『Abstract
Nitrogen dioxide is an important gaseous air pollutant. It plays
a major role in atmospheric chemistry, particularly in the formation
of secondary air pollutants, and contributes to environmental
acidification. A comprehensive assessment of NO2
levels in the atmosphere is required for developing effective
strategies for control of air pollution and air quality improvement.
Air pollution is a serious problem in all major cities of Pakistan
and needs to be addressed to minimize detrimental effects on human
health and urban vegetation. In this research, we focused on the
monitoring of NO2 levels in the urban environment
of Rawalpindi city. Because of the lack of expensive continuous
sampling devices and to get a good spatial coverage of the NO2 concentrations in the study area, NO2
passive samplers were exposed at 42 different cites within the
city limits of Rawalpindi from January to December, 2008. Samplers
were exchanged every 10 days and the associated meteorological
conditions like temperature, wind speed, rainfall and relative
humidity were also monitored. The average NO2
concentration was found to be 27.46±0.32 ppb. The highest values
of NO2 were measured near to main roads and
educational institutions due to intense flow of road vehicles.
Moreover, the study showed that the values obtained for NO2 for all sampling points exceeded the annual
limit value set by World Health Organization. So, this is very
important to take different steps to control this before it becomes
a serious hazard for people living in those areas.
Keywords: NO2; Air pollution; Urban areas;
Rawalpindi; Pakistan; Human health』
1. Introduction
2. materials and methods
2.1. Study area
2.2. Passive sampling of NO2
2.2.1. Diffusion tube preparation
2.2.2. NO2 sampling
2.2.3. Analysis of NO2
2.2.4. Calculations
3. Results and discussion
3.1. Data analysis
3.2. Monthly trends in the level of NO2
3.3. Relationship with climatologic variables
3.4. Statistical analysis
3.5. Spatial distribution map
3.6. Comparison with international standards
4. Conclusion
Acknowledgements
References