One thing you can try is this,,,,
Disclaimer: I am not an asbestos police policy person
But I have been spraying this junk forever,,,,
Take a 6" or so knife, and scrap the popcorn, IF you reveal brown spots (cork) you are dealing with asbestos. If you don't, that means the "popcorns" are styrofoam, and you are not dealing with asbestos.
As i said, this is not an "approved" test, but it will let you know if you want to deal with it or not.
Asbestos in popcorn is a possibility and should be checked by a lab. One good lab is http://www.emsl.com/. While you are at it, it would hurt to take another sample and test for lead content.
Call your nearest lab and they can probably let you know more about it.
You could also contact an environmental consultant.