From Space to Health: Satellite-Derived Microplastic Exposure and Health

Abstract Marine microplastic pollution represents an emerging global environmental health threat, yet population-level evidence of health impacts remains scarce, particularly in developing countries. This study provides a comprehensive analysis of microplastic exposure and health outcomes utilizing Chile's extensive coastline as a natural laboratory. We examine the relationship between marine microplastic concentrations and birth outcomes using administrative health data combined with innovative satellite-based exposure assessment from NASA's Cyclone Global Navigation Satellite System (CYGNSS). Our identification strategy exploits quasi-random temporal and spatial variation in microplastic concentrations derived from remote sensing measurements to establish causal relationships. Results demonstrate that cumulative in-utero microplastic exposure significantly increases low birth weight: moving from the 25th percentile of cumulative exposure to the 75th percentile implies an increase of 6.32 cases of low birth weight per 1,000 births (+9.1%), with effects most pronounced during the third trimester of pregnancy. Notably, we find no evidence that seafood consumption mediates these health impacts. The study reveals no significant effects on infant mortality rates. These findings carry important policy implications for coastal nations worldwide. Chile's progressive plastic pollution regulations provide a foundation for targeted interventions, yet our results highlight the need for comprehensive microplastic monitoring systems, and pregnancy-specific exposure guidelines.