Ultraviolet (UV) waves, also known as ultraviolet radiation, are a type of electromagnetic radiation that falls within the electromagnetic spectrum at higher frequencies and energies than visible light. UV waves have wavelengths shorter than those of visible light, ranging from approximately 10 nanometers (nm) to 400 nm.
UV waves are classified into three main categories based on their wavelengths:
UVA (Long-wave UV): UVA rays have longer wavelengths (315 to 400 nm) and are the least energetic among the three types of UV rays. They are commonly referred to as "black light" and are often used in applications such as counterfeit detection, insect traps, and some medical treatments.
UVB (Medium-wave UV): UVB rays have shorter wavelengths (280 to 315 nm) and are more energetic than UVA rays. They are partially absorbed by the Earth's ozone layer and play a crucial role in causing sunburn, skin damage, and increased risk of skin cancer.
UVC (Short-wave UV): UVC rays have the shortest wavelengths (100 to 280 nm) and are the most energetic. Fortunately, the Earth's atmosphere, particularly the ozone layer, absorbs the majority of UVC radiation, preventing it from reaching the Earth's surface. UVC rays are commonly used for sterilization purposes in medical, industrial, and water treatment settings due to their ability to kill or inactivate microorganisms.
Excessive exposure to UV radiation, particularly UVB and UVC, can have harmful effects on living organisms, including damage to DNA, skin aging, and an increased risk of skin cancer. However, moderate exposure to UVA radiation is not as damaging and is sometimes used in medical treatments like phototherapy for certain skin conditions.
It's important to take precautions when exposed to UV radiation, such as using sunscreen, wearing protective clothing, and avoiding prolonged exposure to direct sunlight, especially during peak hours.