Which UV band is considered the most dangerous and is associated with sunburn, skin aging, and eye damage?

Which UV band is considered the most dangerous and is associated with sunburn, skin aging, and eye damage?

• A. UVA
• B. UVB
• C. UVC
• D. Infrared

Answer: (B)

Ultraviolet light from the sun is grouped into UVA, UVB, and UVC, with UVC mostly blocked by the atmosphere so surface exposure comes mainly from UVA and UVB. UVB has enough energy to directly damage DNA in skin cells, which is what causes sunburn and is a major driver of skin aging and eye damage with enough exposure. It’s this direct DNA-damaging ability that makes UVB the primary culprit for acute burns and for long-term effects like cataracts or photokeratitis in the eye. UVA also harms the skin and eyes but tends to contribute more to aging and cumulative cancer risk rather than immediate sunburn, while infrared is heat radiation and isn’t responsible for these UV-specific harms.

Ultraviolet light from the sun is grouped into UVA, UVB, and UVC, with UVC mostly blocked by the atmosphere so surface exposure comes mainly from UVA and UVB. UVB has enough energy to directly damage DNA in skin cells, which is what causes sunburn and is a major driver of skin aging and eye damage with enough exposure. It’s this direct DNA-damaging ability that makes UVB the primary culprit for acute burns and for long-term effects like cataracts or photokeratitis in the eye. UVA also harms the skin and eyes but tends to contribute more to aging and cumulative cancer risk rather than immediate sunburn, while infrared is heat radiation and isn’t responsible for these UV-specific harms.