Skin Tanning- Is It Spontaneous or Gradual?Skin tanning is the process of darkening the color of the skin by exposing it for prolonged periods to sunlight (or an indoor tanning light). When exposed to light, the skin responds to the ultraviolet component present in light by absorbing it and darkening its color.
Is Tanning Safe?
Ultraviolet light is considered harmful for the skin. Over-exposure to this type of radiation can cause skin cancer. However, when done in moderation (and with some form of protective guard on the skin) it can be safely deployed to darken the color of the skin.
The Real Process of Tanning
The mantra of a successful tan lies in the right amount of exposure to light. The time spent under sunlight (or an indoor tanning light) should neither be too less nor too much. Too less tanning can stop the skin coloration even before it has started. Similarly, too much tanning can result in too dark a color of the skin.
Tanning is a two step process which happens gradually. It is of two types and is explained below:
Immediate Pigment Darkening: The first type of tanning which takes place is the Immediate Pigment Darkening. This type of darkening occurs when the skin comes in contact with ultraviolet and other type of rays in the visible spectrum. The color of the skin goes on darkening till the time the exposure to UV rays remains.
In this type of tanning, the coloration of the skin is not a result of production of excess melanin. Instead, it depends upon factors such as skin pigment type and the time for which the skin was previously exposed to light. As a result, best tanning results are obtained if the skin pigment color is dark or when the skin has been previously tanned.
Delayed Tanning: The second type of tanning which takes place is called Delayed Tanning. In this process, the coloration of the skin takes places after 2 to 3 days of tanning. Delayed tanning goes on to increase for the next 7 to 10 days. The tan goes on to increase because of the increase in the size of cells containing the pigment melanin.
Additionally, an increase in melanosomes within these cells is also observed. This is seen as a positive development as an increased number of melanosomes mean enhanced protection from overexposure to UVA and UVB light. Both these band of radiation, though essential for tanning of the skin, are considered harmful when the skin is overexposed to them.
Hence, tanning is not an overnight process and may take some time to fully materialize.