Even as the state government continues to rave about the success of the odd-even car policy, not many are applauding the reported decline in the air's toxicity. That is because not every monitoring agency is noticing any decline, and some in fact report a rise.

An independent portal - IndiaSpend - reported that pollution levels in the capital rose by 50% in the first week of the odd-even plan which began from January 1. IndiaSpend installed several low-cost air sensors across the city and compared the data to figures recorded between December 25 and 31.

While several factors determine the level of toxicity in the air, rationing of cars has been seen as an experiment to try to help Delhi citizens breathe better. The AAP government has repeatedly hinted that the experiment is working but not all are seeing the result. The first to slam the state government was the Delhi High Court which asked why the experiment should be extended beyond a week. "What is the need to run odd-even scheme after a week?" the court had asked. "You will have to admit that you don't have enough public transport to ferry the public."

In turn, the government had said that there has been a positive impact in the city. "According to the scientists of the Delhi Pollution Control Committee (DPCC), 80 per cent of PM2.5 air pollution is caused by vehicular traffic and reduction in its levels, even in outer areas of Delhi shows that reduction of four wheeled vehicles on roads since the New Year Day is having a positive impact," the AAP government said in a statement.

The problem though is that not all monitoring agencies are seeing the 'positives.' Apart from IndiaSpend, figures from System of Air Quality and Weather Forecasting And Research (SAFAR) too have not backed any trend in air quality either. There have been days when pollutants have remained high while on others, SAFAR observed a decline.

Regardless of the impact on air quality, most agree that Delhi-ites have largely shown a lot of spirit in keeping odd-numbered cars off the road on even days, and vice-versa. Peak-hour traffic has fallen by almost 30% while road accidents have dipped as well. As for the pollution levels, experts believe that odd-even car policy is not a definite step but one of many required to clean Delhi's air.