radiation risks

Question 1

• Have a threshold
• severity is proportional to
  the dose
  -erythema
  -xerostomia
  -cataract
  -fertility
  -alopecia
  -fetal development

Answer 1

deterministic risk/effect

Question 2

• Have no dose threshold
• Probability of occurrence
  is proportional to dose
• Severity of effects does not
  depend on dose

Answer 2

stoachastic effect

Question 3

-genetic mutations cause
malignancy= ___cells

Answer 3

to somatic cells

Question 4

genetic mutations cause heritable
effects= ___cells

Answer 4

to germ cells

Question 5

more you apply dose, the greater the risk
(risk at every dose)

Answer 5

stochastic effect

Question 6

below threshold wont see affect

Answer 6

deterministic

Question 7

That amount of radiation which in the light of
present knowledge will not produce any
serious, harmful, or deleterious effects on the
individual receiving it.

Answer 7

max permissible dose

Question 8

max permissible dose
occupational limits:
non-occupational limits:

Answer 8

occupational limits: 5.0rem/year (5,000 mrem) 50 mSv
non-occupational limits:
0.5 rem/year (500 mrem) 5 mSv

Question 9

average annual effective dose of ionizing radiation (mSv) to a member of US population

x-ray diagnosis:
nuclear medicine:
natural plus artifical total:

Answer 9

x-ray diagnosis: 0.39
nuclear medicine: 0.14
natural plus artifical total: 3.60

Question 10

medical xrays and nuclear medicine is only ____of radiation exposure

Answer 10

1/6

Question 11

source of radiation exposure is ___times greater with medical and nuclear medicine?????

Answer 11

6 times greater

Question 12

these patients are at risk

Answer 12

pediatric patients

Question 13

this rate of growth puts tissues at greatest level of radiosensitivity (children)

Answer 13

rate of cellular and organ growth

Question 14

greater life expectancy puts children at ___times greater risk of being afflicted with radiation induced cancer

Answer 14

2-6 times

Question 15

females ____ years old are 5 to 6 times more likely to develop fatal cancer than 50 year old

males <10 yo are ___times

Answer 15

females <10 years old
males 4 to 5 times

Question 16

20 yo female are ___times than 50
30 yo female __times

Answer 16

3.5
3

Question 17

Cancer risks __ with increasing
age

Answer 17

decrease

Question 18

effective dose for FMX d-speed round coll

Answer 18

usv 388
days background radiation- 46

[1 day of background radiation ~8.5 uSv]

Question 19

efffective dose for dental exam procedure

Answer 19

1.5 dose (mrem)

Question 20

these cancers have the highest risk from dental radiographic exposure

Answer 20

leukemia and thyroid

Question 21

artifical/manmade radiation sources - 2%:

Answer 21

1. consumer products (TV, wristwatch, computers)
2. airport scanners
3. nuclear fuel cycle
4. weapons production
5. fall-out from atomic weapons

Question 22

1959, dental radiation dose was ___rad/second with 8 incih distance 10mA, 65 kv

one periapical exposure averaged 2 seconds, so this equates to

Answer 22

1 rad/second

2 rads/exposure

Question 23

in 1959,

1,250/2 = ____ exposures delivers the TED

Answer 23

620 exposures delivers the TED in 1959

Question 24

in 2024, an 8 inch focal distance at 7mAs and 0.2s =

1,250/1.4 = ___ exposures delivers the TED

Answer 24

1.4 mAs/ exposure
893 exposures

Question 25

in 2024, Using properties of the Inverse Square Law,
the dose is decreased ~37 % if the focal distance is
doubled to 16”
and at 16” focal distance; __+___ exposures delivers
the TED or, __exposures delivers the TED

Answer 25

893 + 330
1m223 exposures delivers the TED

Question 26

studies show risk for congenital defects at

Answer 26

50 mSv or less

Question 27

OMR imaging fetal dose

Answer 27

0.01 mGy; 10uGy

Question 28

at absorbed doses of 0 to 50 mGy, there is ___risk of fetal death, malformation, growth retardation or impairment of mental facility

Answer 28

NO

Question 29

stochastic risk estimates for pregnancy
absorbed dose to the coceptus of ~25 mGy (25,000 uGy) does what

Answer 29

double natural childhood cancer rate

Question 30

dental imaging exams of pregnant women should/should not be restricted if clinically indicated

Answer 30

should not

Question 31

Radiographs of pregnant patients as part of any new
patient or recall exam must be :

Answer 31

postponed until postpartum.

Question 32

If urgent care dental treatment is required during
pregnancy, radiographs may be :

Answer 32

necessary as the
standard of care to treat and diagnose a condition that
threatens the health of the mother and the unborn
child.
The clinician must assure that the primary beam
is not directed toward the child-bearing area.

Question 33

risk of death for FMS exam

Answer 33

2.5 per 1,000,000