Association of COVID-19 distribution with air quality, sociodemographic factors, and comorbidities: an ecological study of US states

This ecological study investigated the association between COVID-19 distribution and air quality index (AQI), comorbidities and sociodemographic factors in the USA. The AQI factors included in the study are total AQI, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide (NO₂). Other demographic, socioeconomic, and geographic variables were included as covariates. The correlations of COVID-19 variables—proportion of cases and deaths in each population, as well as case fatality rate with independent variables were determined by Pearson and Spearman correlation and multiple linear regression analyses. The results revealed that AQI-NO₂, population density, longitude, gross domestic product per capita, median age, total death of disease, and pneumonia per population were significantly associated with the COVID-19 variables (P < 0.05). Air pollutants, especially NO₂ in the US case, could be addressed as an important factor linked with COVID-19 susceptibility and mortality.