Final answer:
Actinic rays, primarily composed of ultraviolet (UV) light, are a form of electromagnetic radiation capable of causing photochemical reactions and damage to living cells, potentially leading to skin cancer and contributing to premature aging.
Step-by-step explanation:
The term actinic rays refers to a type of electromagnetic radiation that has the potential to cause photochemical reactions upon exposure. In the context of the sun's radiation, actinic rays are primarily composed of ultraviolet (UV) light. UV light is known for its energetic nature due to its shorter wavelengths compared to visible light, and it is significant for its potential to cause damage to living cells, particularly the skin.
UV light from the sun includes both UV-A and UV-B rays, and exposure can lead to conditions such as skin cancer and premature skin aging like wrinkles.
UV light is considered ionizing radiation because it carries enough energy to liberate electrons from atoms or molecules, thereby creating ions. Prolonged or intense exposure to UV rays can result in harmful effects such as skin malignancies because they can alter DNA within cells.
The World Health Organization has classified UV radiation as a Group 1 carcinogen, which is a category that identifies substances with a definitive causal link to cancer. More cases of skin cancer are attributed to UV light exposure than lung cancer is to smoking.