Ozone Levels and its Correlation with other Air Pollutants in North Central part of India
Concentrations of O3, NO2 and lower molecular weight (LMW) PAHs were measured in winter season, near the surface at roadside location of Agra, India. O3 and NO2 were measured by the impinger technique using neutral KI buffer and Saltzman methods and the samples were analyzed by using UV-VIS Spectrophotometer. PAHs were collected by aspirating air through XAD-2 resin at a flow rate of 2 LPM. The XAD resin tubes were extracted with methylene chloride and were analyzed by GC-MS. Average concentrations of O3 and NO2 were 32.8-ug m-3, 19.2-ug m-3 respectively and t-PAHs was 7.5 ng m-3. O3 and NO2 show diurnal variations during winter season. During the day, the average amount of O3 increases due to active photochemical production mechanism along with favorable meteorological conditions and the related increasing precursor’s concentration. In order to elucidate the relationship between O3 and its precursors the regression analysis was performed. A good positive correlation of O3 and NO2 was found (r2 = 0.68) indicating that O3 concentrations are dependent on NO2 concentrations. While a negative correlation was found between O3 and PAHs levels.