To be perfectly honest here, I think that the idea of getting silica fiber that deep into your lungs is likely not something to get worked up over. I am no medical professional, but if your body is working as intended, there is quite a bit of moisture between your mouth and your lungs that will trap the fiber, and send it flying right back out with the next sneeze or cough that you produce... At worse, it might make it to your belly when you swallow and get eaten up by stomach acid, or find its way out the rear end exhaust...
That's pure speculation on my part, but a fair educated guess...
Not like we're sucking on the drip tip with the power of a Kirby... That might cause some real issues to be concerned about... But with the slow, controlled drags we're taking, I don't think there's much to be concerned about...
I have experimented with several forms of cotton and silica wicks, and have some SS mesh coming in the mail... But that experimentation is all in the name of finding the best flavor, not out of health concerns.