Air quality and health risk assessment during Middle Eastern dust storms: a study of particulate matter

Abstract

This study evaluates the concentration levels of PM_2.5 and PM₁₀ associated with a series of dust storm events in the Middle East during May 2022 (1–6 May, 15–17 May, and 24–27 May). A comprehensive dataset, including ERA5 reanalysis, ground air quality datasets, HYSPLIT trajectory model, and weather station observations, was utilized to identify the dynamic processes driving these dust storms. The findings reveal that the dust storms were triggered by a blocking ridge over Saudi Arabia separated by two deep troughs between north Africa and western Iran associated with a cut off low from the mid-latitudes fueled by tropical atmospheric rivers flow from Africa which enhanced unstable weather conditions over northern Arabian Peninsula. Particulate Matter (PM) concentration levels were evaluated at three Omani cities: Muscat in the north, Sur at the eastern tip, and Salalah in the south. The results indicated that dust storms affected PM₁₀ levels in all three cities, with a significant increase in PM_2.5 levels (25–80 µg m^-3) in Salalah. By using the HYSPLIT trajectory model, the study identified dust emission pathways originating from Iraq and the eastern Arabian Peninsula, propagating southward. Additionally, global satellite-gridded PM_2.5 estimates were used to analyze PM_2.5 concentration trends in Muscat, Sur, Duqm, and Salalah from 1998 to 2021, showing an upward trend. Annual PM_2.5 satellite concentrations of the year 2019 compared with and without dust and salt inclusions, indicating that mineral dusts are the primary source air pollution. Based on the satellite trend datasets of PM_2.5, the results indicate a significant upward increase trend in the Middle East. According to the satellite trend datasets of PM_2.5, and by using Mann-Kendall test and Thiel-Sen Salalah and Duqm have a significant upward trend compared to Muscat and Sur. Furthermore, Salalah and Duqm are found to have higher asthma rates than Muscat, due to the natural dust shield created by mountain ranges in northern Sultanate. The study concludes that PM_2.5 and PM₁₀ concentrations are significantly influenced by atmospheric conditions, topography of the area, and transport routes.