Since we were children we’ve been taught that oxygen is essential for all life on Earth, and too little of the element will most surely result in death. But, increasingly, research has suggested that too much of the “good stuff” can result in the same. A recent study has found a startling correlation between areas of high oxygen concentration and areas of high lung cancer rates, sparking the question: Can oxygen cause cancer?

Lung cancer claims around 160,000 lives in the United States each year, and it’s believed that around 90 percent of all cases of lung cancer can be traced back to smoking. Co-author Kamen Simeonov told Medical Daily that initially he was interested in how cancer was distributed geographically and wanted to see if there was anything unusual in the rate fluctuations.

“Lung cancer and smoking in certain areas didn’t match what you’d expect,” explained Simeonov, who after a bit of research realized that he wasn’t the first to propose that oxygen may play a role in lung cancer rates.

Simeonov and his research partner, Daniel S. Himmelstein, decided to conduct a study to measure just how much atmospheric differences were related to lung cancer rates. For the study, the team explored the lung cancer rates across varying elevations on the American West Coast — oxygen levels decrease with higher elevations. To ensure that there was a control in the study, the team also recorded the rates of breast, colorectal, and prostate cancer in the areas, according to the press release.

Results showed that as the elevation levels increased, the levels of lung cancer decreased. To be specific, incidence decreased by 7.23 cases per 100,000 individuals for every 3,281 feet rise in elevation. These rates remained, even after the team adjusted for other lung cancer influences that may have explained the connection.

“I was surprised by how big the association was, how strong it was,” Simeonov said. “When we adjusted for a bunch of different factors we saw that the association got stronger.”

Oxygen is a highly reactive element. Even after it is absorbed and then consumed by our body it still produces reactive oxygen species, which in turn could lead to cellular damage and mutation, the press release explains. A 2013 study agreed with the theory, finding that “in excessive concentrations, ROS-mediated oxidative stress can lead to cellular necrosis or apoptosis,” and also speculating that high concentrations of oxygen may be “perpetuating lung injury in some patients.”

The researchers hope that their research can help raise awareness about the possible effects that oxygen has on the body. “Once you understand that, you can go on to helping people,” concluded Simeonov, explaining that in the long run knowing the effects of oxygen on human lungs could result in lung cancer treatments and even preventions. For now, however, far more research is needed and for those living in areas of lower elevation, it’s best not to pack up and move just yet.

Source: Simeonov KP, Himmelstein DS. Lung cancer incidence decreases with elevation: evidence for oxygen as an inhaled carcinogen. PEERJ. 2015.