CPCB should release peak values of air pollution, use it for calculating AQI: Experts

The Central Pollution Control Board (CPCB) should stop capping particulate matter readings at 1,000 micrograms per cubic metre and make the actual peak values available in the public domain, experts have told The Hindu. The CPCB, in an official statement on Tuesday, said the difference between its AQI readings and those calculated by private entities was due to variations in the measurement of pollutant concentrations and calculation methodologies, and not “under-reporting”.

However, experts said excluding peak readings above 1,000 micrograms per cubic metre artificially lowers the calculated AQI, making air quality appear better than it actually is. Responding to reports of missing pollution data on Deepavali night, the CPCB said it measured particulate matter (PM) levels only up to 1,000 micrograms per cubic metre for AQI calculations.

Readings exceeding this limit were therefore excluded, resulting in gaps in the data. The CPCB currently records PM readings above 1,000 micrograms per cubic metre as blanks.