Did unprecedented Covid deaths, funerals cause spike in Delhi’s pollution levels during second wave

It was this time last year when India, especially Delhi, was nearing the start of the deadly second wave of COVID-19. Preliminary media reports had revealed thick smoke to be hanging over homes located near crematoriums during the second lockdown in the national capital.

For long, researchers remained silent about the impact of overburdened crematoriums on Delhi’s air quality. But now, a study has finally drawn a link.

“There are many studies addressing air quality concerns with COVID-19 during the first wave of 2020 but work assessing the second wave of 2021 in India in terms of air quality is sparse,” a new study, published in Chemosphere last month, noted. Chemosphere is a peer-reviewed journal on chemicals in the environment.

The study recorded an unusual increase in particulate matter (PM) during the second wave lockdown.

“It is believed that an unaccounted emission source was playing a leading role after balancing off the impact of curtailed lockdown emissions,” the study noted, adding that it is “related to biomass burning at the crematorium in all likelihood.”

The study was conducted by:

• Gufran Beig, founder project director, SAFAR (System of Air Quality and Weather Forecasting and Research)
• KS Jayachandran, member secretary, Delhi Pollution Control Committee (DPCC)
• MP George, scientist, DPCC
• Aditi Rathod, S B Sobhana and R Shinde, from the Indian Institute of Tropical Meteorology, Pune
• V Jindal from the Indraprastha Institute of Information Technology, Delhi
• SK Sahu from Utkal University, Bhubaneswar

The study assessed two of the main toxic air pollutants — PM10 and PM2.5 — between March and June 2021. Estimated PM2.5 levels April fell in the 30-40 microgram per cubic metre (µg/m3) bracket keeping in mind lockdown restrictions that resulted in less traffic and industries not working at full capacity.

The estimate increased to 75-80 µg/m3 in the absence of any restrictions. The actual figures for April were significantly higher than both estimates at 100-125 µg/m3.

Pollution levels surged particularly between April 24 and May 2, a time period which “coincided with the time when a rapid surge in COVID-19-related mortality and morbidity was recorded.”

Delhi recorded the highest-ever daily deaths May 3, at 448. The figures prior to this were 306 on April 22. On April 1, just as the delta wave was picking up pace, Delhi’s cumulative death toll was at a little over 11,000. It shot up to 24,299 by June 1.

Delhi has more than 50 crematoriums, the majority of which use the traditional open pyre method of burning bodies. This process requires 300-400 kg of wood per pyre, the flue gas of which largely emits organic, inorganic matter and particulate dust material.

“The peak mortality period was directly coinciding with peak levels of PM2.5,” the study noted.

In 2020, an expected decline in air pollution was recorded. However, 2021 was an anomaly, recording no “appreciable decline in PM” as compared to the levels from 2017 to 2019.