Pollution went down during odd-even phase-1, finds DTU study
The peer reviewed study found that in the 15 days when the vehicle rationing plan was in place in Delhi, PM 2.5 levels reduced by 5.73%, while the PM1 levels in the ambient air around these corridors came down by 4.70%. The scientists in DTU measured the fine PM1 levels by specialised instruments.Updated: Sep 26, 2019 23:59 IST
The first phase of the odd-even vehicle rationing scheme in January 2016 brought down the level of particulate matter (PM) in the city’s air by 4.7 to 5.7%, a study by the Delhi Technological University (DTU) has found.
The study titled ‘The effect of odd-even driving scheme on PM2.5 and PM1.0 emission’ — which was conducted by a team of researchers from the department of environment engineering at DTU, led by assistant professor Rajeev Kumar Mishra — was carried out in three traffic heavy stretches, Pitampura (Madhuban Chowk), Panchkuian Road and Najafgarh Road in January 2016.
After the first round, the Aam Aadmi Party (AAP) government in Delhi had introduced another round of vehicle rationing scheme in April. Chief minister Arvind Kejriwal has announced that the odd-even scheme will be implemented for a third time in Delhi between November 4 and November 15, as a measure of controlling the pollution levels in winter.
The peer reviewed study found that in the 15 days when the vehicle rationing plan was in place in Delhi, PM 2.5 levels reduced by 5.73%, while the PM1 levels in the ambient air around these corridors came down by 4.70%. The scientists in DTU measured the fine PM1 levels by specialised instruments.
“During the study, it was found that the reduction of PM 2.5 is higher than that of PM 1 during the implementation of odd-even scheme. Since PM2.5 includes finer particles, this is a sign that the reduction of vehicles on the road contributed in bringing down the pollution levels,” said Mishra.
He added that this, though small, was a “significant” impact towards the fight against the alarming pollution levels in the national capital.
PM10 is the coarse dust that mainly comes from road sides and construction sites. The primary source of PM 2.5 is combustion, including vehicular emissions and garbage burning. PM 1, on the other hand, is among the finest particles that can reach the blood stream and percolate the organs. These fine particles are nearly 50 to 70 times finer than human hair.
Earlier studies assessing the impact of the odd-even scheme showed only a minor drop in pollution levels during the period.
A study done by a team of scientists from IIT-Delhi, IIT-Kanpur, IITM-Pune CSIR and TERI showed that the first round of the odd-even plan in January brought down pollution levels by just around 2-3%.
Experts from Centre for Science and Environment (CSE), however, suggested the arrangement as an effective “emergency measure” that could prevent pollution levels from getting worse.