Delhi records poor air quality for fifth consecutive day, likely to improve

The national capital's air quality was recorded in the "poor" category for the fifth consecutive day on Sunday, while a government agency said it is likely to improve slightly in the coming days due to a change in the wind direction.

The city recorded a 24-hour average air quality index (AQI) of 216. It was 221 on Saturday.

Delhi's air quality had turned poor on Wednesday, the first time in since June 29, with the Central Pollution Control Board recording a 24-hour average AQI of 215.

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 Ministry of Earth Sciences' air quality monitor, SAFAR, said the AQI is likely to improve to the "moderate" category by Monday.

A total of 448 farm fires were observed in Punjab, adjoining Pakistan, Haryana and Uttar Pradesh which impacted Delhi's air quality on Sunday, SAFAR said.

However, the wind direction will change from northwesterly to southeasterly and the impact of farm fires will reduce, it said.

On Sunday morning, Delhi's minimum temperature settled at 19.8 degrees Celsius. The maximum wind speed was 15 kilometers per hour and the direction was west-north westerly.

Low temperatures and stagnant winds help in accumulation of pollutants near the ground, affecting air quality.

High levels of air pollution in Delhi is a year-round problem, which can be attributed to unfavourable meteorological conditions, farm fires in neighbouring regions and local sources of pollution.

According to an analysis by the Council on Energy, Environment and Water, a Delhi-based think tank, transportation contributes the most -- 18 to 39 per cent -- to Delhi's air pollution.

Road dust is the second largest source of air pollution in the city (18 to 38 percent), followed by industries (2 to 29 per cent), thermal power plants (3 to 11 per cent) and construction (8 per cent).