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 (Ambient Air Quality) Measure (Air NEPM) and the Environmental Protection (Air) Policy (Air EPP).
- Airborne particles—visibility reducing particles
- Airborne particles—PM10
- Airborne particles—PM2.5
- Nitrogen dioxide
- Photochemical smog as ozone
- Carbon monoxide
- Sulfur dioxide
Airborne particles—visibility reducing particles
| Year | Days <10km | Days <20km (EPP(Air) objective) |
|---|---|---|
| 1978 | 6 | 64 |
| 1979 | 15 | 92 |
| 1980 | 9 | 51 |
| 1981 | 7 | 45 |
| 1982 | 8 | 56 |
| 1983 | 2 | 18 |
| 1984 | 13 | 60 |
| 1985 | 3 | 46 |
| 1986 | 6 | 17 |
| 1987 | 3 | 12 |
| 1988 | 3 | 26 |
| 1989 | 5 | 11 |
| 1990 | 0 | 11 |
| 1991 | 4 | 30 |
| 1992 | 1 | 9 |
| 1993 | 6 | 43 |
| 1994 | 9 | 32 |
| 1995 | 11 | 36 |
| 1996 | 8 | 35 |
| 1997 | 8 | 24 |
| 1998 | 1 | 8 |
| 1999 | 0 | 2 |
| 2000 | 10 | 33 |
| 2001 | 3 | 12 |
| 2002 | 0 | 5 |
| 2003 | 2 | 9 |
| 2004 | 4 | 13 |
| 2005 | 2 | 5 |
| 2006 | 2 | 4 |
| 2007 | 3 | 9 |
| 2008 | 0 | 2 |
| 2009 | 4 | 12 |
| 2010 | 0 | 4 |
| 2011 | 0 | 4 |
| 2012 | 7 | 14 |
| 2013 | 2 | 8 |
| 2014 | 3 | 10 |
| 2015 | 1 | 4 |
| 2016 | 1 | 6 |
| 2017 | 1 | 7 |
| 2018 | 3 | 7 |
| 2019 | 5 | 21 |
| 2020 | 0 | 7 |
| 2021 | 0 | 2 |
| 2022 | 0 | 1 |
A build-up of fine particles in the air can reduce how far we can see. The Environmental Protection (Air) Policy 2019 (Air EPP) provides a visual amenity objective of 20km. This means it should be possible on a fine day to see an object 20km away.
Reductions in visibility are largely attributable to visibility-reducing particles produced by burning activities such as motor vehicle and industry emissions, bushfires and hazard-reduction burning; fine particles resulting from photochemical smog formation; and windblown dust.
Since monitoring began in 1978, there has been an overall downward trend in the number of days with reduced visibility in South East Queensland.
The closing of Brisbane’s metropolitan power stations in 1986 and the banning of backyard burning in Brisbane in 1987 were major influences in reducing the levels of visibility reducing particles.
Reduced visibility is often associated with dry conditions and bushfires or hazard-reduction burning. Better management of smoke from hazard-reduction burns (carried out to reduce the risk of severe bushfires) has further reduced the number of low visibility days. In the last two decades, years with a higher number of low visibility days have been associated with dry conditions and widespread bushfires.
Airborne particles—PM10
| Year | Days >50µg/m^3 (Air NEPM standard) |
|---|---|
| 1986 | 15 |
| 1987 | 19 |
| 1988 | 14 |
| 1989 | 12 |
| 1990 | 11 |
| 1991 | 10 |
| 1992 | 4 |
| 1993 | 8 |
| 1994 | 22 |
| 1995 | 11 |
| 1996 | 7 |
| 1997 | 1 |
| 1998 | 2 |
| 1999 | 4 |
| 2000 | 16 |
| 2001 | 6 |
| 2002 | 18 |
| 2003 | 4 |
| 2004 | 9 |
| 2005 | 13 |
| 2006 | 4 |
| 2007 | 11 |
| 2008 | 10 |
| 2009 | 19 |
| 2010 | 3 |
| 2011 | 6 |
| 2012 | 6 |
| 2013 | 2 |
| 2014 | 9 |
| 2015 | 6 |
| 2016 | 0 |
| 2017 | 2 |
| 2018 | 9 |
| 2019 | 30 |
| 2020 | 6 |
| 2021 | 11 |
| 2022 | 4 |
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.
Climatic conditions exert the greatest influence on year-to-year variations in PM10 levels, with the number of exceedances of the PM10 24-hour standard of 50µg/m3 declining in wetter years (e.g. 2010, 2013, 2016 and 2022) and increasing in drier years (e.g. 1994, 2000, 2002, 2009 and 2019) due to higher windblown dust levels and rises in the number of vegetation fires and area burnt.
Peaks in annual PM10 exceedances are associated with years when major dust storms occurred (1994, 2002, 2009 and 2019). Higher predicted temperatures and lower predicted rainfall as a result of climate change are likely to increase the occurrence of particle pollution with conditions leading to more prevalent dust storms and bushfires.
Airborne particles—PM2.5
| Year | Days >25µg/m^3 (Air NEPM standard) |
|---|---|
| 1995 | 2 |
| 1996 | 3 |
| 1997 | 1 |
| 1998 | 1 |
| 1999 | 0 |
| 2000 | 9 |
| 2001 | 4 |
| 2002 | 5 |
| 2003 | 3 |
| 2004 | 7 |
| 2005 | 1 |
| 2006 | 1 |
| 2007 | 0 |
| 2008 | 0 |
| 2009 | 11 |
| 2010 | 3 |
| 2011 | 4 |
| 2012 | 1 |
| 2013 | 0 |
| 2014 | 1 |
| 2015 | 1 |
| 2016 | 1 |
| 2017 | 1 |
| 2018 | 8 |
| 2019 | 27 |
| 2020 | 3 |
| 2021 | 1 |
| 2022 | 1 |
PM2.5 refers to airborne particles less than 2.5 micrometres in diameter.
These particles are capable of penetrating humans’ lower airways, possibly causing health effects.
PM2.5 particles originate mainly from combustion processes such as:
- motor vehicle emissions
- industrial processes
- solid fuel heaters
- fires.
Climatic conditions exert the greatest influence on year-to-year variations in PM2.5 levels, with an increased number of exceedances of the PM2.5 24-hour standard of 25µg/m3 largely associated with years with heightened bushfire activity (2000, 2004, 2009, 2018 and 2019).
Higher predicted temperatures and lower predicted rainfall as a result of climate change are likely to increase the occurrence of particle pollution with conditions leading to more prevalent dust storms and bushfires.
Nitrogen dioxide
| Year | Days >0.080ppm (Air NEPM standard) | Days >0.040ppm |
|---|---|---|
| 1978 | 19 | 135 |
| 1979 | 3 | 72 |
| 1980 | 5 | 135 |
| 1981 | 4 | 86 |
| 1982 | 4 | 121 |
| 1983 | 11 | 99 |
| 1984 | 0 | 98 |
| 1985 | 3 | 103 |
| 1986 | 4 | 98 |
| 1987 | 4 | 123 |
| 1988 | 7 | 107 |
| 1989 | 0 | 91 |
| 1990 | 3 | 106 |
| 1991 | 9 | 127 |
| 1992 | 13 | 84 |
| 1993 | 6 | 90 |
| 1994 | 2 | 85 |
| 1995 | 0 | 73 |
| 1996 | 0 | 52 |
| 1997 | 0 | 43 |
| 1998 | 0 | 49 |
| 1999 | 1 | 16 |
| 2000 | 0 | 34 |
| 2001 | 0 | 42 |
| 2002 | 0 | 65 |
| 2003 | 0 | 34 |
| 2004 | 0 | 37 |
| 2005 | 0 | 20 |
| 2006 | 0 | 12 |
| 2007 | 0 | 33 |
| 2008 | 0 | 25 |
| 2009 | 0 | 41 |
| 2010 | 0 | 39 |
| 2011 | 0 | 55 |
| 2012 | 1 | 46 |
| 2013 | 0 | 51 |
| 2014 | 0 | 48 |
| 2015 | 0 | 77 |
| 2016 | 0 | 35 |
| 2017 | 0 | 41 |
| 2018 | 0 | 45 |
| 2019 | 0 | 41 |
| 2020 | 0 | 17 |
| 2021 | 0 | 24 |
| 2022 | 0 | 23 |
Nitrogen dioxide is the product of high-temperature combustion processes such as motor vehicle engines and industries such as coal-fired power stations.
In recent years nitrogen dioxide levels have not exceeded the 1-hour standard for the protection of human health.
Progressive tightening of exhaust emission limits for new motor vehicles has reduced nitrogen dioxide levels in the air and is currently keeping pace with increasing vehicle use. However, with an increase in urban growth and motor vehicle use, the number of days with elevated nitrogen dioxide levels could become more frequent.
Photochemical smog as ozone
| Year | Days >0.065ppm (Air NEPM standard) | Days >0.050ppm |
|---|---|---|
| 1978 | 0 | 3 |
| 1979 | 3 | 24 |
| 1980 | 4 | 21 |
| 1981 | 2 | 8 |
| 1982 | 4 | 22 |
| 1983 | 2 | 17 |
| 1984 | 0 | 6 |
| 1985 | 2 | 8 |
| 1986 | 0 | 10 |
| 1987 | 12 | 18 |
| 1988 | 3 | 15 |
| 1989 | 1 | 1 |
| 1990 | 0 | 2 |
| 1991 | 1 | 4 |
| 1992 | 0 | 3 |
| 1993 | 1 | 4 |
| 1994 | 3 | 17 |
| 1995 | 4 | 34 |
| 1996 | 6 | 41 |
| 1997 | 3 | 29 |
| 1998 | 2 | 24 |
| 1999 | 2 | 18 |
| 2000 | 3 | 19 |
| 2001 | 1 | 15 |
| 2002 | 5 | 38 |
| 2003 | 2 | 11 |
| 2004 | 2 | 29 |
| 2005 | 1 | 23 |
| 2006 | 1 | 13 |
| 2007 | 1 | 14 |
| 2008 | 0 | 16 |
| 2009 | 0 | 20 |
| 2010 | 0 | 6 |
| 2011 | 2 | 11 |
| 2012 | 1 | 12 |
| 2013 | 0 | 11 |
| 2014 | 0 | 19 |
| 2015 | 0 | 19 |
| 2016 | 0 | 9 |
| 2017 | 0 | 17 |
| 2018 | 1 | 12 |
| 2019 | 5 | 36 |
| 2020 | 0 | 16 |
| 2021 | 0 | 7 |
| 2022 | 0 | 4 |
Photochemical smog is formed by reactions involving nitrogen oxides, volatile organic compounds and sunlight. A major component of this smog is ozone.
Exceedances of the 8-hour ozone standard occur occasionally, usually when favourable weather conditions and extra emissions of photochemical smog-forming pollutants from bushfires or hazard-reduction burning coincide.
An expanded ozone monitoring network has been in place in South East Queensland since 1994. The increase in network coverage has contributed to the increase in the number of days exceeding the specified levels seen from this time.
No discernible trend in ozone levels has been identified to date. However, with an increase in urban growth and motor vehicle use, the number of days with elevated photochemical smog levels could become more frequent.
Carbon monoxide
| Year | Days >9ppm (Air NEPM standard) | Days >2ppm |
|---|---|---|
| 1978 | 62 | 312 |
| 1979 | 160 | 362 |
| 1980 | 131 | 366 |
| 1981 | 142 | 346 |
| 1982 | 86 | 309 |
| 1983 | 7 | 249 |
| 1984 | 9 | 240 |
| 1985 | 6 | 220 |
| 1986 | 0 | 318 |
| 1987 | 2 | 300 |
| 1988 | 0 | 211 |
| 1989 | 0 | 284 |
| 1990 | 0 | 285 |
| 1991 | 0 | 268 |
| 1992 | 0 | 228 |
| 1993 | 0 | 154 |
| 1994 | 0 | 208 |
| 1995 | 0 | 192 |
| 1996 | 1 | 318 |
| 1997 | 0 | 333 |
| 1998 | 0 | 162 |
| 1999 | 0 | 168 |
| 2000 | 0 | 78 |
| 2001 | 0 | 111 |
| 2002 | 0 | 84 |
| 2003 | 0 | 82 |
| 2004 | 0 | 66 |
| 2005 | 0 | 37 |
| 2006 | 0 | 37 |
| 2007 | 0 | 4 |
| 2008 | 0 | 15 |
| 2009 | 0 | 8 |
| 2010 | 0 | 2 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 0 |
| 2021 | 0 | 0 |
| 2022 | 0 | 0 |
Carbon monoxide is formed through incomplete combustion of fuels containing carbon.
In South East Queensland, motor vehicles are the largest producer of carbon monoxide.
Progressive tightening of exhaust emission limits for new motor vehicles, in particular the fitting of catalytic converters, have significantly reduced carbon monoxide emissions and levels in the air have steadily declined over the past three decades.
Sulfur dioxide
| Year | Days >0.100ppm (Air NEPM standard) | Days >0.050ppm |
|---|---|---|
| 1978 | 0 | 4 |
| 1979 | 9 | 41 |
| 1980 | 1 | 1 |
| 1981 | 0 | 0 |
| 1982 | 0 | 2 |
| 1983 | 0 | 1 |
| 1984 | 0 | 0 |
| 1985 | 0 | 2 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 16 |
| 1990 | 0 | 2 |
| 1991 | 0 | 3 |
| 1992 | 0 | 1 |
| 1993 | 0 | 1 |
| 1994 | 0 | 0 |
| 1995 | 0 | 1 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 2 |
| 1999 | 0 | 2 |
| 2000 | 0 | 2 |
| 2001 | 0 | 3 |
| 2002 | 0 | 2 |
| 2003 | 0 | 1 |
| 2004 | 1 | 4 |
| 2005 | 0 | 12 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 1 |
| 2009 | 0 | 4 |
| 2010 | 0 | 0 |
| 2011 | 0 | 1 |
| 2012 | 0 | 7 |
| 2013 | 1 | 4 |
| 2014 | 0 | 8 |
| 2015 | 1 | 8 |
| 2016 | 0 | 11 |
| 2017 | 1 | 7 |
| 2018 | 0 | 3 |
| 2019 | 0 | 2 |
| 2020 | 0 | 1 |
| 2021 | 1 | 10 |
| 2022 | 0 | 4 |
Sulfur dioxide is formed in combustion processes burning fossil fuels containing sulfur.
Levels in South East Queensland are generally low due to the small number of sulfur dioxide emission sources in the region.
Increased levels since 2012 are a result of the processing crude oil with a higher sulfur content at the oil refinery at the mouth of the Brisbane River.