When thinking about sun exposure, you might envision yourself on the beach or exercising outdoors. But millions of Americans receive a large portion of their sun exposure when they don’t even realize it — in their cars.

For years, dermatologists have observed that patients in the US often have more sun damage on the left side of their faces than on the right. Research increasingly points to ultraviolet A (UVA) radiation penetrating through car windows.

UV radiation from the sun is associated with almost 90 percent of all skin cancers. Glass effectively blocks UVB, and windshields are specially treated to block UVA as well, but a car’s side and rear windows allow UVA to penetrate.

UV exposure we receive while driving a car adds up. The more time spent driving a vehicle, the more severe this photo damage is to the left side. In countries where the driver’s side is the right side, people tend to develop more sun damage and skin precancers on the right. Certain precancers can turn into squamous cell carcinoma, the second most common form of  skin cancer.

Ways to Protect Yourself

Apply a broad-spectrum sunscreen with an SPF (sun protection factor) of 15 or higher to your face, arms, neck and hands, about half an hour before you drive.

Wear protective clothing, such as long-sleeved shirts, long pants, UV-blocking sunglasses, and hats with a brim of at least three inches all around.

Apply tinting or laminating (applying UV-protective film) to the window glass. Window tinting is regulated in many states, so be sure to check the laws.

Source: Skincancer.org