New research shows lung cancer is caused by air pollution
Radical new research by the Francis Crick biomedical research institute in London suggests that air pollution is instrumental in triggering cancer. The findings are not only a breakthrough in terms of understanding and combating cancer, but also in realising the potential danger faced by populations across the world from air pollution.
Air pollution is a widespread threat
Air pollution has to date been linked to a wide variety of health problems, including asthma, chronic obstructive pulmonary disease (COPD), heart disease and dementia. This latest research explains how it causes cancer to start in people who are non-smokers.
Smoking is the biggest risk factor for lung cancer, but air pollution is believed to cause roughly 1 in 10 cases. Globally, around 300,000 lung cancer deaths in 2019 among non-smokers were attributed to exposure to airborne particulate matter.
Commenting on the significance of the findings, Dr Emilia Lim, one of the Crick researchers, said: “It’s super-important – 99% of people in the world live in places where air pollution exceeds the WHO guidelines so it really impacts all of us.”
Exposure to particles is the root cause of cancer
The research, part of the £14m TRACERx Lung Study funded by Cancer Research UK, examined data from 400,000 people and found that exposure to fine airborne particulate matter (PM2.5) causes a chain reaction that results in cancer. Tiny PM2.5 particles, around 3% of the width of a human hair, start by causing inflammation in the lungs. The lungs in turn activate dormant cells that carry cancer-causing mutations. This combination can trigger the cells to grow uncontrollably, forming tumours.
Cancer Research UK Chief Clinician, Professor Charles Swanton, explains: “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.”
Blocking inflammation is key
The research team examined a type of lung cancer known as Epidermal Growth Factor Receptor (EGFR) mutant lung cancer. Mutations in the EGFR gene are commonly found in lung cancer in non-smokers. They found higher rates of EGFR mutant lung cancer, as well as higher rates of other types of cancer, in people living in areas with higher levels of PM2.5 pollution.
Breathing in PM2.5 particulate matter triggers a chemical response in the lungs, releasing the molecule interleukin-1-beta (IL-1β).The research trials showed that, by blocking IL-1β, the formation of cancer was successfully prevented.
The research team concluded that the model presented in their study could be responsible for the early stages of many different types of cancer, where environmental triggers awaken cells carrying cancer-causing mutations in different parts of the body.
Clean air has never been more important
With a better understanding of the driving forces behind lung cancer in non-smokers, scientists hope to develop preventative measures. Doctors have already trialled an interleukin-1-beta drug in cardiovascular disease and found out, by complete accident, that it cuts the risk of lung cancer.
However, such developments take time and prescribing ongoing drugs is surely less desirable than dealing with the issue at hand – air pollution. We spend up to 90% of our time indoors, where air quality can be 2 to 5 times worse than outdoors. Simple, cost effective solutions that are proven to substantially improve Indoor Air Quality already exist. Air purification using HEPA filtration is widely used by the health service, government departments and multiple business sectors to provide clean indoor air, not only protecting us from common air pollution particles but also from pathogens like Covid-19.
The best preventative method is to ensure that the air around us, where we spend the majority of our lives, is pure. With indoor air regulation already in the pipeline, this latest cancer research will no doubt act as a catalyst to improve standards and controls sooner rather than later.
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