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UV rays

Extracts from this document...

Introduction

Waves – Electromagnetic Spectrum – Ultraviolet Rays

Electromagnetic energy comes in many different forms because of the varying wavelengths of each wave. Ultraviolet (UV) light is electromagnetic waves of frequencies higher than those of violet (visible) light; though these waves are invisible to the human eye. Ultraviolet light is a part of the electromagnetic spectrum, and of course UV rays do have uses, advantages, disadvantages, and a rising issue and affect our society and the environment.

The main properties of UV radiation (a form of the electromagnetic spectrum) are as follows:

  1. It can travel through empty space.
  2. The speed of light is constant in space. From highest energy to lowest energy the forms of light are Gamma rays, X-rays, Ultraviolet, Visible, Infrared, Radio. (Microwaves are high-energy radio waves.
  3. A wavelength of light is defined similarly to that of water waves ---distance between crests or between troughs. The abbreviation used for wavelength is the Greek letter lambda.

Three main sources of UV rays are sunlight, mercury vapor lamp and fluorescent tubes.

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Middle

As mentioned above excessive UV rays could cause skin cancer. Ultraviolet light has high enough energy to damage our skin cells, so our bodies will produce a darker pigment in our skin to prevent exposure of the deeper skin cells to the UV (we tan as a defense mechanism). One of the variables that increase the incidence of skin cancer is the greater intensity of UV-radiation that is reaching the earth's surface - this increase is due to an unprecedented thinning of the Stratospheric Ozone Shield.

The ozone layer is very important because it stops too many of the sun’s UV rays getting through to the Earth. Too much UV can cause skin cancer and will also harm all plants and animals. Life on Earth could not exist without the protective shield of the ozone layer. The ozone layer is like a sunscreen, a thinning of it would mean that more UV rays would be reaching us.

One way of protecting your skin from skin cancer, is by applying sun tan lotion.

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Conclusion

     (NASA). Doha, Qatar. 5 Nov. 2007 <http://science.hq.nasa.gov/kids/imagers/ems/

     index.html>.

Saddleback Valley Unified School District, Kristal Pride. "Properties of Light." 11 Oct. 1999. UCI

     Summer Science Institute 1999. Doha, Qatar. 5 Nov. 2007 <http://can-do.com/uci/lessons99/

     light.html>.

Astronomy Notes, Nick Strobel. "Electromagnetic Radiation - Properties of Light." 17 May 2001.

     Astronomy Notes. Doha, Qatar. 5 Nov. 2007 <http://www.astronomynotes.com/light/s3.htm>.

ARIC. "Atmosphere, Climate and Environment." ARIC - Information and Teaching Resources. Doha, Qatar.

     5 Nov. 2007 <http://www.ace.mmu.ac.uk/kids/ozonehole.html>.

"Free Drinking Water." APEC. Doha, Qatar. 5 Nov. 2007 <http://www.freedrinkingwater.com/

     water-education2/86-water-disinfection1.htm>.

"Types of Physiotherapy - UV rays." 5 Nov. 2007. Medindia Health Network . Doha, Qatar. 5 Nov. 2007

     <http://www.medindia.net/patients/patientinfo/physiotherapytypes_uv.htm>.

U.S. Environmental Protection Agency, et al. "Ultraviolet Disinfection." 1998. National Small Flows

     - Clearing House. Doha, Qatar. 5 Nov. 2007 <http://www.nesc.wvu.edu/nsfc/pdf/eti/

     UV_Dis_tech.pdf>.

Simonetti, John. "Frequently Asked Questions About Light and Lasers." Virginia Tech Physics. Doha,

     Qatar. 5 Nov. 2007 <http://www.phys.vt.edu/~jhs/faq/light.html#q6>.

...read more.

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