1 Summary

This report contains the 2009 annual ambient air quality data set, measured from Auckland and Christchurch. In the past, this data set formed New Zealand’s contribution to the Global Environmental Monitoring System (GEMS) run by the World Health Organization (WHO). The WHO stopped aggregating international air quality information from GEMS in 2006.

The GEMS monitoring sites were established to measure key air pollutants associated with adverse effects on people’s health and well-being. The GEMS sites have provided monitoring data for Auckland and Christchurch, and have recorded trends in pollution levels in two of New Zealand’s largest cities.

The Gavin Street, Penrose site in Auckland is representative of primarily vehicle and industrial emissions. The Greers Road, Burnside site in Christchurch is located within a residential area and represents emissions primarily from domestic properties.

Air pollutants arise from a number of different sources. The pollutants monitored at the GEMS sites include:

  • particulate matter (PM10) – principally from domestic heating, vehicle emissions and industrial processes (as well as natural processes)
  • nitrogen oxides (NO and NO2) – mostly from motor vehicle emissions
  • sulphur dioxide (SO2) – from the burning of fossil fuels, particularly coal and oil
  • carbon monoxide (CO) – from incomplete combustion of carbon containing fuels, especially from motor vehicles
  • total suspended particulates (TSP) – from various chemical and physical processes including all particulates less than 100 μm in aerodynamic diameter
  • volatile organic compounds (VOCs) – organic chemicals, such as hydrocarbons, that are closely tied to vehicle emissions and many industrial processes
  • lead (Pb) – historically from petrol but since the removal of lead in petrol from 1996, levels have declined in New Zealand.

Ambient air quality standards for CO, NO2, SO2, PM10 and ozone were promulgated in October 2004. The purpose of these standards is to provide a guaranteed level of protection for the health of all New Zealanders.1 These standards are based largely on the ambient air quality guidelines (AAQG) developed in 1994 and revised in 2002. Guideline levels for pollutants (and averaging periods) not covered by the standards still apply.

At Gavin Street, Penrose there were two exceedences of the national environmental standards (NES) for air quality. There was one exceedence of the 1-hour NO2 standard due to local construction work and one exceedence of the 24-hour PM10 standard caused by an Australian dust storm.

The Greers Road, Burnside site exceeded the 24-hour standard for PM10 on nine occasions. Of these nine exceedences, one exceedence was caused by Australian dust in September 2009 and eight exceedences occurred during the colder months from June to July 2009, most likely due to home heating emissions.

The NES for air quality allows for one exceedence of the PM10 24-hour threshold per year before the standard is breached, meaning the Greers Road, Burnside site breached the PM10 standard on eight occasions. All other air pollutants monitored at both sites were below the NES as well as the ambient air quality guidelines (AAQG) for all averaging periods.

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1 Ministry for the Environment. 2005. Updated Users Guide to Resource Management (National Environmental Standards Relating to Certain Air Pollutants, Dioxins and Other Toxics) Regulations 2004. Wellington: Ministry for the Environment.