CARBON MONOXIDE - AN INSIDEOUS POISON I
by David G. Penney, Ph.D.
People are now becoming aware of the dangers of carbon monoxide (CO) poisoning. It can cause sickness, permanent health damage, and indeed death. My late father George, a Royal Oak Fire Captain, who during his career carried many gassed people out of houses, warned me as boy about the dangers of fumes containing CO.
CO is a colorless, odorless, tasteless and non-irritating gas. For these reasons it cannot be detected by us. Add into the equation the fact that it has the same density as air, means it neither rises nor falls. All of this makes it a very insideous poison.
CO results from the incomplete combustion of any material containing carbon - paper, tobacco, wood, charcoal, gasoline, whatever. On the other hand, when these fuels are burned completely with oxygen, little CO results, just carbon dioxide and water.
The symptoms of low level CO poisoning are multitudinous, but several are commonly reported - headache, drowsiness, nausea. A big problem is that these conditions also have other causes - eyestrain, stress, lack of sleep, flu, etc. Weakness, difficulty breathing, reddish nail beds, skin and lips, and unconsciousness occur at higher CO levels.
The mechanism of CO's effects on the body are due to the fact that it combines with the hemoglobin in blood, the substance that carries oxygen to the organs and tissues. It renders hemoglobin incapable of doing this. The cells essentially suffocate and shortly begin to die. The brain and heart are the organs most at risk, especially the brain.
The advent of home CO detectors now allows everyone to constantly guard against CO poisoning. While they are wonderful safety devices, like home smoke detectors were when they came out more than 20 years ago, they've had their problems. Some models repeatedly sounded at CO levels considered safe, causing folks to ignore or disconnect them. Choose your CO detector carefully.
Various groups and agencies have attempted to define the upper limits of safe CO exposure. The author has assisted the Environmental Protection Agency and the World Health Organization in doing this. EPA currently says this limit for outside air is 35 parts per million (ppm) continuing for one hour, or 9 ppm continuing for 8 hours. For work environments, upper limits have variously been set at 25-50 ppm.
When a person has inhaled CO on one occasion for a short time, we call that an acute exposure. Normal treatment consists of immediate removal from the source of the gas, and rapid transport to a clinic or hospital. The patient is started breathing 100% oxygen, and if the poisoning is deemed severe, he/she is placed in a hyperbaric oxygen chamber. This treatment forces the CO out of the blood even faster than 100% oxygen.
People most at risk from the deleterious effects of CO poisoning are pregnant women and those with coronary heart disease.
If you suspect that you a victim of CO poisoning, you should immediately call the fire or police departments for help. At the hospital, elevated levels of CO in your blood is proof positive.
For additional information on this poison, use the internet to access Carbon Monoxide Headquarters on the World Wide Web, at http://www.phypc.med.wayne.edu. It is one of the foremost sites in cyberspace on CO for both the layman and medical professional.
Mirror Article of October 9, 1997
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