OK guys. No more drunk posing!
The OP said metal particles inhaled. Never said metal vaporized. One person said "Since they'd have to vaporize to be inhaled, not a problem" (paraphrased... meaning they wouldn't be inhaled).
Then 20 posts about metal vaporization

Doesn't the OP deserve an answer?
1) Pre drilled cartos are pre-drilled at factory and probably few if any metal particles... one answer
2) Plastic cartos... people have used em in tanks....but IDK how they punch them. I'd be more concerned about the plastic getting on wicks, melting into a gas, inhaling.
So... rule of thumb... metal cartos, IMO. Also, check vivi-nova tanks or CE2 tanks so you don't have to punch the stupid things to begin with.....
http://www.e-cigarette-forum.com/forum/cartomizers/318812-safe-cut-slot-into-cartomizer.html