Sunscreen

Authors : Suraj Venna Melanoma Center Washington Cancer Institute, Felix Kuo FAAD NY 2009-07-20

(Photo: Fraunhofer Lines Diagram spectrum of visible light ( Sun ). Source : NASA)

Introduction

We are constantly exposed to all types of electromagnetic energy, whether from cellular phones, microwaves, televisions, radio waves, or the ultraviolet light from the sun.
The electromagnetic spectrum includes several types of energy forms, including cosmic rays, gamma rays, X-rays, ultraviolet (UV), visible light (Red, Orange, Yellow, Green, Blue, Violet), infrared, and radio waves. The shorter the wavelength, the more energy it contains and potentially the more damaging (mutagenic) it may be to the building blocks of our cells, our DNA. At one end of this electromagnetic spectrum are very short waves, but extremely high energy and very mutagenic (cosmic, gamma, X-ray). Fortunately, these most damaging types of waves don’t reach earth’s surface. We are exposed to visible light, infrared and ultraviolet ray. The ultraviolet spectrum of light includes UVA, UVB, and UVC. Again, the shorter the wavelength, the more mutagenic it is, thus UVC is most dangerous.