health risk of air pollutionNew estimates released by the World Health Organisation (WHO) reveal that air pollution as a health risk, both indoor and outdoor, is a more serious threat to humans than previously realised.

In 2012, around seven million people died as a result of air pollution exposure. That is one in eight of all deaths, globally, making air pollution the world's biggest health risk. The WHO believes that 4.3 million deaths can be linked to indoor air pollution exposures. This figure is derived from new information that about 2.9 billion people live in homes that have wood, coal or dung as cooking fuel. There were also an estimated 3.7 million deaths arising from exposure to urban and rural outdoor air pollution. Since many people are exposed to both indoor and outdoor air pollution, it is hard to separate the two, and analysis results in the seven million total.

The new data shows a strong link between air pollution exposure and cardiovascular disease (heart disease and stroke) and cancer. Air pollution such as smog also plays a major role in lung disease. Improved technology and measurements have led to the ability to make a more detailed analysis of the impact of air pollution as a health risk. Estimates of exposure were gathered through a new system of global data mapping. This incorporated satellite data, ground-level monitoring measurements and data on pollution emissions from key sources, along with modelling of how pollution drifts through the air.

It is the low and middle income countries in the WHO South-East Asia and Western Pacific regions that bear the heaviest burden of air pollution-linked mortality – with 3.3 million deaths linked to indoor air pollution and 2.6 million deaths related to outdoor air pollution. The shocking scenes of smog incidents in Beijing and other Chinese cities, as well as Paris and London, over the last year or so merely highlight this finding.

Dr. Flavia Bustreo, WHO Assistant Director General for Women and Children's Health pointed out that women and children pay the price through exposure to smoke from coal and wood cooking stoves in the home. ‘Cleaning up the air we breathe prevents non-communicable diseases as well as reducing disease risks among women and vulnerable groups, including children and the elderly,’ she said.

Fuller analysis of the new WHO data shows the following:

Outdoor air pollution as a health risk-related deaths

  • 40% - heart disease
  • 40% - stroke
  • 11% - chronic obstructive pulmonary disease
  • 6% - lung cancer
  • 3% - acute lower respiratory infections in children

Indoor air pollution as a health risk-related deaths

  • 34% - stroke
  • 26% - heart disease
  • 22% - chronic obstructive pulmonary disease
  • 12% - acute lower respiratory infections in children
  • 6% - lung cancer

‘Excessive air pollution is often a by-product of unsustainable policies in sectors such as transport, energy, waste management and industry. In most cases, healthier strategies will also be more economical in the long term due to healthcare cost savings as well as climate gains,’ said Dr. Carlos Dora, WHO Coordinator for Public Health, Environmental and Social Determinants of Health. ‘WHO and health sectors have a unique role in translating scientific evidence into policies that can deliver impact and improvements that will save lives.’

The release of this data is a significant step in advancing a WHO roadmap for preventing diseases related to air pollution. This involves the development of a WHO-hosted global platform on air quality and health to generate better data on air pollution-related diseases and strengthened support to countries and cities through guidance, information and evidence about health gains from key interventions. Later this year, WHO will release indoor air quality guidelines on household fuel combustion, as well as country data on outdoor and indoor air pollution exposures and related mortality, plus an update of air quality measurements in 1,600 cities around the world.

More information
World Health Organisation - Burden of disease from air pollution report for 2012: http://www.who.int/phe/health_topics/outdoorair/databases/FINAL_HAP_AAP_BoD_24March2014.pdf?ua=1