Race-ethnicity disparities in COVID-19 outcomes may be worsened by shorter- and long-term aerosol pollutants exposure

BACKGROUND AND AIM: The importance of ultrafine particles (UFP or PM₀.₁) exposure to respiratory disease has been identified. However, its effect (and that of PM₂.₅) on COVID-19 outcomes remain unknown. This study aims to identify and quantify shorter- and long-term aerosol impacts on COVID-19 in context of disparate outcomes observed for minority race-ethnicity groups in New York State (NYS). METHODS: COVID-19 outcomes included infections, hospitalizations, ICU admissions, and deaths reported by the CDC COVID-19 Case Surveillance Restricted Access Detailed Data, 2020–2022. UFP and PM₂.₅ data were simulated by a global three-dimensional model of chemical transport with state-of-the-science aerosol microphysical processes extensively validated with observations. For shorter-term (0–30 lag days) UFP and PM₂.₅ exposure, Distributed Lag Non-linear Model (DLNM) were used to examine the association at county-level, adjusting for meteorological factors. Long-term (average level of 2013–2020) associations with COVID-19 were assessed by Negative Binomial Mixed Models adjusting for county-level confounders. County-level confounders from the Census Bureau, Behavioral Survey, and Homeland Infrastructure Data were used. RESULTS: Compared to White, Hispanic/Black subgroups had greater excess risk of COVID-19 infection (+25%), hospitalization (+31%), ICU admission (+60%), and death (+5.5%). Excess risk per IQR increase for long-term UFP (PM₂.₅) exposure was significant for COVID-19 hospitalization: +40%; 95%-CI=20.5–63.6% (+22%;18.8–25.5%), ICU admission: +44%;39.1–49.2% (+24%;18.6–30.5%), and death: +40%;38.0–42.4% (+19%;8.2–30.7%). For short-term exposures, risks for all COVID-19 outcomes were elevated (RRs range from 1.0–4.6, all p < 0.05) when UFP > 2000 #·cm−3 and PM₂.₅ > 6.3 µg·m−3. CONCLUSIONS: Both shorter- and long-term exposure to aerosols increased the risk of COVID-19 infection and subsequent outcomes, with ultrafine particles (UFP) exerting larger effects than PM₂.₅, and with greater likelihood. The UFP and PM₂.₅-associated risks were disproportionately higher for race-ethnicity minorities (particularly Hispanic and Black) and for their economically vulnerable subgroups. KEYWORDS: COVID-19, ultrafine aerosol, particulate matter, environmental justice, socioeconomic status