EFFECTS OF THE SUN

ON THE SKIN

PRESENTER : MI HYUN HWANGINSTRUCTOR : 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.

The Four Warning Signs of CancerThese "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. 

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.

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.

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.

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.

• 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