Final answer:
Excessive sun exposure is responsible for about 80% of wrinkles, due to UV radiation damaging the skin's collagen fibers. While necessary for vitamin D synthesis, UV radiation can also lead to skin cancer and should be moderated with protective measures.
Step-by-step explanation:
The percentage of wrinkles that is caused by excessive sun exposure is approximately 80%. The harmful UV radiation, especially UV-A and UV-B, can damage the skin's collagen fibers leading to accelerated skin aging and wrinkle formation. This exposure, while creating visible changes like wrinkles, can also lead to skin cancer and other serious skin conditions. To protect the skin, it is important to limit sun exposure, wear protective clothing, and apply sunscreen when outdoors.
Too much sun exposure not only contributes to wrinkling but also increases the risk of skin cancer, including melanoma, the most deadly form of skin cancer. Freckles and moles can also be a result of sun exposure and may need to be monitored for indications of cancerous changes. Additionally, while UV radiation can be hazardous, it is also necessary for vitamin D synthesis in the skin, which is essential for bone health and the immune system.