Some usual and unusual poisonings due to carbon monoxide.

Carbon monoxide poisoning is a frequent occurrence in both developed and under developed countries of the world. Carbon monoxide can be produced in fires, automobile engine exhausts and the incomplete combustion of organic matter. It is a "silent killer" that initially produces a mild progressive frontal headache, drowsiness and sleep that is usually ignored as common place. Continued low-level CO exposure for a long period of time in a confined space is cumulative and these accidental deaths are frequent but should be avoidable. Several usual and unusual poisonings are reported to illustrate its various forms of exposure. It all began many years ago when a bolt of lightening hit a fallen tree and produced a fire. Early cave man later learned to enjoy some of the benefits of this new discovery. They could now see at night, they could keep warm, keep the predators at bay, cook their food and make it taste better and be more gentle to their teeth. Also meat could be preserved and eaten at a later date especially if it were dried and smoked. They learned by trial and error that it was dangerous to bring their fire deep into their cave without a chimney. Carbon monoxide (CO) also can be easily produced by many other sources besides fire. Very common today is the incomplete combustion of gasoline in the engine of an automobile which can produce about 6% carbon monoxide.