Particulate matter (PM) is a collective term used to describe very small solid or liquid particles in the air, such as dust, smoke or fog.
Most PM10 in New Zealand comes from burning solid fuels (ie, coal and wood) for home heating. This, along with the more frequent settled weather conditions during winter, is why most peak PM10 levels occur during this time of year. Exhaust emissions from vehicles are another significant source of PM10 in cities like Auckland.
Industry, as well as natural sources such as pollen, mineral dust and sea salt, can also contribute to PM10 levels.

This section reports on the daily levels of particulate matter in the 43 monitored airsheds in New Zealand. It does so by comparing daily PM10 levels to the national environmental standard which sets an acceptable daily level of 50 μg/m3. Reporting peak daily levels of PM10 provides an important short-term snapshot of air quality in an airshed. It allows us to understand the intensity of air pollution to which people are being exposed.
This section reports on how many times the national standard is exceeded over a year in the 43 monitored airsheds in New Zealand. Monitoring this allows us to understand how frequently people are being exposed to poor air quality.
This section reports on the average annual level of particulate matter compared to the New Zealand guideline, a health-based guideline which sets an acceptable annual level for PM10 of 20 μg/m3. Annual averages take into account both peak and low pollution periods in an airshed, giving an important long-term picture of air quality.
Human exposure to air pollution can create health risks that may lead or contribute to various health conditions. The Health and Air Pollution in New Zealand report discusses these effects in detail and provides information on air pollution in 67 areas around New Zealand.
This summarises air quality information for airsheds throughout New Zealand. This information is provided by regional and unitary authorities and will be updated approximately every year.
Information on the limitations of the air quality indicator.
Last updated: November 2009