Pigments of the skin
The pigment melanin is primarily responsible for the skin color. In addition to 28 other cell types, so-called melanocytes are located in the germ layer of the epidermis. The melanocytes form the pigment melanin, which, due to its dark color, creates a brown skin color.
The melanin protects the cells of the skin lying in the deeper layers from the high-energy UV radiation, which can cause damage there. The amount of melanocytes is roughly the same in all people, averaging 1,500 cells per square millimeter of skin. A person from Central Africa has the same number of melanocytes as a Scandinavian. Their skin color is different because their melanocytes are differently active. In the African, the melanocytes are constantly in action, in the Scandinavian only rarely and less intensively.
In all fair-skinned people, the melanocytes must first be stimulated before they can produce large amounts of melanin. This excitation is carried out by UV light. When the sun shines on the skin, the UV component triggers the formation of melanin. Melanin production is different depending on the skin type. That is why people with light skin types do not tan as quickly and strongly as people with darker skin types.
This dye melanin is a natural protective mechanism that serves to shield the cells of the skin from UV radiation.
The skin types
There are various classifications according to which the pigmentation of people and thus their sensitivity to UV radiation are classified. A common classification in Germany is based on four types, but the very dark types are left out. The following six skin types are common internationally:
|Celtic (Type I)|
People with Celtic type skin have very light skin with freckles and blonde or red hair. You practically do not turn brown, but react with sunburn after 5 to 10 minutes of sunbathing.
|Nordic (Type II)|
People with Nordic type skin have fair skin and sometimes freckles. Her hair is blonde or light brown, and her eyes are blue, gray, or green. They get sunburned after about 10 to 20 minutes if they don't protect themselves.
|European dark (type III)|
People with skin of the European dark type have light to light brown skin and are dark blonde to brown-haired. You can stay in the sun for up to half an hour without getting sunburn.
|Mediterranean light (Type IV)|
People with skin of the light Mediterranean type have light to olive brown skin and rarely get sunburn. Unprotected, they can lie in the blazing sun for 30 to 40 minutes before they get sunburned.
|Mediterranean dark / Asian (type V)|
People with skin of the Mediterranean dark or Asian type, regardless of the sun exposure, have dark skin that can be exposed to intense solar radiation for up to 45 minutes without reacting with sunburn.
|Negroid (Type VI)|
People with skin of the negroid type are almost insensitive to UV radiation. Still, you can get sunburn in less pigmented areas like the palms of your hands.