The answer is driving your car! A recent study in the Journal of the American Academy of Dermatology revealed that nearly 53% of skin cancers in the US occur on the left side of the individual. The sun's ultraviolet radiation is associated with most cases of skin cancer. Ultraviolet radiation is made up of shortwave UVB and long wave UVA rays. Glass blocks UVB rays effectively but only partially blocks UVA rays. Your car's windshield are partially treated to filter some UVA rays. The side windows of your car let in about 63% of the UVA radiation.
Solutions: Have sunscreen in your car and apply it! Wear long sleeve shirts. Finally you can have a transparent window film installed into your car windows. This will block out all UVA and UVB rays, as long as the window is closed.
Information for this blog came from www.skincancer.org