Pollution sources
Metropolitan Adelaide
Figure 22 shows sources of air pollution for different regions in South Australia as well as related impacts. Air quality in metropolitan Adelaide is affected by:
- emissions from transport
- industrial processes
- solid fuel heaters
- small engines, for example lawnmowers and leaf blowers
- occasional fires, for example planned burns, bushfires and emergency incidents.
Figure 22: Key pressures and impacts on air quality in South Australia
Our growing population and related increase in vehicles can potentially worsen Adelaide’s air quality over time unless a substantial change occurs in vehicle technology or use.
Data from the National Pollutant Inventory shows combined vehicle and domestic emissions make up 70% or more of metropolitan Adelaide’s total emissions.
The SA Government is actively promoting cleaner technologies for vehicles through its Low Emission Vehicle Strategy. Nationally, vehicle emission standards are set through Australian Design Rules, and the Fuel Quality Standards Act 2000 regulates fuel quality.
The other 30% of emissions come from industrial and other sources, such as soil dust. The exposure from these sources varies between locations and seasons. Examples as follows:
- People living or working near major roads or industrial/commercial activities are more likely to be exposed to higher levels of air pollutants.
- During summer, dust storms and fires contribute to increased air pollution.
- On still, cold winter nights, smoke and other fine particles may build up in Adelaide and exceed national standards.
- A series of still, hot days in summer can build up significant levels of ozone, which is produced when pollutants from vehicles and other fuel-burning activities are mixed together under sunlight, producing a cocktail of photochemical smog.
- Summer is also a season of windy days when dust, on the ground or from stockpiles of industrial materials, can be blown around causing higher particle levels.
Airborne particles cause problems
Figure 23 presents a summary diagram of monitoring results that shows the extent to which the PM10 standard for particles (50 µg/m3) is exceeded from time to time.
Figure 23: Exceedences of the 24-hour PM10 standard at EPA monitoring stations in metropolitan Adelaide
The dry conditions characterising the Millennium Drought leading up to 2009–10 resulted in the PM10 standard recorded at metropolitan stations being exceeded more times than in subsequent years. This was probably due to a combination of more dust being raised by winds and less rain falling to suppress dust and smaller particle emissions. It was a widespread effect in SA, which was also reflected in PM10 data recorded in regional centres, such as Whyalla (Figure 24) and Port Pirie (Figure 26).
No exceedences were recorded in 2011 and from 2012 onwards, most stations recorded that the PM10 standard was exceeded 1 to 3 times per year resulting from specific regional events, usually dust storms.
Over recent years, the EPA has built on its ability to measure PM2.5 particles at metropolitan monitoring sites. This has been done, in part, to bring us in line with the national PM2.5 standards, which were established in December 2015 to replace the previous advisory reporting standards.
Formation of PM2.5 particles is largely from combustion, typically burning fuels in vehicles and domestic wood heaters in urban areas, as well as contributions from a range of industrial processes. Domestic heaters generate substantial quantities of PM2.5 in both the metropolitan area and regional centres, such as Mount Gambier and the Adelaide Hills.
Wood is an effective, renewable fuel if burnt efficiently. Unfortunately, heater design and poor operating practices can prevent efficient burning. Modern heaters are designed to burn a lot cleaner than older models. However, even with the better heaters, issues with wood smoke can be made worse by cold, still weather conditions called temperature inversions, which typically occur during the cooler months of the year. Individuals can play an active role in improving local air quality by ensuring they operate heaters correctly.
Other sources in our homes include fuel-powered garden equipment and other small engines, many of which, especially two-stroke engines, are comparatively ‘dirty’. Some types may emit 40 times the particles and volatile organic compounds emitted by a typical car. This means, for their size and weight, they can be significant contributors to both local and broad metropolitan air quality issues.
The Product Emissions Standards Act 2017, passed on 11 September 2017, now allows the government to set emissions standards and establish controls for non-road spark ignition engines and equipment, such as lawn mowers, gardening equipment and marine engines.
Odours
Regional centres
Air quality in regional centres and rural areas is influenced by:
- land management practices (farming)
- mining and other major industrial processes
- domestic solid fuel heaters
- fires
- material handling
- transport
- natural sources, such as dust storms.
Mount Gambier
Whyalla
Whyalla, with its major steelworks, also experienced high particle concentrations at times (Figure 24). Major investments in the plant, coupled with the drought breaking in 2010, have significantly reduced population exposure.
Figure 24: Exceedences of the PM10 24-hour GLC criterion (50 µg/m3)
at Whyalla monitoring sites
Port Pirie
Port Pirie is the site of one of the world’s largest primary lead smelters. It has attracted considerable attention over the years because of the effects of lead, especially on children.
Emissions have shown a steady decline, mainly due to regulatory oversight by the EPA (Figure 25). In addition, the Targeted Lead Abatement Program has focused on further measures to limit childrens lead uptake. The program continues to build on the previous ‘Ten by 10’ (Nyrstar/EPA partnership) and Nyrstar’s ‘Ten for them’ projects.
However, the reduction in lead emissions plateaued around 2012 due to technical constraints of the old plant. Following an EPA direction for Nyrstar to take action, Nyrstar reached an agreement with the SA and Australian Governments to undertake a major upgrade of the facility to provide step-change reductions in emissions. Known as the Nyrstar Transformation Project, the upgrade will deliver significant improvements in community health and environmental performance, including reductions in carbon emissions.
Figure 25: Trends in airborne lead at Port Pirie measured at EPA monitoring sites
Particle emissions have been declining in Port Pirie since the millennium drought (Figure 26).
Figure 26: Exceedences of the PM10 24-hour GLC criterion (50 µg/m3) at Port Pirie monitoring sites since 2003
Sulfur dioxide emissions have shown an upward trend in recent years (Figure 27). While levels are still below the annual average GLC criterion, there is a growing occurrence of higher than the 1-hour and 24-hour GLC criteria (Figure 28). However, the Port Pirie Transformation Project is also expected to result in significantly reduced sulfur dioxide emissions.
Figure 27: Annual average sulfur dioxide (SO₂) at Port Pirie since 2003
Figure 28: Recorded exceedences of the 1-hour (0.02 ppm) and 24-hour (0.08 ppm) sulfur dioxide GLC criteria at Port Pirie since 2003
Rural areas
South Australia’s regional centres are surrounded by activities ranging from crop farming, meat and wool production, forestry and fishing, through to major transport centres, extensive mining operations, and major ports and their associated wharfing operations (Tables 12 and 13).
Agricultural activities can create issues for regional communities through:
- dust raising, either from cultivation or transport
- chemical handling
- spray drift
- odour from intensive animal husbandry.
Odour can be an extremely vexed and intractable problem because of variations in how individuals experience and respond to odours.
Mining and its related transport may have impacts on rural communities through dust coming from the mining operations themselves, or from transport to ports and ship loading.
Table 12: Pollutant types in regional centres
|
Location |
Pollutant type |
Effects |
|---|---|---|
|
Mount Gambier |
Wood smoke Agricultural and material-handling activities |
PM2.5 particles exceed national standards especially during winter, largely due to wood smoke PM10 particles are generated from agricultural and material-handling activities in warmer months |
|
Port Pirie |
Smelter operations Wharf operations and ship loading
|
PM10 particles and lead levels exceed regulatory targets and limits for lead in Port Pirie Lead-containing dust from smelter operations and historic contamination Sulfur dioxide concentrations regularly exceed the 1-hour GLC Windblown dust can also cause elevated particle levels at times |
|
Whyalla |
Steel-making operations |
PM10 particle levels exceed GLC criteria at times Windblown dust causes elevated levels at times |
|
Roxby Downs |
Mining operations |
Particles from extraction, processing and transporting of minerals |
Table 13: Pollutants types in rural and agricultural areas
|
Pollutant type |
Effects |
|---|---|
|
Mining operations and related transport, and ship loading |
PM2.5 and PM10 particles from mineral extraction, processing and transport cause adverse impacts through inhalation and deposition Nuisance dust impacts |
|
Agricultural and forestry operations |
Exposure of people and plants to spray drift from chemical applications Windblown dust from cleared land Smoke from forestry coupe burns, following felling operations Particles from stubble burning Odour from intensive animal keeping |
|
Controlled burns and bushfires |
Particles, visibility and deposition |