Delhi's air quality 'poor' due to spike in farm fires, unfavourable weather

Delhi's air quality was recorded in the "poor" category on Thursday and is likely to deteriorate further due to unfavourable meteorological conditions and a spike in farm fires.

The city recorded a 24-hour average air quality index (AQI) of 208, which falls in the "poor" category.

The national capital's air quality turned poor on Wednesday, the first time since June 29, with the Central Pollution Control Board (CPCB) recording a 24-hour average AQI of 215.

The AQI was 230 on June 29.

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 be recorded in the "poor" category on Friday as well. However, it is expected to improve to the "moderate" category thereafter.

A gradual increase was observed in farm fires around Punjab, Haryana and the border regions of the national capital on Wednesday. The fire count was 399, the SAFAR said.

"The boundary layer wind direction and speed are favourable for the transport of pollutants towards Delhi at present, but a shift in the wind direction is predicted," it said.

On Thursday morning, Delhi's minimum temperature settled at 19.1 degrees Celsius. The wind speed was 12 kilometres per hour and the direction was northwesterly.

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

High levels of air pollution is a year-round problem in Delhi, which can be attributed to unfavourable meteorological conditions, farm fires in the 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 per cent), followed by industries (two to 29 per cent), thermal power plants (three to 11 per cent) and construction (eight per cent).

The Delhi government launched a massive anti-air pollution campaign on Monday.

Chief Minister Arvind Kejriwal said he himself will review the situation on a daily basis.

A "green" war room was also inaugurated at the Delhi Secretariat by Environment Minister Gopal Rai to monitor the steps being taken to deal with the high levels of air pollution in winters.

The government will also start spraying the "Pusa bio-decomposer" solution in the non-basmati rice fields of the national capital from October 11.

The solution, experts say, can turn the stubble into manure in 15 to 20 days and therefore, can prevent stubble burning.

Starting October 15, stricter measures to fight air pollution will also come into force in Delhi and its neighbouring areas as part of the Graded Response Action Plan (GRAP), which was first implemented in Delhi-NCR in 2017.

These measures include increasing the frequency of bus and metro services, hiking parking fees and stopping the use of diesel generator sets when the air quality turns poor.

When the situation turns "severe", the GRAP recommends a closure of brick kilns, stone crushers and hot-mix plants, sprinkling of water, frequent mechanised cleaning of roads and maximising power generation from natural gas.

The measures to be followed in the "emergency" situation include stopping the entry of trucks in Delhi, a ban on construction activities and introduction of the odd-even car-rationing scheme.