Philips KL7071 sunlamp
TANNING
Ultraviolet radiation can be divided into three main
categories that differ from each other by their effect
on living organisms. These three categories are
UV-A with wavelengths ranging from 400 to 315
nanometers, UV-B with wavelengths from 315 to
280 nanometers and UV-C with wavelengths from
280 to 100 nanometers. UV-C carries the most
energy and it is the most harmful of the three.
Exposure of the skin to UV-C very quickly leads to
symptoms of burning and it is suspected to cause
skin cancer. UV-C that is emitted by the sun is
almost completely absorbed in the ozone layer of
the atmosphere. Dedicated UV-C radiators were
designed for disinfecting of surgical instruments or
for sterilisation of food but small quantities of UV-C
could also be present in UV-A and UV-B radiators.
The significance of ultraviolet radiation for
therapeutic applications was mainly limited to UV-A
and UV-B as emitted by devices like the Philips KL7071 sunlamp on display here.
UV-A penetrated deeper into the skin than did UV-B and it was responsible for the
tanning of pigment that was already present there. The difference in the tanning effect
of UV-radiators of various types and brands could mainly be explained by differences
in the relative contribution of UV-A and UV-B. UV-A leaded to a quicker tanning, the
tanning of UV-B lasted longer.
