Estimation of mortality and economic burden attributable to ground-level O₃ in Central Iran using BenMAP CE

Air pollution remains one of the most significant environmental health threats in urban areas. Ground-level O₃, a secondary pollutant formed through photochemical reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) under sunlight, can lead to serious respiratory and cardiovascular effects. This study aimed to quantify the short-term mortality and economic burden attributable to O₃ exposure in Qom, central Iran, during the summer of 2019, providing local evidence to support air quality management policies.

Hourly O₃ concentration data were collected from the Qom Environmental Protection Agency for April to August 2019. After data cleaning and interpolation, the daily maximum 8-h average O₃ concentration was calculated. Health impact and related economic burden were estimated using the U.S. EPA's BenMAP-CE model (version 1.5.8.11). Relative risk (RR) and baseline incidence (BI) values for cardiovascular and respiratory mortality were obtained from previous epidemiological studies. The Value of Statistical Life (VSL) was adjusted for Iran's gross domestic product (GDP) to estimate the economic cost. Descriptive statistics and concentration-response functions were applied to determine avoidable deaths and associated losses.

The mean 8-h maximum O₃ concentration during the study period was 0.16 ppm, exceeding the EPA guideline (0.07 ppm) by 2.18 times. Short-term exposure at this level was linked to an estimated 239 premature deaths, including 190 from cardiovascular and 49 from respiratory diseases. The highest impact was observed in adults aged 30-39 years. The total economic loss attributed to these deaths was approximately 43.6 million USD, indicating a substantial burden on public health and the economy.

This study highlights the urgent need for effective air quality management in Qom. Reducing emissions of O₃ precursors such as NOx and VOCs, especially during warm months, could yield considerable public health and economic benefits. Localized assessments using tools like BenMAP-CE can inform evidence-based policymaking and contribute to sustainable urban development.