Delhi witnesses severe air pollution, AQI at 452

New Delhi, Nov 05: Air quality in Delhi has rapidly worsened to "severe" on the air quality index (AQI) on Thursday morning, as residents woke up to an AQI of 452.

According to the AQI, 401 and 500 is considered to be severe, which can impact healthy people and seriously affect those with existing health conditions, according to the Central Pollution Control Board (CPCB).

Till Wednesday afternoon, the AQI was in the "very poor" category - between 301 and 400, but worsened rapidly to "severe" due to a shift in meteorological conditions.

Wind speed gradually reduced and became calm, which left no room for dispersal of pollutants at night.

India Meteorological Department (IMD) scientists said a layer of smoke and pollution had settled closer to the surface on Wednesday, which blocked sunlight and reduced visibility through the day. The weather condition led to a dip in the maximum temperature to 28 degrees Celsius (C) -- 2 degrees C below normal - on Wednesday.

"Smog-like conditions have developed because of air pollution, low wind speed and subsidence of cold air over this region. Air is subsiding over the northern plains, particularly Delhi-national capital region (NCR). As a result, dispersal of pollutants is not possible," said Vijay Soni, scientist, air quality division, IMD.

The Air Quality Early Warning System under the Union Ministry of Earth Sciences (MoES) had said air quality has started worsening significantly after 10:00 am on Wednesday due to strong subsidence and accumulation of pollutants.

The minimum temperature on Thursday increased to 12.1 degrees Celsius, as compared to 10.6 degrees Celsius on the previous day.