India, June 13 -- Relative ozone concentrations in Gurugram increased after sunrise and peaked during afternoon hours from 12pm to 4pm at nearly twice their normalised mean values, according to an analysis of hourly air quality monitoring data from the Central Pollution Control Board (CPCB) between January and May.

The analysis by the Centre for Research on Energy and Clean Air (CREA) released on Friday examined seasonal variations in the city's pollutant profile and found that ozone becomes increasingly prominent during warmer months beginning in March.

While particulate matter (PM) concentrations - ultrafine PM2.5 and dust-like PM10 - were elevated during late-night and early-morning hours, ozone levels rose during the day as sunlight...