No clear pollution trend during odd-even trial: CPCB reports

The lack of any clear trend and wide fluctuations in concentration of pollutants during the odd-even experiment suggest that no single action can substantially reduce air pollution levels in the capital, the Central Pollution Control Board (CPCB) has said in a report.

“With no clear trend and wide fluctuations observed in the concentrations, it is evident that the meteorology and emissions from other polluting sources have been major factors impacting air quality of Delhi during the period.

“Overall, it can be stated that while some reduction in air pollution is likely to happen due to the odd-even scheme, a single factor or action cannot substantially reduce air pollution levels in Delhi,” says the report that analyses air quality in Delhi before, during and after the odd-even experiment.

The board has also called for a “comprehensive” set of actions and an “integrated” approach to make substantial improvement in air quality.

The air quality in Delhi is monitored through a set of Continuous Ambient Air Quality Monitoring System (CAAQMS) and manual stations by National Air Quality Monitoring Programme (NAMP).

The CPCB analysis is based on the data collected by eight operational CAAQMSs, including four of its own (Shadipur, Dwarka, Dilshad Garden and Parivesh Bhavan) and other four belonging to Delhi Pollution Control Committee (DPCC) (Mandir Masg, R.K. Puram, Punjabi Bagh and Anand Vihar).

Apart from this, data has also been collected from seven manual stations of CPCB (Pitampura, Sirifort, Janakpuri, Nizamuddin, Shahzada Bagh, Shahdara and Bahadur Shah Zafar Marg) which operate on alternate days.

According to the CSE’s analysis, data from the Delhi Pollution Control Committee (DPCC) indicates that PM 2.5 levels rose by over 57 per cent on January 18, with an average concentration across the city of 277 micrograms per cubic metre, which falls in the “severe” category.

Other studies carried out by the School of Planning and Architecture (SPA) showed that traffic congestion had also reduced considerably while the scheme was in force.