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Sources of nitrogen oxides in air

Why we monitor sources of nitrogen oxides

This indicator estimates the proportion of nitrogen oxides in the air coming from industry, motor vehicles and domestic heating in the Waikato Region. Motor vehicles are the main source of nitrogen oxides in Hamilton, Tokoroa, Taupo Te Kuiti, Matamata, Putaruru, Ngaruawahia and Turangi. Industry is the main contributor to nitrogen oxide levels in Te Awamutu and Waihi.

Photograph of motor vehicles driving along a city street

Nitrogen oxides can affect people’s health by causing respiratory problems and our environment by contributing to ozone loss and greenhouse gases. Waikato Regional Council estimates the amount of nitrogen oxides being produced by motor vehicles, industry and home heating to determine where measured levels of nitrogen oxides are coming from. We need to know where the nitrogen oxides in our air come from, so that we can reduce existing sources of pollution and predict any future problems that may arise. For example, we can use this information to predict how changes in home heating methods and fuels in one part of the Region are likely to affect local air quality.

What's happening?

The main sources of air pollution in the Waikato region are motor vehicles, home heating and industry.

Waikato Regional Council monitors air pollution from motor vehicles, home heating and industry in:

  • Hamilton
  • Tokoroa
  • Taupo
  • Te Kuiti
  • Putaruru
  • Matamata
  • Waihi
  • Te Awamutu
  • Ngaruawahia
  • Turangi

We usually monitor air pollution in winter, as levels of air pollution are usually highest during this season. We estimate where nitrogen oxides in air come from and how much is coming from each of the three main sources. This information helps us to identify potential impacts on air quality in different parts of the Region and changes in air quality over time.

Nitrogen oxides in the air include nitrogen dioxide (NO2), nitric oxide (NO), and nitrous oxide (N2O). They can affect people’s health and the environment.

More information

Useful links


When this indicator is updated

This indicator will be updated every three to five years as new emission inventory data becomes available.

Contact at Waikato Regional Council 

Air quality scientist - Science and Strategy Directorate.

Last updated 16 December 2008