Hazards and Uses of Radioactive emissions and Background Radiation

Question 1

Give 4 sources of backgraound radiation.

Answer 1

1. Rocks
2. Cosmic rays from space
3. Nuclear weapon testing
4. Nuclear accidents

Question 2

How should background radiation be dealt with in calculations?

Answer 2

The background radiation should be subtracted form any readings before any calculations ( half life etc.) are attempted.

Question 3

What is the unit used to measure radiation dosage?

Answer 3

Sieverts (Sv)

Question 4

How many millisieverts are in 1 sievery?

Answer 4

1,000 millisieverts = 1 sievert.

Question 5

Why might the radiation dosage that different people get differ?

Answer 5

• Some occupations involve working with radiation
• Background radiation differs with location due to things such ad the locality of nuclear power stations or radiation related testing.

Question 6

What factors determines how dangerous a particular radioactive isotope is?

Answer 6

The half-life of the isotope.

Question 7

Why are isotopes with long half-lives particularly harmful?

Answer 7

• They remain radioactive for much longer periods of time

* They must be stored in specific ways to avoid human and environment from being exposed to radiation for too long

Question 8

Stat 2 uses of nuclear radiation in the field of medicine.

Answer 8

1. Examining of internal organs

2. Controlling and destroying unwanted tissue.

Question 9

How is radiation used in sterilisation?

Answer 9

Gamma emitters are used to kill bacteria/parasites on equipment.

Question 10

Explain the process of radiotherapy.

Answer 10

• Gamma emitters direct gamma rays at the cancerous cells

* The cancerous cells absorb the radiation and are killed

Question 11

How are medical tracer chosen?

Answer 11

They should have a short half life and decay into a stable isotope which can be excreted.
They should only release gamma radiation since it is weakly ionising and can easily pass through the body tissue without damaging it.