Flying Dirty over Sydney Backyards


Air Pollution in the Sydney Basin - Sources, Cycles and Health Impacts

Flying Dirty over Sydney Backyards

Sydney's Daily Smog Cycle

The cartoon strip below shows the key steps in the process that pumps and concentrates pollution and adverse health impacts in Sydney's West and South West. Options for airport expansion are discussed in this context.

Click on an image to step forward through the Daily Cycle.

Use browser back button to Step Backward. Start by clicking here.

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© J Barros Click Here To Email Copyright Owner , April 2001, reproduced by permission June 22nd 2001
Web page, diagrams and recent updates by BEAR July 2001 - Mar 2004.

First published July 2001, Last revised

Last Change: vdeck mod

Visitor since Sat 21-Feb-2004.

Sydney Second Airport - The God's Must be Crazy | References/Links


Sydney Basin - Smog Boundary
Figure 1 - Sydney Basin Smog Boundary
100m contour is indicative only of the smog boundary. Pollution slops around in the basin and impacts a wider area.

Smog Sources
Figure 2 - Morning Smog Sources
Lighter red shading represents developed residential areas. Large areas in the west are semi-rural still, including a 10 km buffer zone around the Badgery's Creek site

Black lines are motorways, freeways and major roads. Brown lines are rail lines.

Mid-Morning Drift
Figure 3 - Morning Cold Land Breezes take Pollution off-shore - Priming Pump
During the night, cold air accumulates on the Tablelands south of Lake Burrogorang (Warragamba Dam), then in the early morning flows down the ridge between Mittagong and the Illawarra Scarp (the South Westerly-Regional Flow identified by Hyde) - injecting a South-Westerly flow into the Sydney Basin - through the upper reaches of the Nepean River, the South Creek Valley, and the Georges River Valley.

Similarly, cold air accumulated on the Blue Mountains west of Richmond flows down into the Richmond area, and passes east along the Hawkesbury River Valley and spills over into the Parramatta River Valley around Blacktown.

AfterNoon Pump
Figure 4 - Breezes turn-around Mid Afternoon - Smog Pumped inland by onshore Sea Breeze
For more information on Sydney's Sea Breezes see Sea Breezes on the Sydney Coast(Bureau of Meterology site)..

Evidence of sea breezes in last 72 hours can also be found at Bureau of Meterology Observations for NSW site - follow link Hourly Data from NSW AWS then click on a site to get last 72 hours data.

Night Time
Figure 5 - At Night, Cool flow from South Pushes Smog North and East
Night Time
Figure 6 - Lung Cancer Hotspots - Matches Smog Clouds
Blue shading represent local government areas (LGA's) where rates of lung cancer are significantly higher than state averages. Compiled by superimposing Cancer Council's map for male and female cancer rates . Darker blue shading represents signficantly higher than average rates; lighter intensity blue are higher than average rates.
Out of Basin Options
Figure 7 - Out of Basin Options
 Click here to return to Figure 1

Sydney's Airports and Smog Pumps

In most countries, airports are exempt from air pollution monitoring and regulatory laws (have you heard of lead-free Avgas yet ? ). Yet they are often the largest single point source of pollution in a city.

Jannette Barros shows how Sydney is built in a topographical basin which traps pollution for Sydney Airport and demonstrates the already considerable adverse health impacts attributable to air pollution in the Sydney Basin....

As we enter the new millennium, Australian planning is moving further away from delivering sustainable airport developments for the Sydney region.

Sydney Airport is adjacent to the Central Sydney Industrial Area, Port Botany and an oil refinery. In suburbs surrounding these facilities there is anecdotal evidence for higher than usual incidence of certain cancers and respiratory disease.

Daily Pollution Cycle

The figures above show the typical daily cycle of air pollution in the Sydney basin. The Sydney basin is a classic "closed" basin, bounded by high ground to the south, west and north, and by the temperature differential between land and ocean on the eastern side. Trapped pollution may accumulate and circulate inside the basin for several days [1, 2], exacerbated by relatively frequent temperature inversions.

Sydney's highest lung cancer occurrences are found at the primary pollution sources in the eastern part of the basin and in the western Sydney basin pollution sink area. Higher than NSW State average lung cancer patterns shown in dark blue on the Figure 6 above are sourced from NSW Cancer Council [3]

Cancer Council statistics were compiled on the basis of totals for local-government areas until 2003. Large parts of the Western end of the basin are still sparsely populated (see map for urban development). The NSW government plans 1.3 million more people for the area, mainly North of the M4 and in the Campbelltown-Camden corridor.

The cancer occurrence patterns cannot be simply explained away by tobacco usage. It is logical to conclude that smokers living in areas of high air pollution attract a higher risk of lung disease than smokers living in cleaner air environments. And the same is true of non-smokers.

The patterns indicate that Sydney is experiencing a significant number of certain types of cancers representing calculable costs. The average direct cost for treating a cancer case over time is A$100,000 and rising [4].

Areas of above-average lung cancer occurrences in Sydney (see Figure 6 above) show striking similarities to the patterns of high cancer risk associated with major US airports at Minneapolis St Paul [5], Seattle [6] and Chicago [7] which in turn support the results of overseas studies. [8, 9]. See also the Sierra Club Cancer Pollution Report for more information on the link between cancer and pollution.

Cars - Benzene and Particulates

It is relevant to note that in car-dependent Sydney, public transport is regularly neglected in favour of building more roads. The legal maximum for benzene in Australian petrol (leaded and unleaded) is still 5%, whereas most European countries now allow only 1%. It is believed that the Australian level of benzene may be around 2-3% in both leaded and unleaded. Health warning labels should be compulsory on all petrol bowzers to inform people about the contents of fuel at self-service stations

{ Ed.- benzene is a well-proven carcinogen, More hazardous than most chemicals in 5 out of 14 ranking systems. Ranked as one of the most hazardous compounds (worst 10%) to ecosystems and human health (see Benzene Hazard - ).}

Where PM2.5 particles descend through a polluted urban air column, it is suspected that they may "piggyback" carcinogens, which may be breathed deep into human lung tissue, beyond the lungs' ability to expel them, becoming potential tumours.

Negative health implications for children of exposure to air toxics has been summarised by NRDC [10]. Negative health implications from diesel fumes are well known, and summarised recently by Dr Peter Fisher, of Gladstone University, Qld. [11]

In addition to cancer, premature mortalities from particulates are in the order of 400 per annum [12], and asthma is also common in Sydney.

More than 95% of all access to and from Sydney airport is by road, making it far from world's best practice. Thus, airport-related road traffic emissions must never be excluded from total airport emissions calculations.

In Sydney, the numbers, average size, weight and age of motor vehicles is rising, outstripping gains made by improvements in fuel quality [13]. Similarly, aircraft numbers have risen fast, older aircraft have been kept in service longer than originally intended, outstripping gains made by reductions in aircraft engine noise. [14]

Air pollution 'bigger killer than road accidents'

Air pollution 'bigger killer than road accidents' March 2, 2004
Sydney Morning Herald

Air pollution was responsible for more deaths among Australians than road accidents, the nation's leading science body said today.

"Mortality due to air pollution in Australia is higher than the road toll," CSIRO Atmospheric Research scientist Tom Beer said in a statement.

"Each year, on average, 2,400 of the 140,000 Australian deaths are linked to air quality and health issues - much more than the 1,700 people who die on our roads.

"That's an average of a death every four hours. This number increases if long-term effects of air toxics on cancer are included."

Dr Beer is one of the organisers of a forum in Melbourne starting today for scientists, medical researchers and government agency representatives considering the issue of air quality.

The link between mortality and air particulate pollution is also very quantitatively described in the Medical Journal of Australia (MJA 1998; 169: 452-453) - see Something particular in the air we breathe?

Government Turns a Blind Eye

Government studies of health impacts of air pollution have been limited to the effects of carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide, lead and particulates. Specific known carcinogens and toxics related to total airport operations, such as benzene, 1,3 butadiene, formaldehyde, etc., have never been measured nor their health implications assessed for Sydney Airport.

Despite this, SACL recently made the startlingly ingenuous claim that emissions from the airport have not increased significantly since 1992 (despite there having been a one-third increase in aircraft traffic and subsequently an even greater increase in motor vehicle traffic to and from the airport). SACL claimed that the emissions measured at their 2 monitors -- one at the airport and one at Botany) do not represent a significant health risk to surrounding residents [15]. One possible explanation -- SACL’s monitors not turned on?

The Value of Health

To date there has been no cost/benefit analysis of the comparative value of within-the-city airports against the value of a healthy and productive population.

One possible reason why ill health is discounted by economic rationalist transport planners, and in effect encouraged, stems from the daft practice of counting health costs as contributing positively to economic growth

(Ed.: for example, economists count smoking as contributing positively to economic growth - the cost of cancer treatment for smokers is counted as a productivity plus, and even their premature death relieves the drain on old age pensions).

There is a clear need to distinguish "good" from "bad" economic growth.

But, just like the tobacco industry has not avoided having to compensate smokers, the aviation industry cannot expect to be exempted forever from taking fiscal responsibility for the toll urban airports inflict on human health and well-being.

Big City Killer

If the cigarettes don't get you the traffic pollution will

UP TO a fifth of all lung cancer deaths in cities are caused by tiny particles of pollution, most of them from vehicle exhausts.

That's the conclusion of the biggest study into city pollution to date, which tracked half a million Americans for 16 years. It suggests the impact is far greater than feared.

The study is important because it followed individuals, says British expert Roy Harrison of the University of Birmingham, allowing the researchers to separate the effects of smoking and pollution. "In the past, we have often just compared urban areas and rural areas. But more people smoke in cities, and it is difficult to compensate for that."

The research focused on particles less than 2.5 micrometres in diameter, known as PM2.5s. These fine particles are thought to kill by lodging deep in the lungs. The researchers found that the long-term death rate from lung cancer rose by 8 per cent for every 10-microgram increase in the average concentration of PM2.5s per cubic metre. The increased risk is comparable with the risks to long-term passive smokers.

Typical PM2.5 levels in the US are 20 micrograms in Los Angeles and 16 micrograms in New York-the limit set in 1997 by the Environmental Protection Agency is 15 micrograms. British levels are similar, though one PM2.5 monitor at Marylebone Road in London records an average of 32 micrograms. "I'd say London has a special problem because of the high proportion of diesel fumes," says George Thurston of New York University, co-leader of the study.

The implications are bleakest for developing countries. In heavily polluted cities such as Beijing or Delhi, particulate levels average over 300 micrograms and most of this is probably PM2.5s.

Further reading:

More at: The Journal of the American Medical Association (vol 287, p 1132)

Fred Pearce

From New Scientist 09 March 2002.


dirty jets


  1. Forest , Dr James, Sydney's Growth: Directions and Impacts, School of Earth Sciences, Macquarie University, Sydney, 1995.
  2. Bell, Dr. F.C., Air Pollution Problems in Western Sydney, Sydney, March 1992 (unpubl)
  3. New South Wales Cancer Council, Cancer maps for NSW: variation by local government area 1991-1995. ( was ).

    These maps have not been continued for the latest data. The Cancer in NSW Incidence and Mortality 2001 Report, launched in June 2003, gives the latest report on cancer available. The Report is compiled by the NSW Central Cancer Registry. The Registry is managed by The Cancer Council, New South Wales and funded by the NSW Health Department. The report compiles data at the higher Area Health Service Level, that broadly reflects the 1994-1995 situation. More detailed statistics for Local Government Areas can be queried in table form at , and continues to show higher than average lung cancer rates in the south-west of Sydney.

  4. McCarthy, Prof. W, Royal Prince Alfred Hospital, Sydney, pers. Comm
  5. Minneapolis Pollution Control Agency, Air Toxics, US EPA Cumulative Exposure Project, Minnesota and Minneapolis St Paul metropolitan area, 1999.
  6. National Resources Defense Council (NRDC), Toxic air pollution: Risk of top carcinogens in major metropolitan areas, analysis of US Environmental Protection Agency’s Cumulative Exposure Project, May 1999,
  7. City of Park Ridge, Illinois, Preliminary study and analysis of toxic air pollutant emissions from O'Hare International Airport and the resulting health risks created by these toxic emissions in surrounding residential communities. August 2000
  8. Pershagen P et al, 1999: Urban air pollution and lung cancer - a population-based case-control study from Stockholm; unpublished paper; National Institute of Environmental Medicine, Stockholm.
  9. Knox B G and Gilman E A, 1997: Hazard proximities of childhood cancers in Great Britain from 1953-80, Journal of Epidemiology and Community Health; 1997: 51: 151-159
  10. National Resources Defense Council (NRDC), Our children at risk November 1997 (
  11. Fisher, Dr Peter, The trouble with diesel, Australian Financial Review, Review Section, 3 September 1999:
  12. Rona Barusch, NSW Health Department, paper presented at AMA Forum on Air Pollution and Health, Canberra (~Nov 1997)
  13. New Scientist, 11 April 1998, p52
  14. Airports Council International, The key challenges facing the world’s airports was "" in Jan 2003. (see extract below)
  15. Sydney Airports Corporation Limited, evidence presented in Sydney to Commission of Inquiry into a precision runway monitor for Sydney airport, March 2000, Environment Australia, Parliament House, Canberra, ACT, 2600.
dirty jets

Airport Environmental Capacity Constraints

As extracted from the Airports Council International site, June 2001:

Present indications suggest that the phase-out of Chapter 2 aircraft by 2002 will not alleviate the noise problem as effectively as was once thought. As air traffic increases, overall aircraft noise levels around airports are expected to rise some time after 2002. ACI's goal is to ensure that traffic growth can be maintained within the environmental capacity limitations imposed upon airports by governments. These limits may be set lower than the current capacity of airports. Future traffic growth will only be possible if noise and emissions are reduced at the source. The industry cannot wait! More stringent noise and emissions certification standards have to be achieved in order to encourage manufacturers and airlines to produce and operate quieter and cleaner aircraft.

Sea Breeze:

A local onshore wind. Cooler air from over the sea flows onto the shore to replace the warm air rising over the land. On sunny days the land heats up more quickly, and to a greater extent, than the sea. The air in contact with the land warms and expands and the resulting changes in the pressure and temperature differences and distributions cause the sea breeze circulation. At night, when the land cools more quickly, and to a greater extent, than the sea, the reverse land breeze circulation is set up.