Delhi air pollution dips from ‘severe’ to ‘very poor’ level

Air pollution levels in the Indian capital dipped Tuesday moving from ‘severe’ to ‘very poor’ category with an increase in wind speed which reduced the noxious haze that had covered Delhi's skies for about a week. A day after pollution levels peaked to a three-year high (494), the city's air quality index at 4 pm local time on Monday stood at 407. It dipped further and at 8.30 pm the AQI stood at 370, which falls in the "very poor" category.

The relief came as Delhi government’s vehicle-rationing system kicked in on Delhi’s roads. With winds gusting up to 20 km per hour dispersing pollutants faster, the visibility level improved to 2,000 metres. Kuldeep Srivastava, a senior scientist at the Indian Met Department, said "the two main reasons for the improvement in air quality are increased wind speed and no cloud cover. The situation will improve on Tuesday with wind speed increasing further."

An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'. Above 500 falls in the 'severe plus' category. The IMD said Cyclone Maha approaching Gujarat and Maharashtra coasts and a western disturbance will cause rainfall in parts of the northern India covering Rajasthan, Punjab, Haryana, western Uttar Pradesh and Delhi and its adjoining areas. The situation will improve further on Wednesday and Thursday.

The Delhi government also shared data that showed a drastic improvement in PM10 and PM2.5 levels in the city. According to the data, the levels of PM2.5 -- tiny particulate matter less than 2.5 microns in diameter that can enter the lungs and even the bloodstream, reduced from 562 micrograms per cubic metre at 6am to 94 micrograms per cubic meter at 6 pm.