Carbon monoxide, or CO, is a toxic gas that is invisible and odorless. Breathing high levels of CO can cause severe illness or death in a matter of minutes. All people and animals are at risk for CO poisoning. Certain individuals, such as unborn babies, infants, and people with chronic heart disease, anemia, or respiratory problems, are more susceptible to its effects. Every year thousands of people across the U.S. seek medical care for non-fatal CO poisoning. Survivors of severe poisoning may suffer long-term neurological problems.
Even though unintentional CO poisoning can almost always be prevented, more than 400 Americans die every year as a result of it. Furthermore, the New Hampshire Carbon Monoxide Working group reports that several deaths occur in the State every year due to carbon monoxide poisoning caused by malfunctioning or improperly used fuel-burning furnaces, stoves, or appliances.
Breathing carbon monoxide can cause headache, dizziness, and nausea. If CO levels are high enough, loss of consciousness or sudden death may occur. For an explanation of how CO poisoning happens, visit the Centers for Disease Control and Prevention website.
Exposure and Risk
Exposure to moderate and high levels of CO over extended periods of time has also been linked with an increased risk of cardiovascular disease (CVD).
The health effects of long -term exposure to low levels of CO are less well understood. Better tracking of CO poisoning and exposure may provide opportunities to learn about the effects of low-dose exposures.
CO is given off whenever fuel or other materials are burned. People may be exposed to unsafe levels of CO as the result of:
- Using poorly maintained or unvented heating equipment
- “Warming up” vehicles in garages or other enclosed spaces
- Using a gas stove or oven to heat the home
- Clogged chimneys or blocked heating exhaust vents
- Running generators or gas-powered tools in enclosed areas or near windows, doors, or vents
- Using a propane camp stove, heater, or light inside a tent or home
- Activities near boat engine exhaust outlets
Reduce Your Risk
DO have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.
DO install a battery-powered CO detector (or electric-powered device with battery back-up) in your home, near the furnace and all sleeping areas. Replace the batteries when you change the time on your clocks each spring and fall, the same as for smoke detectors. If the alarm sounds, leave your home immediately and then call 9-1-1.
DO seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed, or nauseous.
DO NOT use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage, near a window, or under a tent.
DO NOT run a car or truck inside a garage attached to your house, even if you leave the door open.
DO NOT burn anything in a stove or fireplace which is not vented, or may be clogged.
DO NOT use a gas cooking range or oven to heat your home [1].
Tracking Carbon Monoxide Poisoning
The New Hampshire Environmental Public Health Tracking (EPHT) Program tracks carbon monoxide poisoning hospitalizations caused by exposures to carbon monoxide gas produced by combustion sources. Data about carbon monoxide poisoning in New Hampshire are available in Environmental Health Data Integration Network (EHDIN).
References
1. Centers for Disease Control and Prevention website, Prevention Guidelines.
To Learn More About Carbon Monoxide

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