Outline the three different types of UV radiation and clarify why UVC radiation from the Sun does not damage our skin.

Three Types of UV Radiation

1. UVA (Ultraviolet A)

   • Wavelength: 320-400 nm
   • Characteristics: UVA rays penetrate the skin more deeply and are primarily responsible for premature skin aging and long-term skin damage. They can also contribute to the development of skin cancer.

2. UVB (Ultraviolet B)

   • Wavelength: 290-320 nm
   • Characteristics: UVB rays are responsible for causing sunburn and play a significant role in the development of skin cancer. These rays have varying intensity throughout the year and are more potent in the summer months.

3. UVC (Ultraviolet C)

   • Wavelength: 100-290 nm
   • Characteristics: UVC rays are the most harmful type of UV radiation. They are mostly absorbed by the Earth's atmosphere, particularly by the ozone layer, and do not reach the surface.

Why UVC Radiation from the Sun Does Not Damage Our Skin

UVC radiation does not damage our skin primarily because:

1. Absorption by the Atmosphere: UVC rays are absorbed by the ozone layer and other atmospheric components. This ensures that very little to no UVC rays reach the surface of the Earth where we reside.

2. Non-Exposure: Since UVC rays do not penetrate the atmosphere significantly, humans are not exposed to these wavelengths under normal circumstances, thereby preventing any potential skin damage that could be caused by UVC radiation.

Overall, while UVA and UVB contribute to skin damage, UVC is effectively blocked and poses no risk to our skin.