There doesn't seem to be enough data to truly say what the ideal amount of time outdoors is.
Outdoor classes used to be pretty common, so being outdoors isn't even necessarily bad for learning maths...
https://www.researchgate.net/publication/348839525/figure/fi...
That means UV exposure outdoors is worse now than it used to be.
Unfortunately, it seems nobody measured UV at ground level before we started destroying the ozone layer, but there are barely any historical accounts of serious sunburn before ~1930. Everyone just talks of heat stroke and dehydration rather than actual burning/peeling of the skin.
It isn't about cancer. It is about modern standards of beauty. Sun ages skin. People learned to avoid the sun because of cancer, but they hide in the shade today to keep their skin looking youthful.
Tanning certainly ages skin. But just being outdoors, going about your day, wearing sensible clothing?
We're raising generations of people who aren't even developing basic human abilities like having more than 5 second of attention span, being physically fit or being able to see apparently, the drawbacks are starting to weight a lot imho
I heard my whole life how my generation was going to be useless too. Ruined by arcades and violent tv shows. I am not saying there aren’t going to be drawbacks but “5 second attention span” sounds like the same ole same ole to me.