Carbon monoxide, or CO, is a poisonous gas and one of many harmful chemicals found in cigarette smoke. In low quantities, carbon monoxide is harmless and a normal part of the air around us, but in higher quantities it is toxic to humans and other animals.
Cigarette smoke contains large amounts of carbon monoxide which is inhaled directly into the lungs and enters the bloodstream. CO reduces our blood’s ability to carry oxygen around the body and large amounts of carbon monoxide in the blood causes carbon monoxide poisoning.
Carbon monoxide poisoning has flu like symptoms and in the most extreme cases can lead to loss of consciousness or death.
What is Carbon Monoxide?
Carbon monoxide, or CO, is a poisonous gas produced by burning carbon fuels like wood or the gas used in stoves and central heating. Cigarette smoke contains particularly high levels of carbon monoxide. CO molecules contain one carbon and one oxygen atom and the gas is odourless and colourless, which is why it can go undetected as it builds up to dangerous levels.
There is a small amount of carbon monoxide in the air around us from car exhausts and other sources. CO only becomes harmful in concentrations above 35 ppm, or 35 parts per million. As the amount of CO in the air increases, the amount of harm it does increases too, leading to carbon monoxide poisoning and even death.
Carbon Monoxide Poisoning
Carbon monoxide Poisoning occurs when the level of carbon monoxide in the blood reaches high enough levels to have immediate, noticeable effects on the body. Carbon monoxide poisoning is what happens if you stay in a closed garage with a car running or if you have a gas leak from a faulty stove.
Every year dozens of people in the UK die of carbon monoxide poisoning and it is the most common form of fatal gas poisoning in many countries.
Carbon monoxide is sometimes known as the silent killer because it can go unnoticed in the air around us and build up to lethal levels without us realising. We have carbon monoxide sensors in our homes to detect the presence of this poisonous gas. CO can come from many sources, like gas stoves, wood burning furnaces, cigarette smoke and heating systems.
Most smokers won’t experience carbon monoxide poisoning, but it is possible for heavier smokers to reach dangerous levels of CO in their bloodstream. While many smokers won’t face this immediate risk, there still have to deal with the consequences of long term damage caused by carbon monoxide.
As carbon monoxide is breathed into the lungs and then enters the bloodstream it attaches to the hemoglobin to form carboxyhemoglobin, or COHb. Hemoglobin in our blood is used to carry oxygen around the body, but when carbon monoxide bonds with the hemoglobin it takes us the space where oxygen would normally be carried. So, the more CO in our bloodstream the less oxygen we receive.
While carbon monoxide is quickly absorbed into the bloodstream it is much slower to expel. It takes time for the body to slowly remove CO from the blood, which is why heavy smokers are most at risk of poisoning.
Carbon monoxide poisoning can cause flu like symptoms including dizziness, headaches, chest pain, fatigue, vomiting and disorientation. These symptoms are often overlooked or dismissed in most confirmed cases of carbon monoxide poisoning. More serious exposure to CO leads to neurological problems and loss of consciousness as well as seizures and even death.
Carbon Monoxide In The Bloodstream
The level of carbon monoxide attached to hemoglobin, known as COHb, in non-smokers is usually less than 1% as a result of CO in the air around us. In smokers the levels of COHb are much higher, usually between 3% and 10% depending on cigarette usage. In some extreme cases smokers have had COHb levels of more than 20%.
Increased heart rate can start with a COHb level of above 1% and the symptoms tend to get worse as the amount of carbon monoxide in the blood gets higher.
Treatment for Carbon Monoxide Poisoning
After being diagnosed, usually through a blood test, treatment of carbon monoxide poisoning is relatively straightforward. 100% oxygen is given until the level of COHb in the bloodstream has dropped back to below 10%. Although this treatment helps restore the levels of carbon monoxide in the blood to a healthier level, it doesn’t repair damage to the heart and central nervous system caused by carbon monoxide.
Longterm Exposure to Carbon Monoxide
While very heavy smokers are the most at risk of carbon monoxide poisoning, all smokers face health problem from this poisonous gas. The amount of CO in the blood of smokers is more than double that of non smokers, and can be more than ten times higher in heavy smokers.
The human body can handle some carbon monoxide, but even exposure to CO levels a little above normal can cause serious damage over time with higher levels causing damage faster. Long term exposure to carbon monoxide can damage the heart and nervous system as well as leading to brain damage and neurological symptoms like trouble concentrating, depression and emotional difficulties.
As carbon monoxide in the blood reduces the amount of oxygen available, it forces the heart to work harder to supply oxygen to the body. This means that carbon monoxide contributes to heart disease and can result in heart attacks.
Smokers are most at risk from this long term exposure as they have elevated levels of carbon monoxide from cigarette smoke. But CO is one of the many things that makes second hand smoke harmful, meaning people around smokers also risk health problems because of this poisonous gas.
Carbon monoxide is just one of the harmful chemicals found in cigarette smoke but its dangers are worth remembering, especially if you are a heavy smoker. Smoking can greatly increase the amount of CO in the bloodstream, leading to heart disease, fatigue and flu like symptoms as well as long term problems, loss of consciousness and even death in the most extreme cases.