Dress for sun protection, even when you're driving.

Your driving habits may leave you exposed to damaging ultraviolet rays.

RODALE NEWS, EMMAUS, PA—Left-sided skin cancers are more common than right-sided ones in the United States, apparently because of sun we're exposed on our left-sides while driving, according to a new study appearing in the Journal of the American Academy of Dermatology. "We tend to see more skin cancer on the left side of the face; drivers need to be aware of the amount of sun exposure they receive behind the wheel," says Scott Fosko, MD, chair of dermatology at Saint Louis University School of Medicine, and coauthor of the study. "The cumulative effect of being exposed to the sun builds up over many years."

THE DETAILS: Of the nearly 1,050 cases of skin cancer reviewed, researchers found that basal cell carcinoma and squamous cell carcinoma were the two most common types of skin cancer, collectively affecting almost 90 percent of patients in the skin cancer study. About 2 percent suffered from the more serious invasive melanoma. The head or neck was the most common area for skin cancers, accounting for more than 80 percent of the cases, followed by the arms. Most skin cancers occurred on the left side of the body and, looking at cases of men and women separately, men were significantly more likely to have skin cancer on their left side. Head and neck skin cancers were even more prominently found on the left side, and the authors credit that to extra exposure to the sun's ultraviolet (UV) rays during driving. (The phenomenon may be less common in women because they wear sun-protective makeup, or tend to be more cautious about sun exposure.)

WHAT IT MEANS: There are more than 1 million cases of non-melanoma skin cancer diagnosed each year in the United States; melanoma, the most serious type of skin cancer, is responsible for the majority of nearly 12,000 skin cancer–related deaths each year. And while we often think of sun overexposure as from tanning bed use and long days at the beach, this study reminds us that small amounts of damage skin can occur every day as we commute to work or run errands.