There's lots to understand about air pollution. In the questions below we've pulled together some of the most useful information.

What is air pollution and where does it come from? Does the amount of air pollution around me change at different times?
How can I find out how much pollution there is where I am? How much of a problem is air pollution in the UK anyway?
What’s the government doing to reduce air pollution?



What is air pollution and where does it come from?

Air pollution is an umbrella term for lots of different types of pollution in the air around us. All these pollutants can be inhaled and absorbed into your body. Different types of pollution are caused by different things, and can affect your body in different ways. For the most part, air pollution is invisible to the naked eye, so just because you can’t see it, doesn’t mean it’s not there.


Particle pollution Gases
Chemicals Mould


Particle pollution

Some pollution, often called PM10 or PM2.5, is made up of little bits of material, which can be from all sorts of places including smoke from fires, exhaust fumes, smoking or the dust from brake pads on cars. These particles are smaller than the width of a human hair (and PM2.5 is four times smaller even than PM10: the numbers refer to particles up to 10 or 2.5 micrometers in width) and we can breathe them in without noticing.

Normally these particles are too small to see, but on some days with especially high pollution levels they can mix with other types of pollution to make the sky look a little hazy.

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As well as particles, there are also gases. Sulphur Dioxide (SO2) and Nitrogen Oxides (NOX) come mostly from burning fuels or other materials, so levels are especially high around roads. But you also get them from home gas boilers, bonfires and other sources as well.

These gases also mix with the air we breathe and get absorbed into our bodies.


Ozone (O3) in the upper atmosphere is really valuable to protect us from UV-B rays, helping to prevent sunburn and cancer. But when it’s in the lower atmosphere and the air around us, Ozone gas is an irritant and can cause swelling in various parts of the body such as the lungs.

Lower level ozone is created when other types of pollution are exposed to sunlight, so we get the most ozone when other pollution levels are high.


While lots of pollution can have long term health impacts on people, some pollution can be dangerous straight away when there is enough of it. Carbon Monoxide (CO) is made when things are burned without enough oxygen around them and it stops your blood from being able to transport oxygen around your body. A lot of Carbon Monoxide is produced by vehicles, but it is most dangerous in enclosed areas, like your home, where the amount can build up to high levels.

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There are lots of chemicals which can create air pollution including those known as Volatile Organic Compounds or VOCs. This is the name for a group of chemicals that start as liquids or solids, but disperse into the air very easily. You can often tell when things contain a lot of these chemicals because they can have a very strong smell after you have used them, like lots of paints and varnishes. They also come from products like air fresheners, hair sprays and cleaning products. Once the chemicals mix with the air, they become very easy for us to breathe in and can have harmful effects.

Formaldehyde can be given off by furniture made from combined materials like MDF, as well as furnishings, fabrics, glues and insulation materials. It can cause irritation of the lungs.

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Mould tends to grow in damp places. The damp might be because of leaking pipes or roofs, but is often because of condensation. Condensation often forms in bathrooms from the use of showers or baths with inadequate ventillation, in kitchens from washing up and from cooking, and also from drying clothes indoors. The mould spores that are released can trigger allergic reactions in some people and breathing difficulties in others.

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For more information on pollution, visit The Clean Breathing Institute.



Does the amount of air pollution around me change at different times?

Yes it can. Air pollution levels change with location, different weather conditions, and with the activities that are taking place.

Air pollution concentrates around the areas where it is formed. So places that have lots of traffic, industry or farming can have higher levels of pollution.

Closing roads to traffic can reduce air pollution on those roads almost straightaway. This year air pollution on a major road in London was 97% lower when the roads were closed for the London Marathon than on a normal Sunday. This means that the more traffic there is, the more pollution there usually is, so rush hour can be particularly bad.

Pollution can change at different times of year too. Ozone pollution forms in direct sunlight, so more is generated on particularly sunny days and levels are likely to be higher in spring and summer. In winter, some weather patterns, when there is particularly cold air at ground level and warmer air above it, air pollution can become trapped until the weather changes again.

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How much of a problem is air pollution in the UK anyway?

It’s a big problem. It is thought that up to 36,000 deaths each year in the UK are caused by air pollution.

The World Health Organisation (WHO) sets maximum limits for how air pollution that shouldn't be passed. These limits look at daily and annual averages. Almost 2,000 locations in the UK are above these limits and there are places in the UK where the air pollution is three times as high as the WHO limits.

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What’s the government doing to reduce air pollution?

The UK government has recently launched its Clean Air Strategy.

The strategy sets out their plans for dealing with sources of air pollution. This includes things like developing new guidance on things that create pollution: like tyres, brakes and wood stoves. They are also working to make sure that only the cleanest fuels are available for sale.

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How polluted is it where I am?

The UK government has a web page with an air quality forecast (a bit like a weather forecast) where you can see the latest air pollution levels for your area on a map.

On that page you can also search by town or postcode to see more local information.

The forecast is graded from pale green (low) to purple (very high). If you suffer from medial conditions that are made worse by air pollution, it's best to avoid doing strenuous activity outside on high pollution days.

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 Find out more:How air pollution affects your health