Issue: Air quality - Urban air quality
This is an issue under the Atmosphere theme of the Data Reporting System.
Australians consistently rank air pollution as a major environmental concern. The state of our air is an important factor in the quality of life in Australian cities. It affects the health of the community and our environment and directly influences the sustainability of our lifestyles and production methods.
- A-17 Concentrations of carbon monoxide in urban areas
The main sources of carbon monoxide are from motor vehicles and from wildfires and vegetation (e.g. hazard reduction) and agricultural burning.
Carbon monoxide combines with haemoglobin to reduce the oxygen carrying ability of the blood. Long term (chronic) exposure to low levels of carbon monoxide may produce heart disease and damage to the nervous system. Exposure of pregnant women to carbon monoxide may cause low birthrates and nervous system damage to offspring.
High levels of carbon monoxide will cause the same problems for animals that are experienced by us, although these levels are very unlikely to be encountered in the environment except during extreme events like bushfires. Exposure of pregnant animals to carbon monoxide may cause low birthrates and nervous system damage to the offspring. At high levels carbon monoxide will cause illness (fatigue, gastric upset) to animals. Atmospheric concentrations of carbon monoxide are a direct indicator for this issue.
- A-18 Concentrations of ozone in urban areas
Ozone is an important constituent of the stratosphere, where it protects the earth from harmful ultraviolet radiation from the sun. However, at ground level, it is a major health and environmental concern. At ground level, ozone is not emitted directly but is formed as a result of reactions involving oxides of nitrogen and volatile organic compounds.
The main sources of volatile organic compounds are from vegetation (biogenic), motor vehicles, refineries and petrochemicals.
Ozone has adverse health effects on various parts of the respiratory system. Prolonged short-term exposures have been linked with significant decreases in lung function and increased respiratory symptoms, as well as aggravation of pre-existing respiratory diseases such as asthma. Ozone also has adverse effects on vegetation and building materials. Atmospheric concentrations of ozone are a direct indicator for this issue.
- A-19 Concentration of lead in urban areas
Exposure to lead at high concentrations may have severe health effects particularly for children and an unborn child. Young children exposed to lead and lead compounds can experience a decrease in intelligence scores, learning difficulties, slow growth and defective hearing. Lead exposure during pregnancy can contribute to premature birth, low birth weight or miscarriage.
The immediate effects of exposure to lead can mean death of animals and death or low growth rate in plants. Especially in soft water, lead is highly poisonous to plants, birds and other animals. Long-term effects on animal life are shortened lifespan, reproductive problems, lower fertility and changes in appearance or behaviour. Because lead does not break down and is highly persistent in water, it is expected that fish tissues will contain lead from polluted waters.
Prior to 2001, other than the major industrial sources such as manufacturing and lead-smelting facilities, motor vehicles using leaded petrol were the main sources of lead emissions to ambient air. Leaded petrol was phased out nationally on 1 January 2002. This has led to reductions in ambient lead levels. Atmospheric concentrations of lead are a direct indicator for this issue.
- A-20 Concentrations of nitrogen dioxide in urban areas
Nitrogen dioxide is formed in the ambient air through the oxidation of nitric oxide and plays an important role in the formation of photochemical smog. The major sources of nitrogen oxides are motor vehicles and industry, especially power plants.
The health effects of short-term exposure to nitrogen dioxide include respiratory illnesses in children. Long-term exposure may lower resistance to respiratory infections.
Excessive levels of nitrogen dioxide can cause death in plants and roots and damage to the leaves of many agricultural crops. Excessive levels increase the acidity of rain (lower the pH) and thus lower the pH of surface and groundwaters as well as soils. In turn, this lowered pH can have harmful effects, including death, on a variety of biota. Atmospheric concentrations of nitrogen dioxide are a direct indicator for this issue.
- A-21 Concentration of sulphur dioxide in urban areas
Sulphur dioxide is formed when sulphur-containing fuels are burnt. Generally, the low sulphur content of fuels in Australia means that sulphur dioxide is not a pollutant of concern, particularly in capital cities. The major sources are power plants, refineries and smelters.
Exposure to concentrations of ten to fifty parts per million for five to fifteen minutes causes irritation of the eyes, nose and throat, choking and coughing. Exposure of the eyes to liquid sulphur dioxide from an industrial accident, for example, can cause severe burns, resulting in the loss of vision. On the skin it produces burns. Other health effects include headache, general discomfort and anxiety. Those with impaired heart or lung function and asthmatics are at increased risk. Repeated or prolonged exposure to moderate concentrations may cause inflammation of the respiratory tract, wheezing and lung damage.
It has also proved to be harmful to the reproductive systems of animals and caused developmental changes in their newborn. Even low concentrations of sulphur dioxide can harm plants and trees and reduce crop productivity. Higher levels, and especially the acidic deposits from acid rain, will adversely affect both land and water ecosystems. Atmospheric concentrations of sulphur dioxide are a direct indicator for this issue.
- A-22 Concentration of Particles PM10 and PM2.5 in urban areas
Particles less than 10 micrometres are referred to as PM10 and are called ‘inhalable particles’. Particles less than 2.5 micrometres are known as PM2.5 or ‘respirable particles’.
The main sources of include motor vehicles, domestic wood heaters, bushfires and controlled burns, wind-blown dust, sea-salt, industrial facilities such as power stations, and photochemical processes.
The specific effects of particulate matter will depend on its composition, concentration and the presence of other pollutants such as acid forming gases. However, particles are associated with increased respiratory symptoms, aggravation of asthma, increased hospitalisation for heart and lung diseases, and premature death in humans and animals. Atmospheric concentrations of particles are a direct indicator for this issue.
- A-23 Concentration of benzene in urban areas
The major sources of benzene are motor vehicles, the burning of domestic solid fuels, lawn mowers, some industrial processes and cigarette smoking.
The health effects of exposure to benzene depends on how much benzene you have been exposed to, for how long, and your current state of health. In certain circumstances, even a brief exposure to very high levels of benzene can result in death. Exposure can result in symptoms such as skin and eye irritations, drowsiness, dizziness, headaches, and vomiting. Benzene is carcinogenic and long-term exposure at various levels can affect normal blood production and can be harmful to the immune system. It can cause leukaemia (cancer of the tissues that form white blood cells) and has also been linked with birth defects in animals including humans.
Benzene has a high acute toxic effect on aquatic life. Long-term effects on marine life can mean shortened lifespan, reproductive problems, lower fertility and changes in appearance or behaviour. It can cause death in plants and roots and damage to the leaves of many agricultural crops. Atmospheric concentrations of benzene are a direct indicator for this issue.