I have limited ability to tan; in a nutshell, I just burn. I try to avoid overexposure to the sun for that reason alone. However, there are times when I know I'm going to be out in it, and would reach for the sunscreen to help prolong my ability to remain in the sun. (it never really stops me from burning regardless of the SPF number) . However, after reading your post, I have to say I'm not so sure I want to reach for it. That's scary stuff! From a natural perspective; Aspen trees have a white powder on their bark that actually helps to block the sun. On an SPF reading, it's minimal, but it's natural. Now, just to find an older aspen. The ones I have near are youngsters and don't have the powder yet. Thank you for sharing.