Drivers:  Butter up Before You Buckle Up

The answer:  We drive on the left side of the road and the Aussies drive on the right, which exposes those sides to the sun more often.

Dr. James M. Spencer, director of dermatologic surgery at Mount Sinai Hospital in New York, has noticed more sun damage to the left arms and left sides of his patients' faces.

Car windshields and windows block some UV-B rays.  UV-B rays cause the outer layer of skin to burn, and UV-A rays penetrate deep into the skin, causing wrinkles.  Exposure to both kinds of rays could lead to skin cancer.  Kids, who often sit in the backseat, tend to have more exposure to UV-A rays because side and back windows aren't treated.

"The car is one more source of possible sun exposure," says Dr. Spencer.  "Over the course of a lifetime, all the exposures added up.  I don't expect people to live in caves, but I do encourage them to be smart."

To protect yourself and your family, you can buy a UV-A blocking film for side and back windows.  Tinting windows with transparent film is legal in all 50 states.  Most film has to be professionally installed and costs between $150 and $500, depending on vehicle size.  

One brand, Llumar^® UVShield, received The Skin Cancer Foundation's Seal of Recommendation.