We’ve already run that experiment on millions of schoolchildren. It turns out pencils are safe. And even safer without the wood around them — those are stabby bits. The graphene layers that make up graphite seem to be pretty harmless.
Asbestos is just a silicate, which is also not harmful in many cases, including almost anything made of glass. The problem is the physical form, not the chemical composition or the atomic-scale structure.
Not to say that graphene is carcinogenic; I don’t know the literature. But it probably should not be dismissed out of hand purely because graphite is common.
That's just for things that you are supposed to do, only too much of. Graphene is not useful or an important part of your body's functions; doing things you aren't even supposed to be doing with it (breathing it in, for example) can only have a negative effect.
Speaking of pure carbon, carbon nanotubes are known to cause lung tumors.
> That's where Andre Geim and Konstantin Novoselov came in. They took a hunk of graphite and used Scotch tape to peel off layer after layer after layer. Geim and Novoselov then analyzed what they had left, and found graphene. For their discovery – which was published in 2004 – they were awarded the 2010 Nobel Prize in Physics.
https://science.osti.gov/Science-Features/News-Archive/Featu...
Small particles of ANYTHING entering the lungs isn't exactly healthy.