J Expo Sci Environ Epidemiol. 2026 Aug 15. doi: 10.1038/s41370-026-00957-5. Online ahead of print.
ABSTRACT
BACKGROUND: Short-term air pollution exposure may exacerbate respiratory health outcomes in vulnerable populations, particularly those with pre-existing cardiovascular conditions. Given the persistent burden of COVID-19 pneumonia, there is a need to better understand how environmental exposures influence risk of COVID-19 pneumonia.
OBJECTIVE: We aimed to explore whether associations between short-term particulate matter (PM2.5) exposure and COVID-19 pneumonia risk are stronger among those with pre-existing cardiovascular conditions.
METHODS: We used NYC COVID-19 hospitalization records (March-December 2020; N = 15,361) and defined short-term PM2.5 as a 7-day residential ZIP Code average prior to and including hospitalization, using Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeled data. Pre-existing cardiovascular conditions included 15 ICD-coded circulatory conditions (e.g. myocardial infarction, atrial fibrillation, ischemic heart disease). Modified Poisson regression estimated risks of acute respiratory distress syndrome, pneumonia, ventilation use, and dialysis use, and Cox hazards regression estimated COVID-19 fatality risk and length of stay, adjusting for age, sex, smoking status, and environmental vulnerability. Relative excess risks of interaction (RERI) estimated additive interaction between short-term PM2.5 exposure and cardiovascular conditions on risk of COVID-19 pneumonia during hospitalization. Targeted maximum likelihood estimation estimated average treatment effects (ATE) of short-term PM2.5 exposure on COVID-19 pneumonia, among those with and without cardiovascular conditions.
RESULTS: Short-term PM2.5 and pre-existing cardiovascular conditions together increased pneumonia risk from July to December 2020. For example, joint exposure to an interquartile range increase in short-term PM2.5 and pre-existing myocardial infarction amplified pneumonia risk (RR:1.67; 95%CI:1.41,1.99), with smaller increases observed for PM2.5 alone (RR:1.03; 95%CI:0.95,1.12) or myocardial infarction alone (RR:1.34; 95%CI:1.14,1.58). Upper-quartile short-term PM2.5 increased pneumonia risk only among individuals with cardiovascular conditions (ATE:0.05, 95%CI:0.02,0.08).
IMPACT: COVID-19 pneumonia drives substantial hospitalizations, but little is known about the link between environmental exposures and pneumonia. We aimed to examine whether short-term air pollution influences pneumonia risk, and if pre-existing cardiovascular conditions modify this link. We found that pre-existing cardiovascular conditions increase vulnerability to short-term air pollution, amplifying COVID-19 pneumonia risk during hospitalization. These study findings may help identify populations that may be more vulnerable to the effects of short-term air pollution exposure during future respiratory infectious disease outbreaks.
PMID:42603825 | DOI:10.1038/s41370-026-00957-5