Pollution Free Cities: Global Satellite Mapping of Particulates Over Long Term

Tuesday, October 5, 2010

Global Satellite Mapping of Particulates Over Long Term

Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application (9 page pdf, Environ Health Perspect 118:847–855, 16 March 2010)

Also discussed here: New Map Offers a Global View of Health-Sapping Air Pollution (Science Daily, Sept. 23, 2010)

The first estimates of long term air quality, based on satellite measurements, for many cities in the world is the result of scientists who published the article under review today. Even for those cities such as Ottawa whose air quality has been monitored by satellite for short term pilot projects, as described in this paper in 2009 Mapping Small Scale Air Pollution Distribution Using Satellite Observations in a Large Canadian City. These data are useful in comparing comparative population exposures– which shows that over 80% of the world’s population breathes air that exceeds the WHO criteria of 10 ugm/km3 (annual average).

Key Quotes:

“In addition to using satellite data from NASA's Multi-angle Imaging SpectroRadiometer (MISR) ..and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument .. the researchers used output from a chemical transport model called GEOS-Chem to create the new map”

“Their map, which shows the average PM2.5 results between 2001 and 2006.. the first PM2.5 satellite estimates in a number of developing countries that have had no estimates of air pollution levels until now”

“more than 80 percent of the world's population breathe polluted air that exceeds the World Health Organization's recommended level of 10 micrograms per cubic meter. Levels of PM2.5 are comparatively low in the United States, though noticeable pockets are clearly visible over urban areas in the Midwest and East”

“Human-generated particles often predominate in urban air -- what most people actually breathe -- and these particles trouble medical experts the most.. smaller PM2.5 particles evade the body defenses -- small hair-like structures in the respiratory tract called cilia and hairs in our noses -- that do a reasonably good job of clearing or filtering out the larger particles”

“in the United States alone, PM2.5 air pollution spark some 60,000 deaths a year”

"We still have some work to do in order to realize the full potential of satellite measurements of air pollution.. But this is an important step forward"