Decline in vehicular emission had no impact on pollution: CPCB

The apex pollution monitoring body today told the National Green Tribunal that the decline in vehicular emission during the second week of odd-even car rationing scheme here in April was not a dominant enough factor to impact the pollution levels.
"The decrease in vehicular emission was not a dominant enough factor to impact observed data. Since meteorological factors as well as emission from various sources outside Delhi in the air-shed varies from time to time, data for different periods do not lend themselves to scientifically accurate comparison," Central Pollution Control Board report said.
The CPCB had monitored several pollutants between April 1 to 14 before the odd-even period and April 15 to 30 during it to arrive at the conclusion.

The data covered PM (particulate matter) 10, PM 2.5, benzene, ozone, nitrogen dioxide, carbon monoxide for CPCB's automatic stations at Shadipur, Dwarka, Dilshad Garden, DCE and ITO and 8 manual stations - Pitampura, Sirifort, ITO, Janakpuri, Nizamuddin, Shahzada Bagh, Shahdara and BSZ Marg.
The tribunal, after perusing the details, directed CPCB to submit the ambient air quality data from January to May, after a plea claimed that vehicular emission was not a major contributing factor to pollution.
A bench headed by NGT chairperson Swatanter Kumar asked the apex pollution monitoring body to place on record analytical data for different time periods before and after the fortnight-long scheme.

"We direct CPCB to file a complete analytical data including PM 2.5, PM 10 and other air pollutants in NCT Delhi. The report should cover the period from January to May," the bench said.

The order came during the hearing of a petition filed by scientist Mahendra Pandey who had sought independent monitoring of air quality index and alleged that vehicular emission was not a major contributing factor to pollution.
In his petition, while referring to an IIT Roorkee study, Pandey had claimed that no significant change in air quality was registered during the first phase of the scheme which was in force between January 1 and 15.

"In fact as per the data provided by CPCB, it is clear that during odd-even days, the pollution levels were much higher than the pre-period and the post-period which raises serious concern about the much-hyped odd-even formula.
"After completion of first phase of odd-even scheme, tall claims were made by Delhi government by publishing advertisements in newspapers about its success. However, no data was made public regarding the level of pollution ... Therefore, the claims of success of the odd-even scheme is meaningless as it is not supported by any data," the plea had said.