Results confirmed acidic pH in both the tree species, which was mainly due to rising sulphur-dioxide and nitrous oxide levels in the ambient air at these study areas.
A study by a group of Pune-based researchers has recommended planting Ashoka and cluster fig trees (Umbar) in the Shivajinagar and Pashan areas of the city, as they were most resistant to air pollution.
These trees can act as pollution barriers and as a sink to control air pollution and should be planted more to mitigate air pollution menace, experts said. The city generally witnesses moderate air quality during the summer and winter seasons and improved air quality in the monsoon season.
Any increase in the concentrations of either oxides of sulphur or nitrogen in addition to particulate matter (PM) 2.5 or PM 10 contributed by vehicular emissions, construction works, burning of farmlands and similar activities can lead to deterioration in air quality.
Both these localities see heavy vehicular population, which is the main source of pollution apart, from other sources.
In the joint study — conducted by the Indian Institute of Tropical Meteorology, Abeda Inamdar Senior College, Savitribai Phule Pune University, New Arts, Commerce and Science College in Ahmednagar, and Solapur University — leaf samples from trees were collected during pre-monsoon and post-monsoon seasons of 2018.
The samples were tested for the total chlorophyll, relative water content, pH and the concentration of ascorbic acid after which the air pollution tolerance index was calculated.
Results confirmed acidic pH in both the tree species, which was mainly due to rising sulphur-dioxide and nitrous oxide levels in the ambient air at these study areas. At the sites with high pollution levels, the chlorophyll levels were found to be lower compared to cleaner sites.
“Loss of chlorophyll could be due to particulate matter and other pollutants,” the researchers stated. Positively, the concentration of ascorbic acid was found to be high in both the plant species at the study sites.
“The higher concentration of ascorbic acid is an indication of the plant’s tolerance to air pollution. This also means that the plant is being highly exposed to sulphur-dioxide,” the study noted.
The PM10 levels recorded at Shivajinagar was far higher than Pashan, which is relatively a greener and less-crowded area.
Overall, the study published in the journal ES Food and Agroforestry, said that the PM levels were beyond permissible limits at both these sites, particularly during the winter months.
Whereas, sulphur-dioxide and NOx were high but within permissible standards, internationally, the study concluded.
Source: Read Full Article