Delhi's air quality was in the very poor category on Monday due to unfavourable weather conditions and slow dispersion of pollutants trapped in air, authorities said.
The overall air quality index was recorded at 382 which falls in the very poor category, according to data by the Central Pollution Control Board.
Fifteen areas in Delhi recorded severe air quality while 14 were in the very poor category, according to the data.
On Monday, the PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) level was recorded at 247 while the PM10 (particles with a diameter of less than 10 micrometres) level was recorded at 433 in Delhi.
An AQI between 0 and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe".
According to the Indian Institute of Tropical Meteorology, the increase in PM2.5 concentration is due to stable meteorological conditions which are trapping the polluted air mass in Delhi (very less dispersion) and also marginal impact of biomass burning in north-west India.
Large number of stubble burning incidents were observed on Saturday (fire count -- 1027) over north west region of India which was almost 10 times more than Friday, the IITM said.
The Centre-run System of Air Quality and Weather Forecasting (SAFAR) said the AQI is fluctuating between very poor to severe as significant amount of local emissions (smoke from fire crackers) added on Wednesday and Thursday could not be flushed out.
The SAFAR has predicted that the air quality would "significantly improve" by Monday.
Over one lakh children under five years of age died in India in 2016 due to exposure to toxic air, as per a WHO report. The study noted that about 98 per cent of children in the same age group in low and middle-income countries were exposed to air pollution.
PTI
