A new study has revealed that almost 80% of the soot that spreads from China to other parts of East Asia is a result of city traffic and fossil fuel combustion. Home cooking is one of the good examples of fossil fuel combustion.

The study was published in Environmental Science and Technology. There have been concerns over a long period of time about the sources of air pollution responsible for Asian's infamous atmospheric brown clouds.

The team included researchers from China, South Korea, Sweden and the United States. Örjan Gustafsson, who led the team, said that nobody has been able to figure out the exact sources of soot or black carbon.

It is estimated that 500, 000 people die every year in China alone because of inhaling these tiny particles. Sunlight is also absorbed by black carbon in the atmosphere. Scientists believe that it is second only to carbon dioxide to contribute to global warming.

Gustafsson and his team precisely figured out the exact sources of black carbon in China with the help of a powerful carbon-14 identification method.

"To mitigate near-term climate effects and improve air quality in East Asia, activities such as residential coal combustion and city traffic should be targeted", concluded the authors in their paper.