CAUL Hub Project 1 – Western Air-Shed and Particulate Study for Sydney (WASPSS)

Project Leader: Dr Clare Murphy (Paton-Walsh), University of Wollongong

Project Summary

The negative health impacts of airborne particulates on urban populations are now well established. Whilst the air quality in Australian cities is generally very good compared to many other parts of the world, Sydney experiences occasional poor air quality events that expose the population to heightened health risks.

The Western Air-Shed and Particulate Study for Sydney (WASPSS) project will contribute to the understanding of poor air-quality events within Western Sydney, by conducting targeted measurement campaigns which can supplement information from on-going air quality monitoring stations, to address specific knowledge gaps. This will provide the tools and evidence to develop a Clean Air Plan for Western Sydney that will enable policy makers to estimate the benefits of different mitigation strategies to the future air quality in Western Sydney. These tools will be applicable more broadly to other cities.

See here for a project update.


Research activities will be focussed around three main research aims each with their own subproject:

  1. Extend air quality measurement/monitoring capacity to support improved characterisation of air quality in Western Sydney.
  2. Implement and validate state-of-the-science regional air quality modelling to assess major sources contributing to air pollution in Western Sydney and assess benefits arising from a range of possible mitigation measures.
  3. Evaluate existing methods applied internationally and locally for estimating human exposure to airborne pollutants, in order to estimate air pollution related exposures and health effects for Western Sydney.

Subproject 1: Extending air quality measurement/monitoring capacity

In this project we will significantly develop our measurement capacity in collaboration with our research partners OEH, CSIRO and ANSTO. We will extend the measurements available to evaluate air quality and test our air quality models via a number of complementary research activities outlined below.

Activity 1a: Targeted Air Quality Measurements/Monitoring in Western Sydney

Radon measurements will improve our modelling of the meteorological conditions most likely to accompany poor air quality and help us evaluate local sources and their trapping in the atmosphere.

Activity 1b: Kilometre Scale Measurements for validating model simulations

To provide the best measurements for model validation it is important for measurements to match the spatial resolution achieved by air quality models.

Activity 1c: Bridging the Scales in Aerosol Measurements

Emerging satellite technology can play a cost effective role in monitoring various pollutants in real time and at high resolution over large areas. This data can provide much information to the public and policy makers but the data must be integrated with local measurements.

Activity 1d: Improving our Understanding of the Impact of Vegetation on Air Quality

Direct emissions are not the only source of particles in the atmosphere; they can also form from chemical reactions of other pollutants. Biogenic volatile organic compound (VOC) emissions can be precursors for up to 70% of organic aerosols. This activity aims to consolidate the knowledge gained from previous studies and address knowledge gaps in this area.

Activity 1e: Major measurement campaign involving AIRBOX

CAUL will support a major measurement campaign in Western Sydney to aid better understanding of the drivers of poor air quality in Sydney..

Subproject 2: Implementing state-of-the-science air quality modelling to assess particle pollution in Western Sydney

It is now well understood that, given the limitations of any particular air quality model, more reliable results are achieved with an ensemble of models. This subproject hence draws on the heritage of several groups to advance the reliability of modelling current and future air quality for Western Sydney.

Activity 2a: Developing an Australian domain of the GEOS-Chem chemical transport model

In this research activity we will characterize the interaction of Western Sydney with the larger Australian domain, for both evaluation and modelling.

Activity 2b: Improving emissions inventory data for New South Wales

We will review research underway on NSW emissions inventory to identify any knowledge gaps.

Activity 2c: Testing our Air Quality models against existing campaign data

We will initially establish the best framework for using an ensemble of air quality models. We will then assess the skill of our ensemble of models by comparing their simulation of the atmosphere against observations made from previous measurement campaigns.

Activity 2d: Developing and improving our Air Quality models

Activity 2e: Identify and model the impact of policy options (and future scenarios) that address particle pollution in Western Sydney

In this research activity we will identify a number of potential policy options and mitigation strategies that are particularly beneficial to Western Sydney.

Activity 2f: Efficient assessment tool for policy makers.

We will pre-package a broad range of emission possibilities into an efficient desktop tool. This will allow policy-makers to explore options much more freely while maintaining a strong scientific basis.

Subproject 3: Exploring potential measurement and modelling techniques for estimating human exposure to airborne pollutants

This subproject responds to a natural community concern that modelling and measurement should capture what is actually happening at the individual exposure level, since this is where the health impacts occur. It will seek to extend the air quality modelling capabilities down to the level of predicting individual human exposure, coupled this with a measurement campaign that deploys a range of personal monitors to measure exposure levels in Western Sydney.

Activity 3a: Estimate Exposure Levels from Air Quality Models and Link to Health Outcomes

In this research activity we will review the current work that is being undertaken in NSW to identify areas where we can add value to this work.

Activity 3b: Measure individual exposure to airborne pollutants using personal monitors (UoM)

We will seek to test a range of emerging technologies and then deploy a significant number of monitors (most probably via a citizen science program) to determine typical human exposure levels to air pollutants (primary target is PM2.5 in Western Sydney).

Expected Outcomes


  • Meaningful, exposure-based goals for particulate levels in Western Sydney.
  • Options for optimal policies (packages of policies) to reach these goals
  • Improved air quality modelling and assessment tools

Specific policy or management outcomes

The outcomes of this project will provide better knowledge and tools to inform the most cost effective policies to reduce population exposure to particulates within Western Sydney, and an understanding of new capabilities for atmospheric composition measurements over model-relevant spatial scales. The project will inform management on any future requirements for further monitoring of particulate matter in Western Sydney.


Ultimately this project will inform the management of air quality within Sydney and Australia more generally. Health impact studies will allow for cost-benefit analysis to determine the most effective strategies for improving air quality outcomes. Policy makers will need to implement those strategies for actual environmental gains to be made.

Further details can be read in the public version of the CAUL Hub Research Plan. Return to the overview of CAUL Hub research projects.