Eight dirtiest surfaces Keeping your children healthy can be the key to missing fewer days at the office so be aware of where germs lurk. The University of Arizona in Tucson swabbed 800 surfaces to determine the most unhygienic areas. Here they are in order of dirtiness. 1) Public telephones 2) Public rest-room surfaces 3) Counter pens 4) Chair armrests 5) Elevator buttons 6) Escalator handrails 7) Shopping cart handrails 8) Grocery store refrigerator handles