4.4.2.4 - Radioactive contamination

Define ‘radioactive contamination’

Radioactive contamination - is the unwanted presence of materials containing radioactive atoms

What is the hazard from contamination from?

The hazard from contamination is due to the decay of the contaminating atoms

What affects the level of hazard (from contamination) ?

The type of contamination emitted affects the level of hazard

Define ‘irradiation’.

Irradiation - refers to the process of exposing an object to nuclear radiation

Does an irradiated object become radioactive?

No, the irradiated object does not become radioactive

Describe how you can prevent contamination.

• Avoid particles on your skin and under your nails by using gloves and tongs when handling sources

• Protective suits - prevent breathing in any particles

Describe how you can prevent irradiation.

• Keep sources in a lead-lined boxes

• Standing behind barriers

• Being in a different room and using remote-controlled hands

What does the seriousness of irradiation and contamination depend on?

They depend on the source and whether it’s inside or outside the body.

What radioactive sources are the most dangerous outside the body?

Beta and Gamma

Why are beta and gamma the most dangerous outside the body?

They are able to penetrate the body and get to delicate organs

Alpha is less dangerous as it can’t penetrate the skin and is easily blocked by a small air gap

Outside the body, is irradiation more dangerous or contamination?

Irradiation by beta and gamma rays

What radioactive source is most dangerous inside the body?

Alpha sources are the most dangerous inside the body

Why are alpha sources the most dangerous inside the body?

Alpha sources do their damage in a very localised area due to their inability to penetrate far into materials

Beta sources are less damaging inside the body - as the radiation is absorbed over a wider area (some passing out the body altogether)

What source is the least dangerous inside the body (and why)?

Gamma sources are the least dangerous - as they mostly pass straight out

(have the lowest ionising power)

Why is it important for the findings of studies into the effects of radiation on humans to be peer-reviewed?

It’s important for the findings of studies into the effects of radiation on humans to be published and shared with other scientists

This means that any accepted data can then lead to improvements in our use of radioactive sources