32 / 44
32
Extrusion International 4/2016
MEASUREMENT TECHNOLOGY
Blessing and risk –
X-ray radiation
Several applications for the ionizing radiation
With its moderate radiation, the sunmakes all
life on earth possible. Nevertheless, humans
should not expose themselves for too long
to the radiation. Protection is especially
necessary when it comes to the invisible, hard
ultraviolet rays of the sunlight and hence, the
risk of possible skin changes.
X-ray radiation
X-rays, with a spectrum starting where the hard UV
radiation devolves to ultra-hard UV radiation, proved
as a blessed instrument for many areas, especially for
the medical diagnosis and cancer therapy. Also, the
X-ray radiation has become indispensable over the
last decades for valuable applications in the industrial
area. While the energy of the UV radiation rate of the
sunlight shows only low penetration regarding the hu-
man skin, X-ray radiation is able to penetrate the tis-
sue completely. In both cases, damages of cells in the
skin respectively the body may occur, which can result
in the malign change of the cells. In principle, all sub-
stances of a body cell may be damaged but eventually
only damages regarding the hereditary material (DNA)
is of importance.
Single and double-strand breaks of the DNA are not
only caused by X-ray radiation. Nowadays it is a com-
mon understanding that oxygen radicals, produced
by the metabolism of a cell, continuously cause DNA
changes. Modern methods proved that on a daily ba-
sis between 0.1 and 5 DNA double-strand breaks occur
per cell. This number is increased with the progressive
age. 99.9 % of these damages are eliminated by the
DNA double-strand break