As the ban on firecrackers in Delhi-NCR increased in Smoke during Diwali on Saturday night, the average concentration of PM 2.5 per hour reached 910 micrograms per cubic meter (g / m3) at midnight, 15 times the standard safe. Later it fell due to the increase in wind speed.
The AQI hit ‘severe’ on Diwali with a reading of 414 as people circumvented the ban on firecrackers on Saturday. The AQI registered at 435 on Sunday, according to a Times of India report.
Diwali this year has been worse since 2016 in terms of AQI, with a reading of 431 recorded, while the next day it was 445, data from the Central Pollution Control Board and Air Quality System showed. .
Diwali registrations for the past year were comparatively low. The AQI was 337 on Diwali and 368 the next day in 2019; while 281 on Diwali and 390 the next day in 2018.
However, SAFAR had predicted that the level of pollution would reach a ‘severe’ level the day after Diwali, even if no firecrackers were exploding.
Data from the CPCM showed that the level of contamination was at its highest around midnight from 12 am to 1 am. “Diwali was in mid-November this year, which has unfavorable weather conditions for the dispersal of pollutants compared to 2019 when it was the last week of October,” he said. The contribution of stubble burning to Delhi’s PM2.5 concentration was 32% on Diwali this year, compared to 19% last year. “Therefore, it can be inferred that the high concentrations of PM2.5 in 2020 compared to the previous year had a greater contribution from the burning of stubble and the same is also reflected in high levels of CO and NO2,” said the pollution supervisory body.
“The surface temperature was the lowest in the last five years, which could have contributed to more inverse conditions and lower average mixing height, limiting vertical dispersion. The wind speed and the day before Diwali and Diwali were similar. Overall, this Diwali saw higher levels of pollutants and more particulate matter added during the night from the firecrackers, ”added CPCB.
The rain wave on Sunday afternoon not only helped settle pollutants, but also increased wind speeds. Improved air quality.
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