Carbon Monoxide

Carbon monoxide is an odorless, tasteless, colorless, and poisonous gas. Although most of the carbon monoxide in the atmosphere comes from natural sources, a great deal is also added by the burning of fossil fuels by automobiles and industry. It is an extremely poisonous gas if inhaled, since it kills by preventing oxygen from reaching the cells.

Carbon monoxide (CO) is a compound consisting of one carbon atom (the smallest unit of an element) and one oxygen atom. It is normally in the air people breathe, although in extremely small amounts. It is produced naturally when a substance that contains carbon decays or breaks down in the absence of oxygen. This happens in swamps where there is little oxygen. Carbon monoxide is also produced in greater quantity when carbon-containing substances are burned without enough oxygen being present. This often happens when gas furnaces, wood stoves, and space heaters malfunction or are not properly vented. Automobile engines and other gasoline or diesel-powered motors also generate carbon monoxide. The exhaust from these motors can be deadly if they are operated in enclosed areas or attached garages.

Carbon monoxide can kill a person who breathes it. It does this by preventing the blood from being able to carry oxygen. Without oxygen, people and animals soon die. Once inhaled, carbon monoxide combines with the hemoglobin (the oxygen-carrying substance in the blood) to the exclusion of oxygen. In fact, carbon monoxide combines with hemoglobin two hundred times faster than oxygen does. Additionally, the hemoglobin does not release the carbon monoxide as it does the oxygen. Thus, as more and more red blood cells pick up carbon monoxide, the total number available to deliver oxygen to the cells keeps decreasing, and soon the person slowly falls into a sleeplike state. Deprived of oxygen, the brain begins to slow its functions. Eventually, bodily functions stop, and the person dies.

This oxygen deprivation does not always kill immediately. Low-level exposure can cause flu-like symptoms including shortness of breath, mild headaches, fatigue, and nausea. Higher levels may cause dizziness, severe headaches, mental confusion, and fainting. Prolonged exposure can cause death. According to the U. S. Consumer Product Safety Commission, more than 2,500 people will die and 100,000 will be seriously injured by carbon monoxide poisoning over the next 10 years.

People who smoke also run the risk of harming themselves with this toxic gas. The carbon monoxide present in cigarette smoke not only excludes oxygen from binding to hemoglobin, but it also prevents it from picking up carbon dioxide (which is the waste product of breathing). This means that the person's heart has to pump harder to try and rid the body of carbon dioxide wastes.

Large cities had an especially bad problem in the past as unhealthy amounts of carbon monoxide would build up during rush hour because of automobile exhaust. Newer cars are now equipped with catalytic converters that chemically change carbon monoxide into harmless carbon dioxide. Also, in the last decade or so, carbon monoxide detectors for the

home have become practical, and many cities are now requiring that at least one carbon monoxide detector be installed in every home, apartment, and hotel. Since carbon monoxide is odorless, tasteless, and colorless, these monitors are invaluable in alerting people to possible exposure.

[See alsoCarbon Family ]