A new study has estimated that outdoor particulate air pollution (pictured, Shanghai shrouded in smog) results in around 3.2 million premature deaths from heart attack, stroke, lung cancer and other illnesses, each year
Air pollution kills more people every year than Aids and malaria combined, warns new research.

Scientists say meeting global air quality guidelines could prevent 2.1 million deaths per year.

They developed a global model of how changes in outdoor air pollution could reduce health problems, including heart attack, stroke and lung cancer.

And their findings reveal outdoor particulate air pollution results in 3.2 million premature deaths each year - more than the combined impact of HIV-Aids and malaria.

By meeting the World Health Organisation's (WHO) particulate air quality guidelines, the team of environmental engineering and public health researchers estimate 2.1 million early deaths could be prevented.

The new study is the first detailed analysis of how improvements in particulate air pollution worldwide would yield improvement in health, and where those improvements would occur.

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

Breathing PM is associated with increased risk of heart attack, stroke and other cardiovascular disease; respiratory illnesses such as emphysema; and cancer.

PM pollution comes from fires, coal power plants, cars and lorries, plus agricultural and industrial emissions.

In low-income countries, PM also comes from burning coal, wood, crop waste and animal dung for cooking and heating, and from open burning rubbish.

Lead author Doctor Joshua Apte, of the University of Texas, said: 'We wanted to determine how much cleaner different parts of the world would need to be in order to substantially reduce death from particulate matter.

'We believe our model could help in designing strategies to protect public health.'

He said, worldwide, most people live in areas with PM concentrations far above WHO's air quality guideline of 10 micrograms per cubic metre, with some parts of India and China experiencing levels that exceed 100.

Confirming the researchers' expectations, the study demonstrated major potential to reduce mortality from PM in the world's most polluted regions.

But one of the study's unexpected findings was that cleaning air in less polluted parts of the world, including Western Europe, can have as much health benefit as similar measures taken in the most polluted areas.

Co-authored Doctor Julian Marshall, of the University of Minnesota, said: 'We were surprised to find the importance of cleaning air not just in the dirtiest parts of the world - which we expected to find - but also in cleaner environments like the US, Canada and Europe.'

The study determined that meeting WHO's air quality guidelines could prevent up to 1.4 million premature deaths per year in polluted areas such as China, India and Russia.

And meeting WHO guidelines in clean regions could reduce premature deaths from outdoor pollution by more than half a million per year.

Dr Marshall said another important finding was that because of ageing populations, health risks in many countries will increase even if pollution levels are constant.

Older people are more susceptible to air pollution and more at risk than younger people for health problems such as heart attacks and strokes.

The study was published in the journal Environmental Science and Technology.