Short and long-term impacts of ambient ozone on health in Ahvaz, Iran

The objective of the study was to investigate short- and long-term mortality due to exposure of the inhabitants of Ahvaz (Iran) to ground-level ozone (O₃). The study employed the World Health Organization Regional Office for Europe’s (WHO/Europe) AirQ + modeling system to estimate total mortality (TM), cardiovascular mortality (CM), and respiratory mortality (RM) using relative risks (RR) and baseline incidences (BI). The AirQ + model estimates that 2.08% (95% CI: 1.39 - 2.76) of TM, 2.78% of CM (95% CI: 0 - 4.13), and 5.48% of RM (95% CI: 2.76 - 8.14) in 2015 are attributed to surface O₃ concentration exceeding 10 µg m⁻³. Due to lower surface O₃ concentrations in 2016 (35.2 µg/m³), compared to 2015 (79.2 µg/m³), the attributable proportions of health endpoints to O₃ exposure were significantly lower, i.e.,.72% for TM,.96% for CM and 1.92% for RM. The long-term excess risks for RM were 1.53% (95% CI:.77 - 2.28) and.14% (95% CI:.07 -.2) in 2015 and 2016, respectively. The estimated health effects from O₃ exposures in Ahvaz were low compared to other studies in Iran and across the world. Introduction of electric and hybrid cars with good urban planning could further reduce the health impacts of O₃ exposure in Ahvaz.