Website of the UK government

What is air pollution?

The air contains substances that can be harmful to health. Air pollutants include ozone, oxides of nitrogen, ammonia, sulphur dioxide, carbon monoxide and particulate matter (bits of soot, dust or liquid, for example).

What causes air pollution?

In the past, most air pollution was caused by fossil fuels like coal being burnt to create heat and energy in homes and for industry. Laws were introduced in the 1950s and 1960s to control the amount of gases given off by industry. But power stations and some industrial processes still produce sulphur dioxide and oxides of nitrogen among other pollutants. These both contribute to acid rain, which damages trees and plants, and can be harmful to lakes and rivers.

Nowadays the main threat to clean air comes from car and road vehicle fumes. Cars burn petrol and diesel, giving off air pollutants like oxides of nitrogen and particulate matter. These can cause problems for people, wildlife and the environment.

• The causes of air pollution: Air Quality Archive Opens new window

• Air quality, emissions and greenhouse gases: Environment Agency Opens new window

Effects of air pollution on people

Polluted air can cause problems for people who have lung diseases, heart conditions and asthma. Some pollutants are known to cause cancer. Children and older people are particularly at risk and it is estimated that in the UK, air pollution lowers everyone’s life expectancy by around seven to eight months.

If your health is good, the normal levels of air pollution in the UK are unlikely to cause you any problems.

Particulate matter

When people breathe in polluted air, very fine particles can get into their lungs and cause breathing difficulties; over time this can lead to heart and lung problems.

Ground-level ozone

Sunlight can cause some chemicals to react and form ozone near the ground – in some cases this can damage people’s eyes and throats. If you have asthma the symptoms can be even worse.

Carbon monoxide

Carbon monoxide from older cars, cigarette smoke and faulty gas appliances affects the blood and is especially dangerous for pregnant women and their unborn babies.

Lead

Lead in petrol has been reduced but it is still released into the air by industry and coal power stations. If people are exposed to high levels of lead, organs in the body such as the kidneys, heart and brain can be damaged. Children are more sensitive to the effects of lead pollution than adults, and a child's intelligence may suffer.

What to do if you have breathing problem

If you know you have breathing problems, you can stay indoors when pollution levels are high and always take your medication with you when you go out.

• Forecast of air pollution: Air Quality Archive Opens new window

• Effects of air pollution on human health: order a booklet from the Department of Health Opens new window

• A-Z factsheets of air pollutants: Environment Agency Opens new window

Effects of air pollution on plants and animals

Air pollution also affects plants and wildlife. This is why it can be more difficult for plants to thrive in city centres. Pollutants can also get into animals’ food and water.

Sulphur dioxide and nitrogen oxides can make water and soil more acidic (and therefore harmful to some plants and animals). This can also reduce the amount of plants that provide food and shelter, causing serious problems for other wildlife.

Ozone can damage many types of plants, including farmed crops.

Is air pollution getting better or worse?

Air quality in the UK is now generally good, but there are still sometimes unacceptably high levels of pollution in some areas.

Cars and road vehicles pose the main threat to clean air, so it is important to cut down on the pollution they make. Petrol now contains much less lead and sulphur, and newer cars are manufactured to produce fewer emissions. New fuels are also being made that are cleaner than petrol and diesel, and electric cars produce no emissions when they are driven.

• Greener cars and driving

• The UK's air quality strategy: Department for the Environment, Food and Rural Affairs (Defra) Opens new window

Natural sources of air pollution

Pollution can also be caused by natural events like volcanoes erupting, forest fires and lightning strikes. These put pollutants like sulphur dioxide and nitrogen oxide into the air. Dust blown over from the Sahara desert in Africa, and salt evaporating from the sea can affect the UK.

Air pollution from natural events is more difficult to control and reduce than pollution from man-made sources. However, people can reduce the air pollution they create and help to make the air cleaner and safer to breathe.

What you can do about air pollution

There are many ways to prevent and reduce air pollution:

• using less energy at home means that less coal, oil and gas will have to be burnt, and less air pollution will be given off
• using public transport, cycling or walking more instead of driving
• if you need to drive, there are techniques that help you use less fuel, like driving more slowly and smoothly
• when buying paints, varnishes or glues, look for products that are water-based or have low solvent content

• Saving energy at home

• Greener travel and leisure

• Greener DIY

More useful links

• Look up a car's CO2 emissions: ACT ON CO2 Opens new window

• How the UK government is working to control air pollution: Defra Opens new window