Risks of source and species-specific air pollution for COVID-19 incidence and mortality in Los Angeles

Growing evidence from ecological studies suggests that chronic exposure to standard air pollutants (PM 2.5 , NO 2 , and ozone) exacerbates risks of coronavirus 2 (COVID-19) incidence and mortality. This study assessed the associations between an expanded list of air pollutants and COVID-19 incidence and mortality in Los Angeles. Annual mean exposure to air pollutants in 2019—including PM 0.1 mass, PM 2.5 mass, PM 2.5 elemental carbon (EC), PM 2.5 tracer from mobile sources, NO 2 , and ozone—were estimated at the ZIP code level in residential areas throughout Los Angeles. Negative binomial models and a spatial model were used to explore associations between health outcomes and exposures in single pollutant and multi-pollutant models. Exposure to PM 0.1 mass, ozone, NO 2 , and PM 2.5 EC were identified as risk factors for COVID-19 incidence and mortality. The results also suggest that PM 2.5 and NO 2 together may have synergistic effects on harmful COVID-19 outcomes. The study provides localized insights into the spatial and temporal associations between species-specific air pollutants and COVID-19 outcomes, highlighting the potential for policy recommendations to mitigate specific aspects of air pollution to protect public health.