EPA’s purpose is to protect, care for and improve our environment. Monitoring provides information on the condition of the environment and guides decisions aimed at reducing pollution impacts.

Air quality is assessed against the national and/or state objectives and goals shown in the table below.

In 2008, EPA monitored air quality at 17 sites across Victoria, with:

• 13 in metropolitan Melbourne
• two in Geelong
• two in the Latrobe Valley.

Port Phillip region

Victoria

Air quality in 2008 was affected by:

• smoke from planned burning in April 2008.
• windblown dust, including widespread dust storms during the early part of the year. Windblown dust is typically coarse compared to urban pollution and tends to impact PM₁₀ more than visibility.
• urban sources, mostly motor vehicle and wood heater emissions accumulating in stable atmospheric conditions. These stable conditions tend to occur on calm, cold autumn/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.
• ozone formed under urban summer smog conditions.

An assessment against Victoria’s air quality objectives and goals is shown in the 2008 data tables.

In Melbourne there were fewer days when the particle (PM₁₀ and visibility) objectives were not met, compared with the previous two years. Elevated PM₁₀ levels occurred mainly on days affected by planned burning (in April) and windblown dust (during the warmer months). Low visibility days were caused mainly by planned burning and urban emissions (particularly from motor vehicles and wood heaters) that were trapped in calm, highly stable conditions.

The four-hour ozone objective was exceeded at one coastal station in Melbourne (Point Cook) on two days under conditions suitable for the generation of photochemical smog. The ozone objectives were met at all other stations.

The air quality objectives for nitrogen dioxide, carbon monoxide and sulfur dioxide were met on all days in 2008.

As part of EPA’s monitoring plan for air toxics, benzo(a)pyrene monitoring concluded at Mooroolbark in January 2008 and commenced at Campbellfield in February 2008. Levels were low and met the limits specified in the National Environment Protection Measure (NEPM) for Air Toxics.

In Geelong, there were fewer days when the particle (PM₁₀ and visibility) objectives were not met, compared with the previous two years. As was observed in 2006 and 2007, windblown dust was the major cause of high PM₁₀ levels. Geelong had fewer days that did not meet the visibility objective than most Melbourne stations in 2008. Days of poor visibility were caused mainly by planned burning and urban emissions.

The objectives for ozone, nitrogen dioxide, carbon monoxide and sulfur dioxide were all met.

In the Latrobe Valley, there were fewer days when the particle (particularly PM₁₀ and visibility) objectives were not met, compared with the previous two years. The main causes of high PM₁₀ were smoke from planned burns (in April) and windblown dust. Low visibility days were caused mainly by the accumulation of urban emissions, such as smoke from wood fires (in the colder months) and planned burning.

The objectives for ozone, nitrogen dioxide and sulfur dioxide were met on all days.

Air toxics monitoring at Traralgon concluded in January 2008. Levels were low and met the limits specified in the Air Toxics NEPM.

There was no monitoring in other rural regions in 2008.

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 2008 monthly data tables. An increase in PM₁₀ since 2002 is influenced by major bushfires in 2003, 2006 and 2007.

Melbourne’s air quality is better than, or comparable to, interstate and international cities in countries of a similar level of development to Australia. A comparison was presented in EPA’s report on Victoria’s air quality in 2006 (publication 1140). Maintaining and improving Victoria’s air quality will be a challenge, with increased pressures from continued population growth and the impacts of climate change.