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Air Quality

Good air quality is central to human health and the health of our environment.  New Zealand has relatively good air quality, however at certain times of the year some areas have undesirable levels of air pollution.  This topic presents the results of regional air quality monitoring, why it is important, and tips for how we can help improve the quality of the air we breathe.

The National Picture tab provides an overview of air quality monitoring in New Zealand.  Desktop and tablet users can view air quality results for different indicators on the interactive map.

Click on the Regions tab to find information about air quality at towns in each region.  Here you can discover the causes of local air pollution and explore current and historical results from monitoring sites.

UPDATE 21 June 2023: We've simplified the way we report air quality, with air quality indicators compared to existing national standards (NES-AQ) and updated international guidelines (WHO 2021).  

 

Select an indicator:

  • Annual PM10
  • PM10 Yesterday
  • PM10 exceedances (2023)
  • PM10 exceedances (2024)
  • Annual PM2.5
  • PM2.5 Yesterday
  • PM2.5 exceedances (2023)
  • PM2.5 exceedances (2024)

The most recent data shown on the LAWA map and in graphs may not have been validated by councils. Please interpret these data with care and check with the responsible regional council or unitary authority if you have questions. Air quality data on LAWA are compared to New Zealand's National Environmental Standards for Air Quality (NES-AQ) and World Health Organization (WHO) 2021 air quality guidelines. Amendments to the NES-AQ, which inform reporting requirements are pending. 

LAWA Air Quality - National Picture 2023

 

Published: 26 June 2023*

Why air quality is important

Breathing good quality air is fundamental to our well-being. The health impacts of polluted air are wide-ranging with the elderly, young people, and vulnerable groups being most at-risk. Good air quality is also important for ecosystem health (e.g. dust on vegetation can impact the ability to photosynthesize).

Air quality context in New Zealand

New Zealand has relatively good air quality due to its low population density and island geography.  Over the last 15 to 20 years the air pollutant of most concern in many parts of New Zealand has been particulate matter (PM) from burning wood and coal, and these concentrations have been reducing. The World Health Organization guidelines updated in late 2021 and the Health and Air Pollution in New Zealand report released in 2022 show health impacts from motor vehicle emissions (nitrogen dioxide) are more significant than previously thought.

What is monitored and shown on LAWA?

To help safeguard air quality in New Zealand, outdoor air is monitored for key air pollutants by regional councils and unitary authorities.  Long-term monitoring sites are used to track levels of air pollutants generated from different activities (e.g. residential, industrial, traffic).

LAWA shows air quality information from around 60 active and 85 historical monitoring sites at towns and cities throughout the 16 regions in New Zealand.  Monitoring locations are focused in areas that are known, or suspected, to have poor air quality.  As such the data on LAWA are not intended to be representative of overall air quality in New Zealand, and are used to inform our understanding of air quality and identify the main contributors to poor air quality at local levels. 

Most monitoring sites measure particulate matter (PM), which are airborne particles that are both naturally occurring (e.g. windblown dust, pollen and sea salt) and produced by human activities (e.g. burning of fuels). The size of PM plays an important role in how PM impacts on our health. Coarse and fine sized particles less than 10 micrometres (µm) in diameter (measured as PM10) can enter our airways.  The fine sized particles under 2.5 µm (PM2.5) can go further and lodge deep into our lungs with the ultrafine particles (less than 0.1 um) entering the bloodstream.

Gas pollutants, including sulphur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3) and benzene are monitored by some councils, mainly city sites in New Zealand where traffic and industry are often the main sources.

Air quality data are reported against standards and guidelines. The two main standards and guidelines used on LAWA are:

  • National Environmental Standards for Air Quality (NES-AQ) – these are regulations set in 2004 under the Resource Management Act, and are legally binding to set a minimum level of health protection for people in New Zealand.
  • World Health Organization (WHO) 2021 guidelines – these newer guidelines are informed by recent scientific understanding on health impacts from air pollution, and are non-regulatory.

 

Particulate matter - current state

In parts of the country, many people are exposed to relatively high levels of PM in winter produced by wood and coal burning for home heating.  In these areas the levels of PM can exceed national air quality standards or guidelines.  This is usually associated with colder winter days and nights when there is no wind to disperse the PM.

PM10 is the most monitored air quality indicator.  It tells us about the particulate matter in the air from both the coarser size particles (ranging from 2.5 – 10 µm in size) through to the smaller fine particles (PM2.5, with a diameter of 2.5 µm or less).  PM2.5 are generated by combustion (e.g. burning wood, coal and diesel) and are likely to be more harmful to our health.  The ability to measure specifically for PM2.5 enables us to understand more about which areas pose a higher health risk compared to when measuring PM10 alone.  At sites that monitor for both PM10 and PM2.5, results show that PM2.5 concentrations frequently make up a large proportion of the PM10 concentrations, when combustion sources are present.

During 2022, the National Environmental Standard (NES-AQ) for daily average PM10 concentrations were met at 42 (70%) of 60 monitored sites, and not met at 18 (30%) of monitored sites.

PM2.5 was monitored at 32 sites with only five sites meeting the new daily and annual average non-regulatory WHO guidelines during 2022.

The towns where the most PM10 and PM2.5 exceedances occurred in 2022 were Arrowtown, Waimate, Timaru, Geraldine, Ashburton, Christchurch, Kaiapoi, Rangiora, Blenheim, Richmond, Nelson, Masterton, Taihape, Hastings, Taupo, Gisborne, Te Kuiti, Tokoroa, Rotorua and Hamilton.

When a PM10 exceedance occurs, councils publicly notify this and work towards improving the air quality.

Note:  The World Health Organization (WHO 2021) guidelines shown on LAWA from 21 June 2023 are more stringent than the previously reported WHO 2005 guidelines.  As a consequence, there are more PM2.5 exceedances than previously reported.   While many councils monitor and report on PM2.5, it is not a current requirement in New Zealand.  The Ministry for the Environment is considering, as part of resource management reforms, how best to include PM2.5 in New Zealand’s outdoor air quality regulations. We expect, in time, PM2.5 will be monitored at more sites, and these sites displayed on LAWA.

 

How has air quality (particulate matter) changed over time?

Most monitored towns and cities are showing signs of improved air quality over the last ten years (2013 - 2022).  Of the 44 monitoring sites where a 10-year trend could be determined, 29 (or 66%) show improving air quality, one (or 2%) show worsening air quality, and 14 (or 32%) have indeterminate trends for particulate matter (PM10).  A further 10 towns or cities did not have enough data to determine a trend.  This can happen if monitoring started after 2013 or there were changes to the monitoring instruments over this time.  

Of the 18 monitoring sites that breached the national standards (NES-AQ) for PM10 in 2022, nine sites (or 50%) have had improving air quality and one site had declining air quality over the last 10 years.  The remaining eight sites did not have enough data to determine a trend.

 

Gas pollutants

Gas pollutants are monitored at mainly city sites in New Zealand where traffic and industry are often the main sources. The levels of gas pollutants typically meet the national standard (NES-AQ), and continued monitoring of these sources of air pollution provide useful information on trends.  However, levels of nitrogen dioxide (NO2) are typically highest, and do not meet the new WHO guidelines, in the larger city sites close to busy transport corridors. Results of monitoring nitrogen dioxide can be found at sites in Auckland, Wellington, Masterton, Christchurch and Hamilton. Waka Kotahi has an extensive monitoring network on highways around New Zealand and more information can be found here.

 

Air quality monitoring and reporting

Monitoring data help scientists and decision-makers evaluate the current state of air quality, identify the main contributors to poor air quality, and how air quality is changing over time.  This informs the policies and actions required to improve air quality to benefit people's health and wellbeing.

Explore more on LAWA

Click on the Regions tab to explore the summary information for each region, and then the Towns tab to find out about the main contributors of air pollutants, and how air quality changes over the seasons.  Monitoring site information can be accessed either by clicking on a site dot on the map to the left of the LAWA main screen (desktop and tablet users), or by navigating menus to the region, then town, and then site of interest.  The organisation responsible for monitoring an individual site can provide further contextual information to the results shown here.

National environmental reporting on air quality

The Ministry for the Environment and Stats NZ provide a national picture of the environment in regular reports produced under the Environmental Reporting Act 2015.  Our air 2021 was published on 10 December 2021.

Our air 2021: final release

Stats NZ collect information to publish insights and data about New Zealand, including environmental indicators of air quality.

Stats NZ: Air indicators

The HAPINZ 3.0 report was released by Ministry for the Environment, Ministry of Health, Ministry of Transport, and Waka Kotahi (NZ Transport Agency) on 6 July 2022. HAPINZ 3.0 is the latest update of this report series and assesses the air pollution health impacts experienced by New Zealanders for 2016.

A significant finding was that of the more than 3,300 deaths associated with anthropogenic air pollution, more than 60% were associated with nitrogen dioxide (NO2) pollution – largely from motor vehicles, while the other 40% were associated with fine particulate (PM2.5) pollution – largely from home wood burning. The report acknowledged the overall improvements in particulate matter concentrations and the increase in regional and unitary council monitoring of PM since the previous HAPINZ 2.0 report.

HAPINZ 3.0 report

 

What can I do?

We all have a role to play in the quality of our air:

  • Use clean heating
  • Burn smokefree
  • Reduce outdoor burning
  • Reduce transport emissions
  • Report pollution to your local council

 

*update to version published 21 June 2023