Dr. Shyam P. Lohani

Every winter, Nepal records about a hundred deaths from accidental carbon monoxide (CO) poisoning. Most of those cases are preventable. Everyone is at risk of carbon monoxide poisoning. However, people who are at a higher risk include infants, the elderly, and those with chronic heart disease, anemia, or breathing problems. Those deaths are unintentional as CO poisoning not linked to fires. Few thousands visit the emergency rooms, and about 1,000 are hospitalised.
Once carbon monoxide is breathed in, it enters our bloodstream and mixes with hemoglobin which is a part of red blood cells that carry oxygen around our body to form carboxyhemoglobin. Then, the blood becomes unable to carry oxygen, and this lack of oxygen causes the body's cells and tissue to suffocate and die. CO is found in fumes produced when fuel is incompletely burned in small engines, stoves, lanterns, grills, fireplaces, gas appliances, or furnaces. Carbon monoxide gas can build up indoors and people may be poisoned.

Common symptoms
Headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion are the most common symptoms following CO exposure. CO symptoms are often described as flu-like. Breathing in a lot of CO can be fatal. Usually, people who are sleeping or drunk can die from CO poisoning before they experience any symptoms.
The symptoms of carbon monoxide poisoning are not always apparent, particularly during low-level exposure. The most common symptom of mild carbon monoxide poisoning is tension-type headache. Other symptoms include dizziness, feeling and being sick, tiredness and confusion, stomach pain, shortness of breath, and difficulty in breathing. But, it is here important to note that the symptoms of exposure to low levels of carbon monoxide can be similar to those of food poisoning and flu. However, carbon monoxide poisoning does not cause a high temperature like in case of flu.
Exposure to high levels of carbon monoxide gas can cause more severe symptoms. These may include impaired mental state and personality changes, the feeling that the environment around you is spinning (vertigo), loss of physical coordination and nervous system (ataxia), breathlessness, and a heart rate of more than 100 beats per minute (tachycardia), chest pain caused by angina or a heart attack, muscle spasms (seizures), loss of consciousness in cases of exposure to very high levels of carbon monoxide, and death may occur within minutes.
The longer we are exposed to the gas, the worse our symptoms will be. This may result in loss of balance, vision, and memory and, eventually, loss consciousness. However, this depends on the concentration of carbon monoxide in the air. Long-term exposure to low levels of carbon monoxide is dangerous that can also lead to neurological symptoms such as difficulty in thinking or concentrating, repeated emotional changes such as easy irritation, depression, or making impulsive or irrational decisions.
The symptoms can gradually get worse with prolonged exposure to carbon monoxide, leading to a delay and/or confusion in diagnosis. These symptoms may be less severe when we are away from the source of the carbon monoxide production. If this is the case, the possibility of a carbon monoxide leak should be promptly investigated and consult suitably qualified professional to check any appliances that may be faulty and leaking gas.
The most common causes of accidental exposure to carbon monoxide include incorrectly installed, poorly maintained or poorly ventilated household appliances, such as cookers, heaters, and central heating boilers. Other possible sources of carbon monoxide poisoning include blocked chimneys which can stop carbon monoxide exhaust leading to reach dangerous levels of CO, burning fuel in an enclosed or poorly ventilated space such as keeping a car engine on, petrol-powered generator, or barbecue inside a garage, or a faulty boiler in an enclosed kitchen or water heater in bathrooms.

Prevention
There are a few important preventive measures to avoid carbon monoxide poisoning during the winter season. First, it is suggested to install a carbon monoxide alarm in your home to alert when there is carbon monoxide leakage. However, an alarm is not an alternative to maintaining and regularly servicing household appliances that are in use.
Awareness is the key to know the dangers and thus, people to be aware of identifying any appliances in the house that could potentially cause carbon monoxide leakage. Maintaining and servicing appliances such as boilers, cookers, heating systems, and appliances should be installed properly and regularly serviced by a reputable, registered engineer. It is suggested not to attempt to install or service appliances.
Following the safety tips may help protect yourself at home and in the workplace. Ovens or gas ranges should not be used to heat your home. The use of oversized pots on your gas stove or place foil around the burners should be avoided. It is important to have rooms that are well ventilated and not block air circulation.
If the house that is double glazed or draught proofed, it is advised to allow enough air circulation for any heaters that are in the room. People are urged to avoid the use of gas-powered equipment and tools inside the room and use them only in a well-ventilated area. Wearing a safety mask is recommended when using chemicals that contain methylene chloride to protect us from possible CO poisoning.
Lastly, it is suggested not to burn charcoal in an enclosed space, such as in an indoor barbecue. People are advised not to sleep in a room that has a gas fire or kerosene heater in it, and install an exhaust fan in the kitchen if it does not already have one.

(A Professor, Lohani is the founder and academic director at Nobel College. lohanis@gmail.com)