Current air quality
South Australia is performing well
Adelaide and SA generally have good air quality relative to national and international benchmarks. This results from our comparatively small population, few and declining polluting industries, and high-level electricity and gas use for cooking and heating.
Adelaide’s weather patterns also mean that, on most days, pollution is cleared away from the metropolitan area, reducing the potential for it to build up to levels that exceed national standards. This is particularly evident in the average exposure to PM2.5 levels in comparison with other OECD countries and other Australian cities.
What does PM10 and PM2.5 mean?
PM10 is how we describe very small liquid and solid airborne particles, which we can inhale. These particles are 10 micrometres (μm) or less in diameter. Within the PM10 fraction, there are even finer particles known as PM2.5. These particles are less than 2.5 μm in diameter and can get into the deepest parts of our lungs.
PM10 can include smoke, soot, dust, salt, acids, and metals. Particulate matter also forms when gases emitted from motor vehicles and industry undergo chemical reactions in the atmosphere.
By way of comparison, a human hair is about is 70 μm and a grain of sand is 90 μm (Figure 19).
Figure 19: Illustration of size comparisons for PM2.5 and PM10
Monitoring air quality
The EPA operates 8 long-term ambient monitoring stations in metropolitan Adelaide and a further 7 stations in the regional centres of Port Pirie (5) and Whyalla (2). At times, the EPA also conducts shorter-term monitoring, as was recenty undertaken in Port Augusta. Some industries conduct ambient monitoring as a condition of their licence. Our current urban air quality monitoring regime has been in place since 2001, relevant to the commencement of the National Environment Protection (Ambient Air Quality) Measure (AAQ NEPM).
The SA Government initially installed 6 metropolitan stations based on modelling of secondary photochemical pollution (ozone and other oxidants) rather than primary pollutants, such as nitrogen oxides and particles. As it became evident that fine particles create the greatest risk for communities in urban areas, further stations were established. This includes two in the Port Adelaide area and one in the Adelaide CBD.
The EPA publicly reports the results of monitoring which shows a steady improvement in air quality over the past 10 years. South Australia is participating in a national project that is looking at a range of tools to determine population exposure more effectively. Tools include monitoring, modelling and satellite imagery within an integrated approach to improve understanding of community exposure. Figure 20 shows a diagram, developed by the CSIRO, that illustrates this approach.
Figure 20: Science framework for exposure overlay modelling. Source: CSIRO 2014