Delhi Enforces Stage 4 Restrictions as Air Quality Index Surpasses Severe Levels

The air quality panel for Delhi-NCR has enforced Stage 4 restrictions under the winter pollution control plan. This includes a ban on all construction activities as air quality worsened to severe levels due to adverse weather. The Graded Response Action Plan (GRAP) Stage 4 also restricts polluting trucks carrying non-essential goods from entering Delhi and mandates hybrid learning for most school classes.

Delhi's Air Quality Index (AQI) reached 400 around 10 pm, worsening from an earlier reading of 379 at 4 pm. This deterioration was due to calm winds and an inversion layer that hindered pollutant dispersion. The decision to implement Stage 4 restrictions followed the Commission for Air Quality Management's (CAQM) earlier Stage 3 measures when the AQI exceeded 350 in the afternoon.

Stage 4 Restrictions and Measures

Under the revised GRAP schedule, students in grades VI-IX and XI in Delhi, Gurugram, Faridabad, Ghaziabad, and Gautam Buddh Nagar must attend classes in a hybrid format. Classes up to grade V have already shifted to hybrid mode under Stage 3. Parents can opt for online education where available. Stage 4 also bans all construction and demolition activities, including public projects like highways and pipelines.

Non-essential diesel trucks are barred from entering Delhi. Offices, whether public, municipal, or private, must consider allowing only half of their staff to work on-site, with others working remotely. States may also consider closing colleges and non-essential businesses or implementing odd-even vehicle restrictions.

Previous Stage 3 Restrictions

Earlier in the day, Stage 3 restrictions were imposed, limiting the use of BS-III petrol and BS-IV diesel cars in Delhi and nearby NCR districts. Persons with disabilities are exempt from this rule. Non-essential diesel-operated medium goods vehicles with BS-IV or older standards are also banned in Delhi under Stage 3.

The Delhi and NCR state governments have been advised to stagger office timings for public and municipal offices under Stage 3. The Centre might consider similar measures for its offices in Delhi-NCR.

Impact of Pollution on Health

During winters, GRAP categorises air quality into four stages: Poor (AQI 201-300), Very Poor (AQI 301-400), Severe (AQI 401-450), and Severe Plus (AQI above 450). GRAP Stage 4 was first invoked this season in November due to persistently high pollution levels in Delhi and surrounding areas. The Supreme Court allowed CAQM to ease restrictions in early December after air quality improved.

Unfavourable weather conditions combined with emissions from vehicles, paddy-straw burning, firecrackers, and other local sources contribute to hazardous air quality levels during winters in Delhi-NCR. Doctors warn that breathing Delhi's polluted air is akin to smoking about ten cigarettes daily. Prolonged exposure can worsen respiratory issues like asthma and bronchitis and significantly increase cardiovascular disease risks.