Ambient Levels of TSP, PM10, PM2.5 and Particle Number Concentration in Al Samha, UAE

Abstract

The Arabian Peninsula experiences elevated levels of airborne particulate originated from both natural and anthropogenic sources. This study is mainly aimed to determine the ambient levels of TSP, PM 10 and PM 2.5 ) at one of the monitoring locations "Al Samha" that is located in the northeast quadrant of UAE. Mass concentrations, particle count, as well as meteorological parameters were simultaneously measured using a spectrometer, PM 10 beta attenuation monitor and weather sensors for the period from April 10 to December 31, 2011. The hourly mean concentrations of TSP, PM 10 , PM 2.5-10 and PM 2.5 were 245, 110, 64 and 46 µg/m 3 , respectively. About 34%, 15% and 56% of the monitored days had daily concentrations above the allowable limits for TSP, PM 10 and PM 2.5 , respectively. Diurnal peak occurred at 14:00 for TSP, at 10:00 for PM 10 , and at 04:00 for PM 2.5 reaching values of up to 410, 122, and 54 µg/m 3 , respectively. The highest concentrations were observed on Saturdays for TSP and PM 10 , but on Sundays for PM 2.5 . July had the greatest monthly level of PM compared to other months of this study. The average ratios of PM 10 /TSP, PM 2.5 /TSP and PM 2.5 /PM 10 were 0.61, 0.31 and 0.47, respectively. Weak relationships were found between the particle number and mass concentrations, while very strong to moderate correlations were observed among all PM size fractions as well as between TSP and wind speed. The measurement results of the light scattering spectrometer were strongly correlated with the beta attenuation monitor, but the mean value of the spectrometer was higher by 18%.