Sitting in the midday sun for 10-15 minutes a day, how dangerous?

Lately I’ve taken to enjoying the warmth of the summer by sitting outside in bright sunllight for 10 to 15 minutes after I eat my lunch. Do I need to use sunblock for such short exposure? I’m not seeing any change in my coloration from doing so, which seems to suggest I don’t have anything to worry about. On the other hand, a brother, uncle, and cousin (that uncle’s daughter) have all had melanomas.

FTR I’m quite bald, fair skinned, and entirely of Northern European ancestry.

Sun block. Always. Without exception. Damage due to UV and stuff like that is cumulative, and you have a family history that suggests suceptability.

I never go into the sun for longer than 5 minutes without a hat and sunblock, and my description is just like yours (only I would have added “fat and lazy” to mine!) :smiley:

When scientists exposed skin on people’s butts (which had presumably never seen sun before) to the level of UV light in sunlight, they found new mutations after two minute exposures. Any sunlight at all can be a mutagen. So you can pick your poison - vitamin D deficiency from lack of unfiltered sunlight, or an increased likelihood of skin cancer from unfiltered sunlight.

Count me in the “sunlight is not instant death” camp, even if I am vampire-white.

It’s a little more complicated that “always use sunblock”. People really do need some sunlight on their skin for the vitamin D. Very pale folks don’t need much, but they do need it.

Tanning is the skin’s reaction to damage from solar radiation. Therefore, if your exposure is minimal enough (regardless of time of day) that your skin color is not changed then the damage is probably minimal as well.

Sunblock does not prevent all damage, but it does encourage people to stay out in the sun longer, at least in some cases. It is possible to cause more damage to your skin by slathering on the block and staying out in the sunlight 8-10 hours than by doing without the block and getting much shorter exposures.

Family and personal history is also important. Folks with family histories of skin cancer, or with a personal history of severe burns in childhood, should err on the side of more sunblock, shade, hats, and long sleeves. But even they need some direct sunlight.

I’d say the only people who truly have an argument for “never” in regards to sun exposure are albinos and those who have xeroderma pigmentosum. In which cases vitamin D supplements may be called for.