PM10 daily concentrations

  • Image, PM10 daily concentrations.

    2018 air indicators are now available

    Particulate matter 10 micrometres or less in diameter (PM10) in the air comprises solid particles and liquid droplets from both natural and human-made sources. The main sources are burning wood or coal for home heating, and sea spray. PM10 is of particular concern because it is found in high concentrations in some areas. It can damage health and is associated with effects ranging from respiratory irritation to some forms of cancer.

    We classified PM10 daily concentrations as a case study.

    Key findings

    The number of airsheds with PM10 concentrations exceeding the national short-term (daily) standard on two or more days peaked in 2009 (26 airsheds) and dropped to 21 in 2013.

    • Of 37 airsheds monitored in 2013, 21 (57 percent) exceeded the national daily standard, with:
      • 12 exceeding the daily PM10 standard on 2–10 days
      • 6 exceeding it on 11–20 days
      • 2 exceeding it on 21–50 days
      • 1 exceeding it on more than 50 days.
    • The majority of these exceedances (96 percent) occurred in the colder months (May–August). This can be attributed to greater emissions from burning wood or coal for home heating and more settled weather conditions (slowing the dispersal of pollutants) during these months.
    • Of these 21 airsheds, 14 are in the South Island and 7 are in the North Island.

    Figure 1

    Note: PM10 – particulate matter 10 micrometres or less in diameter. Data from regional councils of Northland, Bay of Plenty, Waikato, Hawke’s Bay, Manawatu-Wanganui, Wellington, Canterbury, West Coast, Otago, Southland; district councils of Marlborough and Tasman; Nelson City Council; Auckland Council.

    Figure 2

    Map, PM10 exceedances in airsheds, 2013.

    Note: Results at these monitoring sites do not necessarily represent the whole location. PM10 – particulate matter 10 micrometres or less in diameter. Data from regional councils of Northland, Bay of Plenty, Waikato, Hawke’s Bay, Manawatu-Wanganui, Wellington, Canterbury, West Coast, Otago, Southland; district councils of Marlborough and Tasman; Nelson City Council; Auckland Council.

    Figure 3

    PM10 exceedances in airsheds, 2006–13 – interactive map

    Definition and methodology

    Particulate matter 10 micrometres or less in diameter (PM10) can be emitted from the combustion of fuels, such as wood and coal (eg from home heating and industry), and petrol and diesel (from vehicles). Natural sources of PM10 include sea salt, dust, pollen, smoke (from bush fires), and volcanic ash. It is also formed from reactions between gases or between gases and other particles.

    The four main human-made sources of key pollutants in New Zealand are burning wood or coal for home heating, road motor vehicle use, industry, and household outdoor burning.

    See Relative contribution of key human-made emissions for more details on emission rates for each source.

    This case study assesses the number of airsheds where daily PM10 concentrations exceed the National Environmental Standards for Air Quality short-term (daily) standard on two or more days. Exceedances occur when daily concentrations are above 50 micrograms per cubic metre (µg/m3). An airshed is a designated area that may or does have unacceptable levels of pollutants, requiring air-quality management.

    The national standard provides a set level of protection against health risks from exposure to PM10. It does not provide complete protection as there is no threshold concentration below which health effects do not occur.

    Some of the monitoring locations are expected to have high concentrations of PM10 (eg sites where home-heating emissions accumulate or are close to high-volume road traffic).

    Data quality

    We classified PM10 daily concentrations as a case study.

    Relevance

     This case study is a partial measure of the ‘Airborne particles of concern to human health’ topic.

    Accuracy

     The accuracy of the data source is of high quality.

    See Data quality information for more detail.

    Supporting information

    Seasonality of PM10 exceedances 

     

    Updated 17 December 2015

Top
  • Share this page
  • Share this page to Facebook
  • Share this page to Twitter
  • Share this page to Google+