I found an interesting article about how nuclear fallout has aided in studies on brain development. Nuclear fallout introduced small amounts of carbon 14 into our atmosphere. When our cells divide, they incorporate carbon from the environment. So the carbon 14 released from nuclear bombs eventually makes it way into the human body. This means that carbon 14 can be used to measure the age of cells. A team at the Karolinska Institute used this to show that new neurons were produced in a small part of the hippocampus called the dentate gyrus. I guess nuclear fallout has some positive benefits in terms of research.