EFFECTS OF THE SUN
ON THE SKIN
PRESENTER : MI HYUN HWANG
INSTRUCTOR : LYRA RIABOV
OUTLINE

What is UV radiation?

Cellular skin changes caused by UV radiation

Visible skin changes caused by UV radiation

Sun Protection

What you must know
What is UV radiation?
 UVC : 100 - 290nm
UVC is almost completely absorbed by
the ozone layer and does not affect the skin.
 UVB : 290 - 320nm UVB affects the outer layer of skin and
is the primary agent responsible for sunburns. UVB does not penetrate
glass.
 UVA : 320 - 400nm UVA penetrates deeper into the skin and
works more efficiently. UVA is also not filtered by glass.
Cellular skin changes Caused
by UV radiation
 Damaging effects of UVA and UVB
 Collagen breakdown
 Free radicals
 DNA repair
 Immune system effects
 Cell death
Collagen Breakdown
The accumulation of abnormal elastin.
 Metalloproteinase are produced in large quantities.
 Some of the metalloproteinase actually break down collagen.
Free Radicals
 Unstable oxygen molecules that have only 1 electron instead of 2
 The molecule must scavenge other molecules for another electron.
 Repeating the process
 This process can damage cell function and alter genetic material.
DNA Repair
 UV radiation can affect enzymes that help repair damaged DNA.
Immune System Effects
 Immune system factors include white blood cells called T lymphocytes
and specialized skin cells in the dermis.
 When the skin is exposed to sunlight, certain chemicals are released
that suppress these immune factors.
Cell Death
 Apoptosis is a process of cell-suicide that kills severely damaged cells
so they cannot become cancerous.
 There are certain factors, including UV exposure, that prevent this cell
death allowing cells to continue to divide and possibly become cancerous.
Visible skin changes caused
by UV radiation
 Texture changes caused by the sun
 Blood vessel changes caused by the sun
 Pigment changes caused by the sun
 Skin bumps caused by the sun
 Skin cancer caused by the sun
Texture changes Caused by the Sun
 Thickening and thinning of the skin
 Thickened, coarse wrinkling and yellow discoloration
 Thinning of the skin causing fine wrinkles, easy bruising, and skin tearing.
Blood Vessel Changes Caused by the Sun
 The walls of blood vessels to become thinner leading to bruising with
only minor trauma in sun-exposed areas.
The appearance of telangiectasias in the skin especially on the face
Pigment Changes caused by the Sun
 Light-skinned people tend to freckle more noticeably.
 A freckle is caused when the melanin-producing cell is damaged.
 Age spots or liver spots are not actually age related.
 White spots especially on the legs as melanocytes are destroyed.
Skin Bumps Caused by the Sun
 UV radiation causes a number of moles in sun-exposed areas.
 Sun exposure causes precancerous lesions called actinic keratoses.
 Actinic keratoses are felt to be precancerous lesions because 1 in 100
cases per year will develop into squamous cell carcinoma.
Skin Cancer Caused by the Sun
 Melanoma is the most deadly skin cancer because it metastasizes
more readily than the other skin cancers.
 Basal cell carcinoma is the most common skin cancer and tends to
spread locally, not metastasize.
 Squamous cell carcinoma is the second most common skin cancer,
and it can metastasize although not as commonly as melanoma.
Sun Protection
1.
Enjoy the Sun
2.
What is SPF?
3.
Is it that simple?
4.
What if I have blue eyes?
5.
When is the sun most dangerous?
6.
Is it safer to tan in a tanning booth?
7.
What else can I do to protect myself?
8.
The four warning signs of cancer?
9.
Will I die if I get skin cancer?
10.
A healthy suntan!
Enjoy the Sun
 Always use a sunscreen.
 The higher the SPF rating of the sunscreen, the longer you can stay
out before re-applying the sunscreen.
What is SPF?
 Sun Protection Factor.
 Take the amount of time it would take to burn without sunscreen and
multiply it by the sunscreen's SPF .
 If it will take 15 minutes to burn today without sunscreen, and you use
an SPF 8 product, you can stay outside 2 hours without burning (8 x 15=
120 minutes or 2 hours).
Is It That Simple?
 How sunscreen affects and protects you that depends on your skin
type, the strength of the sunlight, the type of sunscreen you use (gel,
cream, lotion, or oil), and the amount you apply.
 In general, don't be skimpy when applying your sunscreen, and reapply
it after you have been sweating or swimming.
What If I Have Blue Eyes?
 People who sunburn easily are more likely to develop skin cancer.
 If you have blue eyes, blonde hair, red hair or get freckles in the sun,
you are at greater risk.
 90% of all skin cancers occur on the face, ears and hands.
When Is the Sun Most Dangerous?
 Between 10 a.m. and 3 p.m.
 Up to 80% of the ultraviolet rays of the sun that burn you are getting
through clouds.
Is It Safer to Tan in a Tanning Booth?
 The UVB and UVA radiation from sun lamps and other tanning devices
can be dangerous.
What Else Can I Do To Protect Myself?
 Check your skin regularly to see if you notice any changes in your skin.
See your doctor if you notice any changes in moles you might have or if
a sore on your skin does not heal.
The Four Warning Signs of Cancer
These "ABCD" guidelines are commonly used to help you be aware of the
warning signs of cancer:
 A is for Asymmetry--one half of a mole is different than the other.
 B is for Border irregularity--mole has poorly defined edges.
 C is for Color variations--inconsistent colors on the mole.
 D is for Diameter--larger than a pencil eraser.
Will I Die If I Get Skin Cancer?
There are 3 types of skin cancer:
 Basal cell carcinoma is the most common and it is likely that your
doctor can cure it.
 Squamous cell carcinoma, if detected early, can be cured.
 Melanoma is the worst and could result in death. With a family history of
melanoma, you could get it even if you've never been out in the sun.
A Healthy Suntan!
 It may look good now, but spending too much time in the sun without
sun protection and burning your skin will age your skin prematurely and
lead you down the path to skin cancer.
What you must know
1. There is no such thing as a safe suntan.
2. UVB radiation is the sun’s burning ray.
3. UVA rays are the sun’s silent killers.
4. Even on a cloudy or hazy day, the sun’s rays are
present.
5. A product’s SPF number tells you how long you can
stay in the sun before getting burnt.
6. Always apply sunscreen at least 15 to 20 minutes
before going outside.
 There is no such thing as a safe suntan. Even if you tan
slowly without burning, the damage is hazardous to the health of your
skin.
 UVB radiation is the sun's burning ray, which has an
immediate, harmful impact on skin. Damage from UVB rays takes
place the very first minute of walking outside.
 UVA rays are the sun's silent killers. You don't feel them
but they are the primary cause of skin cancer and wrinkles.
 Even on a cloudy or hazy day, the sun's rays are
present and attacking the skin.
 According to the FDA, a product's SPF number tells
you how long you can stay in the sun before getting
burnt.
•
•
•
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A SPF 2 blocks about 50% of the UVB rays
A SPF 10 filters out about 85% of the UVB rays
A SPF 15 stops about 95% of the UVB rays
A SPF 30 stops about 97% of the UVB rays
 Always apply sunscreen at least 15 to 20 minutes
before going outside. This gives the sunscreen time to absorb
and to spread over and into the skin.
REFFERENCES

http://dermatology.about.com

http://www.sun-tog.com

http://www.sciense.org.au