From: Paul Doherty (pauld@exploratorium.edu)
Date: Mon Feb 07 2005 - 18:13:03 PST
Message-Id: <F6A13DE6-7976-11D9-9FF9-000A95B38012@exploratorium.edu> From: Paul Doherty <pauld@exploratorium.edu> Subject: Re: pinhole pigments of red heads Date: Mon, 7 Feb 2005 18:13:03 -0800
Hi Eric
Blonde, brown and black hair color is caused by melanin in various
amounts.
Melanin in the skin causes tanning and dark skin pigmentation, it
protects from UV.
Red hair is caused by trichosiderin it is independently inherited from
the melanin so you can have black hair with red highlights or
strawberry blonde hair or just red hair of different intensities.
It takes more UVA than UVB to make a sunburn.
UVA penetrates more deeply into the skin, where it can break apart
molecules that lead to sun poisoning.
I know this. I used to have reddish blonde hair (now its whitening) I
had little melanin in my skin. When I used to use sun screen that
blocked only UVB I would get sick on my first sun exposure each year.
Now I use sun block that stops UVA and UVB and I no longer get sun
poisoning (Hooray!) (After the first sun exposure I would tan and then
for the rest of the year the tan would block the UVA and I wouldn't get
sick.)
Sun dose that causes a sunburn is bad.
No sun is bad (you get rickets)
Scientists are currently arguing about what the right does of sun (UV)
is.
Some say none, others say a little is good, there is no definitive
answer.
I've personally decided to allow myself a little natural sun exposure
to make a tan to protect me when I go to the mountains. I worry about
overexposure to UV in a tanning salon since I know the evils of UVA
induced sickness. But I expect that a little controlled exposure to UV
is probably OK.
Paul D
On Feb 7, 2005, at 4:33 PM, Eric Plett wrote:
> Paul D.,
>
>
>
> In one of our classes at the Exploratorium, you told us that
> red-headed people have a different skin pigment (or was it hair
> pigment) than the rest of the people of the world. Instead of just
> having different amounts of pigment, they have a different pigment
> altogether.
>
>
>
> In one of my physics classes today we started talking about how
> fluorescent light bulbs work. That led to talking about ultra violet
> rays and sunburns and tanning booths and such. Many of the students
> had stories about “over-exposing” themselves to the sun and the after
> effects of the exposures and the dangers of tanning booths. For short
> term effects throwing up, outbreaks of shingles, and fatigue were all
> mentioned besides the sunburn itself. We were also wondering about
> long term effects on the skin and eyes.
>
>
>
> As a red head yourself, could you remind me of the significance of red
> hair related to the effects of sun rays? For a second question, are
> there any safe tanning booths today? The only way that I can think
> that they could be is if they emitted the less energetic UVA’s nearest
> to the visible spectrum. But would these rays even cause a tan? (And
> wouldn’t they still increase the wrinkling of the skin?) I still see
> tanning booths around from time to time.
>
>
>
> Eric Plett
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