Is cooking directly on campfire coals safe?

[Canadaexplorer]

I've seen plenty of people go full caveman style and cook meat directly on the coals. Do you think this is healthy. Any scientific evidence to it?

 

[Northernexplorer]

Many say it's safe, haven't done any research myself. I can see how it may be bad for you though as the ashes may still be on the meat