Radiation Exposure

Question 1

alpha particles

Answer 1

most dangerous if exposed internally
BUT stopped by even a piece of paper

Question 2

Ci

Answer 2

• Curie
• measure of how much radiation one fram of a radium isotope emits

Question 3

Bq

Answer 3

• Becquerel
• number of particles or photons (in the case of wave radiation) that are emitted per sec

Question 4

absorbed dose

Answer 4

the amount of ionizing radiation or ;dose; received by a person or object is expressed as energy absorbed er unit of ass

dose = E/mass (Gy or Joules/kg)

1 Gy = 100 rad

Question 5

effective dose

Answer 5

represents the amount of E deposited to the body, taking into account the tissue being irradiated and the type of incident radiation

effective dose usually expressed in milliSieverts or microSieverts

1 Sv = 1/kg equivalent
1 Sv = 100 rem

Question 6

amount of annual natural background radiation received per person in Canad

Answer 6

2-4 mSv

Question 7

occupational limit set by Canadian Nuclear Safety Commission

Answer 7

50 mSv in a single year and 100 mSv over 5 yrs (20 mSv per year avg)

Question 8

natural radioactivity in food

Answer 8

banana = 15 Bq of potassium 40

radioactivity of a few banas is sufficient to trigger radiation sensors used to detect possible smuggling of nuclear materials

Question 9

acute radiation sickness occur through…

Answer 9

nuclear weapons
accidental nuclear release
industrial exposure
medical exposure

Question 10

limit for a pregnant worker

Answer 10

once pregnancy declared = 4 mSv for remainder of pregnancy

Question 11

radiation-induced cancer

Answer 11

Level & type of exposure
- nuclear weapons
- accidental nuclear release
- industrial exposure
- medical exposure
- environmental exposure

Genetic factors
- DNA damage and repair

Question 12

radon as carcinogen

Answer 12

• gas, inhaled
• decays to release alpha particles

Question 13

radon

Answer 13

inert gas
doesn’t react easily w anything; can get through certain barriers including house basement

Question 14

how many alpha particles are emitted per atom of decaying radon

Answer 14

4

Question 15

0.05-0.5 Gy

Answer 15

no clinical symptoms
minor lymph reductions
potential chromosomal damage

Question 16

1 Gy

Answer 16

nausea and vomiting within 48 hrs of exposure (10% of patients)

Question 17

2 Gy

Answer 17

nausea and vomiting within 24 hrs of exposure (50% of patients)
prominent decreases in lymphs and granulocytes

Question 18

4 Gy

Answer 18

nausea and vomiting within 12 hrs of exposure (90% of patients),
mortality of 50% without medical support

Question 19

6 Gy

Answer 19

mortality of 100% within 30 d without medical support

Question 20

10 Gy

Answer 20

maximum survivable dose with aggressive medical support

Question 21

50 - 100 Gy

Answer 21

CNS and C collapse within 24-48 hrs, mortality 100%

Question 22

The radioactive isotopes from nuclear disasters include

Answer 22

iodine-31
cesium-134/137
strontium-90
plutonium-241
americium-241

Question 23

the total worldwide average effective dose from natural background radiation is around _____ mSv per year

Answer 23

2.4

Question 24

what is the dose of a medical CT scan?

Answer 24

10 mSv

Question 25

__% of lung cancer deaths are related to being exposed to radon in the home

Answer 25

16

Question 26

this is the leading cause of lung cancer in non-smokers

Answer 26

radon exposure

Question 27

types of DNA damage

Answer 27

base modification
single and double strand breaks

Question 28

ataxia telangiectasia (AT)

Answer 28

• individuals with this condition extremely radiosensitive and are at an elevated risk of cancer
• caused by genetically inherited mutations in the ATM gene
• rare! 1 in 40 000 live births
• 1 in 100 ppl carry a mutation in the ATM

Question 29

genetic risk scores

Answer 29

recognition of multi-genic nature of radiation response

intended initially for younger cancer pts receiving radiotherapy to avoid radiation-induced secondary cancers later in life

GRS should improve as genomic sequencing becomes more commonplace