Sun rays UVA and UVB: what is their impact on our skin?
What is UVB radiation?
First, UVA. UVA radiation is almost always the same everywhere in the world (regardless of the temperature). It represents 95% of the UV that touches the surface of the earth and crosses the clouds, the glass, the water and the epidermis (up to our eyes). It is responsible for age spots, skin aging, wrinkles and certain skin cancers.
What is UVA radiation?
As for UVB, they depend on the position of the sun, where we are and the time we expose ourselves. Stopped by clouds and glass, UVB represents 5% of the UV received on the earth and is responsible for sunburn, burns, blisters and the majority of skin cancers.
How to protect your skin from UVA and UVB rays?
Faced with them, only one solution: sunscreen. And not just any Solar protections are divided into 4 groups. Low (SPF 10), medium (SPF 15 to 25), high (30 to 50) and very high (+50). "Knowing that below 20, sun protection has no use, according to Nina Roos, dermatologist in Paris, and this, whatever our skin color". But by the way, what are the sun cream indices? "The SPF index of a sunscreen is the power of defense against UVB rays, responsible for sunburn, burns, blisters and the majority of skin cancers"explains Nina Roos, dermatologist and venerologist in Paris. By power of defense, the professional hears, the time necessary to present a sunburn, mixed with the phototype of the skin, its color and the conditions in which you find yourself - according to whether you are in the middle of the rainforest of Guadeloupe or in hiking in Iceland, the rays will not be quite the same -. This is to protect against UVB rays. For UVA, two indices are trusted. UVA letters in a black or colored circle, which means that the cream protects against UVA and PPD (Persistent Pigment Darkening), which guarantees the same thing.
Read also :
⋙ 30, 40, 50 years: which after sun to choose according to his age?
⋙ How much sun cream to apply to be well protected?
⋙ Discover the famous and affordable French sunscreen used by Meghan Markle