Bioeffects trivia Flashcards
Dose rate required to double the mutation rate in man has been extrapolated from mouse models. This dose is:
At lease 1 Gray Low dose rate, low LET. Called the doubling dose
Analysis of Japanese bomb survivors was limited to those person who had doses:
Less than 4 Gy. Because the analyses were used to determine stochastic risk coefficient
Innermost layer of the epidermis.
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.
According to BEIR V, the minimum dose required to cause permanent male sterility is a an acute dose to the testes of
3-5 Gy
Peak thyroid uptake values will not be reached until _____ after exposure
12 hours
An Active person who eats a high fiber diet and has adequate fluids will have a gastrointestinal tract transit time of
24-36 hours
Cigarette smokers who smoke 1.5 packs a day receive approximately 8 Rem/yr to the lungs due to
Pb-210 and Po-210
Clearance times for respiratory tract are
a) Trachea: 0.1 hoursb) Bronchi: 1.0 hoursc) Bronchioles: 4 hoursd) Alveoli: 10-1500+ days
Radio-sensative cells in the bone
Endosteal and epitheal cells on the bone surface
Three types of deleterious effects due to radiation exposure
Tumor Induction, Fertility effects, and Hereditary effects
Most soils have the ability to release more than _____ of the radon formed
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.
The absorbed dose to cells in the _____ in the upper airways of the tracheobronchial tree is the significant dose for cancer induction in miners
Bronchial epithelium
Cancer induced by radon daughters in underground mines is found primarily in the
upper trachea and bronchial tree
BIER V estimates _____ additional cancer deaths in a population of 100,000 exposed to 10 Rad
- 0.8% per 10 rem
The ICRP 26 risk factor used for stochastic effects is
0.01 per sievert
Erythrocytes
Red blood cells
Leukocytes
White blood cells
Rank cells from most to lease radio-sensitive: Intestinal crypt cells, nerve cells, mature spermatocytes, lymphocytes, erythrocytes
Lymphocytes, Intestional crypt cells, mature spermatocytes, erythrocytes, nerve cells.
In the interaction of thermal neutrons with tissue, the major dose is from
H-1 (n, gamma) H-2 reaction
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:
800
Normal background radiation exposures are partially due to ingestion/inhalation and subsequent accumulation in the thyroid of:
I-131
Fission products considered environmental indicators of contamination, e.g. Sr-90 and I-131 are considered such because
The exposure pathways are significant
Plutonium, taken into the circulatory system, will deposit in what areas of the body?
Bone- for soluble plutonium. Lungs- for insoluble forms.
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:
Milk. Cereals are good indicators for Cs-137 and Sr-90, but not I-131
Radium is considered to be a _____ seeker when internal to the body
Bone. All group II elements are considered bone seekers.
What is the law of Bergonie and Tribondeau?
Radio-sensitivity of a cell is directly proportional to metabolic activity and inversely proportional to the degree of differentiation.
Outermost layer of skin that provides protection to the underlying tisses
Stratum corneum
The DAC for Rn-222 is _____ of the working level
1/3
Average activity of K-40 found in the human body
100nCi
Non-Stochastic ALI (nALI)
Amount of radioactive material which will produce a 50 year committed dose equivalent to an individual organ or tissue of 50 Rems. (H50,T)
Stochastic ALI (sALI)
Amount of radioactive material which will produce a 50 year committed effective dose equivalent of 5 rem (adds in the sum of the weighting factors). (SUM(wT H50,T)
Largest respirable particle is considered to be
10 microns
General area dose rates should be recorded
as the highest dose rate between the head and knees
Equilibrium ratio
[WL comprised of daughters in pCi/L]/Radon pCi/l * 100WL for daughters is 1 = 100pCi/L for 3 daughter nuclides.
WLM
(WL*exposure time(hours)/170 hoursThe 170 is amount of hours spent working per month
1 WLM =
~ 14 mSv/WLM
ALIs and DACs for inhalation classes in Table 1 of Appendix B
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.
Chemically, Uranium is toxic to:
The Kidneys
The limits for air and liquid effluents when added together, would result in ____ mrem
- Limit fro general public.
For inhaled radionuclides, ___ is least dependent upon particle size or mass
Tracheobronchial deposition
The ALIs and DACs for inhalation by the NRC are given for an aerosol with an activity median aerodynamic diameter (AMAD) of _____ µm
1
The three classes of inhaled radioactive material, thier retention, and region of retention in the lung
D, W, Y
D = celarance half-time of <10 days
W = 10 to 100 days
Y - greater than 100 days
All in the pulmonary region of the lung
Critical organ for Sr-90
Bone
Critical organ for Cs-137
Total Body
Critical organ for Pu-239 (Class Y)
Bone
Critical organ for U-238 (class W)
Lung
Fast neutrons are more effective at producing cataracts than other forms of radiation
True
Cerebrovascular syndrome dose (approximate)
100 Gy
Gastrointestional syndrom dose (approximate)
5-12 Gy
Hematopoietic syndrome dose (approximate)
2.5-5 Gy
Define the Derived Air Concentration (DAC)
The concentration of a given radionuclide in air which, if breathed by the refernce man for a working year of 2,000 hours under conditions of light work (inhalation rate of 1.2 cubic meters of air per hour), results in an intake of one ALI
Annual limit on Intake (ALI)
Derived limit for the amount of radioactive material taken into the body of an adult worker by inhalation or ingestion in a year. ALI is the samller value of intake of a given radionuclide in a year by the reference man that would result in a committeed effective dose equivalent (CEDE) of 5 rems (0.05 Sv) or a committed dose equivalent (CDE) of 50 rems (0.5 Sv) to any individual organ or tissue.
