race/ethnicity. In age-stratified analyses, significant associations were observed among the 15-19 y age group, but not the 0-14 y age group. No significant differences were found by race/ethnicity. DISCUSSION: and O-ALAN and pediatric papillary thyroid cancer. Given that O-ALAN may also represent other air pollutants or broader urbanization patterns, further research and refinements to exposure metrics are needed to disentangle these factors. https://doi.org/10.1289/EHP14849.