A haze engulfed the national capital today as the air quality nosedived to "very poor" category, a day after a slight improvement was recorded on Friday.
The PM10 level (presence of particles in the air with a diameter of less than 10 micrometres) in Delhi stood at 266 and the PM 2.5 (presence of particles in the air with a diameter of less than 2.5 micrometres) level touched a new high at 158, according to the SAFAR data.
About 31 areas in Delhi recorded 'very poor' air quality while two areas showed 'severe' air quality levels, it said.
| Place | PM2.5 | PM10 |
| R K PURAM | 214 | 186 |
| NATIONAL STADIUM | 81 | 227 |
| DWARKA | 222.15 | N/A |
| FARIDABAD | 137 | N/A |
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".
The PM2.5 is said to have a greater impact than PM10 on health and is said to be more dangerous.
The permissible range or PM2.5 is 60 as per national standards and 25 by the international standards.
Meanwhile, System of Air Quality and Weather Forecasting And Research (SAFAR) labelled NCR's air quality as toxic and recommended keeping relief medicine handy. SAFAR advised everyone to avoid tiring outdoor physical activity.
The deterioration of air quality comes a day after firecrackers were burst on the occasion of Dusshera.
Images by NASA showed rampant stubble burning in Punjab and Haryana in the last two weeks.
Delhi Chief Minister Arvind Kejriwal had on Friday warned that the city would become a "gas chamber soon" as the Centre, Punjab and Haryana governments did "absolutely nothing" for farmers involved in stubble burning.
"V sad that Central, Punjab and Haryana Govts did absolutely nothing for the farmers. As a result, the farmers will suffer on one hand and Delhi will become a gas chamber soon (sic)," he tweeted.
Deputy Chief Minister Manish Sisodia Thursday appealed to the Centre and the governments of Haryana and Punjab to initiate measures in the wake of the deteriorating air quality in north India, including Delhi.
A number of factors are responsible for the deteriorating air quality, including vehicular pollution and construction activities. Besides, pollution from stubble burning in neighbouring Punjab and Haryana adds to the woes of Delhi.
Among factors, the main reason is the drop and change of wind speed which is now flowing from the stubble burning areas, a CPCB official said.