Tanning booths are not dangerous for internal organs. It does not matter that there is no negative effect produced by them on a human body.

The main danger is Ultraviolet (UV) rays. One can distinguish two types of UV rays:

UVA and UVB. UVB rays are produced with the sun; this kind of rays is the cause of sunburn. UVA rays are produced with tanning booths, these rays are connected with radiation that penetrates into the skin entering its deeper layers. UVA rays are more dangerous for the skin; the damage produced by them on the skin is more obvious.

There is a statement that people don’t get sunburned with emitted UVA rays while being in tanning booths. UVA rays have hidden danger; they can lead to malignant melanoma, the most dangerous form of skin cancer.

Nowadays the sun tanning booths have become very popular; accordingly cases of malignant melanoma have become frequent.

UV rays are very dangerous for the skin, because they lead to premature aging and loss of skin elasticity. Tanning booths are also very dangerous due to their long harmful effect, besides they are the cause of premature aging and cancer.

UV ray exposure is not safe due to some factors. UVB rays are healthy for a human body, because they promote the production of vitamin D. It should be kept in mind that UVB rays are required in small quantities due to their radioactivity and possible damage. UVA and UVB rays can make damage to immune system.
Sun tanning booths can be used as therapy for the treatment of some skin diseases, but it should be used properly.