Impact of COVID-19 pandemic on air pollution and hospitalization risk for cardiovascular and respiratory diseases in Suzhou, China

During the COVID-19 pandemic in China, a notable reduction in ambient air pollution levels has been documented. The risk of exposure to pollutants for the population is influenced by various factors, including the types of pollutants, seasonal variations, and demographic characteristics. However, it remains unclear whether the effects of these factors differ when comparing the periods before and during the COVID-19 pandemic. This study aims to evaluate the relationships between specific air pollutants (PM2.5, NO2 and SO2) and hospitalization risk for cardiovascular and respiratory diseases in Suzhou, China, both prior to and during the pandemic. A timeseries analysis was conducted utilizing a Distributed Lagged Nonlinear Model, incorporating data from 95,235 hospital admissions in Suzhou spanning from 2018 to 2022. The study also accounted for the influences of seasonal variations, gender, and age on these associations. The findings reveal a positive correlation between exposure to air pollution and hospitalization risk, with significant variations based on seasonal factors, gender, and age. Specifically, the risk of hospitalization is markedly increased during cold seasons, while in warm seasons during the pandemic, exposure to NO2 also contributes to increased risk. Furthermore, female individuals exposed to NO2 exhibit a higher hospitalization risk compared to males during the pandemic. Notably, elderly individuals aged 65 and above are at a higher risk of hospitalization due to air pollution exposure, highlighting the necessity for careful consideration in the design of environments that are conducive to the well-being of older adults.