In 2012, EPA monitored air quality at 16 sites across Victoria, with:

• 13 in metropolitan Melbourne (11 long-term and two 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.

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.

See a comparison in Victoria’s air quality – 2006 (publication 1140).

Air quality in 2012 was mainly affected by: 

• local dust, smoke from planned burning
• urban sources – predominantly motor vehicle and wood-heater emissions – accumulating in stable atmospheric conditions. Such conditions tend to occur on calm, cold autumn or winter nights. These urban sources typically impact on visibility more than on PM₁₀ levels. 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.

An assessment against Victoria’s air quality objectives and goals is shown in the 2012 data tables (PDF 692KB)

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 were the only pollutant measured by EPA’s air monitoring network above the Ambient Air Quality National Environment Protection Measure (AAQ NEPM) air quality standard. The 24-hour reporting standard for PM_2.5 was not exceeded. The air quality standards for nitrogen dioxide, carbon monoxide, sulfur dioxide and ozone were met on all days in 2012 (where there was sufficient data to demonstrate compliance).

Overall at the permanent monitoring sites, five days were measured above the air quality standard for particles as PM₁₀. The five days exceeding the PM₁₀ standard in the Port Phillip Region were local dust (23 March, 4 October), planned burning (5 April) and urban emissions (19 April, 1 June). Urban sources are typically vehicle traffic or domestic wood heaters.

For the third time, the Port Phillip Region in 2012 (2010 and 2011 previously) met the AAQ NEPM goal of not exceeding the particles as PM₁₀ air quality objective on five days at one monitoring site since AAQ NEPM reporting commenced in 2002.

Low visibility generally occurring for one to a few hours on a day was measured across Melbourne exceeding the standard at all sites, with the highest frequency of events measured at Mooroolbark (12 days). This was an improvement on 2011 (18 days). The goal for visibility was not met at all sites. This was mainly caused from small particle emissions such as PM_2.5 from planned burning and urban emissions.

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 30 days during the year in Brooklyn. This was an increase on 2011 (13 days), due in part to strategies put in place to reduce PM₁₀ dust emissions from the estate. PM₁₀ at the short-term air monitoring station at Francis St, Yarraville exceeded the air quality standard on one day.

• Francis Street monitoring program – Report two (publication 1520)

Monitoring for benzo(a)pyrene at a roadside site in Yarraville commenced in late May 2012 and ran for 12 months.

During 2012 air toxics monitoring was conducted and completed at Dandenong South (a residential area surrounding a prescribed landfill and numerous small to medium enterprises) and Tullamarine (a residential area surrounding a former prescribed landfill). The results show the levels of benzene, toluene, xylene and formaldehyde (monitored only at Tullamarine) measured were below the Monitoring Investigations Levels.

• Dandenong south air monitoring program – Final report (publication 1496)
• Tullamarine landfill community air monitoring program – Final report (publication 1510)

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

In the Latrobe Valley, there were no days where the PM₁₀ air quality standard was exceeded and low-visibility events were measured on 21 days at Traralgon and eight days at Morwell East. This is an improvement on 2010 (26 low-visibility days) but not as good as 2011 (13 days). Low-visibility days were caused mainly by the accumulation of smoke from planned burns and/or agricultural burning and urban emissions, such as smoke from wood fires in the colder months. Levels of ozone, 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 2012.

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 available with the 2012 data tables (PDF 692KB). Since 2002 the major impacts were influenced by fire generated during major bushfires in 2003, 2006, and 2009, planned burns during 2008 and 2009, and general windblown dust due to the effects of drought and the long-term drying pattern in Victoria.

For the third time since AAQ NEPM reporting commenced in 2002, the Port Phillip Region met the AAQ NEPM goal of not exceeding the particles as PM₁₀ air quality standard on five days at one monitoring site. During 2012 impacts from bushfires were minimal. Smoke impacts were mainly from prescribed burning. During 2012 impacts from bushfires and windblown dust were minimal, contributing to the lower levels of PM₁₀. Smoke impacts were mainly from prescribed burning.

Further analysis of trends in compliance with the air quality goals is in Air monitoring report 2012 – Compliance with the National Environment Protection (Ambient Air Quality) Measure (publication 1536).