Dispersion of Nitrogen Dioxide and Particulate Matter Concentrations in Street Canyons and Open Landscape in Urban Mysore

Prabhakaran Nataraj; Azis Kemal Fauzie; P N Sandhya Rani; G V Venkataramana

doi:10.34293/sijash.v7i3.1352

Prabhakaran Nataraj Department of Studies in Environmental Science, University of Mysore, Mysore, Karnataka, India https://orcid.org/0000-0002-3481-0066
Azis Kemal Fauzie Department of Studies in Environmental Science, University of Mysore, Mysore, Karnataka, India https://orcid.org/0000-0001-6173-3679
P N Sandhya Rani Department of Studies in Environmental Science, University of Mysore, Mysore, Karnataka, India
G V Venkataramana Department of Studies in Environmental Science, University of Mysore, Manasagangotri, Mysore, Karnataka, India

DOI: https://doi.org/10.34293/sijash.v7i3.1352

Keywords: Nitrogen dioxide, Street canyon, Particulate matter, Air quality

Abstract

The variation in nitrogen dioxide (NO₂), particulate matter (PM₁₀ and PM_2.5) concentrations and meteorological data were analyzed at different types of urban spaces in Mysore consisting of four street canyons and one open landscape sites. The NO₂ and PM levels were measured using portable monitoring device and respirable dust sampler, respectively. The maximum NO₂concentration was found at the intersection of both street canyons and open landscape, either in the morning (70-160 µg/m³) or evening (20-60 µg/m³). Result found that concentration of NO₂in street canyons was significantly higher than in open landscape sites (p < 0.001). The ambient NO₂levels were also found lower in the cross roads compared to such in the main roads. The high number of vehicles passing through the roads accounts for the higher NO₂ concentration as we found significant positive correlation between traffic volume and NO_2,SPM, PM₁₀ and PM_2.5 concentrations, either in the street canyon and open landscape sites. Furthermore, a negative association has been observed between both SPM and NO₂ levels and the wind speed (p = 0.002 and p < 0.05 respectively). The factors affecting the different dispersion characteristics of air pollutants were found to be the wind speed, vehicular traffic, and site landscape where congested with high number of tall buildings.