Delhi's air turns 'very poor' for the 1st time this season

New Delhi: Delhi's air quality entered the "very poor" category for the first time this season and had the highest level of pollutants in the last eight months on Tuesday morning as the average Air Quality Index (AQI) for the day settled just a notch shy of the category. Experts have attributed this to calm winds and low temperatures that allowed the accumulation of pollutants.

According to the Ministry of Earth Sciences' Air Quality Early Warning System for Delhi, an increase was also observed in farm fires in Punjab, Haryana and the neighbouring regions of Pakistan, but its impact on the Capital's air quality was marginal.

The city's air quality index (AQI) hit very poor levels in the morning and stood at 306 at 11 am. Thereafter, the pollution levels dipped slightly due to an improvement in the ventilation index. Dwarka Sector-8 (AQI 390) Wazirpur (AQI 372), and Mundka (AQI 352) recorded the highest pollution levels on Tuesday.

The 24-hour average AQI was recorded at 300 at 4 pm, which falls in the poor category. The last time the air quality hit such a poor level was on February 12 when the AQI was 320. It was 261 on Monday, 216 on Sunday and 221 on Saturday.

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'.

PM10 levels in Delhi-NCR dropped from 300 microgram per cubic meter ( g/m3) at 9 am — the highest this season so far — to 293 by 5 pm g/m3. PM10 levels below 100 g/m3 are considered safe in India. The levels of PM2.5 finer particles that can even enter the bloodstream were 128 g/m3. PM2.5 levels up to 60 g/m3 are considered safe.

On Tuesday, the minimum temperature was 19.8 degrees Celsius. During the day, the maximum wind speed was 12 kmph and the direction was southeasterly, according to the IMD.