Pollutants dispersing but air quality still bad, says experts

Tribune News Service

New Delhi, October 21

Environment experts said pollutants in the air are dispersing but air quality is still bad in the city a day after Diwali fireworks.

The Central Pollution Control Board (CPCB), which attributed yesterday's high pollution levels to calm wind movement and a low mixing height, said the situation will improve further by tomorrow if favourable conditions prevail.

"The wind speed is expected to pick up and reach up to 9 km per hour, which is adequate enough for the dispersion of suspended particulates. Yesterday and the day before wind speed and mixing height were extremely low which led to the rapid buildup of pollutants near the surface," an official of the CPCB said.

The improvement was captured by the pollution monitoring stations. Six out of the eight stations maintained by System of Air Quality Forecasting and Research (SAFAR), an agency under the Ministry of Earth Sciences, had air quality index (AQI) in the “very poor” category, a shade better than “severe”.

Among the station maintained by the CPCB, nine out of 17 were in the “very poor” category, while the rest recorded “severe” air quality.

A very poor AQI comes with the warning that people may develop respiratory illness on prolonged exposure while exposure to severe air affects healthy people and seriously impacts those with existing respiratory or cardiovascular diseases.

At 12 PM, the 24-hour rolling average of PM2.5 and PM10, ultra-fine particulates, which are up to 30 times thinner than the width of a human hair, were 206 and 357 microgrammes per cubic metre, respectively, as against yesterday's 407 and 595.