AMID confusion over widely varying air quality index (AQI) readings reported by different sources, authorities have maintained that the Central Pollution Control Board’s (CPCB) Sameer app is the official platform and should be relied upon.

Officials say the app is more reliable because of its extensive network of Continuous Ambient Air Quality Monitoring Stations (CAAQMS). However, mid-day found significant differences even between readings displayed on Sameer from nearby stations operated by two government bodies — the MPCB and the Indian Institute of Tropical Meteorology (IITM), an autonomous institute under the Union Ministry of Earth Sciences.