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Contaminants from home heating

Wood is a popular fuel for home heating in the Waikato. But wood fires can produce large amounts of contaminants that affect our air quality. These include:

  • smoke - made up of fine particles (PM10)
  • combustion gases - such as carbon dioxide, carbon monoxide, nitrogen dioxide
  • other contaminants - such as benzene.

Contaminants from home heating are generally more of a problem in winter when wood burners and open fires tend to be used. This happens especially in inland towns, such as Tokoroa and Te Kuiti where frequent calm conditions and inversion layers mean the smoke stays around. 

View the video clip below for more information about home fires and how they affect you and the region's air quality:



Smoke consists of very small particles (PM10) that are less than 10 microns across - a fifth of the size of a human hair. These particles can get into our lungs causing health problems, especially for people with asthma, small children and the elderly.

Smoke can also reduce visibility and make it unpleasant to be outside at certain times of the day.

The particles in smoke are unburnt and partially burnt fuel so the key to reducing smoke is to burn the fuel more completely.

Carbon dioxide and carbon monoxide

Burning fuel normally gives off carbon dioxide (CO2) when there is plenty of oxygen present. The carbon (C) comes from the fuel and the oxygen (O2) comes from the air. But, when there’s not enough oxygen present only one oxygen molecule binds with a carbon – forming carbon monoxide (CO).

Carbon dioxide is a greenhouse gas. Increases in carbon dioxide in the atmosphere are likely to be responsible for global warming which may cause climate change.

Carbon monoxide is a poisonous gas. It attaches to our red blood cells better than oxygen - reducing the blood’s ability to carry oxygen around the body. Low exposure to carbon monoxide causes in headaches, dizziness and nausea.

Nitrogen dioxide

Solid-fuel burners (for example, wood burners) are a source of nitrogen oxide (NO). Nitrogen oxide oxidises (oxygen is added) to form nitrogen dioxide (NO2). Nitrogen dioxide affects people’s health by aggravating asthma and decreasing their lung’s ability to fight infection.