Carbon monoxide is a gas produced in the incomplete combustion (burning) of fossil fuels and other carbon-rich materials, for example, gas, gasoline, diesel, liquefied petroleum gas, charcoal, wood, among others. Is toxic by inhalation ; It mixes with the air and therefore accumulates in closed spaces ; The harmful effects of its inhalation can occur quickly and be fatal; Its colorless and odorless characteristics, makes it difficult to identify its presence and facilitates intoxication. There can be high concentrations in the air and the gases can be inhaled without being aware of it. What are the possible sources of carbon monoxide in the home? Among the human activities that may be associated with the production of carbon monoxide are several domestic activities that use equipment that runs on various fuels. The production and accumulation of carbon monoxide in the environment occurs when: Equipment is not well installed; Its state of conservation is deficient; Exhaustion is not done correctly; Use is not done properly. Among these devices are, for example: Gas water heaters and boilers; Gas stoves and ovens; Wood-fired ovens; Heating, fireplaces, braziers and other heating systems using gas, wood, or other fuels. Closed garages are also a common place for the potential accumulation of carbon monoxide when motor vehicles or other fuel-powered equipment are working inside. Incorrectly used or malfunctioning outdoor equipment can also be a source of carbon monoxide, for example: Portable or camping gas stoves; Gas or charcoal barbecues. Who can get carbon monoxide poisoning and how does it happen? Anyone who is exposed to high concentrations of carbon monoxide has a significant chance of inhaling it and suffering poisoning, which can be fatal. The risk is even greater in children and the elderly, as well as in people with anemia, respiratory or cardiovascular diseases, or who at the time of exposure are practicing an activity that requires physical effort (and therefore greater respiratory effort). When inhaled, carbon monoxide binds to hemoglobin in the blood at sites normally occupied by oxygen, forming carboxyhemoglobin. For this binding, carbon monoxide competes with oxygen with a 200-250 times higher affinity for binding sites. Thus, when there is inhalation of carbon monoxide, the amount of hemoglobin available to transport oxygen in the body decreases and the organs and tissues no longer receive enough oxygen for their functioning , leading to the appearance of symptoms. Symptoms of carbon monoxide poisoning The symptoms and severity of poisoning depend on the amount of carboxyhemoglobin formed in the blood and this is directly related to: The exposure time; The amount of gas that is inhaled. The first symptoms related to carbon monoxide inhalation are: Tiredness and drowsiness; Dizziness; Headache; Difficulty concentrating; Difficulty coordinating movements. These symptoms can, however, occur in many other situations. So: The danger is not associating them with the possibility of inhalation / intoxication and continuing to breathe carbon monoxide air. When these symptoms occur, it must therefore be ensured that there is no risk of carbon monoxide inhalation. If exposure to carbon monoxide is intermittent and air concentrations are not very high, symptoms may come and go: They get worse when you are at the exhibition site; Disappear when you go out, especially if you go outside. When you are in a place where there is a sudden accumulation and rapid exposure to high concentrations of carbon monoxide , the symptoms mentioned may be associated with: Feeling of confusion; Nausea and vomiting; Loss of consciousness (fainting); If the exposure continues, convulsions, heart and respiratory rate decrease, blood pressure decrease and eventually death may happen if the person is not rescued. Treatment The first measures to be adopted in case of suspected inhalation / carbon monoxide poisoning are: Open doors and windows so that fresh air enters in the place as much as possible; Turn off the equipment that is the source of the emission or, in case of doubt, all combustion equipment (eg water heater, gas boilers, gas heaters, fireplace, etc.); Leave the site / evacuate affected people who are unable to do so themselves. In an emergency, in Portugal, dial 112. If there is a minor inhalation, breathing fresh air may be enough to resolve the symptoms. In cases that require hospital medical care , these include treatment with very high concentrations of oxygen among other interventions. Tests are often performed to confirm intoxication, such as the determination of carboxyhemoglobin in the blood through arterial blood gas analysis. Although the majority of non-fatal cases of carbon monoxide poisoning are completely reversible, in severe poisoning up to 40% of patients may experience memory difficulties, mental disorders and difficulty coordinating movements in the following weeks. Preventing carbon monoxide inhalation / poisoning From small routine habits to strict compliance with good practices with household appliances and equipment that use fuel, there are many measures that help prevent carbon monoxide poisoning. Ensure good ventilation of the house and be aware of the signs of ventilation problems . For example: Renew the air, open the windows and air the house daily; Always try to have a window in the house slightly open, especially if you are using an open fireplace; Keep chimneys and exhaust ducts unobstructed and clean; Excessive moisture and condensation on windows and walls are signs of poor ventilation. Do not leave vehicles working in a closed garage; Ensure correct installation of fuel-powered equipment and regular maintenance. For example: Do not install or use the equipment in confined and poorly ventilated spaces. There is specific legislation on the places where this equipment is installed at home; Carry out the planned periodic inspections and the replacement of materials as necessary. Only use the equipment for its intended purpose and in accordance with the manufacturer's instructions. For example: Do not use charcoal grills, portable gas stoves or outdoor gas heaters indoors or in other enclosed spaces; Do not use equipment that burns charcoal indoors; Do not use the oven and gas cooking stove to heat the room. Know the warning signs of equipment malfunction . For example: Changes in the flame color (which must be blue and turns orange or yellow) of the equipment in which it is visible, such as stoves, water heaters, gas heating, among others; Presence of soot on the burners of a gas stove, next to equipment or under a chimney; Presence of rust in pipes. Consider, if necessary, the use of home carbon monoxide detection devices for use in rooms in the home where fuel-powered equipment is located. Redouble your attention and care during the colder seasons , when fireplaces and other heaters are used more and there is a tendency to air less homes. Be attentive and follow good practices Being aware of small signs, knowing symptoms and not devaluing is fundamental. There can be a build up of carbon monoxide at a location when, for example: There is a headache that improves when you go outside; There are several people and animals in the same place that are not well; Problems appear or worsen when equipment is working (a water heater, a fireplace, for example). If you need it, call LUZ 24 – 217 104 424 – we are available 24 hours, 365 days, to help. LUZ 24 must not be used in an emergency. In Portugal 112 is the emergency number to be used. Author : Betânia Ferreira The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
