当前世界环境

Air pollution kills more than 5.9 million people annually, with more than 90 per cent of these deaths in capital city of India, Delhi. For improving the status of air pollution in Delhi, various policies and laws have been implemented. But even after the implementation of CNG, there was no significant change of pollutants (NOx, O3 , SPM, RSPM & CO) except SO2. The objective of our study is whether CNG conversion has impinged on the primary pollutant and tropospheric ozone pollution profile and for the improvement in the quality of air in post CNG period. To carry out the analysis, daily ambient air quality secondary data (Jan 2002-Dec 2009; Source-CPCB) of all the above discussed pollutants were used. For generating own data, NOX and O3 monitoring were carried out at four different sites viz. Site I (Yamuna Biodiversity Park, away from traffic intersection), Site II (Traffic intersection at outside YBP, outer ring road, Gandhi vihar), Site III (Aravalli Biodiversity Park, away from traffic intersection) and Site IV (traffic intersection at outside ABP, ring road, Vasant vihar) during monsoon season (Aug-Sept, 2009). The concentration of ozone was higher at sites which are at traffic intersection (Site II & IV) than those which are away from traffic intersection (Site I & III). The results however, do not indicate an all round improvement in ambient air quality of Delhi. Hence, our short term study suggests that after the implementation of CNG in Delhi there is no remarkable improvement in the status of the pollutants and moreover, the sites which are near to traffic intersection possess high concentration of pollutants than the sites which are away from traffic intersection.