Ambient PM_2.5: Health policy implications and management in Khuzestan, Iran

Ambient fine particulate matter (PM_2.5) is a major environmental risk for premature mortality worldwide. This study quantifies the health and economic impacts of PM_2.5 exposure in Khuzestan Province of Iran. This study quantifies the health and economic impacts of PM_2.5 exposure in Khuzestan Province, Iran. Validated daily PM_2.5 data from eight monitoring stations in 2021 were preprocessed, including outlier removal and gap-filling using a PM₁₀-to-PM_2.5 conversion factor of 0.45. Population data were projected from the 2016 census. The U.S. EPA's BenMAP-CE tool was used to estimate avoidable premature deaths under two PM_2.5 reduction scenarios (10 and 5 μg/m³). This study assessed mortality for five outcomes: acute lower respiratory infections (ALRI), ischemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), lung cancer (LC), stroke, and all-cause mortality. Economic valuation employed the value of statistical life (VSL), adjusted for Iran's GDP. PM_2.5 concentrations (30-55 μg/m³) surpassed WHO limits by 6-11 times, especially in Ahvaz and Omidiyeh. A total of 3174 avoidable deaths per 100,000 were estimated annually under the WHO's 5 μg/m³ guidelines. Among diseases, ischemic heart disease (IHD) accounted for the largest share of avoidable deaths (≈38 %), followed by stroke (≈23 %) and all-cause mortality (≈18 %). The annual economic benefits of reducing PM_2.5 under the 5 μg/m³ scenario were estimated at USD 46-236.4 million. The greatest health and economic benefits from improved air quality are expected in Ahvaz (central Khuzestan) and Dezful (north), followed by Abadan and Bandar-e-Mahshahr (southwest). This study highlights the high PM_2.5 burden in Khuzestan's urban and industrial centers. Targeted air quality policies in these areas could bring significant health and economic benefits. The results provide a solid basis for targeted policies, including stricter emission controls in high-burden regions, enhanced air quality monitoring, and community-based interventions such as public awareness campaigns in Iran and other middle-income countries.