Yeah, but the cosmonauts were also inhaling pencil shavings in zero gravity. 😆 

 That's just graphite (carbon), shouldn't be worse that radiation and other hazards in space. 

 Wood shaving dust too, great for the lungs. 

 Got plenty of that in my workshop. Sorry I don't buy the danger idea. 

 Also this: https://image.nostr.build/7b82115d2e60a39eb5323483c7facfa0ca3976b1a9202dbb719f538979c0d959.jpg