I'm still troubled by the number of my patients that don't use an adequate amount of sun protection. Even if it's cloudy and you are running one quick errand, you still need sunscreen. Consider these lesser-known facts:
- Windows (e.g. automobile) will not protect you. Windshields are laminated for safety reasons and filter most UV radiation. However side and rear windows allow as much as 79% of UV radiation to pass through1. UV radiation also passes through most residential and commercial architectural windows.
- It takes up to 30 minutes for sunscreen to work. Even with a newly-applied layer of sunscreen, you're still vulnerable to the sun's harmful rays for the first few minutes since it takes about 30 minutes for common ingredients in sunscreen to kick in. It's a good idea to apply sunscreen a half hour before stepping outside.
- Sunscreens with antioxidants are even better. Anti-oxidants provide further protection against cellular insult and help to repair some of the damage induced by UV radiation.
- It's ok to re-apply over make up. Sunscreens containing physical barriers to UVA and UVB rays such as zinc oxide can be reapplied directly over make up. Keep a tube of sunscreen in your bag for regular touch ups.
- Don't skimp! Most people don't use a sufficient amount of sunscreen. The guidelines I've been seeing in the dermatology industry are to use about a shot glass full of sunscreen for body and one half teaspoon full of sunscreen for face to get the full affect.
Skin cancer is serious but can be prevented with adequate protection. So be sure to speak with your dermatologist if you have any questions related to sunscreen and skin cancer prevention.
1. Henry W. Lim, Zoe Diana Draelos. Clinical Guide to Sunscreens and Photoprotection. Informa HealthCare, 2008.