Dangers of Radiation Flashcards

All 8 cards in this deck

What two kinds of harm can ionising radiation do to living cells?

It can damage/kill cells (tissue damage) and cause mutations in the DNA, which can lead to cancer.

What is a mutation caused by ionising radiation?

A change to the DNA of a cell, which may make the cell divide uncontrollably (cancer) or be passed on to offspring.

Name three precautions a worker can take to reduce their radiation dose from a source.

Shielding (lead box/barrier), limiting the time of exposure, and staying at a greater distance (e.g. using tongs).

Why are radioactive sources kept in lead-lined boxes when not in use?

Lead absorbs the radiation, so the dose to people nearby is reduced.

True or false? A radiation monitoring badge protects the person wearing it from radiation.

False. It only measures and records the dose they have received, so exposure can be checked.

How is the radiation dose to a patient kept as low as possible during a diagnostic scan?

Use the smallest activity that still gives a clear result, and an isotope with a short half-life so it soon decays away.

When using a Geiger–Müller tube to compare the count rates from two radioactive sources, what extra count must be measured and allowed for?

The background count rate, measured with no source near the tube, then subtracted from each reading.

True or false? When placing a radioactive source in front of a Geiger–Müller tube, it should be picked up with tongs and held at arm's length rather than with bare fingers.

True. Tongs increase the distance from the source and stop it touching the skin, reducing dose and avoiding contamination.