The wolves are exposed to cancer-causing radiation as they roam the wastelands of the abandoned city - with researchers finding part of their genetic information seems resilient to increased risk of the disease.
My understanding is that while the fallout from Chernobyl wasn’t very dangerous, and didn’t lead to a noticeable increase in cancer rates, the area around the reactor is still very dangerous due to the debris from the reactor core that’s scattered around.
Kyle Hill has some pretty good videos on this topic: https://youtu.be/bmVGwOP_zi8?feature=shared
My understanding is that while the fallout from Chernobyl wasn’t very dangerous, and didn’t lead to a noticeable increase in cancer rates, the area around the reactor is still very dangerous due to the debris from the reactor core that’s scattered around.