I’ve worked in data centers. The constant air circulation causes dust to accumulate in visible places. I assure you, computers are not as sealed up and tidy as you’d think. We used to jokingly call the hard, thick, black dust “cancer”. It’s hard to know what’s in it without study, but when you manufacture something with dangerous materials some amount of that material makes it onto and into the finished product. I’m not advocating for alarm, but your po-pi-ing comment was designed to minimize and it demands counterpoint.

You're not breathing silicon dust!

Chips in all computers are highly encased, either in ceramic, hard plastic, metal, or some combination. They're never, ever, exposed to the air circulating through a computer, because the dust would destroy the delicate circuitry.

If you're regularly cracking open chips to snack on them, you have bigger problems...

Although that sounds like fun (for certain values of fun), the issue would exposure during fabrication and possibly during destruction of nano tube containing equipment.

We have to rely on them handling hazardous substances properly anyway since semiconductor manufacturing already involves many of them. They use ClF₃ and sulfuric acid as cleaning agents, phosphine for doping, silane for CVD, etc.

Industrial scale manufacturing of just about anything probably involves quite a few carcinogens.

I'm afraid that there are already a great number of unfriendly chemicals involved in the manufacture of regular old silicon ICs.