Real-time monitoring of air pollutants in seven cities of North India during crop residue burning and their relationship with meteorology and transboundary movement of air

Air pollutants emissions due to the burning of crop residues could adversely affect human health, environment, and dimate. Hence, a multicity campaign was conducted during crop residue burning period in Indo Gangetic Plains (IGP) to study the impact on ambient air quality. Seventeen air pollutants along with live meteorological parameters, were measured using state of the art continuous air quality monitors. The average concentration of PM10, PM2.5, and PM1 during the whole campaign were 196.7 +/- 30.6, 148.2 +/- 20, and 51.2 +/- 8.9 mu gm(-3) and daily average concentration were found several times higher than national ambient air quality standards for 24 h. Amritsar had the highest average concentration of PM2.5 (178.4 +/- 83.8 mu gm(-3)) followed by Rohtak and Sonipat (158.4 +/- 79.8, 156.5 +/- 105.3 mu gm(-3)), whereas Chandigarh recorded the lowest concentration (112.3 +/- 6.9 mu gm(-3)). The concentration of gaseous pollutants NO, NO2, NOx, and SO2 were also observed highest at Amritsar location, i.e., 6.6 +/- 2.6 ppb, 6.2 +/- 0.7 ppb, 12.7 +/- 3.0 ppb, and 7.5 +/- 3.3 ppb respectively. The highest average O-3 and CO were 22.5 +/- 19.3 ppb and 1.5 +/- 1.2 ppm during the campaign. The level of gaseous pollutants and Volatile organic compounds (VOCs) found to be elevated during the campaign, which can play an important role in the formation of secondary air pollutants. The correlation of meteorology and air pollutants was also studied, and O-3 shows a significant relation with temperature and UV (R = 0.87 and 0.74) whereas VOCs shows a significant correlation with temperature (R = -0.21 to -0.47). Air quality data was also analyzed to identify sources of emissions using principal component analysis, and it identifies biomass burning and vehicular activities as major sources of air pollution. (C) 2019 Elsevier B.V. All rights reserved.