The authorities have recorded a severe drop in Delhi's air quality on 4 January - with a rise in the quantity of pollutants about eight to ten times above the safe limits in real time.
The reports come as a blow for the odd-even formula which has been receiving applause from all the sectors.
- The hourly update of System of Air Quality and Weather Forecasting And Research (SAFAR) have displayed an upward trend of PM 2.5 and PM 10 concentration since the morning of 4 December. At 1 pm, PM 2.5 was at 241 micrograms per cubic metre.
Monitoring stations of Delhi Pollution Control Committee (DPCC) at Anand Vihar and RK Puram had PM 2.5 at 563 and 590 micrograms per cubic metre around the same time while PM 10 was 901 and 694.
- The safe limits of these harmful micro particles, that can enter the respiratory system and subsequently the blood stream, are 60 and 100 respectively.
- In an analysis, The Energy and Resources Institute (TERI) observed that pollution levels on 3 December severely violated the prescribed limits. The 24-hourly averaged concentrations at four locations, Mandir Marg, R K Puram, Punjabi Bagh and Anand Vihar, were found to be 5, 5.4, and 1.1 times higher than the safe standards respectively, TERI said.
- "Analysing the trends between December 24 to January 3, PM 2.5 concentrations have increased by 72-176 per cent at the four stations. However, this is mainly due to reduced wind speeds during the period," the green body said.
- TERI said an immediate assessment of the impact of the odd-even scheme that came into force on January 1 was not possible considering the impact of sources other than emissions from cars and meteorological influences.
- However, the rise is being attributed to the atmospheric factors.