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Air Quality Suffering in China
Residents
of Beijing and many other cities in China were warned to stay inside in
mid-January 2013 as the nation faced one of the worst periods of air
quality in recent history. The Chinese government ordered factories to
scale back emissions, while hospitals saw spikes of more than 20 to 30
percent in patients complaining of respiratory issues, according to news
reports.
At the time that this Jan. 14 image was taken by
satellite, ground-based sensors at the U.S. Embassy in Beijing reported
PM2.5 measurements of 291 micrograms per cubic meter of air. Fine,
airborne particulate matter (PM) that is smaller than 2.5 microns (about
one thirtieth the width of a human hair) is considered dangerous
because it is small enough to enter the passages of the human lungs.
Most PM2.5 aerosol particles come from the burning of fossil fuels and
biomass (wood fires and agricultural burning). The World Health
Organization considers PM2.5 to be safe when it is below 25.
Also at the time of the image, the air quality index (AQI) in Beijing
was 341. An AQI above 300 is considered hazardous to all humans, not
just those with heart or lung ailments. AQI below 50 is considered good.
On January 12, the peak of the current air crisis, AQI was 775 the U.S
Embassy Beijing Air Quality Monitor—off the U.S. Environmental
Protection Agency scale—and PM2.5 was 886 micrograms per cubic meter.
› View image comparisons with annotations. Image Credit: NASA/Terra - MODIS
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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