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South East Queensland air quality trends

We have measured air quality in South East Queensland since 1978.

Our monitoring program provides us with information to identify long-term trends in air quality by comparing measurements with the goals defined in the National Environment Protection Measure for Ambient Air Quality (Air NEPM) and the Environmental Protection Policy (Air) (Air EPP).

Download the air quality trends poster (PDF, 1.75MB) or click on the links below to view the trend graph for the parameter you require.

Airborne particles—visibility reducing particles

Bar graph covering the years from 1978 to 2011

Number of days visibility was below the specified level due to airborne fine particles (view larger version)

The closing of Brisbane’s metropolitan power stations in 1986 and the banning of backyard burning in Brisbane in 1987 have been major influences in reducing the levels of visibility reducing particles (fine particles which cause a reduction in visibility).

Reduced visibility is often associated with dry conditions and bushfires or hazard-reduction burning.

Airborne particles—PM10

Bar graph covering the years from 1986 to 2011.

Number of days per year the 24-hour average PM10 concentration exceeded the specified level (view larger version)

PM10 refers to airborne particles less than 10 micrometres in diameter.

These particles are capable of penetrating humans’ lower airways, causing possible health effects.

PM10 particles are generated by a wide range of natural processes and human activities, including:

  • wind-blown dust
  • industrial processes
  • motor vehicle emissions
  • fires.

The 2002 Environment Protection Policy (Air) goal exceedence occurred when a dust storm passed over the east coast of Australia during October.

Airborne particles—PM2.5

Bar graph covering the years from 1995 to 2011.

Number of days per year the 24-hour average PM2.5 concentration exceeded the specified level (view larger version)

PM2.5 refers to airborne particles less than 2.5 micrometres in diameter.

These particles are capable of penetrating humans’ lower airways, causing possible health effects.

PM2.5 particles originate mainly from combustion processes such as:

  • motor vehicle emissions
  • industrial boilers
  • solid fuel heaters
  • fires.

Nitrogen dioxide

Bar graph covering the years from 1978 to 2011.

Number of days per year the 1-hour average nitrogen dioxide concentration exceeded the specified level (view larger version)

Nitrogen dioxide is the product of high-temperature combustion processes such as motor vehicle emissions and industrial boilers.

The nitrogen dioxide levels measured in recent years have been well below the Queensland Environmental Protection Policy (Air) goal for the protection of human health.

However, with an increase in urban growth and motor vehicle use, the number of days with high nitrogen dioxide levels could become more frequent.

Photochemical smog as ozone

Bar graph covering the years from 1978 to 2011.

Number of days per year the 1-hour average ozone concentration exceeded the specified level (view larger version)

Photochemical smog is formed by reactions involving nitrogen oxides, volatile organic compounds and sunlight. A major component of this smog is ozone.

An expanded ozone monitoring network has been in place in South East Queensland since 1994. Exceedences of the Environmental Protection Policy (Air) goal for ozone occur occasionally, usually when favourable weather conditions and extra emissions from fires coincide.

No discernible trend in ozone has been identified to date. However, with an increase in urban growth and motor vehicle use, the number of days with high photochemical smog could become more frequent.

Carbon monoxide

Bar graph covering the years from 1978 to 2011.

Number of days per year the 8-hour average carbon monoxide concentration exceeded the specified level (view larger version)

Carbon monoxide is formed through incomplete combustion of fuels containing carbon.

In urban areas, motor vehicles are the largest producer of carbon monoxide.

Controls on motor vehicle emissions such as catalytic converters have resulted in reduced carbon monoxide emissions and corresponding levels in the air in recent years.

Sulfur dioxide

Bar graph covering the years from 1978 to 2011.

Number of days per year the 1-hour average sulfur dioxide concentration exceeded the specified level (view larger version)

Sulfur dioxide is formed in combustion processes burning fossil fuels containing sulfur.

Levels in South East Queensland are low due to the small number of sulfur dioxide emission sources in the region.