writes "This story should remind all of us that air pollution controls are not just about addressing global warming. They also help us have cleaner air and fewer health problems resulting from smog and haze. Starting earlier this month, Beijing, China started having worse than normal air pollution issues. On Jan 14, 2013 the US Embassy's air pollution sensors in Beijing found the density of the most dangerous small air particles, PM 2.5, at 291 micrograms per cubic meter of air. The world Health Organization's guidelines for air pollution state that PM 2.5 above 25 micrograms per cubic meter of air is dangerous to a person's health.
To put the problem into perspective for anyone not living in Cloud City..... I mean Beijing, NASA has released two orbital photos of Beijing showing a before and during photo of the air pollution. The photo from Jan 4 shows parts of the Beijing still visible from space. The photo from Jan 14 shows nothing but a huge, thick cloud of haze with no buildings visible."Link to Original Source