Background Radiation And Contamination

Question 1

what is background radiation

Answer 1

the low level radiation that is around us all the time

Question 2

what are the three ways that background radiation has established itself on earth

Answer 2

• radiation of naturally occurring unstable isotopes which are around us
• radiation from space
• radiation due to human activity

Question 3

what are some examples of where naturally occurring radiation can come from

Answer 3

• unstable isotopes in the air
• or is some foods
• or building materials
• or rocks

Question 4

what is radiation from space known as

Answer 4

cosmic rays

Question 5

where do most of the cosmic rays we experience come from

Answer 5

• the sun

- the earths atmosphere protects us from alot of the radiation

Question 6

what are examples of radiation due to human activity and to what extent does it impact the total background radiation

Answer 6

• fallout from nuclear explosions or nuclear waste

- they only represent a tiny proportion of the total background radiation

Question 7

what can the amount of radiation youre exposed to alternatively be called

Answer 7

the amount of energy your body absorbs

Question 8

what is the amount of radiation youre exposed to technically called

Answer 8

absorbed radiation dose

Question 9

what two factors can cause how much radiation youre exposed to to vary

Answer 9

• where you live

- if you have a job that involves radiation

Question 10

what happens to an object near a radioactive source

Answer 10

they are irradiated by it

Question 11

what is irraidiation

Answer 11

• when youre exposed to it (the radiation in this case)

- we are always being irradiated by background radiation sources

Question 12

does irradiating something make it radioactive

Answer 12

no

Question 13

what can you do to reduce the effects of irradiation

Answer 13

• keeping things in lead-lined boxes
• standing behind barriers
• being in a different room and using remote controlled arms

Question 14

why do medical staff who work with radiation wear photographic film badges

Answer 14

to monitor their exposure to radiation

Question 15

when does an object become contaminated by radiation and what is an example of this

Answer 15

• when unwanted radioactive atoms get onto an object

- if you touch a radioactive source without wearing gloves your hands will be contaminated

Question 16

why is radioactive contamination dangerous

Answer 16

• the contaminating atoms could then decay
• releasing radiation which can cause you harm
• especially when radioactive particles get inside your body

Question 17

when does a contaminated person stop being at a risk of harm

Answer 17

• when the contamination is removed

- or all the radioactive atoms have decayed

Question 18

what should be used when handling radioactive sources and why

Answer 18

• gloves an tongs
• to avoid particles getting stuck to your skin or under your nails
• some industrial workers wear protective suits to stop them from breathing in particles

Question 19

when does radiation lead to tissue damage

Answer 19

when it enters living cells and ionises atoms and molecules within them

Question 20

what do lower doses of radiation cause in the body

Answer 20

• minor damage without killing the cells
• this can give rise to mutant cells which divide uncontrollably
• this is cancer

Question 21

what do higher doses of radiation cause in the body

Answer 21

• they tend to kill cells completely
• causing radiation sickness if a lot of cells all get blatted at once
• this can lead to vomiting, tiredness or hair loss

Question 22

when are beta and gamma radiation the most dangerous compared to alpha and why

Answer 22

• when they are outside the body
• because they can penetrate the body and get into delicate organs
• alpha is less dangerous because it cant penetrate the skin

Question 23

when are alpha particles the most dangerous and why

Answer 23

• when they are inside the body
• because they are strongly ionising
• so they do damage on a very localised area
• that means contamination rather than irradiation is the major concern when working with alpha particles