In 2013, EPA monitored air quality at 16 sites across Victoria, with:

• 13 in metropolitan Melbourne (11 long term & 2 short term)
• one in Geelong
• two in the Latrobe Valley.

Port Phillip region

Victoria

Air quality is assessed against national and/or state objectives and goals.

Air quality in 2013 was mainly affected by: 

• windblown dust
• smoke from bushfires and planned burning
• urban sources, predominantly motor vehicle and woodheater emissions accumulating in stable atmospheric conditions. These stable conditions tend to occur on calm, cold autumn or winter nights. These urban sources typically impact visibility more than PM₁₀. When not properly managed, sources such as wood heaters can have a significant local impact
• local sources and emissions from activities such as dust from the Brooklyn Industrial Precinct
• roadside emission from motor vehicles – particularly trucks on arterial roads.
• photochemical smog occurring on warm, sunny days during light winds.

An assessment against Victoria’s air quality objectives and goals is shown in the 2013 data tables (PDF 492KB)

In Melbourne the general air quality was good overall.  Major impacts on air quality during the year were associated with particles from local dust and urban emissions (particularly from motor vehicles and wood heaters) that were trapped in calm, highly stable conditions.

Particles as PM₁₀ was the pollutant most frequently measured above the Ambient Air Quality National Environment Protection Measure (AAQ NEPM) air quality standard in Melbourne during 2013. Despite this, the goal of no site exceeding the particles as PM₁₀ air quality objective on more than 5 days at one monitoring site was met in Melbourne.

There were three days when the particles as PM₁₀ standard was exceeded in Melbourne during 2013. Two were due to urban emissions in Footscray (28 June and 3 September), while the other was due to windblown dust in Dandenong (25 January). Urban sources are typically vehicle traffic or domestic wood heaters.

Low visibility, generally occurring for one to a few hours on a day, was measured across Melbourne exceeding the standard at all sites. The highest frequency of low visibility events was measured at Alphington (12 days). The goal for visibility was not met at all sites except for Footscray and Point Cook. The low visibility events were mainly caused from small particle emissions such as PM_2.5 from planned burning and urban emissions.

The air quality standard for ozone was exceeded on one day at a few monitoring sites due to photochemical smog, while the 24-hour reporting standard for PM_2.5 was exceeded on one day at Alphington due to a buildup of urban emissions (such as woodheater smoke) during light winds. Levels of carbon monoxide, nitrogen dioxide and sulfur dioxide were measured below the air standards on all days during the year.

Unlike the general air quality in Melbourne, the local air quality in Brooklyn was regularly impacted by particles as PM₁₀ due to dust emissions from the local industrial estate. Targeted short-term air monitoring in Brooklyn designed to assess local impacts measured levels of particles as PM₁₀ above the air quality standard on 28 days during the year in Brooklyn. PM₁₀ at the roadside monitoring station at Yarraville (Francis Street) was impacted by particles from motor vehicles, with the PM₁₀ air quality standard exceeded on seven days, while the annual PM_2.5 advisory reporting standard was exceeded for the 12 months of monitoring between June 2012 and June 2013.

The air toxics monitoring for benzo(a)pyrene at a roadside site in Yarraville (Francis Street) was completed during 2013. Monitoring took place over 12 months from May 2012 to May 2013 and the results showed the levels of benzo(a)pyrene were well below the monitoring investigation level.

In Geelong there were eight days when the levels of PM₁₀ exceeded the air quality standard during 2013. These were all attributed to local windblown dust. Low visibility was measured on one day, while the air standards for ozone, nitrogen dioxide, carbon monoxide and sulfur dioxide were all met.  

In the Latrobe Valley there were six days when the PM₁₀ air quality standard was exceeded at Morwell East and four days when it was exceeded at Traralgon, while low visibility was measured on 30 days at Traralgon and 18 days at Morwell East. These exceedances of air quality standards were mainly due to the accumulation of smoke from planned burns and bushfires, and urban emissions such as smoke from wood fires in the colder months. PM_2.5 levels exceeded the PM_2.5 reporting standard at Morwell East on one day during January due to bushfire smoke, while the four-hour ozone air quality standard was exceeded on the same day in Traralgon. Levels of nitrogen dioxide and sulfur dioxide were measured below the air standards on all days during the year.

There was no monitoring in other rural regions in 2013.

Apart from periods of elevated levels of PM₁₀ due to impacts from fire and windblown dust, air quality has changed very little in Melbourne over the past decade. Melbourne’s air quality is considered to be relatively good for a major metropolitan centre.

Long-term trend graphs are shown in the 2013 data tables (PDF 492KB).

Since 2002 the major impacts were influenced by major bushfires in 2003, 2006, and 2009, planned burns in 2008 and 2009, and general windblown dust due to the effects of drought and the long-term drying pattern in Victoria.

Read further analysis of trends in compliance with the air quality goals in Air monitoring report 2013 – Compliance with the National Environment Protection (Ambient Air Quality) Measure (publication 1569).

Melbourne’s air quality is better than or comparable to interstate and international cities in countries of a similar level of development to Australia.

Improvements are necessary, however, to preserve Melbourne’s relatively good air quality, given increasing pressures from population and economic growth and a changing climate. A comparison is presented in Victoria’s air quality – 2006 (publication 1140).