It has a hightened inherent risk, but considering the multitude of deadly things on the track, it's very safe.
Look at the number of deaths in professional racing compared to normal city driving, I'd consider that pretty safe.
At the speeds those guys travel, it just amazes me how they don't detach retinas or anything when they slam the walls. I've been doing auto-x and roadrace for quite a few years, and there are plenty of times where I go from running on pure adrenalin to running on total fear of the next turn when someone is out of the line. I can only hope and dream to travel 240mph around an F1 track in a beautiful Ferarri on day.