Delhi records worst air quality four years after Diwali

New Delhi:

Due to the combined effects of stubble burning and firecrackers, Delhi recorded the worst air quality in the four years following the Diwali festival, as pollution levels in and around the city exceeded the “urgent” threshold on Sunday. Did.

However, higher wind speeds (up to 25 km / h) and light rain under the influence of fresh western disturbances provided some relief.

Stubble burning accounted for 32% of Delhi’s PM2.5 pollution on Saturday evening, making the air quality “serious”, but firecracker emissions and gentle winds made the situation worse.

The level of PM2.5, which is about 3% of the diameter of human hair and can lead to premature death from heart and lung disease, is 396 micrograms / cubic meter (ug / m3) at 6 am Delhi-NCR. )was. The urgent threshold of 300 ug / m3 has been exceeded.

The PM2.5 level was 329 ug / m3 at 7 pm. The safety limit is 60 ug / m3.

The PM10 level was 543 ug / m3 at 6 am, above the emergency threshold of 500 ug / m3 and began to decline. According to data from the Central Contamination Control Board (CPCB), the concentration at 7 pm was 441 ug / m3. PM10 levels below 100 ug / m3 are considered safe in India.

According to the Phased Response Action Plan (GRAP), if PM2.5 and PM10 levels exceed 300 ug / m3 and 500 ug / m3 and last for more than 48 hours, air quality is in the “Critical Plus” or “Urgent” category. Is considered to be. ..

According to data from the Delhi Pollution Control Commission, PM10 levels per hour surged to 1,636 ug / m3 by 1 am in Punjabi Bagh and 1,937 ug / m3 by midnight in Jahan Gilpri.

On Saturday night, many people detonated firecrackers in and around the capital, ignoring the ban imposed by the National Green Court.

On Monday, the court banned the sale or use of all types of firecrackers in Metro Manila (NCR) from midnight November 9th to midnight November 30th. “.

The city recorded an overall AQI of 414 on Saturday. It soared to 454 by 10 pm. The average 24-hour AQI on Sunday was 435 at 4 pm, the worst day after Diwali in the last four years.

Delhi recorded a 24-hour average AQI of 337 in Diwali last year (October 27) and 368 and 400 in the next two days. After that, pollution levels remained in the “severe” category for three days in trot.

In 2018, the 24-hour average AQI (281) for Diwali was recorded in the “bad” category. It deteriorated to 390 the next day and remained in the “severe” category for the third consecutive day.

In 2017, Delhi’s 24-hour average AQI (October 19) in Diwali was 319. However, the next day I slipped into the “harsh” zone and was 403.

According to the India Meteorological Department, Delhi-NCR witnessed a light rain on Sunday and high wind speeds under the influence of the fresh western disturbances that helped spread pollutants.

The maximum wind speed on Sunday was about 25 kilometers per hour. According to Kuldeep Srivastava, head of the IMD Regional Forecast Center, Mondays at speeds of around 12 to 15 km / h will help spread pollutants.

SAFAR, an air quality monitor from the Ministry of Earth Sciences, said that PM2.5 magnitudes were significantly local additional emissions (probably) combined with farm fire-related pollutant concentrations on Saturday night. Concentrations reached over 1000 ug / m3 yesterday midnight (related to fire crushing). “

However, the wind direction at the boundary layer is changing eastward, making it unsuitable for invasions associated with stubble fires.

The number of stubble fires on Sunday decreased from about 2,586 on the previous day to about 350. The rate of farm fires at PM2.5 in Delhi was about 4 percent on Sunday.

Delhi’s early air quality warning system also said on Monday that the situation is likely to “significantly improve.”