Artificial light at night extends pollen season and increases allergen exposure in northeastern United States cities. Lin Meng and colleagues analyzed 12 years of pollen data from 12 monitoring stations across the Northeastern United States, combining measurements with satellite data on artificial light at night and climate records. The authors found that higher exposure to artificial light at night was significantly associated with earlier pollen season starts, later season ends, and longer overall pollen seasons, even after accounting for temperature and precipitation. The effect on season end was larger than on season start. Additionally, areas with artificial light at night had more days classified as severe allergen exposure, with 27% of pollen season days reaching severe levels compared to 17% in areas without artificial light. According to the authors, artificial light at night represents an overlooked driver of allergy risk that should be integrated into urban environmental public health and planning strategies, particularly in cities where both light pollution and allergy prevalence are high.
PNAS Nexus
Artificial light at night extends pollen season and elevates allergen exposure
20-Jan-2026