ultravioletas

Ultraviolet (UV) radiation is a form of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays, typically ranging from about 10 nanometers to 400 nanometers. It lies outside the visible spectrum, which humans perceive as colors from violet to red. UV radiation is produced by the sun and various artificial sources, including black lights, fluorescent lamps, and certain types of lasers.

The sun emits UV radiation across three main categories: UVA (315–400 nm), UVB (280–315 nm), and UVC (100–280 nm). UVA penetrates deeper into the skin, contributing to aging and skin damage, while UVB primarily affects the outer layers and is linked to sunburn and skin cancer. UVC is the most harmful but is largely absorbed by the Earth's ozone layer, preventing it from reaching the surface.

Exposure to excessive UV radiation can cause immediate effects such as sunburn, eye damage (photokeratitis), and long-term consequences like premature skin aging, wrinkles, and an increased risk of skin cancer. Protective measures include wearing sunscreen with broad-spectrum UV protection, protective clothing, hats, and sunglasses with UV-blocking lenses. Artificial UV sources, such as tanning beds, also pose risks and should be used cautiously.

UV radiation has various beneficial applications, including sterilization, water treatment, and the production of vitamin D in the skin when exposed to sunlight. Scientists and industries continue to study its effects and develop safer ways to harness its properties.