PAH are air pollutants generated by combustion sources such as motor vehicles, coal - fired power plants, residential heating and tobacco smoke. (sciencedaily.com)
Discovery of an inexpensive anode «For Integrated steelmaking, the primary sources of GHG emissions are blast furnace stoves (43 percent), miscellaneous combustion sources burning natural gas and process gases (30 percent), other process units (15 percent) and indirect emissions from electricity usage (12 percent),» the report said, estimating that the U.S. steel industry produced 117 million tons of carbon dioxide in 2010. (scientificamerican.com)
So, either way you look at it, switching to combustion sources of light rather the filament sources makes some primal sense. (marksdailyapple.com)