Pollution levels in the national Capital came down to ‘very poor’ levels on Monday after hovering in the ‘severe’ zone over the past three days. Government agencies have forecasted that with light rain expected on Wednesday and Thursday, the air quality could further see improvement.

While the Air Quality Index (AQI) value of Delhi had been hovering between 401 and 423 since November 9, on Monday it came down to 399. On a scale of 0-500, while an AQI value between 401 and 500 is considered as a severe category of air pollution, a value between 301 and 400 is considered as very poor.

Even though technically the government’s pollution control and forecasting agencies have termed this as an ‘improvement’, health experts said that conditions are still not good for outdoor activities as it is still in the very poor category

“Skip strenuous activities. People with known illness should take special care,” said TK Joshi, a health expert with the Central Pollution Control Board’s (CPCB) task force.

Scientists from Indian Institute of Tropical Meteorology, which maintains Delhi’s early warning system for pollution and Safar, the Union government’s pollution forecasting wing, said the air quality is likely to improve further from Tuesday. Pollution levels would, however, continue to remain in the ‘very poor’ category over the next two days at least.

“It is expected to improve further by Tuesday, but would remain in the very poor category till Wednesday,” said a scientist who is maintains the early warning system of Delhi.

The India Meteorological Department has forecasted that Delhi could receive light rain on Wednesday late evening and Thursday morning because of a western disturbance.

“A western disturbance is approaching. It has already hit north India. On Wednesday it is likely to hit the plains of northwest India. As a result light rain could hit Delhi and other NCR states late on Wednesday evening and Thursday morning,” said BP Yadav, deputy director-general of IMD.

Even though the AQI of Delhi had come down to the very poor level, NCR towns including Faridabad, Ghaziabad, Noida and Greater Noida were all still reeling under severe categories of air pollution. Gurugram, however, encountered moderate air pollution with the AQI level dropping to 191 – a condition which Delhi last encountered on November 4.

The levels of particulate matter – PM10 and PM2.5 – were still in the severe categories in the National Capital Region.

Chart: AQI

Nov 12: 399

Nov 11: 405

Nov 10: 401

Nov 9: 423

Nov 8: 390

First Published: Nov 13, 2018 08:54 IST