Lecture 2: Radiation Safety

Question 1

X-rays are __, damage atoms by ejecting electrons

Answer 1

Ionizing

Question 2

What is the result of Compton scatter

Answer 2

Electron is ejected and creates free radicals and affects DNA

Question 3

What is the critical target in the body for radiation induced damage

Answer 3

DNA

Question 4

Ionizing damage to DNA causes what 4 things

Answer 4

1. Increase mutation rate
2. Fetal abnormalities/ death
3. Shortened life span
4. Increase cancer risk

Question 5

What radiation is the major source of exposure to veterinarians and technicians

Answer 5

Scatter radiation

Question 6

Deterministic vs stochastic: which type of exposure has a threshold dose that exists and below that threshold side effects are not seen

Answer 6

Deterministic

Question 7

With deterministic radiation exposure severity ___with dose

Answer 7

Increases

Question 8

What are some side effect examples of deterministic radiation exposure

Answer 8

Radiation induced cataracts, radiation burns, sun burns

Question 9

Deterministic vs stochastic radiation exposure: which can we prove and control

Answer 9

Deterministic

Question 10

Stochastic radiation exposure severity is __of dose

Answer 10

Independent

Question 11

T or F: no safe threshold exists for stochastic radiation exposure

Answer 11

True

Question 12

What are some side effect examples of stochastic radiation exposure

Answer 12

Cancer, hereditary defects, mutations

Question 13

T or F: we can prove stochastic side effects of radiation exposure

Answer 13

False

Question 14

What are dosimeters used for

Answer 14

Measure radiation exposure

Question 15

Where are dosimeters worn

Answer 15

1. External badges at the level of the thyroid
2. Badges under the gown at level of your belt

Question 16

How often are dosimeters badges changed

Answer 16

Monthly or quarterly

Question 17

What units are used to measure radiation exposure

Answer 17

Sv (Sieverts) and rem

Question 18

1 Sv= __rem

Answer 18

100

Question 19

What does Sieverts (Sv) and rem measure and take into account

Answer 19

Takes into account the amount of radiation energy deposited in tissues and also the types of radiation used

Question 20

What is the occupational yearly dose limit for X-ray radiation exposure

Answer 20

0.05 Sv (5 rem)

Question 21

What is the lifetime occupational dose limit for X-ray radiation exposure

Answer 21

Age in years (0.01 Sv) or 1rem

Question 22

What is the dose limit for X-ray radiation exposure for pregnant people

Answer 22

0.05rem/month

Question 23

What is ALARA

Answer 23

As low as reasonably achievable

Question 24

How is ALARA achieved/what are the cardinal rules of radiation protection

Answer 24

1. Decrease time
2. Increase distance
3. Shielding

Question 25

What is passive restraint when performing X-rays

Answer 25

Sedate the patient, use restraints like sandbags and rope to reduce exposure

Question 26

What is the inverse square law

Answer 26

Intensity of radiation at a given distance from a point source is inversely proportional to the square of the distance of the object from the source

Question 27

Ex: if you move 4ft away from x-ray source, your exposure is reduced by __fold

Answer 27

16 fold (4^2)

Question 28

What substances are used as shields placed between individuals and radiation source to reduce exposure

Answer 28

Lead and concrete

Question 29

Body aprons, thyroid shields and gloves are made of ___most commonly

Answer 29

Lead impregnated vinyl

Question 30

What two areas of human tissue are very radiation sensitive

Answer 30

Breast tissue and thyroid gland

Question 31

Women or men: who is 4x more likely to develop radiation induced thyroid tumors

Answer 31

Women

Question 32

Gowns and gloves are good at protecting form ___radiation not __

Answer 32

Scatter, not primary X-ray beam

Question 33

How do you test your PPE equipment

Answer 33

X-ray gowns and gloves every 6 months to look for cracks

Question 34

Why do you want to collimate primary X-rays to area of interest (2 reasons)

Answer 34

1. Reduces scatter because less patient tissue is exposed to primary X-rays 2. Improved image quality and decrease human exposure

Question 35

What is the annual US average radiation exposure

Answer 35

360 mrem

Question 36

How much radiation exposure occurs from a sunburn

Answer 36

200 rem

Question 37

How much radiation exposure occurs from chest X-ray

Answer 37

25 mrem