What is air indoor air pollution?
Most people know about outdoor air pollution, much of which is caused by traffic. But what do we mean by indoor air pollution?
Almost all the air we breathe contains very low levels of pollution - things like gases, dust, moulds and chemicals. Most of them are harmless.
Some pollution, though, can be harmful when it's trapped in a confined space, like a house. Breathing it in can sometimes give you breathing problems, especially if you have allergies, or a lung disease like asthma. As most of us spend about 90% of our time indoors, it's important to ensure that the air we breathe in our homes (or where we work), is as clear and unpolluted as possible.
How can you detect indoor air pollution?
In some cases, indoor air pollution can cause allergic reactions and irritate your eyes, skin, nose and lungs. In severe cases, it can cause dizziness and nausea. You may notice that the symptoms get better when you let in more air from the outside, or when you're away from your home. If that happens, then it's likely that something inside your home is polluting the air you breathe.
What can be done to reduce indoor air pollution?
The most effective way to control most indoor air pollution is to get rid of the cause. You can also improve your ventilation - bring in cleaner outdoor air. Some people have found that an air cleaner can be helpful (although opinions vary a lot).
What are the main causes of indoor air pollution?
Tobacco smoke: the smoke you breathe in from someone else's cigarette or pipe contains a number of dangerous substances, including: carbon monoxide, formaldehyde and other gases and particles, some of which can cause cancer. Smoke that comes from the end of the cigarette does not even pass through the filter.
People with a lung condition often find that other people smoking around them affects them very badly. And, of course, it is not good for children to breathe in tobacco smoke.
If you smoke, please be aware of others who do not, and who may not want to breathe in your smoke.
Animal dusts: the minute particles of fur and skin from household pets - from dogs to budgies - are a major cause of allergy in some people. Cat hair, for example, settles on carpets, upholstery and bedding and can cause long-term allergy. The most effective solution is not to keep pets in your home.
Alternatively, you can keep the levels of animal dusts down by regular and thorough vacuuming. It also helps to keep animals out of bedrooms. And you could also consider pets that produce lower levels of fur or skin such as poodles or gold fish.
Mould, mildew and bacteria: these may come from badly cleaned air conditioners or from a source of damp in your home. Try to make sure that rooms like the bathroom and kitchen are well ventilated. This will help prevent condensation, which causes mildew.
Cooking and heating appliances: heaters and stoves that use gas or propane can produce harmful amounts of nitrogen dioxide and/or carbon monoxide, if they are not properly installed and vented. Low levels can irritate you eyes and breathing, and give you headaches and nausea. High levels can kill you.
Make sure all your appliances are professionally installed and inspected and have a vent to the outside. If you suspect a gas leak, turn off the appliance at the mains, open the doors and windows and get help straight away.
House dust mites: are found in every home, mainly in bedding. Where the atmosphere is warm and moist, it is virtually impossible to get rid of them as they breed very fast. Many people, especially those with asthma, are allergic to house dust mites.
It helps to wash your bedding often. So can using a special mattress and pillow covers that the mites can't pass through.
Household products: the chemicals in some household products such as aerosols, cleaning products, pesticides, paints and solvents can cause dizziness, nausea, or allergic reactions. You should follow the directions on these products carefully, and use them in a well ventilated area. If possible, use non-toxic products.
Formaldehyde gas: some adhesives, carpets, upholstery fabrics, ply and particle boards used in building release this gas. It can give you headaches, dizziness, rashes and nausea, and can irritate your eyes, nose and throat.
It's much more likely to be an issue in the workplace. But if it affects you at home, remove the source if possible. If you can't do that, cover the source with a coating and increase ventilation.
Radon gas: soil or rock which contains small amounts or uranium or radium releases radon gas. In a few areas of the UK where housing is built on granite rock, radon gas can get into your home from the rock below through cracks and drains.
Local consumer advice services will advise you if radon is a problem in your area. If it is, you can have your home tested for radon levels and, if necessary, there are professionals who can treat it.
Asbestos: asbestos fibres can be dangerous. Lagging on pipes, tanks and boilers which is more than about 25 years old may contain asbestos. Asbestos may also be incorporated in roofing, flooring and insulation boarding. Contact your local Council for advice.
If it's crumbling and in poor repair, it may be dangerous and you should get specialists to remove it. But if it's in good condition and sealed, then it's safer to leave it where it is than to try and remove it. But you shouldn't drill, cut or sand it.
Where you might find air pollution in your home
Page last medically reviewed: August '07
