Hi there!
Here's my background: I'm a trained Vet Tech and have worked as the curator of the largest reptile zoo in Canada. I've owned reptiles for almost 20 years and have cared for many, many different species. About 3 years ago I took the plunge and got into chameleons after hearing about all the horror stories about how hard they are to care for. Since then I've gotten out of all the other lizards and snakes and have concentrated solely on these marvelous creatures. I currently have 24 chameleons in my house and also do chameleon rescues. Most of my collection are Veiled's, but I do have Panthers, Fischers (2 different subspecies), Werner's, Giant Spiny's and now Bearded Pygmy Chams. I have also worked with Jackson's and a few others.
As for substrate in chameleon enclosures, they don't need it! The big reason is in case of accidental ingestion when they "zap" their prey items. Their tongues aren't sticky per say, they use muscular contractions to grab the food item, but they can accidently grab sand, dirt, moss, mulch when they do this. Eventually these foreign objects will accumulate in the intestinal tract and cause blockages. They are unable to absorb food and eventually cause slow starvation in the chameleon.
This is a really interesting thread too, that can be applied to chameleons.
http://www.ssnakess.com/forums/showt...highlight=sand
I'll give this a bit more thought, I'm sure I can find some literature and links for you that will be of some assistance.
Good luck at the meeting!
Trace