As is known, ultraviolet ray radiation consists of A (90-95% of that part of the spectrum) and C-type long-wavelength rays cause barely perceptible skin reddening. They penetrate into the dermis and affect the amino acids - precursors of melanin (especially tyrosine), the oxidation of which gives quickly appear, but unstable tan. Under the influence of short-wave rays type B produces the pigment melanin, the amount of which depends on the color of skin. This tan formed about seven days, but on the body and keeps longer. Gamma rays are the most dangerous - they detrimental effect on the skin cells. The composition and the intensity of natural ultraviolet light may vary depending on the time of day, weather conditions and solar activity. A UV lamps used in solariums, provide a constant balanced combination of beams A and B filters installed in them completely cut off aggressive with rays. Use this information from free dating sites without registering and be beautiful in love.