9
9. radiation poisoning
i) is exposure to ionizing radiation over an extended
period of time
10. nuclear fallout
j) is an exposure to ionizing radiation which occurs
during a short period of time
11. radioactive con-
tamination
k) are waste products containing radioactive
materials
5. Read the text and fill in the missing words and word combinations.
approximately; global scale; contamination; radioactive isotopes; rotation of
radionuclides; radiosensitivity; irradiated populations; agriculture, cardinal
principles; natural background; long-lived radionuclides; stock-breeding;
Radiation ecology is a branch from two, independent, scientific disci-
pline, such as general radiobiology and ecology. This is rather young scien-
tific direction, which has gained particular relevance after mass testing of
atomic weapon. By then it was become comprehensible, that 1)……… by ra-
dionuclides was occurring not on the local level (nuclear test areas, industrial
places of atomic industry enterprises), but brings to consequences of
2)…………. . By this, basically, are defined 3)…………… of the given sci-
ence, which is considered in studying of distribution, migration and
4)…………….. in the biosphere as well as by influence of ionization radia-
tion on ecological systems.
Certainly, in natural conditions organisms are irradiated for the account
of natural background of ionization radiation, which is caused by radiation of
5)……………… in lithosphere, hydrosphere and atmosphere, and by cosmic
radiation. Radiation rate is determined by the 6)……………. in the bio-
sphere, so it is rather small, 7)……………… 0,1 rad an year, and in most
cases it does not produce an observable influence upon alive organisms. As a
result of appearance additional amount of radionuclides in the biosphere (ra-
diation sources) alive organisms were subjected both to irradiation, caused by
the natural radioactive background and to artificial radioactive nuclides (not
only external but also internal exposure from incorporated radionuclides).
Because of different 8)…………….. of plant and animal species irradia-
tion of natural biocenoses can bring to change ones species by others, to
change of interspecific and intraspecific relations. Radiation and genetic
changes appear in 9)………………. , natural mutative rate increases, it is oc-
curring radiostability deviance on population level.
Contamination of extensive territory by artificial radionuclides, both in
Ukraine (Chernobyl exclusion zone and zone of the unconditional (obliga-