What percentage of UV rays is UVA responsible for reaching the Earth's surface?

UVA rays make up the majority of the UV radiation that reaches the Earth's surface, accounting for approximately 95 percent. This high percentage is significant because UVA rays penetrate the skin more deeply than UVB rays and are associated with long-term skin damage, including premature aging and an increased risk of skin cancer. Understanding that UVA constitutes such a large portion of the UV radiation that we are exposed to highlights the importance of protecting the skin from all types of UV rays, not just those associated with sunburn. Thus, recognizing the extent of UVA's reach helps in formulating effective sun safety practices and developing better tanning certification standards.