New Delhi, Jan 5: Pollutants in Delhi's air on Monday remained consistently on the higher side, plunging it to 'severe' category at times, which saw a spike from around 8 AM, when the 'odd-even' restrictions began, amid the presence of smog.
Weather experts said the gains of lesser cars on the city's roads seemed to have no immediate impact on pollution levels due to variations of weather conditions, calm wind movement and a fall in day time temperature.
The Delhi government, however, maintained that analysis of data collected by mobile units of the Delhi Pollution Control Committee at 15 locations yesterday shows that Central Delhi and other areas not bordering NCR towns continue to show improvement in air quality.
It has also undertaken the study of PM 1 in Delhi's air, particles which are finer than PM 2.5 and PM 10, whose results would be made public after January 15, at the end of the enforcement period of the pilot scheme.
The hourly update of System of Air Quality and Weather Forecasting And Research (SAFAR) showed an upward trend of PM 2.5 and PM 10 concentration since morning.
At 7 pm, PM 2.5 was at 266 micrograms per cubic metre. Mandir Marg, RK Puram, Anand Vihar and IHBAS stations of Central Pollution Control Board (CPCB) had air quality in the severe category.
Severe category is declared when PM 2.5 crosses 250 micrograms per cubic metre while anything between 120-25 is regarded as 'very poor'.
"The situation would remain similar till at least January 9 due to variations owing to the presence of two sets of Western Disturbance. The wind intensity has also come down significantly. The chill will be back only after January 9," Airport MeT in-charge RK Jenamani said.
As per the hourly air quality index average of IndiaSpend, Connaught Place had PM 2.5 at 365 and PM 10 at 609, which falls in the severe category, at 8.30 PM.
At Anand Vihar and RK Puram, PM 2.5 was at 563 and 509 at 12.50 PM as per DPCC readings. The safe limits of these harmful micro particles, that can enter the respiratory system and subsequently the blood stream, are 60 and 100 respectively.