NIH Study Links Particulate Air Pollution to Cancer Mutations among Nonsmokers

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NIH scientists and their colleagues at the University of California, San Diego, have found that fine-particulate air pollution, which includes pollution from vehicles and industry, was strongly associated with increased genomic changes in lung cancer tumors among people who have never smoked.

By assembling the largest-ever whole-genome analysis of lung cancer in individuals who have never smoked, researchers were able to link air pollution exposure to increased cancer-driving and cancer-promoting genetic mutations. This could potentially lead to more prevention strategies for never-smokers. Results were published in Nature.

Researchers analyzed lung tumors from 871 never-smoker patients across 28 geographic locations worldwide as part of the Sherlock-Lung study. They found associations between air pollution exposure and changes in the TP53 gene, and other genetic mutational signatures previously associated with tobacco smoking.

They also observed a relationship between air pollution and telomeres, which are sections of DNA found at the end of chromosomes that are related to the cells’ inability to replicate. Telomeres shorten naturally with age. However, scientists found fine particulate air pollution was linked to premature shortening of telomeres.

By beginning to uncover the mechanisms through which tissues acquire cancer-causing or cancer-promoting mutations following environmental exposures, this study helps scientists better understand the primary drivers of lung cancer in never-smokers—who represent up to 25% of all lung cancer cases globally.

Interestingly, the researchers found that exposure to secondhand smoke may have a lower overall ability to cause genetic mutations, known as mutagenicity, compared to air pollution.