(7.14-7.16) Uses and Dangers of Radiation

What are some uses of radioactivity?

smoke alarms

monitoring thickness of materials

diagnosis and treatment of cancer

sterilisation

Describe how smoke detectors work.

• alpha particles will ionise air within detector, creating a current

• when smoke enters, the alpha emitter is blocked

• when the sensor no longer detects alpha, a microchip triggers an alarm

Describe how radiation helps measure the thickness of materials.

• the amount of beta particles penetrating a material is monitored with a detector

• if material thickens, more particles will be absorbed, count rate will decrease

• if material thins, less particles absorbed, count rate will increase

• allows manufacturer to adjust

• beta as it will be partially absorbed

Describe how radiation is used for cancer diagnosis and treatment.

radiotherapy:

• ionising radiation kills living cells

  • bacteria + cancer cells are more susceptible than others

• gamma rays directed at tumor

• as they can penetrate the body

• beam moved around tumor to minimise harm to healthy tissues

Describe how radiation is used for sterilisation.

• gamma radiation as it’s most penetrating- enough to irradiate all sides

• to kill any microorganisms present

Define irradiation.

the process of exposing a material to ionising radiation from outside itsel

• can kill living cells, does not make it radioactive

Define contamination.

the accidental transfer of a radioactive substance onto/into a material

• the material becomes radioactive

What are the risks of ioninsing radiation?

• mutations of DNA in cells

• cells and tissue damage

• cancer

How can irradiation be prevented?

lead-lined suits/shielding absorb most of the radiation

How can contamination be prevented?

airtight suit preventing any contact

What is the order, from most to least dangerous, of radiations inside the body?

alpha

beta

gamma

What is the order, from most to least dangerous, of radiations outside the body?

gamma

beta

alpha

How should radioactive material be handled?

• shielded containers

• tongs + gloves

• protective clothing

• limiting time of exposure

• monitor exposure with dosemeter

How should radioactive material be disposed?

alpha- plastic/metal canisters

beta- metal canister/concrete silos

gamma- lead lined, thick concrete silos