Worldsfeed Health Desk:
Air pollution has long been a public health concern, but new research reveals its potentially deadly role in causing genetic mutations linked to lung cancer in non-smokers. A groundbreaking study published in Nature has found a strong association between exposure to outdoor air pollution and DNA changes commonly observed in lung cancer tumors.
The international study, led by scientists from the University of California San Diego (UCSD) and the US National Cancer Institute (NCI), analyzed the cancer genomes of 871 individuals from across four continents. All participants were diagnosed with lung cancer despite having never smoked or having smoked fewer than 100 cigarettes in their lifetime.
The research uncovered that individuals living in areas with high levels of air pollution were significantly more likely to exhibit key DNA mutations. These included alterations in the TP53 and EGFR genes—well-known drivers of lung cancer typically found in smokers. One of the most notable discoveries was the SBS4 DNA mutational signature, previously associated with tobacco smoke, now also found in non-smokers exposed to high pollution levels.
In fact, non-smokers from polluted regions were nearly four times more likely to show this mutation than those from areas with cleaner air. Researchers also identified a new mutational signature, SBS40a, found in 28% of non-smokers’ tumors, which appears unrelated to environmental exposure. The cause of SBS40a remains a mystery.
“Our research shows that air pollution is strongly associated with the same types of DNA mutations we typically associate with smoking,” said Dr. Ludmil Alexandrov of UCSD.
While secondhand smoke showed only a minimal link to genetic mutation in this study, air pollution and direct smoking both displayed strong associations with lung cancer-related genetic damage. These results suggest that breathing in smog and fine particulate matter (PM2.5) may trigger cancerous changes at the cellular level.
Shorter telomeres—markers of accelerated aging—were also more common in individuals exposed to higher air pollution levels, indicating a broader impact on cellular health.
Though the study did not directly measure each individual’s exposure levels, the regional air quality data provide strong circumstantial evidence. The findings emphasize the urgent need for cleaner air policies and further research into pollution-related cancers.
“This is an urgent and growing global problem that we are working to understand regarding never-smokers,” said epidemiologist Maria Teresa Landi of the NCI.
With non-smokers accounting for up to 20% of all lung cancer cases in countries like the U.S., the link between air pollution and cancer mutations cannot be ignored.
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