NO₂ Concentration in Banepa Valley, Nepal

Abstract

This study comprised of air quality monitoring during the day time at three municipalities of Banepa, Dhulikhel and Panauti(Known as Banepa Valley) in Kavre district of Nepal. The study was conducted in order to establish a baseline air quality data for those municipalities as the first time ever in the district. In each of those municipalities three air monitoring stations were established representing predominant industrial, commercial and residential areas. Nitrogen Dioxide (NO₂) had been estimated from air sampling programme which spanned 7 months and a total of 126 days reflecting winter, premonsoon and monsoon seasons. Low Volume Air (LVA) Sampler and Personal air sampler were used for sampling. UV spectrophotometer was used for estimation of the NO₂. The study found that during winter season the concentration of NO₂ was more and among the areas commercial area found to be highest level pollution. The over all mean, minimum and maximum level of NO₂ was found to be 24.62μg/m³, 11.26μg/m³, 91.20μg/m³ in the Banepa valley. The seasonal trend in pollution levels show that winter > pre-monsoon > monsoon. The pollution concentration trend noted among the areas was commercial > industrial > residential on almost all the occasions. This finding conclude that, most of the time NO₂ level are below the National Ambient Air Quality Standards (NAAQS) and World Health Organization (WHO) guideline representing little risk at present in Banepa Valley however commercial area of Banepa is more polluted and is associated with higher NO₂ concentration compared to other areas.

Keywords: NO₂, Nepal, Banepa, air quality, personal air sampler

DOI: 10.3126/kuset.v4i1.2878

Kathmandu University Journal of Science, Engineering and Technology Vol.4, No.1, September 2008, pp 1-11