1. UV radiation
By Andrew Coventry
10LC

2. Contents What is UV radiation? What is a tan?
How does UV radiation tan the skin?
What damage can UV do to the skin?
Pictures of skin cancers.
How to reduce the chance of getting skin cancer.
Other uses of UV light.

3. What is UV radiation?
Ultraviolet radiation or UV for short light is electromagnetic radiation which has a wavelength shorter than visible light, but longer than X-rays. It is named because the spectrum consists of waves with frequencies higher than those humans identify as the colour violet. The name means beyond violet, from Latin ultra, beyond, violet being the colour of the shortest wavelengths of visible light. UV light has a shorter wavelength than that of violet light.
UV light is found as part of the radiation, emitted from the Sun. Ultraviolet radiation in the UVA, UVB, and UVC bands, but because of absorption in the atmosphere's ozone layer, 98.7% of the ultraviolet radiation that reaches the Earth's surface is UVA. (Some of the UVB and UVC radiation is responsible for the generation of the ozone layer.) UV has many other effects, including some that are beneficial and others that are damaging to human health.

4. What is a tan?
A tan is a social way of standing out from each other. It was started in the US when an economic boom meant more people where going on holiday and therefore getting a tan. But it wasn’t always like this as all through history, it has been better to be pure and light skinned as you would be showing wealth and purity.

5. How does UV radiation tan the skin?
Darkening of the skin is caused by an increased release of the pigment, melanin into the skin's cells after exposure to ultraviolet radiation. Melanin is produced by cells called melanocytes and protects the body from absorbing an excess of solar radiation, which can be harmful. Depending on genetics, some people can darken quickly and deeply whereas others do not darken much at all.

6. What damage can it do to the skin?
Skin cancer is a malignant growth on the skin which can have many causes. Skin cancer generally develops in the outermost layer of skin, so a tumor is clearly visible. This makes most skin cancers detectable in the early stages. There are three common types of skin cancer, which are named after the type of skin cell which it comes from. Cancers caused by exposure to UV may be prevented by avoiding exposure to sunlight or other UV sources, wearing sun-protective clothes, and using a broad-spectrum sun screen. Skin cancers are the fastest growing type of cancer in the United States. Skin cancer represents the most commonly diagnosed malignancy, surpassing lung, breast, colorectal and prostate cancer.

7. Pictures of skin cancers.

8. How to reduce the chance of getting skin cancer
Reducing exposure to UV radiation when young especially.
Avoid getting sunburns.
Avoiding exposure during the day when the sun is highest in the sky.
Wearing protective clothing like long sleeves and hats when outdoors or even special UV protective clothing.
Use a sunscreen that blocks both UVA and UVB radiation.
Use a high SPF rating sun block.
Always reapply sun block every hours and always after swimming.

9. Other uses of UV light
UV light can be used for seeing things like UV pen. The pen is used as a security marker to increase the chance of getting the stolen items back. Also, a newer way of protection is using UV tainted water that stains the skin, clearly and unknown to the thief which can then be shown under a UV or ‘Black light’

10. Thank you for taking the time to look at this slide show