Study of particulate matters concentration and radiation rate in the atmosphere of Ilam city during middle east dust storms

The possibility of suspending radioactive particles during dust storms from Iraq and entering Iran has always been a concern. The aim of this study was & xfeff;to investigat & xfeff;e & xfeff;the particulate matter concentration during dusty days and the effect of dust storm on the irradiation rate in the atmosphere of the city of Ilam (capital of Ilam province). The concentration of particulate matter and radiation dose in the study area were monitored between March 2012 and February 2013 (1 year). Sampling was done every 6 days for periodical days. For the dusty days, samples were gathered according to the forecast information of dust plum entrance by the meteorological organisation. The results showed that the average and standard deviation of PM10, PM2.5, and PM1 concentrations in the periodic sampling (every 6 days) were 76.9 +/- 57.1, 17.5 +/- 10.5, and 8 +/- 4 mu g/m(3), respectively, and in the dusty days were286 +/- 164.8, 54.4 +/- 30.3, and 14.6 +/- 6.5 mu g/m(3), respectively. During the study period, the concentration of PM(10)in 35 days were more than 150 mu g/m(3) (Dusty day), and June with 13 days was the highest number dusty days. The average radiation dose in normal and dusty days were 0.152 and 0.150 mu Sv/hr, respectively. The results of Mann-Whitney's test showed that there was no significant difference between measured radiation in normal and dusty days (P > 0.05). Spearman test showed that there was no significant correlation between radiation doses and PM (PM10, PM2.5, and PM1) (P > 0.05). The results of the study show that dust storms and its concentration intensity did not affect the amount of radiation in the Ilam atmosphere. Because of the high density of the uranium element and its rapid sedimentation near the emission sources, the entry of this contamination related to dust storms to Ilam has not been proven.