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Ozone levels in air

Photograph of a smoking chimney

Why we monitor ozone levels in air

Waikato Regional Council measures the amount of ozone in the air we breathe in Hamilton.

Ozone in the lower atmosphere is an air pollutant that can impact on our health. Ozone in the air is primarily formed through reactions involving nitrogen dioxide (NO2), volatile organic compounds (VOC) and oxygen, which occur in the presence of sunlight. The main sources of NO2 and VOC are:

  • motor-vehicle emissions and other combustion sources
  • industrial and domestic use of solvents and coatings.
  • Waikato Regional Council measures the hourly average levels of ozone in the surrounding air at a site in Hamilton.

What's happening?

Most of the time, ozone concentrations in Hamilton are excellent or good. Only around 10 per cent of the ozone levels measured over an eight-hour period and 2 per cent of the levels measured over a one-hour period have been higher than a third of the regional guideline.

The levels have not exceeded two-thirds of the regional guideline.

The proposed Waikato Regional Plan Air Module sets the proposed regional guideline for ozone at:

  • 150 µg/m3 for a one hour period
  • 100 µg/m3 for an eight hour period.

We separate ozone levels into categories relative to the regional guideline.

>>Find out more about these data and trends


More information

Useful links

Contact at Waikato Regional Council

Air quality scientist - Science and Strategy Directorate

Last updated 13 February 2009