NEW DELHI: On Wednesday, government rejected studies of WHO and Yale University which talked about India and its cities being among the most polluted, asserting that the parameters for determining air pollution were not considered by them.

Environment minister Prakash Javadekar said pollution is caused by many factors and the survey took cognizance of only air pollution and that is why India's ranking in Yale University report has come down.

"Actually, there are 20 indicators to judge pollution like access to drinking water, access to sanitation, waste water treatment, agricultural subsidies, pesticides regulation, change in forest cover, coastal shelf forest pressure, fish stalks, etc.

"So, this ranking which you are citing is not based on all these parameters ...The survey of Yale University was also done from the satellite and there was no ground proof," he said, replying a question of BJD member Bhartruhari Mahtab.

Appreciating concerns expressed by members, the minister said that no one should forget that vehicle population has grown from eight crore on roads to 16 crore vehicles on road — it has doubled in ten years.

Javadekar said that the country needed upgradation of diesel, which is a different decision, besides required to give more emphasis to public transport and such other things.

"So, formation of a new committee at this stage is not required because it will just kill time. Instead, whatever is already established we must go ahead on that part and we are committed to that," he said.

The minister expressed concern over increase use of diesel despite the gap between the prices of petrol and diesel being reduced.

"So, we are hoping that people will also switch over to petrol vehicles which cause less pollution. As regards diesel, standards can be upgraded now and that can be done. It is a good suggestion for consideration," he said.

Javadekar said the government is measuring pollution, particularly air quality, in at least 240 cities and is giving emphasis on use of public transport.

"Air pollution is caused by many factors. Roadside dust is a major pollutant in many cities, the number of vehicles and vehicular traffic causes air pollution. Apart from that, industries, construction work, secondary particulate, domestic and diesel generator sets cause pollution," he said.

The minister said that the government has changed diesel norms. Therefore, lead and sulphur contents have gone down. The government was asking all state governments, as well as corporations concerned to take care of that.