If you need persuading to wash your hands and hound your children to do the same, this is it: Nearly half of playground equipment surfaces and a quarter of public restroom surfaces are contaminated with body fluids -- blood, urine, mucus, saliva or sweat.
That's the result of a University of Arizona test of 800 public surfaces over a three-month period.
Tests took place in Tucson, Chicago and San Francisco. Researchers took samples at day-care centers, offices, stores, banks, malls, copy centers, health clubs, playgrounds, restaurants, theaters and doctors' offices.
Body fluids can contain bacteria and viruses that cause illness.
The percentage of surfaces on which bodily fluids were found:
* Playground equipment, 44 percent
* Bus rails or arm rests, 35 percent
* Public restrooms, 25 percent
* Shopping cart handles, 21 percent
* Chair seats or arm rests, 21 percent
* Escalator handrails, 19 percent
* Customer-shared pens, 16 percent
* Vending machine knobs, 14 percent
* Public telephones, 13 percent
* Elevator buttons, 10 percent
* Supermarket freezer handles, 6 percent
The research was underwritten by the Clorox Co., which makes disinfectant products.