PAU Study: Stubble Burning in Punjab Cannot Be Blamed for Air Pollution in Delhi

According to a study conducted by the Punjab Agriculture University (PAU), stubble burning is not the cause of the increase in pollution levels in Delhi. 

PAU's Principal Scientist, Dr. Prabhjot Kaur Sidhu, stated, "We have examined the data from the previous four years, from October 1 to October 16. Due to the withdrawal of the monsoon, the temperature begins to decline and the wind speed drops to 2km/h or less during this period. Wind speeds of 5 km/h are required for contaminants to spread from one place to another." 

She further stated, "Only four times - in 2019 and 2020 - when the wind speed surpass 5km/h or above, according to the data. During this time, the wind was blowing from the south, not from Delhi. As a result, no one can argue that the increase in pollution is the result of stubble burning." 

According to the PAU's principal scientist, the Head of the Department of Climate Change and Agricultural Meteorology, pollutants require significant wind speeds to move and each state is accountable for its own pollution. The AQI in Delhi is already higher than in Punjab. 

According to the varsity's study, the wind speed surpassed 5 kmph only three times between October 1 and November 15, and remained below 2 to 3 kmph the rest of the time. 

"Under the conditions, it is improbable that the smoke travelled 300 kms and contaminated Delhi," she said, adding that the smoke had increased pollution in Punjab more than in Delhi. 

"The wind speed was determined to be more than 5 kilometres per hour on October 23, 24, and November 2.  Photochemical smog was seen locally on the other days when the wind speed was less than two kilometres per hour," she stated. 

Photochemical smog is created when UV rays from the sun react with nitrogen oxide in the atmosphere. 

According to Dr. Prabhjot, Punjab's smoke does not travel 300-400 kms to choke Delhi's lungs; rather, farmers are endangering their own children and brethren by setting fire to their crops. 

When compared to Punjab, Delhi has a higher air quality index (AQI). The city's air quality remained "extremely bad" on Sunday morning, with the AQI reading 382 at 9 a.m. Saturday's 24-hour average AQI was 374. 

The situation has compelled Delhi officials to keep schools shut for physical classes till further notice, but online classes and board exams will proceed. Meanwhile, Delhi Environment Minister Gopal  Rai will host a high-level meeting on Monday to discuss the restrictions imposed to control excessive levels of pollution.