Help with weed and workmates

Hey wives, Last fall I started a new job in a field that is fairly.... Regulated around substances. No drug tests, but people definitely are not open about marijuana usage. (On the other hand, when they go out as a staff they drink like camels!)

In my efforts to make friends, I find myself wondering if any of the people blow trees. Smoking is one of my favorite social activities and I am sure I could have fun with a lot of the people I hang with.

Does anyone have advice on how to determine whether other people smoke?