Stubble-burning doubles pollutant levels: Study

Dushyant Singh Pundir
Tribune News Service
Chandigarh, October 8

Pollutant levels are found to be elevated by 2-2.5 times of the standard value during the crop residue burning period in Haryana and Punjab, reveals a study conducted by the PGIMER.

To study the impact on ambient air quality, the real-time monitoring of air pollutants during the period and its relationship with meteorology and trans-boundary movement of air was conducted in Fatehgarh Sahib, Bathinda and Amritsar in Punjab; Sirsa, Rohtak and Sonepat in Haryana; and Chandigarh.

The measured air pollutants include particulate matter (PM10, PM2.5 and PM1), black carbon, carbon dioxide, carbon monoxide, sulfur dioxide, Ozone, oxides of nitrogen, ammonia and benzene among others. The meteorological parameters monitored were temperature, rain, relative humidity, wind speed, wind direction and ultraviolet radiation.

“The average concentration of PM10, PM2.5 and PM1 during the study period was found to be between 166.1 and 227.3, 128.2 and 168.2 and 42.3 and 60.1 µgm-3. The daily average concentration was found several times higher than the national ambient air quality standards for 24 hours,” the study reveals.

“The concentration of particulate matter was found significantly higher than the national ambient air quality standards at all locations,” said Dr Ravindra Khaiwal, Additional Professor, Department of Community Medicine and School of Public Health, PGIMER, Chandigarh.

The highest average concentration of PM10 was observed in Amritsar (between 144.08 and 360.36 µgm-3), followed by Sonepat (between 62.18 and 365.16 µgm-3) and Bathinda between 133.4 and 274.84 µgm-3), whereas Chandigarh reported the lowest average concentration of coarser particles (between 45.05 and 257.85 µgm-3).

Further, the highest average concentration of PM2.5 was also observed in Amritsar (between 94.63 and 262.25 µgm-3). Rohtak, a semi-urban location, observed the highest PM1 concentration between 24.03 and 100.55 µgm-3. The concentration of gaseous pollutants was also observed highest at Amritsar location.

The average lowest concentration for PM10, PM2.5 and PM1 was in Chandigarh, which is an urban location. Bathinda has the lowest PM1 (between 33.89 and 68.25 µgm-3).

The results show that the stubble burning in north India significantly contributes to atmospheric aerosols and hence these sources should be given priority to reduce particulate pollution. The level of gaseous pollutants and volatile organic compounds (VOCs) like benzene was found to be elevated, which speeds up the formation of secondary air pollutants.

The urban location of Chandigarh has the highest average levels of benzene, whereas the highest average concentration of other VOCs observed in Rohtak.

The crop residue burning period for kharif crop usually starts in the second half of October and lasts for six to eight weeks.

That choking feeling 
Location PM 10 (µgm-3)

Amritsar 144.08 - 360.36
Sonepat 62.18 - 365.16 
Bathinda 133.4 - 274.84 
Chandigarh 45.05-257.85

• Amritsar records the highest average concentration of PM2.5 at 94.63-262.25 µgm-3
• National ambient air quality of PM10 is 100 & PM2.5 is 60