No, humans have been exposed to nanoparticles ever since the invention of fire - combustion of most solid materials generates nanoparticles. Humans have been engineering nanoparticles since the invention of Lustre (a type of pottery). The only novelty with contemporary use of nanoparticles is that we can now create a uniform mix of them - until recently we could only find nanoparticles mixed with larger particles.

You are correct in your observation that dust can be harmful, and I would be surprised if concentrated nano dust behaves differently. In particular, a very real danger from spray on glass might be silicosis - a non-cancerous disease caused by occupational exposure to glass dust.

I'm only responding here to the social phenomenon of "omfg, scary new technology, CANCER", I'm not trying to engage in amateur epidemiology.