Okay, I tried, but there is just no way to make carbon monoxide interesting. Read it anyway, because it’s good for you: you need to know this stuff. Like eating your vegetables. Every one of us encounters carbon monoxide on an almost daily basis, because it is ubiquitous and sneaky. We need to know where it comes from, how to avoid it, the symptoms it causes, and what to do if we or our children are exposed.
Carbon monoxide (CO: one carbon, one oxygen) is a colorless, odorless, tasteless, and initially nonirritating gas produced largely by partial oxygenation of carbon based fuels. Complete oxygenation would produce carbon dioxide (CO2), which we exhale every time we breathe. Plants use that to make us more oxygen.
CO can accumulate in poorly ventilated, enclosed areas. When we breathe in large amounts, the CO binds with the hemoglobin in our blood and forms carboxyhemoglobin. Carboxyhemoglobin circulates through our bloodstreams like the regular stuff, but it does not like to release its oxygen to our brains, hearts, muscles, and organs. We suffocate while still breathing the air around us.
Aristotle, who lived around 300 BC, was the first person to note that coal fumes led to “a heavy head and death.” In ancient times, it was one way criminals were killed: they were locked in a small room with smoldering coals.
It is thought that CO is to blame for some haunted houses: its accumulation can cause hallucinations, disorientation, and delirium.
Oddly, a little CO can be a good thing: it is an anti-inflammatory, encourages growth of nerves and blood vessels, communicates between nerves, and may have some function in long term memory. Very little. Don’t go looking for it.
Statistics on CO poisoning vary significantly with who’s reporting them. It is considered to be the leading cause of poisoning injury and death worldwide. Poison help lines in the US report about 15,000 calls a year, with an estimated 70 deaths. Approximately 40,000 people seek medical care for exposures, and CO accounts for around 15,000 ER visits each year. The CDC estimates more than 500 deaths per year overall in the US, with the largest percentage being in the under 5 age group. More poisonings occur in the winter (gas heaters) and after disasters (generators).
CO is created by burning carbon-based fuels (wood, gasoline, diesel, propane, kerosene, lamp oil), by smoking (tobacco is a carbon based fuel), and by exposure to methylene chloride (degreasers, solvents, paint removers). Don’t smoke (so many reasons), and use degreasers, solvents and paint removers only in well-ventilated areas. Appliances that can produce CO need to be maintained, inspected annually, and well ventilated. Some of the most common ones are:
- Forced air furnaces
- Wood stoves/fireplaces (open that flume!)
- Space heaters (non-electric)
- Gas water heaters
- Gas stoves
- Gas dryers
- Anything with a pilot light
- Barbecues, Hibachis
- Automobiles (never run them in an enclosed space!)
- Fuel powered tools (if you put gas in it, don’t use it indoors)
- Boats (don’t use those indoors either)
Symptoms of acute (not chronic) CO poisoning include effects on the brain (dizziness, headache, confusion, lethargy, drowsiness, irritability, irrational behavior), lungs (shortness of breath) and heart (palpitations, paleness). If exposure continues, loss of consciousness and death will follow.
Chronic exposure to lower levels of CO can result in headaches, depression, confusion, memory loss, nausea, and permanent neurologic damage.
Pregnant women, fetuses, and children are especially sensitive. As with most poisonings, children’s small bodies are more sensitive, their higher metabolic rate brings it into their bodies more quickly, and they don’t have the ability to escape.
People with lung, blood, or heart disease, like asthma or anemia, are also more susceptible.
Of note is that CO damage from methylene chloride can last twice as long as that from burning carbon based fuels, because it is stored in our tissues.
Overall, it is a good idea to prevent any exposure to CO. Maintain and inspect those appliances, and make sure they are vented. Open the flume when you have a fire in the winter. Never barbecue or use a hibachi indoors. Throw out the cigarettes, because people who smoke have levels of CO in their blood streams several times higher than non-smokers. Perhaps most important, since you can’t smell this stuff, install CO detectors near every area where people sleep. Many newer fire alarms contain CO detectors, making this even more convenient.
If you are exposed, go outside into clean air. If you are having any symptoms (light-headedness, shortness of breath, seeing ghosts…) seek medical attention. They will give you oxygen and monitor your heart and brain.
Yay! You made it through, even the dreaded chemistry. Not as bad as you thought, right? Knowledge rules!