Evidence regarding environmental factors associated with disease severity of COVID-19 remained scarce.This study aimed to investigate the association of residential greenness exposure with COVID-19 severity applying a retrospective cross-sectional study in Wuhan, China.We included 30,253 COVID-19 cases aged over baseball scoreboards for sale 45 years from January 1 to February 27, 2020.
Residential greenness was quantitatively assessed using normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI).A multilevel generalized linear model using Poisson regression was implemented to analyze the association between greenness exposure and disease severity of COVID-19, after adjusting for potential covariates.A linear exposure-response relationship was found between greenness and COVID-19 severity.
In the adjusted model, one 0.1 unit increase of NDVI and EVI in the 1000-m buffer radius was significantly associated with a 7.6% (95% confidence interval (CI): 4.
0%, 11.1%) and 10.0% (95% CI: 5.
1%, 14.7%) reduction of the prevalence of COVID-19 severity, respectively.The effect of residential greenness seemed to be viqua-f4 more pronounced among participants with lower population density and economic levels.
Air pollutants mediated 0.82~12.08% of the greenness and COVID-19 severity association, particularly to nitrogen dioxide.
Sensitivity analyses suggested the robustness of the results.Our findings suggested that residential greenness exposure was beneficial to reduce the prevalence of COVID-19 severity.