Ionising radiation

Question 1

What is ionizing radiation

Answer 1

• radiation with enough energy to remove tightly bound electrons from the orbit of an atom
• causing the atom to become charged

Question 2

Nature of alpha

Answer 2

• positively charged
• made of 2 protons + 2 neutrons
• heavy
• slow

Question 3

What is alpha stopped by

Answer 3

• clothing
• dead skin

Question 4

Health risks of alpha

Answer 4

• ingested - particles absorb in a small mass of tissue
• creates increased damage and increase risk of radical interactions

Question 5

Nature of beta

Answer 5

• negatively charged
• fast
• light

Question 6

What is beta stopped by

Answer 6

• thin layer of substance
• e.g aluminum

Question 7

Health risk of beta

Answer 7

• sources near body still pose a risk

Question 8

Nature of gamma

Answer 8

• made up of packets called photons
• light
• no charge

Question 9

What is gamma stopped by

Answer 9

Dense materials e.g. lead

Question 10

Health risks of gamma

Answer 10

Lower danger

Question 11

Nature of neutrons

Answer 11

No electric charge
Heavier than protons

Question 12

What are neutrons stopped by

Answer 12

Thick materials that are rich in hydrogen e.g. water

Question 13

Health risks of neutrons

Answer 13

Very dangerous
High risk after they’ve been absorbed

Question 14

Definition of half-life

Answer 14

Time taken for the radioactivity of a specified isotope to fall to half its original value

Question 15

Which pollutant property does half-life determined

Answer 15

Persistence

Question 16

Why do you think everybody’s risk from each source is not equal

Answer 16

People may live in different geographical areas, so other areas might have less
Different age groups have different medical conditions

Question 17

Definition of contamination

Answer 17

Physically carrying radioactive materials, which when they release radiation, may cause exposure

Question 18

Definition of exposure

Answer 18

Absorption of ionising radiation

Question 19

What is the difference between exposure and contamination

Answer 19

Exposure is about the radiation dose received, while contamination is about the presence of radioactive material

Question 20

Who are most at risk from radiation exposure

Answer 20

Children
Pregnant women
Plants
People living in granite areas

Question 21

Most common uses of radioactive materials and ionising radiation

Answer 21

Research e.g tracers
Medical appliances e.g x-rays
Nuclear power generation

Question 22

Close sources

Answer 22

Prevent workers from coming into direct contact with the source, by enclosing the source in a container

Question 23

Absorbers

Answer 23

Materials should be used as barriers to prevent radiation reaching workers.
Thickness etc will depend upon type of radiation involved and space available

Question 24

Distance from the source and the inverse square law

Answer 24

Inverse square law - distance from the source increases = drop in exposure

1/distance^2

Question 25

Reducing time exposed

Answer 25

Working arrangements should minimise time a worker is close to a source of

Question 26

Monitoring workers

Answer 26

Personal dosemeters which gives a reading of current exposure Air monitors to detect atmospheric particles, including alpha - emitters

Question 27

How can we measure radiation

Answer 27

Becquerel - measures activity of the source Gray - measure of absorbed dose

Question 28

What ionising radiation was released in the Chernobyl incident

Answer 28

Iodine - 131, cesium - 134 and cesium 137

Question 29

What were the effects of the Chernobyl incident on human health

Answer 29

Thyroid cancer Radiation sickness ( vomiting and headaches )

Question 30

What lessons have been learnt? What controls have been put in place to stop another incident like this taking place? (Chernobyl incident)

Answer 30

Public awareness Effective communication Medical care Emergency preparedness

Question 31

Critical pathway analysis definition

Answer 31

Predict the route a pollutant will take Identify where it might become problematic

Question 32

Important pollutant factors in CPA

Answer 32

Physical state (solid,liquid,gas?) Density (how far it travels) Weather conditions (wind direction and speed) River flow or ocean current (strength and direction) Nature of environment (geology) PH and O2 availability (solubility) Ability to bioaccumulate and biomagnify Half-life

Question 33

What information does environmental sampling disclose

Answer 33

Presence or absence of pollutant Type and concentration of pollutant

Question 34

Materials that are often sampled for radioactive materials

Answer 34

Vegetation ,soil,water,meat,fish,dairy

Question 35

Why are these materials often chosen for environmental testing

Answer 35

Most likely to be contaminated Likely to enter the food chain

Question 36

Critical group monitoring definition

Answer 36

Pollutant incident where people are identified most at risk If okay, make an assumption that everyone is

Question 37

Why is critical group monitoring used

Answer 37

Information about radiation and its health effects can be produced Public health management