Assessment of Fractionated Aerosols at a Semiarid Region over the Indo-Gangetic Basin

The present study examines the mass concentration of particulate matter (PM) of different sizes between January and December 2015 at Agra, a semiarid region in the Indo-Gangetic basin. The mean mass concentrations of PM10 and PM2.5 are 146.9 and 54.8 mu g m(-3), respectively. The observed PM2.5 and PM10 concentrations are considerably higher than standard values set by the World Health Organization, United States Environmental Protection Agency, and National Ambient Air Quality Standard (India). Higher concentrations of PM10 and PM2.5 are observed in November and January, respectively. The highest and lowest concentrations of PM10 and PM2.5 are measured in winter and monsoon seasons, respectively. The PM2.5/PM10 mean mass concentration ratio is 0.44, indicating the dominance of coarse particles. The daily average air quality index is 107.7 for PM2.5 and 132.8 for PM10. The exceedance factor (EF) for PM10 is > 1.5, indicating a critical level of PM10, whereas the EF for PM2.5 is < 1.5 indicating a high level of pollution load. The trajectory analysis showed the effect of long-range-transported particles on this region.