How can air pollution cause cancer?

  • Exposure to air pollution increases the risk of lung cancer.
  • Cancer risk from air pollution is relatively small. Many more lung cancer cases are caused by smoking than air pollution. 
  • Air quality in the UK is regulated and pollution levels are mostly within set limits.

Air pollution includes outdoor and indoor air pollution. Both can increase the risk of lung cancer as well as respiratory and heart diseases.


What is outdoor air pollution?

Outdoor air pollution is a mixture of tiny dust-like particles and substances in the air that have the potential to negatively impact health. It can be artificial, such as fumes from vehicles or factories and smoke from burning fuels like wood or coal. But it also includes natural sources of pollutants, such as wind-blown dust, radon and ozone. Research on air pollution usually looks at the smallest particles, called ‘particulate matter’ or PM. 


What is the cancer risk from air pollution in the UK?

Outdoor air pollution causes roughly 1 in 10 cases of lung cancer in the UK. But, it’s important to keep this in perspective. Smoking has a much bigger effect on the risk of developing lung cancer – it causes around nine times more lung cancer cases than air pollution.

Air pollution levels in the UK are lower than in many other countries. There are regulations, limits and targets for air quality that the UK Government agree to meet, to lower the health risks from air pollution. Average levels of most outdoor air pollutants in the UK are within these limits, including particulate matter.



What can I do to reduce my cancer risk?

We can’t avoid air pollution completely, and you don’t need to avoid going outside.

There are other things that affect your risk of cancer more than air pollution.  Not smoking, keeping a healthy weight, staying safe in sun and cutting down on alcohol are all proven ways you can reduce your risk of cancer.


How can air pollution cause lung cancer?

Because air pollution contains a mixture of polluting particles, there are a few ways air pollution could cause lung cancer. For example, tiny particles may build up in the lungs and damage the DNA in cells. This can change how cells divide, which can lead to cancer.

Researchers are investigating how tiny particles may cause inflammation in the lungs that can lead to cancer. You can read more about how air pollution can cause lung cancer in our digital news article.   

It has not been proven that air pollution causes other types of cancer.


How can we reduce air pollution levels?

Cancer Research UK is a member of the Healthy Air Coalition, which calls for national and local strategies to reduce outdoor air pollution across the country.  The UK Government must commit to long-term action to reduce air pollution.

There are some things we can do as individuals to reduce our contribution to air pollution, too. Making more journeys by walking, wheeling or cycling lowers emissions compared with driving, and is a great way to be more active too.


Indoor air pollution is contained indoors. It can increase the risk of lung cancer.

There can be many sources of indoor air pollution. A key source in the UK is second hand smoke from cigarettes, cigars and pipes. Burning wood and coal to heat homes or cook with also adds to indoor air pollution. 

Most exposure to second hand tobacco smoke (passive smoking) happens in the home, so it’s part of indoor air pollution. Smoke can spread from room to room and stay in the air for hours. Passive smoking can cause lung cancer and other health conditions like heart and lung diseases.

Understand more about passive smoking and the health risks to other people.

If you smoke, always smoking outside will help reduce second hand smoke indoors. But stopping smoking completely is the best thing you can do.

Find tools and support for quitting smoking.

International Agency for Research on Cancer (IARC). Air pollution and Cancer. Vol 161 (2012)

Brown, K. F. et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. Br. J. Cancer. 118, 1130-1141 (2018)

DEFRA, Air Pollution in the UK 2022 (2023)


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