Transcript Sun Exposure and Its Effect on Us

Sun Exposure and Its
Effect on Us
Presentation by: Sandra Gajewski
Date: 05/03/06
Normal Skin
– Has 20 cell layers that are organized similar to a
brick wall.
– Contains healthy amounts of collagen, a protein
based substance, that makes up the skin
– Very flexible, with a shiny texture
– Lacks wrinkles and age spots (younger skin)
Skin Damaged By the Sun
• Strong visibility of wrinkles, and age spots
• Drastic loss of flexibility resulting in
sagginess caused from the Elastin in the
skin to be torn down
• Strong affinity for cancer
• Layers decrease in number from
20 to 2
More to it...
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Darkening of the skin
Pigmentation of the skin
Increases dryness, scaly-texture
Too much exposure to the sun can cause a
person to look a lot older than they are!
What exactly is Collagen?
• It provides structural support for the skin, muscles,
and tendons.
• It is found in fibroblast cells where it creates a
fibrous network in which new cells can grow
• Accounts for 75% of the weight of the dermis
• Responsible for skin’s resilience and elasticity
What is Elastin?
• Like Collagen, Elastin is a protein in connective
tissue
• Helps skin resume its original shape after
movement
• Composed of the amino acids, glycine, valine,
alanine, and proline
• Made by linking tropoelastin protein molecules to
make an insoluble, strong linked-array
Why is the sun such a problem?
• Everyone is affected by the sun because we all
need to be outdoors
• We all enjoy activities outdoors
• Skin cancer caused from the sun is one of the
leading causes of death in the U.S. along with
breast cancer, prostate cancer, and lung cancer
• No one seems to realize the importance of
protecting their own skin, but only worry about
their outward appearance
A problem for us…
• Most people receive 80% their lifetime
exposure before the age of 18!!
• You think you might be fine, but the sun
burn you receive this summer might take 20
years to become skin cancer!
• We are more in danger of the getting skin
cancer than our older generations because
of the depletion of the ozone layer.
What is the ozone layer?
• Discovered in 1913 by Henri Buisson and
Charles Fabry, French Physicists
• Also known as ozonosphere layer
• Located in the Earth’s atmosphere and has
high concentrations of O3.
• “Dobson Unit” – device used to measure the
total amount of ozone in a column overhead
How was the Ozone created?
• Sidney Chapman figured out the photochemical
mechanisms that give rise to the ozone.
• Brief Explanation:
– The ozone is created in a process where ultraviolet light
strikes O2 molecules and splits them up to create ozone
O3. Both molecules are unstable, and therefore, create a
cycle, the ozone-oxygen cycle whenever the ultraviolet
light strikes it.
How the ozone helps our skin…
• The Ozone helps prevent biological harmful
ultraviolet radiation emitted from reaching
our skin by absorbing it in the atmosphere.
Ozone Depletion
• Depleted by free radical catalysts:
– Nitric oxide (NO)
– Hydroxyl (OH)
– Atomic Chlorine and Bromine
The Rays of the Sun Reaching
Us…
• When the ultraviolet light hits our skin and
penetrates through, our skin responds in a 3
stage process:
1.) Melanin granules are oxidized by UV light and
become darker.
2.) Melanocytes deeper in the epidermis begin to create
new melanin granules for further protection.
3.) Melanin granules divide and produce more cells, but
the damage has already been done.
Common Cancers Associated
with Skin Damage…
• Basal Cell Carcinoma
– Enlarge slowly and can invade into neighboring tissue
– Most common on the face
– Closely related to Squamous Cell Carcinoma
• *Melanoma*
– Found in melanocytes
– Can spread to other tissue through the lymph system or
through the blood
Sun Protection Factor
-Misunderstanding:
SPF 15, for example does not mean you can
stay in the sun 15 minutes longer than without
sunscreen
What it does mean:
SPF 15- covers 80% of the sun’s rays
SPF 10- covers 90%
SPF 20-covers 95%
SPF 40-97.5%
UVA , UVB, and UVC
• UVA rays- less energy, but penetrate the most into
skin. These rays are best known for aging.
• UVB rays- most potent rays that reach the
earth.These rays cause burns and ultimately, skin
cancer
• UVC rays- Have the shortest wavelength, the most
energy, but do not penetrate the earth’s atmosphere
How we can protect ourselves…
• Wear skin protection everyday! SPF 15, at
the least.
• Wear proper clothing
• Wear UVA and UVB shielding sunglasses
• Try to stay in the shade as much as possible
Readings
• Websites:
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http://en.wikipedia.org/wiki/Ozone_layer
http://www.maui.net/~southsky/introto.html#is
http://www.skin-care.cl/skin-discoloration.htm
http://coolshade.tamu.edu/fx.html