There is a difference between a solid rod of something that tends to end up in someone’s mouth in the worst case scenario and small particles of the same thing that can end up in lungs.
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.
The solid rod of the pencil is graphite, not graphene. You can make a bit of graphene from the graphite by using sticky tape, I read. I'm not sure how much graphene "pollution" would appear spontaneously when using a pencil in a normal way.
Have you never used a pencil sharpener before? Never smelled the sweet aroma of sawdust and shaved graphite? You break it up on purpose, that has to release some graphene sheets.
The parent's point was that graphene was harmless because graphite is widely used. Graphite is just a lot of graphene layers stacked on top of each other. Pretty much no dangerous particles are emitted during normal use of a pencil, which was part of the point.
But small particles surely do end up in the lungs when you're writing with a pencil, right? Certainly when you're drawing with one. Less than 100% of the graphene ends up on the paper ...
Small particles of everything end up in our lungs, the question is whether they remain there, as opposed to break down or get decomposed, and whether they cause any harm. Dose is important as well.
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.