An invisible threat: Ground-level ozone in summer

The 2020 State of Global Air report states that age-standardized rates of death attributable to ozone is among the highest in India and the seasonal 8-hour daily maximum concentrations have recorded one of the highest increases in India between 2010 and 2017– about 17 per cent. [...] 2 Urban Lab - Centre for Science and Environment Analysis Key highlights of the analysis for Delhi-NCR Heatwaves advanced the geographical spread of ground-level ozone: This year due to early onslaught of heatwaves the spatial spread of ground-level ozone started in March itself with April being the worst so far (See Graph 1: Monthly variation in ground-level ozone in Delhi-NCR (2019-22)). [...] Faridabad has least instances of ground-level ozone exceedances in the region (See Table 2: List of locations that recorded lowest intensity of ground-level ozone pollution daily built-up in Delhi-NCR (March-May, 2022)). [...] 6 Urban Lab - Centre for Science and Environment Analysis Ground-level ozone hotspots are located in the areas with low levels of NO2 and PM2.5: The spatial distribution of ground-level ozone is inverse of the NO2 and PM2.5 (See Map 3: Spatial relationship among hotspots for key pollutants in Delhi-NCR (March-May 2022)). [...] Graph 3: Hourly cycle of ground level ozone and NO2 in Delhi-NCR – 2020 lockdowns v/s 2022 heatwaves Note: 24-hr profile is based on mean hourly concentration of ground-level ozone and NO2 recorded at the monitoring stations at Delhi, Gurugram, Faridabad, Ghaziabad, Noida and Greater Noida for month of April in 2020 AND 2022.