A new study warns air pollution is killing over 3 million people each year, reports the Melbourne Herald Sun.
Researchers created a computer model combined with population data and health statistics to estimate how many people around the world may suffer premature death because of dirty air.
Researchers from the Max Planck Institute for Chemistry in Germany found airborne pollutants can penetrate deep into the lungs, contributing to serious diseases.
The scientists estimate that air pollution contributes to the early deaths of more than 3.2 million people around the world.
They warn that if nothing is done, that figure could rise to 6.6 million by the middle of this century.
Most of the deaths were in developing countries.
The main culprits, says the study, are microscopic particles produced from heating and cooking.
The study found that in China alone pollutants from coal and wood used for heating and cooking, local waste disposal, and diesel generators accounted for 1.36 million deaths.
Pollution also accounts for between 50 to 70 percent of deaths in India and other Asian nations, say the researchers.
The study is published in the journal Nature.