While I agree that 10 year olds can be reasoned with, I have to say that giving them statistics may not be much of a help. I don't have pre-teens or teens yet, but I have vivid memories of my pre-teen years. I was in elementary school when that movie "The Day After" was aired. It was the movie about nuclear war (I think it was war, it was a nuclear incident, nonetheless.) I didn't watch the movie, thanks to my mother's good judgement, but I knew what the premise was, and I was terrified. I would lay awake at night in fear, just waiting for the bomb to drop. I really believed that, not only would their be a nuclear war, but that the bomb would hit our house. I know that sounds irrational, but that was truly what I thought.
When I was 12 my mother had breast cancer. It was a best case scenario, she had a mastectomy, they got it all, no chemo, no radiation. For many months I would lay in bed at night until long after midnight worrying about this. I didn't worry that my mom was going to die, because I knew that she was okay, but I was just sure that I was going to get it too, one day. It was a constant fear for me. When I thought about getting it myself, I always thought that I would die from it.
In both of these cases I knew the statistics, but it didn't help me to feel less fearful. Fear is often unreasonable, even with the best of information.
I could give many more examples, but you get the idea. Marg, I think you are lucky that your child told you. I never mentioned it to my parents, I simply spend years worrying about such things in silence. Ask your Dd what she needs from you to help her deal with, not necessarily overcome, these fears. Overcoming her fears may be impossible, but you can help her to deal with them.
Best of luck to you and your daughter.