Do you really think that an anonymous message board is the place to get definitive scientific/medical information?

Why not go to the CDC website, or Columbia "the body" and get some real answers?

Isn't the whole hobby one big risk? If you are worried about the risks this is not the place for you.

Also what are the odds of getting into a serious (meaning injury involved) car accident?

Just about everything you do involves risk, you have to weigh the advantages and disadvantages and decide for yourself if it is worth it.