My friend had an accident. Should he sue?

My great friend Frank has been working in a facility where nuclear content is transported in and out constantly. Unfortunately, Frank worked on the floor where said content is usually stored, and after years of working there we've been noticing changes to his appearance. Over the course of a few months, Franks hair has been losing all color. It's at the point where it is totally devoid of color right now. His health has been steadily declining as well. We haven't told him this yet, but we think he should sue. Would he have a good case? It there some radiation that is doing this to him?