Sun burns and sun tans

[SagaLore]

You expose yourself to the sun for long enough, you may get burned. But after the burn goes away, remains a tan.

I know that melanin increases after sun exposure, to give darker pigmentation as a way to protect from additional sun damage.

What I don't quite understand, is what is the catalyst for the increase in melanin? Does your skin actually have to be damaged first? Is it a reaction to UVA? UVB? Or just light intensity? If it's UVA/UVB, could you get a suntan without light? If it's light, which end of the spectrum is more influential?

 

[Jzero]

I can't comment on the bioligical processes behind it, but in my experience, when you get burned, your tan peels off along with your dead skin.

 

[Eli]

Uhh..

It is exposure to UV that makes you tan.

UV is light(just not visable).

It resides on the... UV end of the spectrum.

So.. yes.. you could get a tan in what appeared to be darkness. But most objects that output UVA/B radiation also get into the visable wavelengths, hence the purple color of tanning lights.

 

[MichaelD]

A tan is the cumulative effect of a mild grade burn. A burn is the result of over exposure.

 

[FoBoT]

some people genetically have enough of what produces mellenin in their skin and some don't

i am a don't, i burn like a french fry == no skin pigment, no mellenin producing whatever thingys

 

[Anubis]

i never burn, if im in the tropics ill get red and then be tan but never burn and peal

hurray for being italian

 

[bmacd]

i don't tan..i just burn. 🙁

-=bmacd=-

 

[SagaLore]

Originally posted by: Eli
Uhh..

It is exposure to UV that makes you tan.

UV is light(just not visable).

It resides on the... UV end of the spectrum.

So.. yes.. you could get a tan in what appeared to be darkness. But most objects that output UVA/B radiation also get into the visable wavelengths, hence the purple color of tanning lights.

how?

 

[dighn]

OMG OMG

http://travel.howstuffworks.com/sunscreen.htm

 

[jurzdevil]

Originally posted by: dighn
OMG OMG

http://travel.howstuffworks.com/sunscreen.htm

post of the day!

 

[Klixxer]

Eli is a man that speaks the truth.

I am blond and blue eyed, getting a tan isn't easily done, basically, UVA beams give you a tan, UVB beams give you a burn, choosing a sup protection lotion that prevents UVB will help.

To understand Alfa, Beta and Gamma radiation you must be familiar with the physics of radiation, alpha will be stopped by paper, beta will be stopped by a thin closed sheet of anything, gamma will be stopped by lead.

That is why you can get a sunburn through a window, but you can never get tanned through a window.

I spent an hour in shining sun today and burned my neck.