No clear pattern emerged out of the pollution data collected so far at Delhi’s borders, leaving doubts about odd-even’s impact on air pollution at Delhi’s exit points.
The government started monitoring air quality at the borders a couple of days before odd-even phase two kicked off.
The plan is to compare air quality before, during and after the traffic-rationing to show that pollution in Delhi reduced, and it went up in neighbouring states as they didn’t follow the restriction.
Delhi Pollution Control Committee (DPCC) data showed pollution on Delhi’s side of a few borders actually went up, instead of coming down. The increase, however, was marginal in some cases.
At most stations, though, pollution in Delhi was lower than that outside — a trend consistent with data collected on April 15 when odd-even started.
PM 2.5 concentration in Delhi increased at four out of seven locations — Ghazipur, Anand Vihar, Shahdara, and Badarpur. At the latter two locations, the increase was marginal.
At Noida border, the pollution dropped considerably, both towards Delhi and towards Noida. At Gurgaon, the concentration remained the same. At Tikri, pollution dipped in Delhi and increased towards Bahadurgarh.
The highest PM 2.5 level out of the 74 spots where samples are being collected from was at Bhajanpura, in the north eastern part of Delhi.
PM 10 concentration at four locations was also higher on April 20 compared to April 15. At Noida border (both inside Delhi and outside) it dropped considerably.
Data collected by different pollution monitoring sources did not paint a clear picture about the scheme’s impact within the city either.
However, independent experts maintained that monitoring pollution is complex as it is dependent on several factors constantly varying factors such as temperature, wind speed and moisture.
A study by the School of Planning and Architecture also questioned odd-even’s impact on congestion and air quality. The study showed that there were 50% more private cars on the roads during odd-even part two compared to the first round held in January.