I put a link in another reply, dunno if you'd consider it credible or not, but I got it from a websearch for "inhaling diatomaceous earth" if you want to look at the many other links.

Food grade isn't as bad as non-food grade, but still not great. And the "aabestos-like" bit was in the context that it causes harm through a similar mechanism (small sharp, jagged particles). Severity and outcome might vary.