I'm super paranoid to do any kind of work anywhere near my iMac which is why I keep the Mac in the living room, which is at the other end of the house. When it's not in use, it, along with all other clean-environment-needing equipment (printers, scanner, etc) get covered. Same with the PC running my CNC in my workroom, when not in use, the pc, screen and Variable Frequency Drive (for the spindle) get covered. Every other month or so, I usually spend the weekend cleaning and dusting the entire house... 1100 sq ft of top-to-bottom dusting and cleaning.