You might think of lung cancer as a “smoker’s disease,” but new research suggests that isn’t the case at all. Instead, there are several factors that have been tied to genetic mutations which can contribute to the development of lung cancer in individuals with little to no history of ever smoking, and air pollution looks like a strong contender in the lineup.
The team behind new research published in the journal Nature looked at lung tumors found in 871 never smokers living in 28 different regions with varying levels of air pollution across Africa, Asia, Europe and North America. They used whole genome sequencing to identify patterns of DNA mutations, which are called mutational signatures. These signatures essentially act like molecular fingerprints of past exposures to things like chemicals and pollution.
By pairing the genome records with detailed pollution data gathered from satellites and ground-level monitors, scientists discovered a striking pattern: non-smokers exposed to higher levels of fine particulate matter (PM2.5) had significantly more genetic mutations in their lung tumors.
These mutations weren’t random, either, as the study found a notable increase in driver mutations, which are directly responsible for fueling cancer growth. Of course, there’s no exact cancer signature that can be tied directly to pollution as a whole. That’s why it was important to corroborate the data from the pollution monitoring with the presence of the mutations.
Surprisingly, too, some of these signatures were nearly identical to those typically seen in smokers. One such mutation pattern was found nearly four times more often in people exposed to areas of heavy air pollution. Another signature, commonly associated with aging, was seen to have increased by nearly 76%.
These findings suggest that long-term exposure to polluted air may be doing damage similar to smoking or natural aging at a cellular level. We always knew that air pollution put us at risk, but with so many Americans exposed to air pollution, understanding those risk factors is extremely important to ensuring we all live long and healthy lives.
