THE mystery behind how air pollution causes cancer has finally been solved by scientists – who said the findings marked a “new era” in cancer research.
This breakthrough is said to explain why so many non-smokers still develop lung cancer.
Researchers at the Francis Crick Institute in London have found that instead of directly damaging cells, air pollution ‘wakes up’ dormant mutations and turns them cancerous.
In what would mark a historic breakthrough, the research means it is now possible for medical experts to develop drugs that prevent humans from getting cancer.
Previously, scientists thought that cancer starts from a healthy cell, which then mutates as its DNA is damaged.
But new findings instead suggest that the damage to our cells that could turn cancerous already exists before the cancer develops, which grows as we age while normally remaining harmless.
However, air pollution “wakes up” these damaged cells, with the damage accelerating and turning into cancerous cells.
Although it is well understood that smoking causes lung cancer, the recent study was launched as an investigation into why non-smokers still develop the disease.
Smoking is by far the biggest cause of lung cancer, but air pollution still causes around one in ten cases in the UK, killing more than 6,000 Britons who have never smoked each year.
Crick scientists found that areas of the UK with higher levels of air pollution had more cases of lung cancer that were not caused by smoking.
Presenting his team’s findings, Professor Charles Swanton said the research marks a “new era”.
“Our study fundamentally changed the way we view lung cancer in people who have never smoked,” he said.
“Cells with carcinogenic mutations naturally accumulate as we age, but they are normally inactive.
“We have demonstrated that air pollution awakens these cells in the lungs, encouraging them to grow and potentially form tumours.
“The mechanism we have identified could ultimately help us find better ways to prevent and treat lung cancer in non-smokers.
“Air pollution is associated with lung cancer, but people have largely ignored it because the underlying mechanisms were unclear.”
How does air pollution cause lung cancer?
According to groundbreaking findings from the Crick Institute, breathing in air pollution triggers a chemical alarm in the lungs.
This process activates cells in the lungs which attempt to repair the damage caused by air pollution.
But with their new understanding that air pollution ‘wakes up’ existing cancerous mutations, it is now thought that this process is instead what causes cancer to develop.
About one in 600,000 cells in the lungs of a 50-year-old person already contains potentially cancerous mutations.
The findings would mean humans may be able to take a ‘cancer blocker’ pill as medical experts gain a new understanding of how to prevent and treat tumours.
The Crick scientists focused their study on a form of pollution called PM 2.5, which is smaller than the width of a human hair.
“Ninety-nine percent of the world’s population lives in areas that exceed the World Health Organization’s annual limits for PM2.5, highlighting the public health challenges posed by air pollution. air around the world,” said Emilia Lim, another member of the Crick research team. .
Michelle Mitchell, chief executive of Cancer Research UK, told the BBC that although “smoking remains the leading cause of lung cancer”, that doesn’t tell the whole story.
“Science, which takes years of painstaking work, is changing the way we think about how cancer develops,” she said.
“We now have a much better understanding of the driving forces behind lung cancer.”
The mystery of why air pollution causes cancer is ‘solved’ in a major breakthrough