IMPACT OF NATIONAL HIGHWAY (NH-22) EXPANSION ACTIVITIES ON AMBIENT AIR QUALITY IN MOUNTAINOUS REGIONShelly Banyal, R.K. Aggarwal and S.K. BhardwajAbstract The study was conducted to analyze the impact of highway expansion activity on air quality. The study area was divided into four equal sites based on distances viz. Site 1, Site 2, Site 3 and Site 4. The observation on different air quality parameters at each site were recorded periodically (three times) at an interval of 15 days during pre-monsoon and post-monsoon seasons. The ambient air quality levels were compared with NAAQS standards. SO2 concentration in the study area lies in between the range from 6.24 ïg m-3 to 7.53 ïg m-3. NO2 concentration in the study area varied from 16.82ìg m-3 to 26.98 ïg m-3. The highest SO2 and NO2 concentration were observed in the post-monsoon season and lowest in the pre-monsoon season and lowest in the pre-monsoon season. The concentration of SO2 and NO2 lies within the permissible limits given by NAAQS in all the sites. |