Over the past few years, the World Health Organization (WHO), an agency of the United Nations concerned with international public health, has conducted the largest ever global systematic study to find the distribution and causes of a wide array of major diseases, injuries and health risk factors. The group's findings contain all kinds of insights about how much progress has been made in certain areas (compared to 20 years ago, there are fewer deaths from infectious diseases, maternal and child illness and malnutrition), and how much work there is left to do in others.

The statistics about air pollution stood out to me, especially because the victims of air pollution don’t get too many headlines.

  • The latest data shows that there are about 3.5 million deaths a year that are caused by indoor air pollution.
  • About 3.3 million deaths are caused by outdoor air pollution.
  • About 0.5 million deaths have been caused by a combination of indoor and outdoor air pollution, so the total number of deaths caused by air pollution is closer to around 6.3 million.
  • This is about twice as many deaths as previously thought.
Indian commuters wait for a bus early on a polluted morning in New Delhi on Jan. 31

Indian commuters wait for a bus early on a polluted morning in New Delhi on Jan. 31. (Photo: Prakash Singh/AFP/Getty Images)

According to the U.N., AIDS kills about 1.7 million people a year worldwide and malaria 660,000. This means that air pollution kills more people every year than both of those terrible scourges combined. (This doesn’t take anything away from the urgency needed to combat AIDS and malaria, but it should mean that we need to pay more attention to air pollution.)

If nothing is done, it’s expected that the number of deaths caused by air pollution worldwide will go up because of rising fossil fuel use. (For example, in 2011, China built as many coal plants as there are in Texas and Ohio combined.)

The good news is that we know what to do to — from replacing dirty electricity sources with clean ones, bringing electricity to the poor or at least providing clean-burning cook stoves (cooking is the #1 source of indoor air pollution), tightening emission regulations and enforcing them, etc. Many areas that used to have terrible air quality have successfully cleaned up their acts. We just need to do it.

Related on MNN:

Michael Graham Richard ( @Michael_GR ) Michael writes for MNN and TreeHugger about science, space and technology and more.