A new study has found that air pollution kills more people than AIDS and malaria, combiined.

The study, published in the journal Environmental Science and Technology, revealed outdoor particulate air pollution results in 3.2 million premature deaths each year, more than the combined impact of HIV/AIDS and malaria.

They therefore developed a global model of how changes in outdoor air pollution could reduce health problems, including heart attack, stroke and lung cancer, thereby potentially preventing 2.1 million deaths per year.

The researchers looked at outdoor air pollution from particulate matter (PM) smaller than 2.5 microns, which can enter deep into the lungs.

PM pollution comes from fires, coal power plants, cars and lorries, plus agricultural and industrial emissions and breathing PM is associated with increased risk of heart attack, stroke and other cardiovascular disease; respiratory illnesses such as emphysema; and cancer.