Monitoring of airborne asbestos fiber concentrations in high traffic areas of Isfahan, Iran in summer 2015

 This research was conducted to measure the concentration of asbestos fibers in the ambient air of high traffic areas of Isfahan and to evaluate their spatio-temporal variation during summer 2015. 

 Air samples were collected from eleven points covering traffic areas of the Isfahan city including Enghelab square, Azadi square, Bozorgmehr bridge, Ghods square, Ahmedabad square, Artesh square, Emam Hossein square, Nazar junction, Vafaei junction, Felezzi bridge, and Tayyeb fork during 3 months of summer 2015. Scanning electron microscope (SEM) coupled to an energy dispersive X-ray system was utilized to count and identify the asbestos fibers. 

 Seasonal average concentration of airborne asbestos fibers in the studied region was 10.04 ± 4.90 SEM f/l. The results of this study showed that the highest concentration of asbestos fibers was measured in Azadi square (18.08 ± 3.863 SEM f/l) and that the lowest was found in Nazar junction(3.92 ± 1.749 SEM f/l). There was a significant correlation between the concentration of asbestos fibers and atmospheric temperature and humidity (P < 0.05). The mean concentration in September was higher than August and July (11.08 ± 4.66). 

 Heavy traffic in the dense areas of the city, and topographical and meteorological features of the city have a major contribution in asbestos fiber emission which resulted in its exceeded levels from the WHO guideline (2.2 SEM f/l). Therefore, effective strategies such as traffic management, industrial movement, and products replacement can be effective in reducing airborne asbestoses fibers concentrations.