Based on NASA’s satellite data, the results of the research were carried by the leading international journal, Geophysical Research Letters published by the American Geophysical Union, on Tuesday.

‘‘These coal-based power plants use thousands of tonnes — upto 40,000 tonnes per day — of very low-grade coal with 30-45 per cent ash content, which is a major source of carbon emission in the air,’’ said Professor R P Singh of the department of civil engineering at IIT-K, a co-author of the research paper.

Uttar Pradesh alone has 35-40 such thermal plants, all located around the Gangetic basin. According to Singh, the Gangetic basin and South India together account for more than 89 plants with over 100-MW capacity. Some of them even produce over 2000-MW of electricity.

As per the law, these plants need to use ‘‘electrostatic precipitator filters’’ to restrict emission of carbon particles in the atmosphere. But it is not sure whether these filters are effective enough to control the emission.

‘‘It is also suspected that the concerned authorities don’t ever check these filters or get them replaced from time to time,’’ said Singh.

While the density of power plants is high along the Gangetic basin, the Himalayas and Vindhyachal mountains also act as a barrier, leading to accumulation of pollutants in the area.

‘‘Due to this, the region suffers dense haze, fog and smog. These then lead to poor agricultural production, health hazards and depletion of ozone layer over the sub-continent. While this affects the whole of the Indian population, the 600 million people living in the region are especially hit,’’ said Singh. The brick kilns concentrated in the basin add to the carbon emission.

Singh pointed out that while the Japanese government had banned such power plants, India, on the other hand, was planning to set up five more thermal plants.

The research also counters the perception that biofuel-cooking in UP and Bihar, beside automobile emissions, are responsible for the air pollution.

Giving details of the studies taken up in the last five years, Anup Krishna Prasad, a PhD student and co-author of the research paper, pointed to the comparitive data provided by NASA on the emissions caused by power plants and other sources.

‘‘It was shocking to find that the emission from power plants was more than the total of various other emissions,’’ he said.

Emission data for around 89 power plants collected during the research indicated that the plants in UP and Bihar were emitting maximum pollutants as compared to plants in South India due to the lower topography and wind pattern in the Gangetic basin.

Prasad added that the Panki power plant, located around 4 km from the IIT-K campus, has an adverse effect not only on the institute but the whole of the city. ‘‘The combustion of 3,300 tonnes of low-grade coal daily leads to concentration of carbon for upto 30 km. The problem becomes more severe during winter,’’ he said.