Which of the following is true about UV-A rays?

The statement that UV-A rays penetrate deeper into the skin is accurate and highlights a key characteristic of this particular type of ultraviolet radiation. UV-A rays are known for their ability to reach the dermis, which is the second layer of skin beneath the epidermis. This deeper penetration contributes to long-term skin effects, such as photoaging, wrinkles, and DNA damage, which can lead to skin cancer. Understanding the penetration depth of UV-A rays is important for both tanning and sun protection practices.

In contrast, other assertions about UV-A rays do not reflect the full scope of their impact. While UV-A rays do play a role in stimulating melanin production to some extent, it is UV-B rays that are more directly responsible for causing sunburn, and the claim that UV-A rays are completely harmless is misleading since they can cause significant skin damage over time. Therefore, recognizing the deeper skin penetration of UV-A rays is crucial for effective tanning consultation and skin health education.