Of 7 cities, Diwali day air was worst in Delhi: CPCB

NEW DELHI: Delhi’s air was the most foul on Diwali day in 2019 among seven cities assessed across the country, as far as particulate matter is concerned, according to a report published by the Central Pollution Control Board (CPCB) earlier this month.

The national capital saw the highest increase in PM2.5 and PM10 levels on Diwali day (October 27), as compared to the other cities. The levels of PM 2.5 — the most harmful aerosol in Delhi’s air, shot up by 592% compared to pre-diwali day, among the cities monitored.

According to Indian standards, the daily permissible level of PM2.5 in the air is 60ug/m3.

“Highest increment was recorded in Delhi (592%), followed by Bengaluru (218%), Kolkata (137%) and Lucknow (113%). However, minimum increase (57%) was reported in Bhopal this year,” it stated.

However, the average concentration of PM2.5 on Diwali last

Delhi

Bengaluru

Kolkata

Lucknow

Agra

Vadodara

Bhopal 83%

137% 112% 113% 107% 68%

33%

64% -9%

57% 59%

247% 218%

year (as per real-time data), recorded at 284 ug/m3, was lower when compared to the past three years — 324 ug/m3 in 2018, 344ug/ m3 in 2017 and 445ug/m3 in 2016.

PM10 (coarse particles) levels too showed the highest increase, going up by around 247% from

PM2.5

PM10 pre-diwali day. “Highest increment in PM10 on Diwali day was reported in Delhi (247%) followed by Kolkata (112%) and Lucknow (107%). In Vadodara, however, it declined (by 9%) on Diwali where torrential rainfall perhaps wiped out coarser particulates,” the report said.

The findings are based on monitoring of pollution levels across two locations in the city — Pitampura and Janakpuri.

The levels spiked despite the use of green crackers, which are claimed to have lower emissions, (30% lower than conventional firecrackers) for the first time in the National Capital Region (NCR).

According to the report, other elements in PM2.5, such as Barium, used in manufacturing firecrackers, exceeded the daily permissible limit of 4.0ug/m3 in the city. The 24-hour average levels of Barium on Diwali day were recorded at 18.77ug/m3.

“This year, with the promotion of green crackers and new formulation crackers, an increase in Barium concentration was not expected,” it said.

However, the report highlighted that average Barium levels were far lower than over the past three years — 54.2 ug/m3 (2018), 34.7ug/m3 (2017) and 74ug/ m3 (2016).

October 27 was also the first pollution peak that Delhi had last season. Prior to Diwali, air quality had largely ranged in the ‘poor’ zone, but plunged to ‘very poor’ for the first time on the day of the festival. As per CPCB data, the 24-hour average air quality index (AQI) on Diwali dropped to 337 (very poor), against 287 (poor) the previous day.

The CPCB came out with a detailed report on pollution levels during Diwali following an SC order. The court had asked the CPCB to monitor pollution levels for 15 days — seven days before Diwali, Diwali day and seven days after Diwali.

Following the order, pollution levels were monitored in seven cities — Delhi, Kolkata, Agra, Bhopal, Bengaluru, Lucknow and Vadodara, where the CPCB’S regional directorates are located.

Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment, said, “Data shows technical solutions like regulating some chemicals are limited. We need greater sensitisation to control the quantum of burning.”