There's also an expert forum on Freedomhealth website - you might find some info there as well.
Hey again
These are the kinda things I struggle with but I found when I ask less questions I find I can move on from the worries much better...because asking is like 'mental checking' which reinforces the idea that the threat is actually real. But like you I like to know a certain amount of info so I know I don't need to worry (or when I should worry).
I think it's better you ask these Qs on the HIV Prevention Expert forum as the Drs there will give you the right answers. My own Dr told me if someone does get pricked by a needle it would have to get into a vein (but since we can't see all our veins if I got pricked I would just go to a Doctor anyway!!! so not sure that info helps us really)
The Drs in HIV Prevention forum say that they never heard of an example where someone acquired HIV from a needle in environment, so that may ease your fears a bit.