I try not to let it show, but if anybody ever comes in my flat, quite rarely thankfully, Iam watching them like a hawk to see the areas they contaminate, then when they are gone Iam up all night washing everything from the ceiling down in the contaminated area.
When I take my car for MOT, I cover the inside in new plastic dust sheeting so the dirty mechanic doesn't contaminate my car which would then contaminate me and then I would contaminate everything I touch in my whole world.
I forgot I was due to go to work one day so didn't turn up, they sent the Police around to break in my front door to check I was ok, not being there to observe, I had to conclude they had contaminated every square inch of everything I owned, so I immediately went off sick for 3 or 4 months with stress so I could decontaminate my life.