Lung cancer is increasingly affecting non-smokers. The reason is clear.

While the number of smokers worldwide continues to decline, lung cancer remains a leading cause of nearly two million deaths each year. Researchers are alarmed by the rising incidence of the disease among people who have never smoked.

A team of scientists from Guangdong Medical University (China) and the International Agency for Research on Cancer (France) has found that high lung cancer rates among non-smokers may be linked to increasing air pollution levels. “As lung cancer is the most common type of cancer globally, it is crucial to have a comprehensive understanding of the changing epidemiological patterns and their potential causes,” the researchers wrote in their report.

What Did the Scientists Discover?

By analyzing statistical data from the Global Cancer Observatory (GLOBOCAN) for 2022, along with other cancer incidence registries from 1988 to 2017, the researchers identified that adenocarcinoma is the most prevalent type of lung cancer worldwide. It accounts for 45.6 percent of cases in men and 59.7 percent in women.

While adenocarcinoma can certainly be caused by smoking, it is not the most common type of cancer among smokers. However, it is the most frequently diagnosed lung cancer in non-smokers, according to Science Alert.

By comparing their findings with previous studies, the team observed a trend of increasing lung cancer cases among individuals who have never smoked. This is an issue that society needs to address, the researchers noted, while continuing efforts to combat smoking, particularly among the youth.

“Notably, lung cancer in people who have never smoked is the fifth leading cause of cancer mortality worldwide, occurring almost exclusively in the form of adenocarcinoma and most often in women and among Asian populations,” the team pointed out.

The researchers believe that the primary reason for the rising lung cancer incidence among non-smokers is the increase in air pollution. It is no surprise that a significant percentage of cases are found among residents of East Asia, particularly in China, where air quality is among the worst in the world.

As one cause of lung cancer declines, another is on the rise, and this cause is linked not so much to personal lifestyle choices but to the global environmental situation.

According to the scientists, the results of the new study will be valuable for those “developing and implementing strategies to control tobacco use and air pollution.”

The findings from the study were published in The Lancet Respiratory Medicine.