Essential
- A study reveals that air pollution can cause genetic mutations related to lung cancer in non-smokers.
- These mutations are similar to those caused by tobacco, especially in very polluted regions.
- Researchers call to expand prevention beyond smoking.
Long associated with tobacco, lung cancer affects more and more people who have never smoked. A new study, published in the journal Naturehighlights the genetic links between certain environmental exhibitions – such as air pollution – and mutations promoting this type of cancer.
Mutations similar to those caused by tobacco
American researchers at the University of California in San Diego and the National Cancer Institute (NCI) analyzed the genomes of pulmonary tumors in 871 people who have never smoked, from 28 different regions. Result: they detected so -called genetic mutations “signatures mutationnelles” which betray the imprint left by past exhibitions. “Our research shows that air pollution is strongly associated with the same types of DNA changes as those that are usually associated with smoking”, Scientists explain a press release.
In detail, pollution results in a global increase in the number of changes, in particular those linked to aging and the development of cancers. The team even observed a dose-efferse relationship: the more patients lived in polluted areas, the more their tumors had mutations. “This is a global, urgent and growing problem”, Alert researchers.
Secondary but present: the effect of passive smoking
Surprise of the study: passive smoking seems to cause few identifiable genetic mutations, although a reduction in the length of the telomeres – a sign of cellular aging – has been observed. “If there is a mutagenic effect, it may be too low to be detected with our current tools”nuance scientists. Finally, the authors of the study discovered a mutational signature present in most non-smokers with lung cancer, but absent from smokers. “We do not yet know what causes it”they recognize.
While this research sheds light on the multiple faces of lung cancer in non-smokers, it reaffirms the importance of acting on all environmental fronts. In France, a symbolic turning point has been crossed: it is now prohibited from smoking in many outdoor public places – shelter, parks, beaches, surroundings of schools or libraries. A strong measure which aims to reduce exposure to passive smoking, but which, in the light of current studies, is no longer enough. Because if smoking is seriously harming health, the air you breathe can also become a silent factor of cancer.
