Road Traffic Pollution Affects Roadside Vegetation, Study Shows

Strategic Insights -

Researchers at Graphic Era Hill University in Uttarakhand, India, conducted a study to examine the impact of motorway flyovers and at-grade roads on air pollution and roadside vegetation in Dehradun. The study found significant seasonal variations in PM10, SOx, and NOx concentrations at three different sites along the busiest highway in Dehradun. The results showed that PM10 and NOx were the most influential factors affecting air quality index (AQI), indicating their significant role in urban pollution. The study also used biochemical parameters to assess the responses to pollution in mango and bougainvillea plants, finding that mango showed a higher tolerance to pollution than the bougainvillea varieties.

Key Takeaways:

  • The study selected five varieties of plants, including Mangifera indica (mango) and four varieties of bougainvillea, along the busiest highway in Dehradun, India, to examine the impact of road traffic pollution on roadside vegetation.
  • The study monitored PM10, SOx, and NOx concentrations during the study period, showing significant seasonal variations at all three sites, with maximum PM10 and NOx observed at Site 2 (on-flyover) during December 2024.
  • The air quality index (AQI) trends from winter to spring declined, with Site 2 experiencing the greatest monthly reduction (-13.25 units month-1; R2 = 0.88) in AQI.
  • PM10 and NOx were the most influential factors affecting AQI, indicating their significant role in urban pollution.
  • Biochemical parameters, such as chlorophyll and ascorbic acid, were used to assess the responses to pollution in mango and bougainvillea plants, finding that mango showed a higher tolerance to pollution than the bougainvillea varieties.

Statistics:

  • Maximum PM10 concentration: 58 mg/m3 (observed at Site 2 on-flyover during December 2024)
  • Maximum NOx concentration: 33 mg/m3 (observed at Site 2 on-flyover during December 2024)
  • Greatest monthly reduction in AQI: -13.25 units month-1 (observed at Site 2)
  • R-squared value for AQI trends: 0.88
  • Tolerance index (APTI) for mango: 8.09
  • Tolerance index (APTI) for bougainvillea varieties: up to 4.65

Sources:

  • Assessment of elevated road traffic pollution on roadside trees and vegetation in urban environments. Frontiers in Environmental Science, 2025, 13.
  • NewsRx. Graphic Era Hill University Researchers Target Environmental Science (Assessment of elevated road traffic pollution on roadside trees and vegetation in urban environments). Life Science Weekly. October 28, 2025; p 1771.