Putting into context air-pollution-statistical ‘estimates’

When it comes to polluted air, there is the abstract part: pollution-related illness and death.

The_Earth_seen_from_Apollo_17[1]On Mar. 25, 2014, the World Health Organization (WHO) in the “7 million premature deaths annually linked to air pollution” news release states: “In new estimates released today, WHO reports that in 2012 around 7 million people died – one in eight of total global deaths – as a result of air pollution exposure. This finding more than doubles previous estimates and confirms that air pollution is now the world’s largest single environmental health risk. Reducing air pollution could save millions of lives.”

So, keeping it all in context, here’s a question: If the 7 million is only an estimate, how can it then be confirmed that polluted air is the world’s biggest risk to health from environmental causes? Add to this information that the estimates are at least twice those of previous ones, apparently.

Making sense of the estimates

Because there are those who are exposed to polluted air from both indoor and outdoor sources, the WHO acknowledges that, “Due to this overlap, mortality attributed to the two sources cannot simply be added together, hence the total estimate of around 7 million deaths in 2012.”

The WHO further explained, “The new estimates are not only based on more knowledge about the diseases caused by air pollution, but also upon better assessment of human exposure to air pollutants through the use of improved measurements and technologies. This has enabled scientists to make a more detailed analysis of health risks from a wider demographic spread that now includes rural as well as urban areas.”

The WHO then went on to point out that there were an estimated 3.3 million premature deaths associated with polluted air from indoor sources and 2.6 million early deaths connected with air pollution from out of doors in WHO regions in the Western Pacific and Southeast Asia, for a grand total of 5.9 million, as I understand things. To me, this means that 1.1 million or the remainder of the 7 million worldwide total have occurred elsewhere. That’s a 6-to-1 ratio.

The WHO identifies specific linked diseases such as acute lower respiratory infections in children, chronic obstructive pulmonary disease (COPD), ischaemic heart disease, lung cancer and stroke with the following breakdowns for both indoor and outdoor pollution:

Indoor air pollution-caused deaths (in percent):

  • Acute lower respiratory infections in children – 12
  • COPD – 22
  • Ischaemic heart disease – 26
  • Lung cancer – 6
  • Stroke – 34

Outdoor air pollution-caused deaths (in percent):

  • Acute lower respiratory infections in children – 3
  • COPD – 11
  • Ischaemic heart disease – 40
  • Lung cancer – 6
  • Stroke – 40

(Source: “7 million premature deaths annually linked to air pollution,” news release, The World Health Organization, Mar. 25, 2014, http://www.who.int/mediacentre/news/releases/2014/air-pollution/en).

From the above data (statistics), while the incidence of early death seems higher with respect to the acute lower respiratory infections in children and COPD categories related to indoor air pollution, and a higher incidence of early death in regards to the ischaemic heart disease and stroke categories related to outdoor air pollution, the incidence of premature death as it has to do with lung cancer appears to be equal for air pollution that is both indoor- and outdoor-sourced.

“After analysing the risk factors and taking into account revisions in methodology, WHO estimates indoor air pollution was linked to 4.3 million deaths in 2012 in households cooking over coal, wood and biomass stoves,” the WHO notes.

Adds the WHO, “In the case of outdoor air pollution, WHO estimates there were 3.7 million deaths in 2012 from urban and rural sources worldwide.”

These numbers can be significantly reduced, but how?

Education can have a huge impact. And consensus-building on the importance of cleaning the air is needed.

In the area of energy production, a far greater reliance on renewable energy sources and far lower dependence on fossil fuel combustion should make a considerable difference as far as further cleansing the air is concerned.

Moreover, from transportation, less dependence on gasoline- and diesel-propelled motor vehicles with greater reliance on hybrid and zero-emissions vehicles (ZEV) should also go a longs ways in helping improve air quality.

For more related to indoor air pollution, see: “Indoor air pollution far more problematic than previously suspected” and “Airing (and sharing) some thoughts about indoor air quality.”

Out of a worldwide population of 7 billion people, 1.78 billion or 25.4 percent – roughly a quarter – are regularly exposed to air deemed poor and that globally attributable to unhealthful air, somewhere in the area of 7 million are dying early yearly, to me, this is just unacceptable.

We can and must do better!

Image above: NASA

– Alan Kandel