If you drive frequently during the day, you may be at a greater risk of developing cancer on the left side of your face or your left arm than you ordinarily would be. Car manufacturers are required by law to install windshields that adequately protect drivers and passengers from ultraviolet A (UVA) and ultraviolet B (UVB) rays. However, manufacturers are not held to the same UV ray protection standard when they install a vehicle’s remaining windows.

As a result, some of these windows contain what amounts to a product defect, in that they do not adequately protect skin from harmful UV rays. In recent years, it has become apparent that some frequent drivers develop skin cancer far more substantially on their left sides than their right sides. Insufficient UV protection in car windows may be either fully or partially to blame for these particular cases.

On average, windshields have an average sun protection factor (SPF) of approximately 50. However, remaining vehicle windows only have an average of 20 SPF or less. Given how devastating and even deadly skin cancer can be, this reality is alarming physicians, other medical experts and drivers with an increasing amount of urgency.

Thicker glass generally results in a higher SPF rating. If you are at risk for skin cancer and have thin windows in your vehicle, you may want to research their SPF factor. Depending on how urgent this issue is for you and your family, you may want to replace your windows for models with a higher SPF rating.

Source: Medical Daily, “Glass In Car Windows Doesn’t Fully Protect From Sun’s UV Rays, Could Explain Left-Side Skin Cancer,” Chris Weller, Sep. 4, 2013