Air quality research areas

A range of evidence is developed and drawn upon to understand air quality impacts and the benefits of air policies and programs.

OEH operates an extensive network of accredited air quality monitoring stations to provide the government and community with accurate and up-to-date air quality data and information.

To supplement the stationary site network, OEH has established portable monitoring pods equipped with compliance air quality monitors and meteorological sensors. These pods can be quickly deployed to monitor air pollution from major incidents posing a risk to the health of NSW communities, and fitted with communication systems for rapid transfer of information to a publicly accessible website.

OEH investigates and deploys a range of advanced measurement methods and collaborates with policy and science partners on research sampling campaigns to help address knowledge gaps.

‘Black carbon’ is a major component of PM2.5 in urban areas and has received increasing attention internationally due to its effects on urban air quality, public health and global climate. These fine particles, directly emitted into the air during the incomplete combustion of fossil fuels, are being measured in a number of European, American and Asian urban environments. OEH is trialling the measurement of ‘black carbon’ using seven wavelength aethalometers in Sydney and the Lower Hunter.

OEH partners with the NSW EPA, NSW Health, CSIRO and the Australian Nuclear Science and Technology Organisation (ANSTO) to sample and study the chemical composition of airborne particles to help identify sources contributing to particle pollution as part of particle characterisation studies.

OEH is engaged in collaborative research with leading science partners and environment agencies in Victoria, South Australia and Queensland to investigate emerging air quality sensor technologies and assess the potential for integrating sensor networks into future air quality monitoring in NSW.

More information on air quality monitoring activities is provided in the Air Quality Monitoring in NSW background paper to the Clean Air Summit 2017 (PDF 279KB).

The goal of Clean Air for NSW (PDF 2.1MB) is to improve average air quality across NSW. Describing average air quality in NSW using one number is challenging because air pollution varies between regions and years.

The Clean Air Metric (PDF 192KB) or CAM was developed by OEH to account for population exposure when assessing changes to average air quality. It combines annual average, multi-pollutant assessments of air pollution levels similarly to the Air Quality Index, but also weights air pollution by population. Air quality data from OEH operated monitoring stations and population data from the Australian Bureau of Statistics are used to calculate the CAM.

OEH has to date calculated the metric for the NSW Greater Metropolitan Region and the Greater Sydney region, and is working to progressively expand the air quality data available to enhance the spatial resolution of air pollution data used for the metric and to calculate a metric for all of NSW.

The National Environment Protection (Ambient Air Quality) Measure requires jurisdictions to “evaluate and report population exposures to particles as PM2.5 annually from June 2018…in accordance with any procedures or methods agreed by participating jurisdictions”. Inter-jurisdictional work to develop a nationally consistent approach to evaluate and report population exposures to PM2.5 is underway. OEH will review the approach adopted to derive the NSW Clean Air Metric once a nationally consistent approach to evaluating population exposure to PM2.5 is agreed as part of the Air NEPM review process.

Since it is not possible to measure air pollution everywhere, air quality models are used to provide additional information on how air pollution levels vary across regions. Models are also useful for:

  • assessing how specific sources affect air quality
  • projecting future changes in air quality
  • evaluating the benefits of proposed clean air interventions to inform air policies and programs.

NSW Government has conducted photochemical ozone modelling for more than two decades. Initially this modelling focused on simulating ozone production on specific ozone episode days, such as was done as part of the Ozone State of Knowledge study.

Building on the modelling approach developed as part of the Sydney Particle Study, NSW Government has expanded its modelling capabilities to include the robust modelling of fine particles, including secondary particles formed in the air. Regional photochemical ozone modelling has been expanded to simulate seasons and years to investigate peak and average ozone levels.

The application of advanced regional meteorological and chemical transport modelling, such as is being implemented in the Sydney Air Quality Study, will substantially grow the evidence to guide NSW air policy.

Air quality forecasting of ozone, particles and other pollutants is done to provide accurate early warning of poor air quality days. OEH currently issues a daily air quality forecast for the Greater Sydney region, and the overall accuracy of forecasts show moderate skill.

A range of advanced tools and capabilities are being established by OEH to improve the accuracy of air quality forecasting, including empirical methods, statistical models and deterministic numerical modelling. This is being done under the Enhancing air quality forecasting in NSW program, in collaboration with other government agencies and leading science partners.

The Air Emissions Inventory for the Greater Metropolitan Region in NSW provides detailed information on natural and human-made sources of air emissions. The NSW Environment Protection Authority updates the inventory every five years. The inventory, for the 2008 calendar year, was published in 2012. The next update, for the 2013 calendar year, is due for release in 2017.

Air emissions from natural sources such as wind-blown dust, biogenic emissions from vegetation and sea salt emissions are influenced by the weather and are calculated dynamically during regional air quality modelling. OEH is collaborating with science partners to test and improve emission estimation schemes for natural sources to more accurately model background air quality, allowing cumulative air pollution concentrations and the influence of human emission sources on air quality to be more accurately assessed.

To model and forecast air quality when there are bushfires and hazard reduction burns, smoke emissions need to be modelled. An in-line bushfire/hazard reduction burn emissions module is being developed by OEH in collaboration with the NSW Rural Fire Service and CSIRO.

Research is also underway to support more dynamic modelling of major human sources of air emissions based on activity data coinciding with the period being investigated or modelled.

Particles can be made up of a range of chemical species depending on the source of the particle or precursor gases from which they form. Particle characterisation studies sample airborne particles, determine their chemical composition, and use statistical models to identify and estimate the contribution of source types to particle pollution.

Particle characterisation studies which have expanded the evidence base on the composition and sources of particle pollution in NSW include the Lower Hunter Particle Characterisation Study, the Upper Hunter Fine Particle Characterisation Study and the 15-year Sydney Particle Characterisation Study.

Bushfires occur across fire-prone vegetation types when high fuel loads, ignition sources and adverse weather inevitably coincide. Hazard reduction burning is widely used in Australia to reduce the severity of bush fires and minimise their potential impacts on life, property and the environment.

OEH forecasters model and assess the likelihood of poor air quality occurring due to bushfires and hazard reduction burns based on weather forecasts from the Bureau of Meteorology, and information on the location and extent of fires and planned burns from the NSW Rural Fire Service. NSW Health issues Air Pollution Alerts when advised by the OEH that poor air quality is forecast.

While committed to carrying out hazard reduction burning as a public safety tool, the NSW Government recognises the need to minimise the associated air quality impacts on NSW communities through continued improvements in smoke management practices.

OEH is collaborating with other agencies and science partners to investigate ways to better understand and manage smoke impacts from hazard reduction burning and wildfires in NSW.

More information can be found in Hazard Reduction Smoke (PDF 246KB) background paper for the Clean Air for NSW Summit 2017.

Even though air quality in NSW is good by international standards, air pollution continues to have a significant impact on human health and the economy of NSW.

The cost to health of ambient air pollution in the Greater Metropolitan Region of NSW - which includes Sydney, the Illawarra and lower Hunter  - was estimated in the Air Pollution Economics: Health costs in the Greater Sydney Metropolitan Region (PDF 212KB) study published in 2005. Research suggests that substantial health benefits are attainable with even modest reductions in air pollution.

Research into the air quality and related health effects and costs associated with air pollution is ongoing as part of the Sydney Air Quality Study. This study will also evaluate the air quality improvements and avoided health impacts and costs that may be achieved by reducing emissions from major sources such as motor vehicles, industry and residential wood heating.

Best practice studies and cost benefit studies are undertaken by the NSW EPA to investigate the feasibility and benefit of air pollution emission reduction measures. These studies integrate information on the health benefits and avoided health costs, and assess the overall gains to be made for the community.