Topic 6.29–6.32: Radiation dangers, safety, contamination and irradiation

How can ionising radiation damage living tissue?

It can ionise atoms and molecules in cells, damaging cell structures and DNA.

What is a mutation?

A change in genetic material, such as DNA.

Why can ionising radiation increase the risk of cancer?

It can cause mutations in DNA that may lead to uncontrolled cell division.

What is the difference between irradiation and contamination?

Irradiation is exposure to radiation from a source; contamination is radioactive material getting onto or into an object or person.

Does irradiation make an object radioactive?

Usually not. Exposure to radiation does not normally make an object radioactive.

Does contamination pose a continuing hazard?

Yes. Radioactive material on or inside the body can continue to emit radiation until it is removed or decays.

Why is internal contamination by an alpha emitter particularly dangerous?

Alpha radiation is strongly ionising and can cause severe local damage to nearby tissues.

What precautions reduce exposure to external radiation?

Reduce exposure time, increase distance from the source and use suitable shielding.

What is the purpose of shielding?

To absorb or reduce radiation before it reaches people.

Which shielding materials can reduce alpha radiation?

Paper, clothing or the outer layer of skin can stop alpha particles.

Which shielding material is commonly used to reduce beta radiation?

A few millimetres of aluminium or suitable plastic.

Which materials can reduce gamma radiation?

Thick lead or concrete can reduce gamma intensity.

Why should radioactive sources be handled with tongs?

To increase distance between the source and the body, reducing exposure.

Why should exposure time be minimised?

A shorter exposure generally results in a lower radiation dose.

Why should radioactive sources be stored in shielded containers?

To reduce radiation exposure when the sources are not in use.

How are medical patients protected from unnecessary radiation?

Use the lowest suitable dose, restrict the exposed area and perform scans only when justified.

How are medical staff protected from radiation?

They use shielding, keep their distance, limit exposure time and monitor doses with personal dosimeters.

Why are radiation doses monitored for medical personnel?

To ensure exposure stays within safety limits and reduce long-term health risks.

Why can contamination be more difficult to manage than irradiation?

Radioactive material must be located and removed or contained, and internal contamination may expose tissues continuously.

How can radioactive contamination on skin be reduced?

Follow radiation-safety procedures, remove contaminated clothing and wash the affected skin carefully.

What is the main difference between the hazards of alpha and gamma radiation outside the body?

Alpha radiation is easily stopped by skin, whereas gamma radiation is penetrating and can irradiate internal tissues from outside the body.

Why can both contamination and irradiation be dangerous?

Both can expose tissues to ionising radiation and cause cell damage, depending on the radiation type, dose and exposure circumstances.