Radiation Biology

Question 1

Dose rate required to double the mutation rate in man has been extrapolated from mouse models. This dose is:

Answer 1

At lease 1 Gray Low dose rate, low LET. Called the doubling dose

Question 2

Analysis of Japanese bomb survivors was limited to those person who had doses:

Answer 2

Less than 4 Gy. Because the analyses were used to determine stochastic risk coefficient

Question 3

Innermost layer of the epidermis.

Answer 3

Basal cell layer. Basal cells continually divide and new cells constantly push older ones up toward the surface of the skin. Also called the stratum germinativum.

Question 4

According to BEIR V, the minimum dose required to cause permanent male sterility is a an acute dose to the testes of

Answer 4

3-5 Gy

Question 5

Peak thyroid uptake values will not be reached until _____ after exposure

Answer 5

12 hours

Question 6

An Active person who eats a high fiber diet and has adequate fluids will have a gastrointestinal tract transit time of

Answer 6

24-36 hours

Question 7

Cigarette smokers who smoke 1.5 packs a day receive approximately 8 Rem/yr to the lungs due to

Answer 7

Pb-210 and Po-210

Question 8

Clearance times for respiratory tract are

Answer 8

a) Trachea: 0.1 hours
b) Bronchi: 1.0 hours
c) Bronchioles: 4 hours
d) Alveoli: 10-1500+ days

Question 9

Radio-sensative cells in the bone

Answer 9

Endosteal and epitheal cells on the bone surface

Question 10

Three types of deleterious effects due to radiation exposure

Answer 10

Tumor Induction, Fertility effects, and Hereditary effects

Question 11

Most soils have the ability to release more than _____ of the radon formed

Answer 11

10%. NCRP no 78: the fraction of radon released from a solid material depends on its porosity and whether is on or near the surface of the material. It is currently believed that the source of most of the radon is the soil beneath a structure.

Question 12

The absorbed dose to cells in the _____ in the upper airways of the tracheobronchial tree is the significant dose for cancer induction in miners

Answer 12

Bronchial epithelium

Question 13

Cancer induced by radon daughters in underground mines is found primarily in the

Answer 13

upper trachea and bronchial tree

Question 14

BIER V estimates _____ additional cancer deaths in a population of 100,000 exposed to 10 Rad

Answer 14

800. 0.8% per 10 rem

Question 15

The ICRP 26 risk factor used for stochastic effects is

Answer 15

0.01 per sievert

Question 16

Erythrocytes

Answer 16

Red blood cells

Question 17

Leukocytes

Answer 17

White blood cells

Question 18

Rank cells from most to lease radio-sensitive: Intestinal crypt cells, nerve cells, mature spermatocytes, lymphocytes, erythrocytes

Answer 18

Lymphocytes, Intestional crypt cells, mature spermatocytes, erythrocytes, nerve cells.

Question 19

In the interaction of thermal neutrons with tissue, the major dose is from

Answer 19

H-1 (n, gamma) H-2 reaction

Question 20

If a linear relationship between somatic effects of radiation and absorbed dose is assumed, the number of additional cancer deaths to be expected per million persons per rad is:

Answer 20

800

Question 21

Normal background radiation exposures are partially due to ingestion/inhalation and subsequent accumulation in the thyroid of:

Answer 21

I-131

Question 22

Fission products considered environmental indicators of contamination, e.g. Sr-90 and I-131 are considered such because

Answer 22

The exposure pathways are significant

Question 23

Plutonium, taken into the circulatory system, will deposit in what areas of the body?

Answer 23

Bone- for soluble plutonium. Lungs- for insoluble forms.

Question 24

Both Cs-137 and I-131 are released as fission products by power plants. The bio-pathways for these two radionuclides can be traced via:

Answer 24

Milk. Cereals are good indicators for Cs-137 and Sr-90, but not I-131

Question 25

Radium is considered to be a _____ seeker when internal to the body

Answer 25

Bone. All group II elements are considered bone seekers.

Question 26

What is the law of Bergonie and Tribondeau?

Answer 26

Radio-sensitivity of a cell is directly proportional to metabolic activity and inversely proportional to the degree of differentiation.

Question 27

Outermost layer of skin that provides protection to the underlying tisses

Answer 27

Stratum corneum

Question 28

The DAC for Rn-222 is _____ of the working level

Answer 28

1/3

Question 29

Average activity of K-40 found in the human body

Answer 29

100nCi

Question 30

Non-Stochastic ALI (nALI)

Answer 30

Amount of radioactive material which will produce a 50 year committed dose equivalent to an individual organ or tissue of 50 Rems.

Question 31

Stochastic ALI (sALI)

Answer 31

Amount of radioactive material which will produce a 50 year committed effective dose equivalent of 5 rem

Question 32

Largest respirable particle is considered to be

Answer 32

10 microns

Question 33

General area dose rates should be recorded

Answer 33

as the highest dose rate between the head and knees

Question 34

Equilibrium ratio

Answer 34

[WL comprised of daughters in pCi/L]/Radon pCi/l * 100

WL for daughters is 1 = 100pCi/L for 3 daughter nuclides.

Question 35

WLM

Answer 35

(WL*exposure time(hours)/170 hours

The 170 is amount of hours spent working per month

Question 36

1 WLM =

Answer 36

~ 14 mSv/WLM

Question 37

ALIs and DACs for inhalation classes in Table 1 of Appendix B

Answer 37

D, W, Y. refers to thier retention in the pulmonary region of the lung. D is less than 10 days, W is 10 to 100 days and Y is greater than 100 days.

Question 38

Chemically, Uranium is toxic to:

Answer 38

The Kidneys

Question 39

The limits for air and liquid effluents when added together, would result in ____ mrem

Answer 39

100. Limit fro general public.