Air quality and air pollution

The air we breathe supports us on earth. It’s all around us, essential yet invisible and easy to take for granted. To understand air pollution and air quality, we must first understand air.

The air we breathe supports us on earth. It’s all around us, essential yet invisible and easy to take for granted. To understand air pollution and air quality, we must first understand air.

Air is all around us, invisible and easy to take for granted

Air is made up of nitrogen (78.09%), oxygen (20.95%), argon (0.93%), carbon dioxide (0.038%) and trace amounts of other gases. This mix of elements sustains life on Earth.

Biological and geological processes maintain this delicate balance of elements. For example:

• Oxygen is released into the atmosphere by oceanic algae and by plants and is used by animals, bacteria and trees (at night).
• Carbon dioxide released by trees and created by animals when they decompose. It also gets dissolved in water and released again.
• Nitrogen is removed from the atmosphere by lightning and bacteria and returned through decaying processes.

Air is all around us, invisible and easy to take for granted

Air is made up of nitrogen (78.09%), oxygen (20.95%), argon (0.93%), carbon dioxide (0.038%) and trace amounts of other gases. This mix of elements sustains life on Earth.

Biological and geological processes maintain this delicate balance of elements. For example:

• Oxygen is released into the atmosphere by oceanic algae and by plants and is used by animals, bacteria and trees (at night).
• Carbon dioxide released by trees and created by animals when they decompose. It also gets dissolved in water and released again.
• Nitrogen is removed from the atmosphere by lightning and bacteria and returned through decaying processes.

In cities a human made souce of air pollution incldues emissions from cars and trucks.
Image courtesy of the RTA

All of us are exposed to some air pollution, however the highest concentrations generally occur in urban areas where the six most common air pollutants in Australia - carbon monoxide, sulfur dioxide, lead, nitrogen dioxide, ozone and particles - are found.

Carbon monoxide, sulfur dioxide and lead are 'primary pollutants'. This means they are emitted directly from sources, such as motor vehicles exhausts and factories. Ozone is a secondary pollutant, formed by the reactions of other pollutants. It is not directly emitted from a particular source. Particles and nitrogen dioxide can be either primary or secondary pollutants.

Technological advances such as lead-free fuel have reduced the levels of most of these pollutants. The most widespread continue to be ozone and particles.

Another category of pollutants, 'air toxics', help to form ground-level ozone pollution. This catagory includes polycyclic aromatic hydrocarbons (PAHs), heavy metals and aldehydes and volatile and semi-volatile organic compounds (VOCs) like benzene.

In cities a human made souce of air pollution incldues emissions from cars and trucks.
Image courtesy of the RTA

All of us are exposed to some air pollution, however the highest concentrations generally occur in urban areas where the six most common air pollutants in Australia - carbon monoxide, sulfur dioxide, lead, nitrogen dioxide, ozone and particles - are found.

Carbon monoxide, sulfur dioxide and lead are 'primary pollutants'. This means they are emitted directly from sources, such as motor vehicles exhausts and factories. Ozone is a secondary pollutant, formed by the reactions of other pollutants. It is not directly emitted from a particular source. Particles and nitrogen dioxide can be either primary or secondary pollutants.

Technological advances such as lead-free fuel have reduced the levels of most of these pollutants. The most widespread continue to be ozone and particles.

Another category of pollutants, 'air toxics', help to form ground-level ozone pollution. This catagory includes polycyclic aromatic hydrocarbons (PAHs), heavy metals and aldehydes and volatile and semi-volatile organic compounds (VOCs) like benzene.

Pollution has two types of sources: anthropogenic (human-made) or biogenic (natural). On this website, we will mostly look at sources resulting from human activity and what we can do to reduce them.

In cities, human-made sources include:

• emissions from cars and trucks
• emissions by major industry, such as power stations
• the use of solvents in homes and businesses
• fuel combustion in homes and businesses
• commercial activities such as in motor vehicle smash repair shops and service stations
• household activities like lawn mowing and wood heating.

In rural areas, agricultural burning, coal heaters and solid-fuel heaters are the most significant sources.

Bushfires and dust storms are also responsible for pollution throughout NSW.

Many of the sources of air pollution, like transport and industry, are also sources of greenhouse gases and thus contribute to climate change. Taking steps to limit emissions from all of these sources is good for everyone.

Pollution has two types of sources: anthropogenic (human-made) or biogenic (natural). On this website, we will mostly look at sources resulting from human activity and what we can do to reduce them.

In cities, human-made sources include:

• emissions from cars and trucks
• emissions by major industry, such as power stations
• the use of solvents in homes and businesses
• fuel combustion in homes and businesses
• commercial activities such as in motor vehicle smash repair shops and service stations
• household activities like lawn mowing and wood heating.

In rural areas, agricultural burning, coal heaters and solid-fuel heaters are the most significant sources.

Bushfires and dust storms are also responsible for pollution throughout NSW.

Many of the sources of air pollution, like transport and industry, are also sources of greenhouse gases and thus contribute to climate change. Taking steps to limit emissions from all of these sources is good for everyone.

Air quality looks at the composition of air in terms of the pollutants outlined above. The level of pollution in a specific area at a certain time is rated using the Air Quality Index, a standard measure used around the world.

In NSW, the Office of Environment and Heritage (OEH) produces a regional Air Quality Index for Sydney, the Illawarra, north-west slopes (Tamworth), south-west slopes (Wagga Wagga), central tablelands (Bathurst) and the Lower Hunter. Air quality is rated from ‘Very good’ through to ‘Hazardous’ each hour, every day. Learn more about air quality monitoring and reporting.

Air quality isn't just about the air outside. Indoor air quality looks at the air inside our homes and buildings, which can contain pollutants - sometimes more than the air outside.

Air quality looks at the composition of air in terms of the pollutants outlined above. The level of pollution in a specific area at a certain time is rated using the Air Quality Index, a standard measure used around the world.

In NSW, the Office of Environment and Heritage (OEH) produces a regional Air Quality Index for Sydney, the Illawarra, north-west slopes (Tamworth), south-west slopes (Wagga Wagga), central tablelands (Bathurst) and the Lower Hunter. Air quality is rated from ‘Very good’ through to ‘Hazardous’ each hour, every day. Learn more about air quality monitoring and reporting.

Air quality isn't just about the air outside. Indoor air quality looks at the air inside our homes and buildings, which can contain pollutants - sometimes more than the air outside.

The air quality in Australian cities is generally better than cities in most parts of the world, even comparable countries. A global air pollution map produced by the European Space Agency shows parts of China, the US and Europe being among the major air pollution hot spots.

Air quality in Australia's major urban centres varies due to weather, geography, local industry, population density and transport use. In NSW, the air we breathe is generally good. It’s certainly much cleaner than it was 15 years ago thanks to Government controls on industry, motor vehicles and fuels, as well as on backyard burning.

The area most susceptible in NSW is the Greater Metropolitan Region, which includes Sydney, the Lower Hunter and Illawarra regions and is home to around 70 per cent of the NSW population. The main source of air pollution in these built-up urban areas is transport.

This is because we are relying on motor vehicles more and more; the number of trips we take and the length of those trips is on the rise. In the last 30 years, the population of Sydney has increased by 50 per cent while the number of cars on the road has increased by 150 per cent.

The air quality in Australian cities is generally better than cities in most parts of the world, even comparable countries. A global air pollution map produced by the European Space Agency shows parts of China, the US and Europe being among the major air pollution hot spots.

Air quality in Australia's major urban centres varies due to weather, geography, local industry, population density and transport use. In NSW, the air we breathe is generally good. It’s certainly much cleaner than it was 15 years ago thanks to Government controls on industry, motor vehicles and fuels, as well as on backyard burning.

The area most susceptible in NSW is the Greater Metropolitan Region, which includes Sydney, the Lower Hunter and Illawarra regions and is home to around 70 per cent of the NSW population. The main source of air pollution in these built-up urban areas is transport.

This is because we are relying on motor vehicles more and more; the number of trips we take and the length of those trips is on the rise. In the last 30 years, the population of Sydney has increased by 50 per cent while the number of cars on the road has increased by 150 per cent.

To find out how we’re faring on air quality each day, bookmark the regional air quality index map on the Office of Environment and Heritage website. You can also register to receive up-to-date SMS alerts for high pollution days.

The Air Emissions Inventory for the Greater Metropolitan Region in NSW identifies how much each source contributes to air pollution.

Detailed information on air toxics can be found in Chapter 4.1 of NSW State of the Environment 2009 report.

Current and Projected Air Quality in NSW is a technical paper released at the Clean Air Forum 2010. It summarises ambient air quality trends from 1994 and details possible emission reduction scenarios to meet the standards for photochemical smog (as ozone) in Sydney.

To find out how we’re faring on air quality each day, bookmark the regional air quality index map on the Office of Environment and Heritage website. You can also register to receive up-to-date SMS alerts for high pollution days.

The Air Emissions Inventory for the Greater Metropolitan Region in NSW identifies how much each source contributes to air pollution.

Detailed information on air toxics can be found in Chapter 4.1 of NSW State of the Environment 2009 report.

Current and Projected Air Quality in NSW is a technical paper released at the Clean Air Forum 2010. It summarises ambient air quality trends from 1994 and details possible emission reduction scenarios to meet the standards for photochemical smog (as ozone) in Sydney.