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Particle levels in air

Photograph of a smoking chimney

Why we monitor particle levels in air

Waikato Regional Council measures the amount of PM10,the portion of the particulate matter in the air less than 10 microns in diameter. These particles are very fine and can remain suspended in the atmosphere for long periods of time.

Health effects associated with exposure to particles range from increased coughs and respiratory complaints to premature mortality. Susceptible people include the young and elderly and those with pre-existing medical conditions.

What's happening?

In our region, PM10 levels are good or acceptable for most of the year. For a few days each year levels approach (alert) or go above (action) the National Environmental Standard and Regional guidelines. This happens mostly in winter, during cold, calm periods.

During winter, the majority of PM10 in the region's urban areas comes from home fires, mainly from burning wood. Other sources such as industry and emissions from motor vehicles can contribute to air pollution.

In 2005 the Government set National Environmental Standards (NES) for air quality including a standard for PM10 of 50 µg/m3 for a 24-hour average.   It allows one day per year when concentrations can be greater than 50 µg/m3.

In 2011 the NES was amended, and as a result all urban airsheds except for Tokoroa must meet the target of no more than one exceedance per year by 1 September 2016.

Tokoroa is required to achieve a target of no more than three exceedances per year by 1 September 2016 and no more than one exceedance per year by 1 September 2020.

The Regional Plan Air Module also sets the regional guideline for PM10 at 50 µg/m3 for a 24 hour period. We separate PM10 levels into categories relative to the NES and regional guideline.

>>Find out more about these data and trends


More information

More detail on this indicator, including how and where Waikato Regional Council collects this information, is available in the Methods page. More information is also available in our Air publications.

Useful links

When this indicator is updated

This indicator is updated every two years.

Contact at the Waikato Regional Council

Air Quality scientist  - Science and Strategy Directorate

Last updated May 2019