Question

discuss how UVA and UVB rays contribute to the process of oncogenesis in skin cells?

Answer 1

Effect of UVA   and UVB   in the process of oncogenesis in skin cell

UV rays is the part of the electromagnetic spectrum that reaches the earth from the sun. Its wavelength is shorter than visible wavelength.. UVA has 400-320 nm wavelength and UVB has its wavelength 320-290 nm. The effect due to UVA and UVB on the skin are sunburn, tanning, premature skin aging, eye damage, suppression of immune system and skin cancer.

Effect of UVA on skin:

It penetrates deep into the skin i.e., in basal layer of epidermis which is the skin thickest layer. UVA changes skin cell known as keratinocytes in the basal layer of epidermis which results in injury to skin’s DNA and thus the skin darkens as it is a tanning dominant ray. The skin darkens in an imperfect attempt to prevent further DNA damage. This imperfection or mutation may cause skin cancer.

Effect of UVB on skin:

It burns the superficial laye of the skin. UVB rays can burn and damage skin especially at high altitudes and at the reflective surface such as snow or ice, which bounce back up to 80% of rays so that they hit the skin twice. It causes direct DNA damage.