Study of Ambient Air Pollutants over Rishikesh at Foothills of North-Western Indian Himalaya

Abstract

Air quality parameters measured over Rishikesh city of Uttarakhand, where a large number of visitors and pilgrimage stay and pass by throughout the year are analyzed and studied. Such intensive human activities lead to the impacts and its manifestation on regional scale environment. Due to consistent infrastructure development and the increased vehicular emission due to transport, a large amount of particulate matters is added to the ambient environment and affects the air quality adversely. Here an attempt is made to understand the growth in level of ambient air pollutants through available measurement. Particulate matter (PM₁₀), suspended particulate matters (SPMs) and the concentration of gaseous pollutants (SO₂ and NO₂) from 2011 to 2014 are measured and analyzed. It is observed that concentrations of the pollutants increase during pre-monsoon season as compared to the winter and monsoon seasons. In addition, PM₁₀ and SPM concentration are found about two times higher than the prescribed national standard. SO₂ and NO₂ levels are found within the limits proposed by the Central Pollution Control Board (CPCB) New Delhi, India. A detailed statistical analysis is carried out on the basis of monthly mean values of the observed pollutants. The PM₁₀ was found to shows significant positive correlation with SO₂ and NO₂ concentrations. In addition, back trajectories show partly long-term transport from North Africa, Saudi Arabia and central Asian region in contributing over the region with local emission that is considered to be the main and direct cause of increasing trend of the pollutants.