this is mind-blowing: smog not only chokes your lungs, but also teems up with bacteria that adversely affect human health. This was found by us meteorologist Forrest Mims, who works independently. He measured levels of airborne bacteria in Alta Floresta, Brazil, by taking air samples at different times of the day.

Mims compared his results with information on atmospheric conditions (especially smog) provided by us-based National Aeronautical and Space Administration's Earth Probe toms satellite. This satellite measures the levels of different wavelengths of light coming off the Earth.

Mims specifically tracked smog, as its particles of soot and dust scatter ultraviolet (uv) radiation. If less uv than expected is coming off a certain area of the Earth, it's probably because there's a cloud of smog in the way. Mims found that levels of atmospheric bacteria were significantly higher during smoggy times. But for some species of plant bacteria that are resistant to uv light, smog had no affect. This provided evidence for a long-standing hypothesis of Mims