health impacts assessment and economic costs of implementing three scenarios of the clean air act in one of the largest middle east cities (2017-2026): an airq+ modeling

Introduction: this study aimed to assess the health impacts and economic costs of implementing the scenarios of decommissioning end-of-life cars and motorcycles and equipping buses with soot filters in tehran, one of the largest cities in the middle east, over a period of ten years (2017-2026) using the airq+ model. materials and methods: to start, the emission weights of particulate matter (pm2.5) emitted from the vehicles mentioned in the scenarios were extracted from the comprehensive national action plan for reducing air pollution. then the concentrations of pm2.5 were calculated using aermod. finally, the airq+ model was used to calculate the health effects of the scenarios over ten years. results: the results indicated that implementing the total of three scenarios during ten years led to a reduction in mortality rates due to all causes, chronic obstructive pulmonary disease (copd), lung cancer, acute lower respiratory tract infection (alri), ischemic heart disease (ihd), and stroke by 14.89%, 6.16%, 31.51%, 19.5%, 16.5%, and 17.38%, respectively. in addition, decommissioning end-oflife cars and motorcycles separately led to a 6.75% and 6.53% reduction in deaths from all causes, 2.54% and 2.46% from copd, 18.40% and 18.01% from lung cancer, 11.16% and 11% from alri, 12.82% and 12.69% from ihd, and 12.12% and 12.96% from stroke. conclusion: the results indicate that the implementation of these scenarios during ten years has positive effects on reducing deaths attributed by pm2.5 particles, but due to population growth, it has no effect on reducing economic costs.