REPOSITORY > RESULTS

Abstract

Radon and its progeny play an important role contributing to the dose of radiation which a person
receives from all natural sources of ionizing radiation. This is one of the reasons why this problem has been
of great interest, as a result of which an increased number of scientific works and monographs have been
written on this issue. Such works have mainly been concerned about the concentration of radon and its
progeny in the air. Certainly, the most interesting areas were those with high levels of radon concentration.
Accordingly, one of the purposes of this research study was to investigate further the causes of high
concentrations of radon. So far, we have been able to understand properly some of the parameters affecting
the radon concentration which increases in the air of the closed rooms. We know that radon comes primarily
from the soil/ground; hence the floors and walls which meet the surface of the soil must be of high quality.
Therefore, prior to building any structure, a feasibility study of the geological conditions of the ground
should be studied. Attention must be paid, of course, to the choice of appropriate building materials. The
concentration of radon in the air of a room is also affected by microclimatological parameters and the life
style of the inhabitants.
Due to the large number of parameters that affect the concentration of radon and its progeny in the
air, it is necessary to make appropriate calculations and to draw correct conclusions from the measurements
by means of mathematical–physical models.
The final purpose of the study was to assess the doses received during the breathing process from
radon and its progeny in several settlements and working facilities. From this dose one can further consider
the likelihood of the appearance of lung cancer.
The primary aim of this doctoral thesis was the measurement of radon concentrations in schools,
houses, mines and caves, which were spread in various locations, different geological, weather and soil
conditions. Measurements were performed on different floors of buildings or in different places, in caves
and different mine horizons. These results were published and presented in tabular form and graphics in
scientific journals, which copies are attached to this doctoral dissertation.
The values of radon concentrations in Kosovo were compared with measurements made in different
countries of the world.
In this study, we were interested in obtaining the most accurate possible data; hence, besides the
current measurements of radon concentration by means of the alpha scintillation method, we also used solid
state nuclear track detectors (SSNTD) for longer measurements in places where preliminary measurements
were made. On comparing measurements obtained from both methods, no significant differences between
the two methods were noticed.
It is worth pointing out that the places where measurements were carried out were selected not only
because of their geological conditions, but also because they were bombed by NATO with depleted uranium
– containing munitions.
Prior to bombing, the radon concentrations in these places were within the normal limits, but an
increase of radon concentrations has been noticed in recent times. Consequently, the measurements were
repeated at different time periods.
Taking into consideration the measurement results in general, and by comparing these
measurements with those in different countries, it can be concluded that the concentrations of radon in
Kosovo are relatively low. But this does not mean that such measurements should not be continued in the
future, because in the course of time these buildings will age and cracks may appear, and thus radon could
penetrate inside such houses. Therefore, in order to avoid this, it should be our task to find out the modes of
penetration of radon into buildings in order to avoid or reduce this problem.
We consider that this doctoral thesis and the published articles are a solid basis for other researchers
dealing with this issue, because it could make their research easier with respect to comparisons and
references dealing with this topic.
The first measurements of radon concentration were made in 2003. Measurements were continued in
the following years, and there were many to perform in order to include all the areas of Kosovo, so as to be
able to create a map of radon concentration.
Indoor air radon (222Rn) concentrations were measured in spring and winter in 30 classrooms of nine
elementary schools and in 19 classrooms of high schools in Prizren.
Indoor air radon (222Rn) concentrations were measured in March, May, August and December in 15
classrooms of five elementary schools and in six classrooms of one high school in Sharr.
At eleven points along the guided tourist route in the Gadime Cave of Kosovo, air radon concentrations
were measured in summer and winter, using alpha scintillation cells and solid state nuclear track detectors.
At two points in summer, values higher than 1700 Bq m–3 were observed. They were otherwise in the 400–
1000 Bq m–3 range. The values were lower in winter. The effective dose received by a person during a 90-
minute visit is 3.7 μSv in summer and 2.5 μSv in winter. For a tourist guide, the annual effective dose does
not exceed 3.5 mSv.
Indoor air radon concentrations were measured by exposing etched SSNTDs in the sleeping and living
rooms of 18 houses in six villages of the Sharri community in Kosovo. Values ranged from 24 Bq m–3 to 209
Bq m–3 (only one exceeding 200 Bq m–3), with a geometric mean and geometric standard deviation of 95.4
Bq m–3 and 1.6 Bq m–3, respectively. Based on the assumption that the spring radon concentrations obtained
in this survey represent the yearly average, annual effective doses of residents were calculated; they ranged
from 0.89 to 4.7 mSv y–1, with a geometric mean of 2.2 mSv y–1 and a geometric standard deviation of 1.5
Bq m-3.