Carbon monoxide of carbon dioxide by electromagnetic radiation of wavelengths shorter than 169 nm. Due to its long lifetime in the mid-troposphere, carbon monoxide is also used as tracer of transport for pollutant plumes. Carbon monoxide is a temporary atmospheric pollutant in some urban areas, chiefly from the exhaust of internal combustion engines (including vehicles, portable and back-up generators, lawn mowers, power washers, etc.), but also from incomplete combustion of various other fuels (including wood, coal, charcoal, oil, paraffin, propane, natural gas, and trash). Large CO pollution events can be observed from space over cities. Carbon monoxide is, along with aldehydes, part
Xenon the lungs. There is, however, a danger associated with any heavy gas in large quantities: it may sit invisibly in a container, and a person who enters an area filled with an odorless, colorless gas may be asphyxiated without warning. Xenon is rarely used in large enough quantities for this to be a concern, though the potential for danger exists any time a tank or container of xenon is kept in an unventilated space. Xenon Xenon is a chemical element with symbol Xe and atomic number 54. It is a colorless, dense, odorless noble gas found in the Earth's atmosphere