Carbon Monoxide

Carbon monoxide is a colorless, odorless, and poisonous gas that occurs from both human and natural sources.

Carbon monoxide is the byproduct of unburnt fossil fuels. Some examples of human-made sources of the pollutant are motor vehicles, industrial processes, residential furnaces, and fireplaces. These sources are responsible for high concentrations found in urban areas, which can contain 100 times more carbon monoxide than any other pollutant.

Naturally, carbon monoxide is the result of oxidation of methane, plant growth and decay, wildfires, and other natural processes.

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