Diwali beginning of air pollution season, worst may be ahead: CPCB data

Diwali is the start of the air pollution season in the states in the Indo-Gangetic Plain, and the worst of the season may be ahead of us, according to data from the Central Pollution Control Board's Continuous Ambient Air Quality Monitoring Station.

According to the analysis by National Clean Air Programme (NCAP) Tracker, average PM 2.5 levels in October this year were higher as compared to 2021 in the capital cities of Delhi, Chandigarh, Lucknow and Patna.

The PM2.5 levels in October 2022 have surpassed those in October 2021, despite delayed withdrawal of monsoon and a comparatively cleaner Diwali over the last five years. The rains also delayed the stubble burning season this year, the NCAP Tracker analysis said.

"The PM 2.5 levels for October 2022 in Delhi and Patna remained above (Central Pollution Control Board) CPCB's daily safe limits of 60 micrograms per cubic metre. Delhi recorded an average PM 2.5 of 105 micrograms per cubic metre in October as opposed to 74.88 micrograms per cubic metre in the previous year," the analysis said.

It said rains also led to delayed stubble burning season which meant its share in the PM 2.5 levels in Delhi was around 7 per cent until October 28.

Among the five capital cities selected for the analysis, Patna's PM 2.5 concentration breached the safe limits to 67 micrograms per cubic metre from 2021 when it was 45.25 micrograms per cubic metre. It was only Kolkata which saw its PM 2.5 levels dip in comparison with 2021.

Director of Climate Trends Aarti Khosla said that long-term solutions like switching to clean energy, managing vehicular pollution and strengthening monitoring to tackle emissions all year round are some of the solutions that can be considered to avoid hazardous levels of pollution during the winters.

"The extremely high PM 2.5 levels for nearly four months over the years are causing long term adverse impacts on health of the citizens in these cities. The governments have also resorted to a blame game as air pollution levels spike in the national capital and around," Khosla said.

Ravindra Khaiwal, professor of Environment at the Post Graduate Institute of Medical Education and Research (PGIMER), said that with increased vehicular and local emissions, small and mid sizes urban centres are also becoming hotspots as seen in the air quality levels they are reporting.

"We need to plan not only for crop residue burning but also other sources for the rest of the year so we can effectively manage pollution during this time when the atmospheric reactivity in play. It is extremely important to prioritise this since air pollution is a major risk to various health issues including respiratory and cardiovascular ailments," Khaiwal said.