Never thought about that... it's kinda like all those things we used to do that kids don't do now, or have changed....
we didn't use sunscreen, I remember my friends actually have somewhat of a competition to see who could get the "darkest" or most even sun-tanning.
I wasn't interested in sitting in the sun as a kid and actually kinda thought it was silly, though all my friends loved to sit out in the sun.
I did love to go running around in our alley and through other areas in our urban neighborhood- barefoot.