Air pollution discovery transforms researchers understanding of how cancer forms

A group of researchers have made a groundbreaking discovery as to how air pollution causes cancer, completely transforming their understanding of how tumours form.

Scientists from London’s Francis Crick Institute found that air pollution does not directly damage cells, but rather wakes up old cells which are already damaged.

These findings are very different from the traditional view that cancer starts in a healthy cell which mutates its DNA until it becomes cancerous, but many substances, such as air pollution, do not appear to damage DNA.

The new discovery could explain how other carcinogenic substances result in cancer and scientists say it may now be possible to create medications which prevent cancer from forming.

Lead author of the study and Cancer Research UK Chief Clinician, Professor Charles Swanton, said: ‘Cells with cancer-causing mutations accumulate naturally as we age, but they are normally inactive. We’ve demonstrated that air pollution wakes these cells up in the lungs, encouraging them to grow and potentially form tumours.

‘The mechanism we’ve identified could ultimately help us to find better ways to prevent and treat lung cancer in never smokers. If we can stop cells from growing in response to air pollution, we can reduce the risk of lung cancer.’

Researchers studied how air pollution causes cancer, particularly in non-smokers, and focused on PM2.5.

Through a series of experiments it was found there was a higher incidence of cancer not related to smoking in areas with high levels of air pollution.

Scientists also revealed that breathing in PM2.5 could release a chemical, interlukin-1-beta, in the lungs which causes inflammation in the lungs and activates cells to repair damage.

However, one in every 600,000 cells in the lungs of an average 50-year-old are potentially cancerous.

This is because we gain these cells as we age which can becomes cancerous once activated by the chemical.

Additionally, researchers experimenting on mice exposed to air pollution found they could stop the cancer from forming when they used a drug which blocks the chemical.

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