Carbon monoxide is a colorless, odorless, tasteless, and potentially dangerous gas. It is a silent killer. Its presence is not known until symptoms of the exposure are experienced. You can\u2019t see it or smell it.\r\n\r\nA by-product of combustion\r\n\r\nIt is produced when combustion reactions are not fully completed, either through lack of oxygen or due to low mixing. It is liberated in the burning of any material.\r\n\r\nCommon household items, such as gas fires, oil-burning furnaces, portable generators, charcoal grills, among others, put people at risk of exposure to this poison gas.\r\n\r\nThe gas is very stable and has a life of 2 to 4 months in the atmosphere. It has been found to be a minor participant in photochemical reactions leading to ozone formation. Concentration in the atmosphere is generally less than 0.001%; however, when there is incomplete combustion of hydrocarbons, the ratio in the atmosphere increases. Such pollution is greater in the air of the urban environment.\r\n\r\nExhaust gases emitted from motor vehicles are the major deadly source of carbon monoxide. Leaving a car in a closed garage with its engine running can produce deadly amounts of carbon monoxide within 10 minutes.\r\n\r\nTobacco Smoke\r\n\r\nThe silent killer gas is one of the more toxic agents present in the gas phase of tobacco smoke. It is not added to tobacco but is formed when tobacco is burned incompletely. This happens when there is too little oxygen present to convert all of the carbon in the tobacco into harmless carbon dioxide. Cigarette smoke can contain large quantities of carbon monoxide.\r\n\r\nSidestream tobacco smoke and the smoke exhaled by active smokers are the most important components of second-hand smoke. Carbon monoxide is present in mainstream smoke which is directly inhaled by active smokers, at levels of 5 to 22 mg\/cigarette. It can also be found in sidestream smoke and is emitted into the atmosphere during puff breaks, on levels of 9 to 35 mg\/cigarette. Thus, second-hand smoke might be a significant source of exposure to passive smokers (people breathing air polluted with tobacco smoke) to carbon monoxide.\r\n\r\nWater pipes are also a major source of exposure to carbon monoxide. More than 90% of the carbon monoxide in water pipe vapors comes from the charcoal and coal used to heat the water pipe tobacco. Breathing carbon monoxide reduces the blood's ability to carry oxygen. Smoking can cause recurrent carbon monoxide poisoning and subsequent cognitive impairment.\r\n\r\nPaint Removers\r\n\r\nFumes from certain paint removers and cleaning fluids can cause carbon monoxide poisoning.\r\nThe vapor of methylene chloride, the component of thinners and other solvents, penetrates the skin, is inhaled through the lungs, and transported to the liver via blood circulation, where it is metabolized, resulting in the release of carbon monoxide.\r\n\r\nMethylene chloride is produced commercially in large volumes by direct chlorination of methane or methyl chloride. Methylene chloride is an important solvent in paint and varnish strippers and in degreasing agents. It is used in the production of photographic films, synthetic fibers, pharmaceuticals, adhesives, inks, and printed circuit boards. It is employed as a blowing agent for polyurethane foams and as a propellant for insecticides, air fresheners, and paints.\r\n\r\nProducts that contain methylene chloride (dichloromethane) should be handled with care because methylene chloride turns into carbon monoxide when it is breathed in. Methylene chloride is absorbed readily after inhalation and ingestion.\r\n\r\nEffects of Carbon Monoxide Poisoning\r\n\r\nCarbon monoxide poisoning is one of the most common types of poisoning causing death worldwide. It has been reported to be the most frequent cause of fatal poisoning.\r\n\r\nCarbon monoxide gas is readily absorbed and is unchanged by the lungs. After absorption, it largely (90%) binds to hemoglobin, and rarely (10%), to myoglobin ( an oxygen-binding protein located primarily in muscles and it has a structure similar to that of hemoglobin). Less than 1% is dissolved in plasma, and less than 1% of carbon monoxide is oxidized to carbon dioxide.\r\n\r\nCarbon monoxide can cause myocardial injury by binding to cardiac myoglobin. It binds to myoglobin with an affinity 60 times stronger than that of oxygen. Cardiac injury has been associated with hypoxia in human and animal studies, and it has been reported that neurological and perivascular injuries were hypoxic as a result of oxidative stress secondary to carbon monoxide exposure. Damage to the central nervous system as a result of hypoxia may lead to cardiovascular insufficiency, and the effect of high doses of carbon monoxide on smooth muscle may result in hypotension.\r\n\r\nCarbon monoxide binds to hemoglobin with higher affinity than oxygen with resultant development of tissue hypoxia. It prevents the delivery of oxygen to tissues via hemoglobin.\r\n\r\nBinding of carbon monoxide to hemoglobin does not explain all the effects seen in carbon monoxide poisoning. Carbon monoxide has a direct effect on causing tissue injury. It impairs the normal respiratory function of cells. It irreversibly binds to hemeproteins, which carry oxygen within the cell, resulting in cellular respiratory dysfunction.\r\n\r\nAs a consequence, there is mitochondrial deterioration in CNS and heart cells, which require a higher level of energy, cellular damage, and eventually tissue damage. It promotes the formation of oxygen free radicals, which may result in reversible tissue damages.\r\n\r\nSymptoms of Carbon Monoxide Poisoning\r\n\r\nFetus, infants, children, the elderly, patients with cardiovascular disease, anemia, pulmonary disease, and pregnant women are at higher risk in event of carbon monoxide poisoning compared with other patients. Although carbon monoxide poisoning is harmful to all systems, most frequently CNS and cardiovascular systems are affected.\r\n\r\nThe person may feel as if they have the flu but without a temperature. If several people in the same building have the same symptoms, they may have carbon monoxide poisoning. If this happens, all cooking and heating appliances should be switched off, all windows opened, and the local gas safety authorities notified.\r\n\r\nThe longer an individual is exposed to carbon monoxide, the more severe the symptoms will become. Within a few hours of first being exposed, a person may experience loss of balance, vision problems, memory problems and eventual loss of consciousness. If the symptoms are mild, there is a very chance of a full recovery.\r\n\r\nOther symptoms may occur later, even months after inhaling carbon monoxide gas. These include confusion, memory problems and coordination difficulties. Serious carbon monoxide gas poisoning can cause long-term problems, including heart damage. People with heart-related or breathing problems tend to be affected more quickly by carbon monoxide gas poisoning.\r\n\r\nThe hidden danger of carbon monoxide poisoning is headache, dizziness, irritability, confusion\/memory loss, disorientation, nausea and vomiting, abnormal reflexes and difficulty in coordinating.\r\n\r\nCarbon Monoxide Poisoning Prevention Tips\r\n\r\nBe aware of the dangers of carbon monoxide poisoning. Make sure all rooms are well ventilated and that vents are not blocked. Wear a mask when using products that contain methylene chloride.\r\n\r\nHave a qualified technician inspect your heating system, water heater and any other fuel-burning appliances every year. Don\u2019t use emergency generators in your garage or basement. Use charcoal grills and portable camp stoves only outdoors.\r\n\r\nHave your car\u2019s exhaust system checked each year. If your garage is attached to your home, don\u2019t leave a vehicle running there. Even with the garage door open, the fumes can seep inside the house.\r\nYou should immediately get out of the environment with a high carbon monoxide level. You should receive oxygen as quickly as possible.\r\n\r\nLook for carbon monoxide detectors. Buy alarms that are certified by a testing laboratory. Detectors should go on each level of the home and outside each sleeping area. Test the alarms once a month. Some alarms also give off audible signals on their own if the battery runs low or they break down.\r\n\r\nYou can protect yourself and your family from second-hand smoke by quitting smoking if you are not already a nonsmoker, not allowing anyone to smoke anywhere in or near your home and not allowing anyone to smoke in your car, even with the windows down. When a smoker stops smoking his carbon monoxide levels drop very quickly. In 24 to 48 hours his carbon monoxide levels go back to the level of a non-smoker.