I'm incredibly sensitive to cross contamination. I can't eat out at all, unless the facility is 100% gluten free. So unfortunately it doesn't take much to trigger symptoms for me
As for the triggers themselves, I have a couple of ideas:
I'm one of those idiots that mindlessly leans on their hands as they look over reports. I try to stop myself, if I remember, but it's such an ingrained habit at this point that sometimes I forget. I'm trying to break it
The only other way I can think of, is others eating at desks. Everyone does, and I know it's unavoidable, however the workspaces in my office are a bit close. And there's a bit of a "gluten spray" when my coworkers get baguette-esque sandwiches or anything similar. I've noticed crumbs on my keyboard later in the day, and I don't eat at my desk so it's not from me