Watch out for that tree! - Sun & Shade - Brief Article

Men's Fitness, August, 2002 by Mike Carlson, Allan Donnelly, Ben Kallen, Bobby Lee, Mark Thorpe, Tom Weede

SOMETHING TO REMEMBER as you play outdoors this summer: Although shade may seem to offer some protection from the sun, you can still absorb plenty of skin-damaging rays while lounging under a leafy tree. Purdue University researchers used a computer model to predict how much ultraviolet-radiation exposure was present underneath various types of tree cover.

They found that that you end up with protection equivalent to wearing sunscreen with an SPF ranging from 2.5 to 15--meaning that, at best, you're getting the minimum recommended amount of protection. So even if it appears relatively dark under all that foliage, hedge your bets against damaging UVA and UVB rays with sunscreen, sunglasses and a hat.