ENVIRONMENT AND HEALTH

Environment And Health



Environment And Health

Sources Of Carbon Monoxide In The Home

Carbon monoxide (CO) is an invisible, odourless, colourless gas created when fossil fuels (such as gasoline, wood, coal, propane, oil and methane) burn incompletely. In the home, heating and cooking equipment are possible sources of carbon monoxide. Vehicles running in an attached garage could also produce dangerous levels of carbon monoxide. (Evans 2006: 2520-2531)

However, consumers can protect themselves against CO poisoning by maintaining, using, and venting heating and cooking equipment and by being cautious when using vehicles in attached garages.

Pollution and atmospheric conditions in some areas cause low levels of CO to be present for long periods of time. In fact, these "background" conditions may increase the COHb level to over 10%, causing CO detectors to alarm even though conditions inside the home are not truly hazardous. Treat all CO detector alarms as real, until it has been verified that there is no threat from equipment inside the dwelling.

Household carbon monoxide detectors measure how much CO has accumulated. Currently, CO detectors sound an alarm when the concentration of CO in the air corresponds to 10% carboxyhemoglobin level in the blood. Since 10% COHb is at the very low end of CO poisoning, the alarm may sound before people feel particularly sick. The best defences against CO poisoning are safe use of vehicles (particularly in attached garages) and proper installation, use and maintenance of household cooking and heating equipment. You may also want to install CO detectors inside your home to provide early warning of accumulating carbon monoxide. However, a CO detector is no substitute for safe use and maintenance of heating and cooking equipment. (Singer 2009: 90)

In general, CO is produced when any material burns. More is produced when there isn't enough oxygen for efficient burning. Common sources of CO in homes include fuel-burning devices such as: furnaces, gas or kerosene space heaters, boilers, gas cooking stoves, water heaters, clothes dryers, fireplaces, charcoal grills, wood stoves, lawn mowers, power generators, camp stoves, motor vehicles and some power tools with internal combustion engines. Smoking is another common source of CO that can negatively impact indoor air quality.

Ideally, CO concentrations indoors are expected to be the same as CO concentrations outdoors. In the Minneapolis/St. Paul area, CO concentration in the outdoor air ranges from 0.03-2.5 parts per million parts (ppm). This is averaged over an 8-hour period. These averages are below the federal standard of 9 ppm for CO in outdoor air. In general, concentrations are lower in rural areas and higher in urban areas. Finding CO concentrations higher indoors than outdoors indicates an indoor source of CO, or a source very close to your home.

Unvented kerosene and gas space heaters; leaking chimneys and furnaces; back-drafting from furnaces, gas water heaters, wood stoves, and fireplaces; gas stoves; generators and other gasoline powered equipment; automobile exhaust from attached garages; and tobacco smoke.  Incomplete oxidation during combustion in gas ranges and unvented gas or kerosene heaters may cause high concentrations of ...