You may not know this, but in America, we keep track of how often someone is exposed to radiation. This exposure happens every time someone has an x-ray, CT scan, and even an MRI. Radiation exposure tracking has been such a big deal that you right now are on a record that every hospital can attain access to. Why do we keep track of this? Simple. Radiation is dangerous and has been proven to kill living beings and even mutate them.
Today, we know that radiation can help in treating things like cancer. However, it slowly kills people. Marie Curie, the woman responsible for most of our knowledge today on radiation, died from radiation poisoning due to her massive amount of exposure to it. Exposed to vast amounts, it is possible a real zombie apocalypse could come out of it if people even survive the major exposure they’ll have to endure.