Particulate Monitoring Information

What is particulate matter?

Particulate matter, or PM, is a term used to describe particles that are suspended in the atmosphere. Particles may be solid or liquid. Particulate matter is a generic term that is commonly used interchangeably with other terms such as smoke, soot, haze and dust.

The potential effect of particulate matter on the environment, human health and amenity depends on the size of the particles, the concentration of particulate matter in the atmosphere and rate of deposition.

Particulate matter is measured by concentration, the mass of particulate matter that is suspended per unit volume of air. It is usually reported in micrograms per cubic metre (µg/m³).

Particulate matter with an aerodynamic diameter greater than 10 micrometres (µm) tends to be associated with amenity impacts, while particulate matter less than 10 µm is associated with health impacts. For this reason, particulate matter is sub-divided into a number of metrics based on particle size.

PM₁₀ refers to particles suspended in the air with an aerodynamic diameter less than 10 µm.
PM_2.5 is a subset of PM₁₀ and refers to particles suspended in the air with an aerodynamic diameter less than 2.5 µm. PM_2.5 is also called fine particulate matter.

Where does particulate matter come from?

Particulate matter can come from a variety of sources, including:

Industrial sources
Residential/domestic sources
Natural sources such as salt spray, bush fires and wind erosion of bare earth
Motor vehicles through both combustion of fuel and wheel and brake generated dust

What are the air quality standards for particulate matter?

The Environment Protection Act 1993 (EP Act) provides for the management of the air environment in South Australia. The Environment Protection (Air Quality) Policy (Air EPP) provides a framework under the EP Act for the regulation of air pollution in South Australia and includes air quality criteria. Adelaide Brighton Cement assesses compliance with the following South Australian EPA air quality standards for particulate matter:

24-hour average PM₁₀ should be below 50 µg/m³
24-hour average PM_2.5 should be below 25 µg/m³

What is a wind/dust rose and what does it mean?

A wind rose shows the distribution of wind speeds and wind directions at a particular location. The bars on the wind rose project from the centre in the direction that the wind is blowing from. The rings show the proportion of winds from that direction.

A dust rose presents the proportion of dust measured by the direction of the wind when the dust was measured. Like the wind rose, dust rose bars point in the direction the wind was blowing from. Wind speed and wind direction is measured at the same location as the dust monitors.

Example wind rose

This wind rose shows the strength of measured winds by colour from blue (weakest) to orange (strongest). The strongest winds measured during the monitoring period were from the south and south-southeast, ranging from 2 to 5 m/s. All winds measured from the east were between 1 and 2 m/s, shown by a bar of a single blue colour. Hover over each bar segment to see the direction the wind was blowing from (labelled t) and the proportion (%) of winds from that direction with a particular speed (labelled r).

Example dust rose

This dust rose shows that approximately 30% of the particulate matter for the monitoring period was measured while winds were from the south. Although the wind rose shows winds from the northwest and west-southwest, very little particulate matter was measured from these directions. Hover over each bar to see the direction the wind was blowing from (labelled t) and the proportion (%) of particulate matter from that direction (labelled r).