Assessment of Dust Concentration and Sediment Load of Dust Storms in the Sistan Region of Iran

摘要

The Sistan region in southeast Iran presents a seasonally varied climate. The region is subject to severe winds that blow with speeds occasionally reaching 30 ms-1 . After the 1999 drought, because of land-use change and drying-up of the Hamoun Lakes, the frequency and severity of dust storms have been significantly increased. To assess the air quality and sediment load of dust storms, Particulate Matter (PM10) concentrations were measured during September 2010 to January 2011 using Beta Attenuation Monitors model 1020 (BAM-1020). The dust sediment load was also measured using dust traps set at up to 8 meters height (1 meter distance between the traps) during the period August 2009 to August 2010. The results of measuring sediment load up to 8 meters height have shown that, yearly, about 31,000 tons of dust enter the Sistan region. Daily mean PM10 levels are found to be around 437 μgm-3, ranging from 66 μgm-3 to 2339 μgm-3. Analyses of the Air Quality Index (AQI) shows that 17 % of the days are unhealthy for sensitive people and 61% have a high health risk or are even hazardous.