The entrepreneurs making money out of thin air

Whether enveloped by the thick smog from factories or choked with invisible poisons from vehicle exhausts, many cities around the world are losing the battle against air pollution. Somewhere between 5.5 million and seven million people die from breathing in the smoke, harmful gases and soot being pumped into the atmosphere.

 

BBC - Capital - The entrepreneurs mak_ - http___www.bbc.com_capital_story_2