Ultraviolet Radiation

Ultraviolet (UV) radiation is a type of electromagnetic radiation that has a shorter wavelength than visible light but longer than X-rays. It is invisible to the human eye. UV radiation is emitted by the sun and artificial sources such as tanning beds and mercury vapor lamps.

Types of Ultraviolet Radiation

• UVA (320-400 nm): Long-wave UV radiation that can penetrate the skin's dermis, causing premature aging and contributing to skin cancer.
• UVB (280-320 nm): Medium-wave UV radiation that affects the skin's epidermis, causing sunburn and contributing to skin cancer.
• UVC (100-280 nm): Short-wave UV radiation that is mostly absorbed by the Earth's atmosphere and does not reach the Earth's surface.

Effects of Ultraviolet Radiation

Exposure to UV radiation can have both positive and negative effects on living organisms. Some of the effects include:

• Positive effects: UV radiation helps in the production of vitamin D in the skin, which is essential for maintaining bone health.
• Negative effects: Overexposure to UV radiation can lead to sunburn, premature aging, and an increased risk of skin cancer.

Protection from Ultraviolet Radiation

It is important to protect the skin and eyes from excessive UV exposure. Some ways to protect oneself from UV radiation include:

• Using sunscreen with a high SPF (Sun Protection Factor)
• Wearing protective clothing, hats, and sunglasses
• Avoiding direct sun exposure during peak UV hours (10 am - 4 pm)

Study Guide

Here are some key points to remember about ultraviolet radiation:

1. Understand the different types of UV radiation and their effects on the skin.
2. Learn about the positive and negative effects of UV radiation on living organisms.
3. Know the ways to protect oneself from excessive UV exposure.
4. Be familiar with the sources of UV radiation and how it can be harmful.