P4 - Irridation and Contamination

What is irradiation?

Exposure to nuclear radiation such as alpha, beta, gamma, or neutrons

Does irradiation make an object radioactive?

No, the object only comes into contact with the radiation, not the radioactive isotope itself

What is a common use of irradiation?

Sterilising medical equipment using gamma radiation

Why is gamma radiation used for sterilisation?

It kills bacteria without heating the object

How is gamma radiation applied during sterilisation?

The object is placed near a gamma-emitting isotope in a lead shielded container

Why doesn't the sterilised object become radioactive?

Because it is only exposed to radiation, not contaminated with radioactive material

What are the hazards of ionising radiation?

It can damage DNA and increase the risk of cancer

What precautions are used to protect people from radiation during irradiation?

Shielding with materials like gloves, lead aprons, lead walls, or glass containing lead

What does a radiation monitor or dosimeter do?

Measures how much radiation a person has been exposed to

What action is taken if a worker receives too much radiation?

They stop working with radioactive sources

What is radioactive contamination?

When unwanted radioactive isotopes end up on or inside a material

What makes contamination hazardous?

The radioactive atoms decay and release ionising radiation directly into or near the body

Why is contamination more dangerous than irradiation?

Because the radioactive material is on or inside the person and continuously emits radiation

How can alpha radiation be hazardous during contamination?

If inhaled or swallowed, alpha particles can cause severe damage inside the body

Why is alpha radiation usually not dangerous during irradiation?

Alpha particles are stopped by dead skin cells

Why are beta particles a contamination risk?

Beta particles can penetrate the body and damage internal cells

Are gamma rays dangerous when a person is contaminated?

Less so, because they are weakly ionising and often pass through the body

Which type of radiation is most dangerous if inside the body?

Alpha radiation, due to its strong ionising power

What is peer review in science?

When other scientists evaluate a study before it is published to check for accuracy

Why is peer review important in radiation studies?

To ensure conclusions about radiation safety are reliable and valid

How can we reduce the risk of contamination?

Wear protective clothing, use tongs to handle sources, and work in controlled environments

How can we reduce the risk of irradiation?

Use shielding, distance, and limit exposure time

Key difference between irradiation and contamination

Irradiation is exposure to radiation; contamination is exposure to radioactive material

Does contamination make something radioactive?

Yes, because the radioactive material is now on or inside the object or person

Does irradiation make something radioactive?

No, because the radiation only passes through or over the object