Air pollution is literally rewriting our DNA. New research links dirty air to the same cancer mutations found in smokers.

Air pollution can cause DNA mutations that have been linked to lung cancer, according to new research showing strong connections between polluted air and the same genetic changes often seen in smokers. 

Scientists analyzed the cancer genomes of 871 non-smokers with lung cancer from four continents and found a clear pattern. People living in areas with high levels of air pollution had more mutations in key genes tied to lung cancer, namely TP53 and EGFR, and were nearly four times more likely to show the SBS4 mutation, a known result of exposure to tobacco smoke. These mutations were far less common in non-smokers from cleaner regions. The study also uncovered a new mutational signature, SBS40a, present in 28% of non-smokers but absent in smokers, with no clear environmental cause identified. The research compared these non-smoker genomes with 345 smoker genomes to show both shared and unique patterns. 

Secondhand smoke was linked to only a small increase in these genetic mutations, which points to air pollution as a potentially stronger contributor than previously thought. While the data relied on regional pollution levels rather than individual exposure, and some participants may have underreported smoking history, the findings reinforce the theory that fine particles in air pollution can alter DNA in ways that promote cancer. 

This is especially relevant as 10 to 20% of lung cancer cases in the U.S. now occur in people who never smoked. The team plans to broaden their dataset to include more diverse populations and better understand the unexplained SBS40a signature.

source

 Wednesday, July 2, 2025. Media Advisory. NIH. 

"NIH study links particulate air pollution to increased mutations in lung cancers among nonsmokers"