Delhi’s air quality index on Friday was recorded at 499 – categorised as “severe” by the System of Air Quality and Weather Forecasting and Research, or Safar.

The national capital remained engulfed in smog, leading to a drop in visibility. “Visibility was around 600-800 metres till 12 noon,” RK Jenamani, senior scientist at India Meteorological Department, told ANI. “Visibility to remain poor for the next three days in Delhi.”

On Friday, 4,000 farm fires accounted for 35% of Delhi’s air pollution, NDTV reported.

An order by Prashant Gargava, the chairperson of the sub-committee on the Graded Response Action Plan, advised people to limit outdoor activities and minimise exposure, The Indian Express reported. It also urged government and private offices and other establishments to reduce vehicle usage by at least 30%.

The order also directed state governments to be prepared to implement measures under the “emergency” category as per the graded plan. These measures include stopping construction activities, rolling out the odd-even scheme for private vehicles and stopping the entry of trucks into Delhi apart from the ones carrying essential items.

Meanwhile, a report from Centre for Science and Environment released on Thursday showed that emission from vehicles is the biggest contributor to particulate pollution in Delhi among local sources.

Particulate matter refers to inhalable particles in the air. PM2.5, or particulate matter smaller than 2.5 microns, is particularly dangerous to human health. Such particles are small enough to travel deep into the respiratory system, potentially impairing lung function.

The Centre for Science and Environment analysed real-time data from the Indian Institute of Tropical Meteorology’s Decision Support System.

The Decision Support System models relative contribution of various sources that pollute Delhi’s air based on an emissions inventory prepared by the Energy and Resources Institute, or TERI, for the national capital and its surrounding 19 districts. However, this system does not take into account transient sources of pollution like firecrackers. The system was put in place on October 19.

The Centre for Science and Environment analysed data for every alternate hour from October 24 to November 8 period. Delhi’s pollution gets worse in October and November because of farmers burning stubble in neighbouring states, unfavourable wind speed and emission of fumes by the local traffic in the city.

“This [the analysis] shows vehicles’ contribution [to pollution] is half or more,” the think tank said. “This is followed by household pollution that has ranged between 12.5- 13.5 per cent, industry – 9.9-13.7 per cent, construction – 6.7-7.9 per cent, waste burning and road dust each varied between 4.6-4.9 per cent and 3.6-4.1 per cent respectively.”

Source: Centre for Science and Environment.

The Centre for Science and Environment report said that traffic peaks also affect the build-up of pollution in a day.

“While PM2.5 is influenced by several other factors, nitrogen dioxide is more closely related to traffic trends,” it said. “During the study period, NO2 levels show a strong correlation with congestion. The levels increase when traffic speeds go down.”

The Centre for Science and Environment also took into consideration the contribution of pollutants from 19 districts in the National Capital Region as well as biomass burning in neighbouring states.

“During November 2-6, the contribution of NCR dominated in the initial phase going upto 70-80 per cent, but its share declined during the smog episode post-Diwali when the relative contribution of Delhi’s own sources increased,” it said. “Similarly, the contribution of biomass burning from other states remained low in the initial pre-Diwali phase but peaked post Diwali.”

The Centre for Science and Environment said that Delhi needs to take quick action to tackle all the main sources of pollution.

“It requires urgent action to scale up integrated public transport systems, walking and cycling infrastructure, and city-wide parking area management plans to restrain vehicle use,” the think tank said. “In absence of this reform, Delhi is unable to enforce emergency action to control traffic volumes during smog episodes.”

Congress blames AAP, BJP for worsening pollution

The Congress on Friday criticised the Bharatiya Janata Party and the Delhi’s Aam Aadmi Party government for their alleged incompetence in managing the air pollution in the Capital.

“The capital of the country is not only in the grips of speechwriters and advertisements but also in the grips of pollution,” the Congress said in a tweet. “The capital of the country is suffocating – responsible for this is the BJP and the advertising campaigner AAP. BJP-AAP should quit making counter-accusations and allegations, and instead should find a solution.”

Bharatiya Janata Party spokesperson Tom Vadakkan blamed the Aam Aadmi Party for the rising pollution levels, the Hindustan Times reported. “The problem is that they [Aam Aadmi Party] are not a proactive government, they are a pro-publicity government,” Vadakkan said. “AAP only does publicity stunts like giving free water and electricity. They can blame Haryana and Punjab for the pollution, but the truth is that they do not want to take responsibility for their city.”

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