Air pollution killed an estimated 7 million people in 2012 according to a World Health Organization (WHO) report published in March – a figure that is double what it was previously thought to be.

“The risks from air pollution are now far greater than previously thought or understood, particularly for heart disease and strokes,” says Dr. Maria Neira, Director of WHO’s Department for Public Health, Environmental and Social Determinants of Health.

The sharp increase comes from a better understanding of pollution’s wide-sweeping effects, taking in new data collected from rural areas and urban settings as well. Scientists have gained crucial knowledge to the link between air pollution and noncommunicable, chronic illnesses that result in premature deaths. In particular, new links were revealed between air pollution and cardiovascular diseases as well as between air pollution and cancer.

“Few risks have a greater impact on global health today than air pollution,” Dr. Niera continues. “The evidence signals the need for concerted action to clean up the air we all breathe.”

The report distinguishes between two types of pollution: indoor and outdoor. Indoor pollution results from the fumes produced by wood or coal burning stoves in kitchen areas of homes that often spread and linger throughout entire living areas with poor ventilation. Outdoor pollution is caused by industrial waste entering soil and water supplies, desert dust, raw sewage and from the soot produced by coal-burning power.

So, which is more dangerous – indoor or outdoor pollution? It turns out that indoor pollution, due to its containment and consistent, extended exposure, is the more deadly of the two. The estimates claim 4.3 million deaths were the result of indoor pollution in 2012 and 3.7 million deaths from outdoor air pollution. That gives a total figure of around 8 million, but the WHO lowered the total estimate to s7 million to account for possible overlap. With these totals, it can be assumed that air pollution kills more people annually than HIV, tuberculosis and malaria combined.

The WHO has been able to target which diseases are caused by pollution that result in early death. The disease breakdown for both types of pollutions goes as follows:

Outdoor air pollution-caused deaths – breakdown by disease

40 percent – ischaemic heart disease
40 percent – stroke
11 percent– chronic obstructive pulmonary disease (COPD)
6 percent – lung cancer
3 percent – acute lower respiratory infections in children

Indoor air pollution-caused deaths – breakdown by disease

34 percent – stroke
26 percent – ischaemic heart disease
22 percent – COPD
12 percent – acute lower respiratory infections in children
6 percent – lung cancer

Those suffering most from the epidemic are the rural poor, and those living in extremely polluted areas in Asia. Since indoor pollution is more of a threat, women, children and the elderly are also at a higher risk.

“Poor women and children pay a heavy price from indoor air pollution since they spend more time at home breathing in smoke and soot from leaky coal and wood cook stoves,” says Dr. Flavia Bustreo, WHO Assistant Director-General Family, Women and Children’s Health. “Cleaning up the air we breathe prevents noncommunicable diseases as well as reduces disease risks among women and vulnerable groups, including children and the elderly.”

— Edward Heinrich

Sources: The Guardian, Scientific American, Media Centre
Photo: Green Peace