Drugs in Whistler BC?

My son is going to a camp in Whistler this July he is a 16 year old and i am a little worried of waht kind of stuff he might be exposed too..... i would like to be able to warn him about what he is going to have to deal with if anyone could tell me so i can tell him. I just want to know what kind of people are in this town what kind of drugs he might be exposed too so i can warn him and teach him ways to respond to this ( I am a therapist so i could help him).