Indoor air pollution

What is indoor air pollution?

You probably know that it’s harmful to breathe in polluted air when you’re outside. The same is true when you’re indoors. We spend about 90% of our time indoors – at home, at work, at school, or when we go to shops or restaurants. Poor indoor air quality has been linked to lung diseases like asthma, COPD and lung cancer.

Indoor air pollution is dust, dirt or gases in the air inside a building such as your home or workplace that harms us if we breathe it in.

Types of air pollution include:

  • particulate matter (PM) – microscopic particles of dust and dirt in the air
  • gases – carbon monoxide, nitrogen oxides, sulphur dioxide

Indoor air pollution can be caused by many things. These include:

  • how you heat your home
  • how you cook
  • poor ventilation
  • damp
  • chemicals in cleaning products
  • some building materials

You may experience indoor air pollution at your home, workplace or in other buildings.

The quality of the air you breathe anywhere is especially important if you’re living with a lung condition like asthma or chronic obstructive pulmonary disease (COPD).

Who’s at risk from poor indoor air quality?

Everyone is at risk from indoor air pollution. If you’ve got COPD, asthma, bronchiectasis or any other lung condition, you’re much more likely to be affected by poor air quality.

If you have a lung condition you may also spend more time indoors. This means you may have more contact with things that affect the air you breathe. These could include cigarette smoke, cleaning materials or mould.

Children are particularly vulnerable to poor indoor air quality as their lungs are still developing. Their airways are smaller, so inflammation caused by pollution can cause them to narrow more easily than in older people. Pollution can also interact with allergens to cause asthma in children. 

Next: What are the effects of indoor air pollution? >

Download our indoor air pollution information (302KB, PDF)

Last medically reviewed: September 2018. Due for review: September 2021

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.