Fine particulate matter (PM2.5)


PM2.5 is the finer particulate fraction of PM. PM2.5 particles are smaller, and therefore able to be transported further and persist for longer in the atmosphere than PM10. In addition, the smaller the particles, the deeper they can penetrate into the respiratory system and the more hazardous they are to breathe. PM2.5 is monitored at fewer sites than PM10. This will change in the future, with the advisory NEPM standard of 25 µg/m3 becoming a compliance standard in 2016. The AQI assessment scorecard has been used for the first time for PM2.5 in SoE 2016.

Typical background concentrations of PM2.5 are around 5 µg/m3, but the concentrations can increase dramatically under extreme conditions—for example, during bushfire events. Maximum concentrations of PM2.5 have greatly exceeded the advisory standard in some areas, particularly in Sydney and Brisbane because of extreme localised events (Figure ATM34). During the 7 years from 2008 to 2014, the PM2.5 advisory standard was met for the following number of years: Adelaide (4 years), Brisbane (5 years), Canberra (0 years), Darwin (0 years), Hobart (1 year), Melbourne (2 years), Perth (1 year) and Sydney (2 years). These data indicate that new emissions reduction strategies will be needed to meet the 2025 goal of 20 µg/m3.

Box ATM11 describes a study to characterise PM2.5 pollution in the upper Hunter Valley

Keywood MD, Emmerson KM, Hibberd MF (2016). Ambient air quality: Fine particulate matter (PM2.5). In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra,, DOI 10.4226/94/58b65c70bc372