Association between Chronic Exposure to Ambient Air Pollutants, Demography, Vaccination Level, and the Spread of COVID-19 during 2021 Delta Variant Morbidity Wave

Studies conducted in the early COVID-19 pandemic stages showed positive associations between chronic exposure to ambient air pollution and COVID-19 morbidity. Here, we examined the associations between populations’ chronic exposure to air pollutants (NO₂, CO, PM₁₀, PM_2.5, and SO₂), demographics, and vaccination rates, to COVID-19 morbidity rates in 280 Israeli municipalities during the Delta-variant-dominated morbidity wave of summer 2021. We found that COVID-19 morbidity was positively associated with chronic exposure to air pollutants, the municipality’s population density, total population size, and the rate of elderly people. Multivariate linear regression models showed similar trends: positive associations between COVID-19 rates and density, ratio of elderly people, and most air pollutants, and a non-significant link to COVID-19 vaccine second dose ratio. Our results emphasized the effects of chronic air pollution exposure on the spread of the pandemic and strengthen the urgent need for uncompromising policy for a dramatic reduction in air pollution. They also highlighted the vulnerable populations (elderly, densely populated municipalities) during the Delta morbidity wave. These findings could assist policy makers to better inform the public and manage health policies in future COVID-19 waves, hopefully leading to a reduced impact on health.