LOS ANGELES, July 2 (Xinhua) -- Exposure to fine particulate air pollution is strongly associated with increased genetic mutations in lung cancer tumors among individuals who have never smoked, a new study led by the U.S. National Institutes of Health (NIH) has found.
The study, published Wednesday in the journal Nature, represents the largest whole-genome analysis to date of lung cancer in nonsmokers, offering new insights into how environmental pollutants may drive cancer in the absence of tobacco use.
Researchers from NIH's National Cancer Institute and the University of California San Diego examined lung tumors from 871 nonsmoking patients across 28 regions worldwide as part of the Sherlock-Lung study.
They found that air pollution exposure -- particularly from traffic and industrial sources -- was linked to cancer-driving mutations, including alterations in the TP53 gene and other mutational signatures typically associated with tobacco-related cancers.
The study also revealed that air pollution was related to shorter telomeres, which are sections of DNA found at the end of chromosomes. Shorter telomeres are associated with aging and reduced cellular replication capacity, potentially accelerating cancer progression.
Understanding how air pollution contributes to the mutational landscape of lung tumors helps explain the cancer risk for nonsmokers and highlights the urgent need for stronger environmental protections, the study suggested.
Lung cancer in nonsmokers accounts for up to 25 percent of all lung cancer cases globally, according to the study. ■