Delhi met WHO standards for PM2.5 only 3 days in 2022

New Delhi: Delhi met the World Health Organization’s daily ambient standard for particulate matter 2

New Delhi: Delhi met the World Health Organization’s daily ambient standard for particulate matter 2.5 or PM2.5 for just three days of the 294 days of this year so far, and breached India’s national ambient air quality standards on 177 days, according to an analysis by the Centre for Research on Energy and Clean Air (CREA).

New Delhi, India - Oct. 19, 2020: Traffic plying on a haze covered NH-24 road as air pollution level is on the rise, near Akshardham Temple, in New Delhi, India, on Monday, October 19, 2020. (Photo by Raj K Raj/ Hindustan Times) (Raj K Raj/HT PHOTO)

The 24-hour PM2.5 concentration is 15 micrograms per cubic metre, according to WHO standards. It is 60 micrograms per cubic metre under the limit prescribed by the Indian government.

PM2.5 particles are so minute that they can even enter the bloodstream, resulting in cardiovascular and respiratory impact diseases. These particles are generated by fuel combustion and agriculture.

The CREA analysis, which was released on Saturday, also said stubble burning is expected to significantly impact Delhi’s air in the last week of October till mid-November, as seen in previous years, with Delhi’s PM 2.5 concentration already at 110 micrograms per cubic metre.

“Data from previous winters suggests that the air quality deteriorates between the last week of October to mid-November. The worsening air quality can be attributed to stubble burning for 15-20 days (between the last week of October and mid-November) and firecrackers around the Diwali festival celebrations, in addition to the existing sources. The PM2.5 concentration during this period has always reached around 500 µg/m3 in the past few years, while PM10 was more than 700 µg/m3 on a 24-hour basis,” said the analysis.

“With Diwali coinciding with the start of the peak intensive biomass burning, the air quality is expected to be worse than the existing 110 µg/m3, which is twice the NAAQS and ten times worse than the WHO guidelines for PM2.5,” it added.

The only three days this year which met the WHO daily standards of PM 2.5 were from October 8 to 10 – all three which saw impact of rains and strong winds. On October 8, the daily PM 2.5 concentration was 14.7 micrograms per cubic metre, on October 9, it 9.6 micrograms per cubic metre and on October 10, it was 15 micrograms per cubic metre.

Sunil Dahiya, analyst at CREA, said despite PM 2.5 levels dropping so low in the second week of October, air pollution has quickly bounced back and is following a similar trend with previous years, where Diwali and peak stubble burning coincides.

“The same or even higher pollution levels are expected across other cities and rural areas in Delhi’s airshed, which includes Gurgaon, Ghaziabad, Noida, Faridabad, Panipat, Ambala, Amritsar, Jalandhar, etc. So, the approach to reduce air pollution levels will need to be comprehensive and systematic in order to have significant pollution reductions across the region and not just focused around the impact on Delhi and its pollution,” he said.