In many developing countries, the absence of surface-based air pollution sensors makes it difficult, and in some cases impossible, to get even a rough estimate of the abundance of a subcategory of airborne particles that epidemiologists suspect contributes to millions of premature deaths each year. The problematic particles, called fine particulate matter (PM2.5), are 2.5 micrometers or less in diameter, about a tenth the fraction of human hair. These small particles can get past the body’s normal defenses and penetrate deep into the lungs.Even satellite measurements are difficult (clouds, snow, sand, elevation, etc.). But not impossible:
However, the view got a bit clearer this summer with the publication of the first long-term global map of PM2.5 in a recent issue of Environmental Health Perspectives. Canadian researchers Aaron van Donkelaar and Randall Martin at Dalhousie University, Halifax, Nova Scotia, Canada, created the map by blending total-column aerosol amount measurements from two NASA satellite instruments with information about the vertical distribution of aerosols from a computer model.
What can be done with this data?
Maybe compare different cities and countries for pollution reputation and health effects, which will probably reinforce that reputation.
Now, with this map and dataset in hand, epidemiologists can start to look more closely at how long term exposure to particulate matter in rarely studied parts of the world — such as Asia's fast-growing cities or areas in North Africa with quantities of dust in the air — affect human health. The new information could even be useful in parts of the United States or Western Europe where surface monitors, still the gold standard for measuring air quality, are sparse.Hm, that could have "social consequences", and not just in China. In the U.S., if people knew how much more polluted areas near coal or biomass plants were, new plants would less likely to be built, and switching over to nonpolluting renewable energy could go faster.