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
Small engine dimensions and power output, relative to larger automobile engines. Power output ranges from less than 1 to about 15 horsepower. The smallest of all are used in handheld garden machinery, such as string trimmers and chainsaws, which may be as small as piston displacement. The most common are four-stroke air-cooled single-cylinder engines running on either petrol or diesel. Engines for small machinery that must be hand-carried, such as string trimmers and chainsaws, are usually a two-stroke design, which is lighter for any given power output. However, two-stroke engines create a relatively large amount of air pollution and noise pollution, and