Where Does Carbon Monoxide (CO) Come From?

CO is Produced when:

Carbonaceous materials are burned with insufficient oxygen. Its lethal effects have been known for centuries; in ancient Rome, "coal gas" was used for executions and suicides.

Man-made sources of CO include:

• Incomplete fuel combustion used in transport -
• Automobile/Truck exhaust
• Airplane exhaust
• Smoking of cigarettes, cigars, pipes, etc.
• Defective heating (furnace, water heater) systems
• Defective cooking appliances
• Industrial plant exhausts
• Burning of solid waste
• Detonation of explosives

Natural sources of CO also exist but they contribute very little to the overall atmospheric CO level.

Geophysical

• Marsh gases
• Forest fires
• Volcanic gases
• Natural gases in coal mines
• Photo-dissociation of CO in upper atmosphere
• Formation of CO during electrical storms

Biological

• Endogenous CO production by land animals
• From vegetation during seed germination
• From marine brown algae or kelp
• Marine hydrozoans: e.g. jellyfish