Ambient Air Quality Status and Its Sources in Urban and Semi-urban Locations of Himachal Pradesh, India

Abstract

Ambient air quality deterioration is one of the major threats to pristine air environment of the Indian Himalayan Region. Keeping this in view, the particulate matter (TSP & PM10), and gaseous pollutants (SO2, NO2 & NH3) were monitored in the three Himalayan towns; Bilaspur (556 m), Mandi (760 m) and Keylong (3100 m) during pre-monsoon in 2009. TSP and PM10 have crossed their permissible limits as are set by Central Pollution Control Board at all three sites. On diurnal basis, TSP was recorded as highest with 418 μg m-3 at Bilaspur, while PM10 with 111.3 μg m−3 at Mandi. A cold desert site-Keylong showed high TSP concentrations compared to PM10. However, SO2, NO2 and NH3 concentrations recorded much below the permissible limits. TSP and PM10 were greatly influenced by local sources such as vehicular exhausts due to visitors’ influx, windblown dust from nearby un-metalled roads and biomass burning (i.e., forest fires, fuel wood and coal burning for cooking and heating and open solid waste burning). Further, external sources such as long-range transport with the pollutants laden air masses are contributing to the existing aerosols in the region.