How does increased UV radiation affect the human immune system?

• A. Strengthens immune system defense
• B. Suppresses immune system defense
• C. No effect on immune system
• D. Enhances immune responses

Answer: (B)

Increased UV radiation has a well-documented impact on the human immune system, specifically in suppressing immune responses. When the skin is exposed to higher levels of ultraviolet (UV) radiation, it can lead to alterations in immune function. This can reduce the body's ability to respond effectively to infections and may also diminish responses to vaccinations.

UV radiation affects the skin’s immune cells, such as Langerhans cells and other antigen-presenting cells, leading to impaired immune surveillance and response. This suppression allows for a greater risk of infectious diseases and possibly increases the chances of skin cancers. Understanding this relationship highlights the importance of protection from UV exposure and underscores why individuals are advised to use sun protection strategies.