Biological Effects

Question 1

What is the average annual radiation dose to the general population of the US from natural background & man-made sources?

Answer 1

620 mrem

Question 2

What are the 4 main sources of naturally occurring radiation exposures?

Answer 2

1. Cosmic radiation
2. Terrestrial sources (in earth’s crust)
3. Internal sources (in body)
4. Radon & other daughter products

Question 3

IDENTIFY the method by which radiation damages cells: Radiation damages cells by _____ the atoms that make up the cell components.

Answer 3

ionizing

Question 4

Any potential radiation damage begins w/ damage to atoms. Radiation damages cells and may cause ____. This is where the radiation deposits energy into an atom, raising its energy level but not enough to eject a bound electron.

Answer 4

excitation

Question 5

Actively dividing cells are more _____ to ionizing radiation. More specialized or slower dividing cells like adult brain cells are less _____.

Answer 5

sensitive x 2

Question 6

IDENTIFY the possible effects of radiation on cells: there are ____ things that can occur.

Answer 6

4

Question 7

1/4 possible effect of radiation on cell: most cells are made primarily of water, and this is what ionizing radiation is most likely to interact with, causing hydrogen peroxide to form which is poisonous to cell. If this is the case, the cell can _____ _____.

Answer 7

repair itself

Question 8

2/4 possible effect of radiation on cell: if a cell chromosome is damaged, does not repair correctly, & continues to reproduce - this is called a _____ & may result in cancer.

Answer 8

mutation (i.e., cell damage)

Question 9

3/4 possible effect of radiation on cell: while it is routine for our cells to die & be replaced continually, a contributing factor to ____ ____ might be radiation exposure.

Answer 9

cell death

Question 10

If an individual receives _____ (range) rad of exposure, the effects are not detectable through symptoms or blood tests.

Answer 10

0-25

Question 11

Detectable changes in blood occur at a rad exposure of ______ (range).

Answer 11

25-100

Question 12

If an individual receives _____ (range) rad of exposure, they will experience nausea, vomiting, & loss of appetite.

Answer 12

100-300

Question 13

If an individual receives _____ (range) rad of exposure, this can cause diarrhea, hemorrhage, & potentially death.

Answer 13

300-600

Question 14

_____ rad is considered the dose where 50% of fatalities occur w/ in 60 days w/o medical help.

Answer 14

450 (LD 50/60)

Question 15

A typical example of ______ radiation dose is the dose we receive f/ natural background, man-made radiation or occupational exposure.

Answer 15

chronic

Question 16

Biological Effects: ______ effects of radiation exposure appear in the exposed person and are further divided into 2 classes - _____ & delayed effects.

Answer 16

Somatic / prompt

Question 17

Biological Effects: ______ somatic effects are those that may occur years after radiation doses are received. This includes the increased potential for development of _____ & cataracts.

Answer 17

Delayed / cancer

Question 18

Biological Effects: _____ effects are physical mutations or traits that are passed on to offspring. Even though these effects have never been observed in humans, they are considered _____.

Answer 18

Heritable / possible

Question 19

The embryo/fetus is most susceptible to developing adverse health effects if exposed during the time period of _____ (range) weeks after conception.

Answer 19

8-15

Question 20

Some of the potential effects associated w/ prenatal radiation doses include (1) ______, (2) lower _____ birth weight, and (3) higher likelihood of _____ disability.

Answer 20

smaller head size / average / intellectual

Question 21

2 examples of radiation exposure which are considered to be chronic radiation doses are natural ______ radiation or man-made radiation & ______ exposure.

Answer 21

background / occupational

Question 22

What is the process by which radiation causes damage to cells?

Answer 22

IONIZATION