New Delhi, November 18: The air quality in the Delhi-NCR region continued to remain in the 'poor' category with the overall AQI at 283, as per the System of Air Quality and Weather Forecasting And Research (SAFAR).
This morning the national capital was shrouded in a layer of smog. The AQI was 305 at Gurugram, 314 at Noida, 315 at Delhi University and 266 at IIT Delhi.
Air quality in Delhi-NCR dipped into the 'poor' category on Thursday morning with an overall AQI at 249. New Delhi's air quality had improved on Wednesday to the "moderate" category.
The air pollution levels in Delhi came down to the 'poor' category from 'very poor' on Tuesday as the national capital recorded an AQI of 221.
The Stage III of the Graded Response Action Plan (GRAP) was revoked in the entire NCR on Monday. However, actions under Stages I to Stage II of the GRAP shall, however, remain invoked and be "implemented, monitored and reviewed by all agencies concerned in the entire NCR to ensure that the AQI levels do not slip further to the 'severe' category".
Air Quality Index is a tool for effective communication of air quality status to people in terms, which are easy to understand. It transforms complex air quality data of various pollutants into a single number (index value), nomenclature and colour.
The Air Quality Index from 0 to 100 is considered as good, while from 100 to 200 it is moderate, from 200 to 300 it is poor, and from 300 to 400 it is said to be very poor and from 400 to 500 or above it is considered as severe.