Healthy indoor environments

Many people with asthma are sensitive to the droppings of house-dust mites. These  are tiny creatures that live in the dust that builds up around the house – in carpets, bedding, soft furnishings and soft toys.

• Find out more about house-dust mites

• Furniture, flooring and shelving made from chipboard or MDF may trigger asthma symptoms in some people.
• If you are buying a new carpet you should ask the shop if they could unroll and air it before you bring it home. People who are allergic to latex should avoid carpet with a foam underlay.
• Some people report that their asthma is triggered by the smell of new sofas and soft furnishings. Try airing new furniture before bringing it into the house and keep the windows open for a few days.
• Those allergic to pets may continue to have symptoms for many months after a cat last lived in the house. This is because pet allergens can linger for a long time on furniture and in carpets and are very difficult to remove. When moving house it is wise to check whether the previous homeowners had pets.

In everyday life lots of domestic products and solvents are used around the home, many of which release chemicals that can cause breathing difficulties in some people with asthma.

Cleaning
Furniture polish, air fresheners, carpet cleaners, oven cleaners and dry-cleaned clothes can all trigger asthma.

• Use solid or liquid alternatives rather than sprays where possible.
• Use as little of the product as possible and open windows.

Decorating
There has been little medical research on the many chemicals used in renovating or decorating a home.

• Wet paint can cause problems as it gives off chemicals that can trigger asthma symptoms in some people. There is no one type of paint that can be guaranteed as safe for everyone with asthma.
• New low-odour, water-based gloss paints are now available that may be slightly better for some people with asthma. These paints are available at most large DIY outlets and manufacturers’ details can be obtained by contacting the Paintmakers Association.
• Stripping wallpaper can unsettle dust so wash down wallpaper before starting as this may help to dampen down the dust. Ensure there is plenty of ventilation.
• Some people prefer to wear a mask during decorating and even during everyday cleaning, but no special masks have been shown to reduce symptoms.

Building work and repairs

• There is a link between poor housing conditions and asthma. It is important to ensure that housing problems such as damp, poor ventilation and inadequate heating are resolved as quickly as possible.
• Major renovation or structural repair can cause a lot of dust and other irritant triggers. Problems can arise when treating a house for woodworm, damp and dry rot. You can also ask your local council’s environmental health department for advice.
• Some insulation materials give off pungent gases which can trigger asthma. It is important that the material covering the insulation is not cracked, as this can leak fumes into the house. If you are having cavity wall insulation installed check with the builder or contractor exactly what they intend to use. Micafil is free of these chemicals.
• If you are contemplating any building work within your home it is worth seeing your doctor or nurse to check if a temporary increase in medicine is needed. Or you might like to consider staying with friends or family while the work is being carried out.

Dampness in housing has been linked with asthma in some people. Research has also shown that asthma symptoms were harder to control in people with homes without central heating.

Wood and coal fires without adequate flues can cause mild worsening of breathing problems, compared with central heating, as it is harder for the smoke to escape. On the other hand if the flues are fine, wood and coal fires my limit the number of house-dust mites.

Vacuum cleaners

• Health Which? magazine (December 1997) found that some ‘ordinary’ vacuum cleaners worked just as well as those with special filters. No single brand was found to be the clear winner in the survey. 

Bedding

• Recent research has shown that barrier bedding on its own does not seem to reduce exposure to house-dust mites enough to improve asthma symptoms. They may reduce symptoms from house-dust mites if used in conjunction with other measures. See the factfile on dust mites. 
  

Ionisers

• Ionisers aim to clean the air through the use of electrostatic charges. Although there is some evidence that they reduce allergens, other research shows that they can increase symptoms such as night-time cough in children. Asthma UK does not recommend their use.
  

Air filters

• Several studies have shown that modern air filters can capture allergens, but evidence that they are capable of reducing symptoms is less clear. See the factfile for more information.
  

Ventilation

• Good ventilation benefits people with asthma. It reduces humidity, which reduces the number of house-dust mites and moulds. It also helps to disperse gases produced by heating and cooking.
• Opening the window generates a significant amount of air exchange.
• There is no need to have air conditioning in addition to windows and vents.