Temporal trend of dust storm events and particulate matter (PM_2.5 and PM₁₀) in Iran's metropolises, 2011-2022

Introduction: This study investigates the temporal trends of Sand and Dust Storms (SDS) and Particulate Matter (PM_2.5 and PM₁₀) concentrations across nine major Iranian cities from 2011 to 2022, assessing long-term air pollution patterns and associated environmental challenges. Materials and methods: PM concentration data were obtained from air quality monitoring stations. Dust storm events were identified using World Meteorological Organization (WMO) criteria. The primary objective was to analyze spatiotemporal variations and trends, which were statistically assessed using Sen’s slope method. Results: PM₁₀ levels consistently exceeded WHO annual guidelines by 2.13 to 12 times, while PM_2.5 levels were 1.37 to 6.89 times higher. Ahvaz recorded the highest cumulative SDS hours (25,318), followed by Yazd (10,062) and Tabriz (9,609), with annual stormy days reaching up to 66. The most pronounced increases in PM₁₀ occurred in Ahvaz, Yazd, and Tabriz. Maximum annual PM₁₀ concentrations were observed in Ahvaz (179.8 µg/m³ in 2013) and Yazd (135.85 µg/m³ in 2022), whereas peak PM_2.5 levels were reported in Ahvaz (57.2 µg/m³ in 2022) and Shiraz (43.37 µg/m³ in 2019). Conclusion: The escalating intensity and frequency of SDS are linked to regional climate variability, drought, and land degradation. The findings underscore an urgent need for comprehensive mitigation strategies, including desertification control, sustainable land management, and enhanced regional cooperation to address these critical environmental and public health challenges.