Ultraviolet (UV) rays are a type of electromagnetic radiation that are invisible to the human eye. They have shorter wavelengths than visible light and are divided into three categories: UVA, UVB, and UVC. Examples of sources of ultraviolet rays include:
1. Sunlight: The sun is the primary natural source of UV rays. UV radiation from the sun is responsible for causing sunburn, skin aging, and an increased risk of skin cancer.
2. Tanning beds: Tanning beds and sun lamps emit UVA and UVB radiation, which can also cause skin damage and increase the risk of skin cancer.
3. Fluorescent lights: Some types of fluorescent lights emit small amounts of UV radiation.
4. Welding torches: Welding torches emit high levels of UV radiation, which can cause eye damage and skin burns if protective gear is not worn.
5. Germicidal lamps: These lamps are used to disinfect surfaces and air, but can also emit UVC radiation, which is harmful to living organisms and can cause skin and eye damage.