Shivajinagar, Katraj report more ozone pollution: IITM study

Published on Sep 27, 2022 12:48 AM IST

The research found volatile organic compounds (VOCs) measured at Pashan to be underestimated by 70% during summers

While atmospheric pollution is usually higher in most parts of Pune city during winters, surface ozone formation is severely underestimated during summers; a recent study conducted by researchers at the IITM has found. (REPRESENTATIVE IMAGE)
While atmospheric pollution is usually higher in most parts of Pune city during winters, surface ozone formation is severely underestimated during summers; a recent study conducted by researchers at the IITM has found. (REPRESENTATIVE IMAGE)
ByNamrata Devikar

While atmospheric pollution is usually higher in most parts of Pune city during winters, surface ozone formation is severely underestimated during summers; a recent study conducted by researchers at the Indian Institute of Tropical Meteorology (IITM) has found. The research found volatile organic compounds (VOCs) measured at Pashan to be underestimated by 70% during summers. Volatile organic compounds contribute to surface ozone and the formation of secondary organic aerosols. While surface ozone is a known pollutant which seriously impacts human- and environmental health, secondary organic aerosols add to the particulate matter (PM) pollution. The study also found Shivajinagar and Katraj to report more ozone pollution as compared to Pashan.

The research paper titled, “Characteristics of VOCs and their contribution to ozone and secondary organic aerosol formation across seasons over a metropolitan region in India,” was published in the International Journal of Atmospheric Pollution Research on August 5.

Ritesh Kalbande, a scientist at IITM and lead author of the paper, said that they worked on VOCs and measured surface ozone over different parts of Pune city with the help of data provided by System of Air Quality and Weather Forecasting and Research (SAFAR). “VOCs lead to the formation of surface ozone and secondary organic aerosols. The secondary organic aerosols contribute to fine particulate matter in the atmosphere, which further causes pollution. However, these VOCs are very reactive to sunlight and their concentration degrades (photochemical) over time. Hence, their concentrations measured at our labs are often underestimated. So, in order to better understand the atmospheric chemistry of our Pune region, it is important to know the original VOC concentrations. Through this research, we have tried to estimate the actual emitted concentration of these VOCs,” Kalbande said. The research team including Ravi Yadav, Sujit Maji, Devendra Singh Rathore and Gufran Beig studied nine such VOCs with surface ozone measured during the year 2019. “Isoprene is one such reactive compound. It is seen that during summer as the temperature is high, this compound degrades faster because of its high hydroxyl reactivity. As such, we underestimate 65 to 70% of this compound. Isoprene contributes significantly to surface ozone formation and hence, this underestimation can hamper our ozone formation understanding. Similarly, knowledge of actual emission of these compounds can help us better understand the extent of pollution,” Kalbande said. The total concentration of these compounds is seen to be the highest during winter followed by summer, he added.

“The total concentration of VOCs during winter is the highest. During summer as the temperatures are high, highly reactive VOCs react more in the presence of sunlight. Whereas in the monsoon season, due to washout and high wind speed, the pollution levels are seen to be the least,” Kalbande said. Areas such as Shivajinagar and Katraj reported more ozone pollution as compared to Pashan, he added.

Dr Maji, part of the research team and author of the paper, said that during winters, local pollution from vehicles dominates the Pune region. “During winter, local pollution dominates; VOCs come here and get locked. Winter is more harmful in terms of ozone, particulate matter and local pollution. In the summer season, VOC emissions are high, temperature and moisture are also high. After the monsoon season, our biogenic emission increases as the vegetation increases after the monsoon. This biogenic precursor compound increases,” Maji said.

SHARE THIS ARTICLE ON
SHARE
Story Saved
×
Saved Articles
Following
My Reads
My Offers
Sign out
New Delhi 0C
Friday, December 09, 2022
Start 15 Days Free Trial Subscribe Now
Register Free and get Exciting Deals