The mortality impacts of implementing the 3-30-300 greenness rule and the WHO air quality guidelines in Bari, Southern Italy

Urban trees and air quality play a pivotal role in shaping the well-being of communities. This health impact assessment study aimed to quantify the mortality impacts of meeting the 3-30-300 greenness rule and the 2021 World Health Organization (WHO) air quality guidelines in Bari, Southern Italy. Population weighted exposures to greenness were calculated in 2013–15 using satellite-derived normalized difference vegetation index at 30 m resolution within a 300 m radius buffer from homes. Population weighted exposures to air pollution were estimated using a combination of atmospheric chemical transportation models and machine learning models at 200 m resolution. Potentially 4–5% of all annual deaths could be avoided by achieving an estimated 30% tree canopy cover, and 11–13% of deaths by achieving the WHO air quality guidelines when combined reduction of PM2.5 and NO2 is considered. The total estimated avoidable deaths in three years are 423 (95% confidence interval: 317;633) and 1,159 (95% CI: 553;1,730), respectively. Hence the importance of greening cities and reducing air pollution to lower mortality rates, while promoting sustainable, pleasant, and healthy conditions.