Final answer:
When exposed to UV radiation without protection, skin cells may undergo apoptosis as a result of the DNA damage sustained, which can lead to mutations and increased skin cancer risk. Sunburn is a clear sign of skin damage, while tanning is a defense mechanism against future exposures. Protective measures like applying sunscreen can help reduce the risk of long-term damage.
Step-by-step explanation:
UV Radiation and Skin Cell Damage
When the skin on your arms begins to turn red due to UV radiation, the affected cells are undergoing apoptosis, which is a process of programmed cell death. Apoptosis occurs when cells are irreversibly damaged and it serves as a protective mechanism to prevent damaged DNA from potentially leading to cancer. Cells that have been damaged by UV radiation, especially by UV-B and UV-A rays, can undergo mutations after the DNA helix is distorted, which significantly increases the risk of skin cancer. Sunburn, in this context, is an indicator of skin damage. The tanning response, while perceived by some to be healthy-looking, is the body's defense mechanism producing pigments to absorb future UV exposure and protect living cells beneath. UV-A light damage, on the other hand, is often an indirect type through the formation of free radicals.
Continuous exposure to UV radiation accelerates the aging process of the skin, causing wrinkles and increasing the risk of developing skin cancer, such as melanoma, particularly if the exposure occurs during childhood. Wearing sunscreen with a high SPF, along with protective clothing and hats, is essential to mitigate this risk