When you first learned how to drive, your instructor probably told you to adjust your seat, fasten your seatbelt, and adjust your mirrors. But, they probably didn’t tell you to put on sunscreen. You might be thinking, “sunscreen? But I’m inside my car, I can’t get a sunburn,” and you’d be right – you can’t get sunburned behind glass. You are, however, still at risk of premature aging (photoaging).
The sun emits both UVA and UVB rays. UVB rays cause sunburn and UVA rays cause premature aging. Glass absorbs almost all UVB radiation emitted by the sun, which is why you won’t get a sunburn when you’re behind glass. However, glass is not very good at absorbing UVA radiation – it lets about 75% of UVA rays through¹.
Windshields in vehicles are specially manufactured to absorb more UVA rays than ordinary glass. They’re made of two layers of glass separated by a layer of plastic, which allows the windshield to absorb 98% of UVA rays. However, not all windows in the vehicle are made like this. The side and back windows usually do not contain any plastic, and therefore do not absorb as much UVA radiation². When the driver’s seat is on the left side of the vehicle, signs of overexposure like premature aging and skin cancer are more common on the left side of the body. When the driver’s seat is on the right side of the vehicle, the same pattern is seen on the right side of the body. Sun safety is especially important if you drive a convertible with the top down, or if you like driving with the sunroof open³.
This information can be concerning, especially if you have kids in the back seat. There are a few things you can do to help protect yourself and your family from UVA overexposure. You can look into getting your windows tinted, since this can block out more UV radiation. Also, continue to use sun protection in the car²⁻³. Since the primary concern here is UVA rays, make sure to choose a sunscreen that is labeled as broad-spectrum. This means that the sunscreen protects against UVA radiation (and UVB, but UVB is absorbed by glass anyways). Also, continue to wear hats and UV protective clothing just as if you were outside³. All things considered, the stress of the commute isn’t the only thing that can give you wrinkles!
- Helmenstine, A. M. (2015). Does Glass Block UV Light? Retrieved July 21, 2016
- Durbin, D. (2013). Car windows offer some sun protection, but can’t block out all harmful rays. Retrieved July 21, 2016
- Butler, S. T. (2013). Sun Hazards in Your Car. Retrieved July 21, 2016