08 June 2009

Nitrogen dioxide (NO2)

Indoor gases produced from combustion of fuels for heating and cooking may be harmful, especially to children's lungs and developing brains. NO2 is one such toxin.

Indoor gases produced from combustion of fuels for heating and cooking may be harmful, especially to children's lungs and developing brains. Nitrogen dioxide (NO2) is one such toxin.

Gas space heaters and other appliances in the home can be dangerous if they are old or faulty. This is not so much because of the gas they contain, but because when this gas burns to produce heat, then the gaseous byproducts of combustion may be toxic.

In addition to the most dangerous gas that may be produced (carbon monoxide), researchers now think that exposure to nitrogen dioxide (NO2), another byproduct of combustion, is bad for children.

What is NO2?
NO2 is one of the gases produced when fuels are burned; the main indoor sources are from kerosene heaters, gas stoves and heaters that don't have a vent to the outdoors, and tobacco smoke.

It is a common component of outdoor air pollution and is also produced by welding.

How does exposure affect health?
NO2 is a toxic gas known to cause irritation to the mucous membranes (eyes, nose and throat). Low-level NO2 exposure may worsen asthma and chronic obstructive pulmonary disease, and increase the risk for respiratory infections, especially in young children.

New research suggests that indoor exposure to NO2 may also affect children's neurological systems and have subtly negative effects on their cognitive development.

Extremely high-dose exposure to NO2, as may happen to people breathing in smoke from a building fire, may result in pulmonary oedema (fluid in the lungs) and other serious injury to the lungs. Ongoing exposure to high NO2 levels can contribute to the development of bronchitis and chronic obstructive pulmonary disease.

How to reduce exposure

  • Keep gas appliances properly adjusted according to manufacturer's instructions.
  • Consider a vented space heater when replacing an un-vented one.
  • Use proper fuel in kerosene space heaters.
  • Install and use an exhaust fan vented to outdoors over gas stoves.
  • Open flues when fireplaces are in use.
  • Make certain that doors on all wood stoves fit tightly.
  • Have central heating systems, including all furnaces, flues and chimneys professionally inspected and cleaned at least once a year - and more often if you notice and damage or leakage.
  • Do not allow the car's engine to idle while still inside the garage.
  • Don't allow smoking in your home, and stay away from smokey and polluted environments - this is especially important for children.

(- Health24, June 2009)

Information sources:
Environmental Protection Agency. September 2008. Care for your air: a guide to indoor air quality. EPA official web site.


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