What are UVB rays and which is their effect?
UVB rays are for the most part absorbed by the ozone layer and have a wave length of 280 – 320 nm. They do not penetrate as deep in the skin as the UVA rays. Due to a higher absorbing energy in the upper skin layer, the UVB rays are responsible for the solar erythema (sunburn). The erythemal reaction normally follows three to six hours after sun exposure. UVB rays have following effects: · slow but long lasting tan due to the increased production of melanin and provocation of the so called light induced callosity. · developing of sunburn, with higher burning risk on the zones with thin skin (areas without hair, nose, shoulders etc.) through its high energy, the UVB rays can directly damage the DNA in the skin cells and in this way overstress the skin’s own repair mechanism.
