Air Pollution

Air pollution occurs when the air is affected by chemicals or particles that are not normally present and have the potential to affect health. Its composition can vary greatly, depending on the season, the weather and the different types and numbers of sources.

The air pollution you may be exposed to includes:

The main pollutants in large cities are ozone, particles, nitrogen dioxide, carbon monoxide and sulfur dioxide.

The two main air pollutants in Sydney are ozone and particle pollution. Vehicle exhaust, industrial emissions, gasoline vapours, and chemical solvents are some of the major sources of ozone. Particle pollution is formed directly from sources such as vehicles, factories, power plants, and smoke from bushfires.

Air pollution levels in the Sydney region are generally quite low compared to large cities overseas. But there are a number of days each year when people sensitive to the effects of air pollution are likely to feel its impacts.

Extreme episodes of air pollution, such as during prolonged bushfires, can affect everyone's health.

In Sydney pollution levels exceed the national standard up to 25 days a year.

Air pollution can have a negative effect on the respiratory system (lungs and airways) and on the cardiovascular system (heart function and blood circulation).

Each individual will react differently to air pollution depending on their health status, the length of time spent outside, and the concentration of pollutants.

Research suggests that air pollution is responsible for 2.3% of all deaths in Australia. It is estimated that between 640 and 1400 people die prematurely and cause almost 2000 hospitalisations per year in the Sydney Greater Metropolitan region.

Air pollution costs New South Wales around $ 4.7 billion dollars per year in health costs.

• Aggravated respiratory illness such as asthma, COPD, bronchitis and emphysema
• Wheezing, coughing, chest pain, dry throat, headache
• Damaged cells in the respiratory system
• Increased fatigue

• coarse particles (such as those found in wind-blown dust), which have diameters between 2.5 and 10 micrometers;
• small particles (known as PM2.5 or fine particulate matter), which are less than 2.5 micrometers in diameter. These probably pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream. Exposure to such particles can affect both your lungs and your heart.

Nitrogen dioxide arises from the combustion of fuel in motor vehicles and industry. It is found at highest concentrations near busy roads and can also be high indoors when unflued gas appliances are used.

The most sensitive group to nitrogen dioxide are those with asthma.

Nitrogen dioxide irritates the lungs and makes those with asthma more susceptible to lung infections and also more susceptible to asthma triggers, such as pollen and excercise.

Carbon monoxide is an odourless, colourless gas. It forms when the carbon in fuels does not completely burn. Vehicle exhaust contributes most carbon monoxide emissions in Sydney. Other sources include fuel combustion in industrial processes and natural sources such as bush fires.

Carbon monoxide levels typically are highest during cold weather, because cold temperatures make combustion less complete and cause inversions that trap pollutants close to the ground.

Carbon monoxide enters the bloodstream through the lungs and binds to haemoglobin, the substance in blood that carries oxygen to cells. Carbon monoxide reduces the amount of oxygen reaching the body's organs and tissues.

The most sensitive group to carbon monoxide are those with cardiovascular disease, such as angina. They may experience chest pain and other cardiovascular symptoms if they are exposed to carbon monoxide, particularly while exercising.

People with marginal or compromised cardiovascular and respiratory systems and possibly young infants also may be at greater risk from carbon monoxide pollution.

Sulfur dioxide is a colourless, reactive gas. The main human activities producing sulfur dioxide are the smelting of mineral ores containing sulfur and the combustion of fossil fuels. Natural processes that release sulfur compounds include decomposition and combustion of organic matter, spray from the sea, and volcanic eruptions.

Sulfur dioxide is a respiratory irritant, and may worsen existing respiratory illness.

People with asthma who are physically active outdoors are most likely to experience the health effects of sulfur dioxide. The main effect is a narrowing of the airways. This may cause wheezing, chest tightness, and shortness of breath. Symptoms increase as sulfur dioxide levels and/or breathing rates increase. When exposure to sulfur dioxide ceases, lung function typically returns to normal within an hour.

The most sensitive groups to sulfur dioxide at very high levels are those with cardiovascular disease or chronic lung disease, as well as children and older adults.

At very high levels sulfur dioxide may cause wheezing, chest tightness and shortness of breath, even in healthy people who do not have asthma. Long-term exposure to sulfur dioxide can cause respiratory illness, alter the lung's defence mechanisms, and aggravate existing cardiovascular disease.