The risk associated with radioactive materials depends on the amount of exposure. Being exposed to radioactive materials for long periods of time or on a regular basis increases the dose received which, in turn, increases the risk.
Given that radioactive materials are hazardous, certain precautions can be taken to reduce the risk of using radioactive sources. These include:
The Sievert (Sv) is the unit used to measure radiation dose and is the amount of damage that would be caused by the absorption of 1 joule of energy in each kilogram of body mass.
Typically, absorption is less than 1 Sv, so milliSieverts (mSv) are often used instead. 1,000 mSv = 1 Sv.
Some example doses are shown below:
|Eating a banana that contains radioactive potassium||0.000000098 Sv||0.000098 mSv|
|Exposure for cabin crew on airliners (per year)||0.0016 Sv||1.6 mSv|
|6 months on the International Space station||0.08 Sv||80 mSv|
|Highest dose to a worker during Fukushima disaster||0.67 Sv||670 mSv|
|Typical fatal dose||10 Sv||10,000 mSv|
The perception of a risk can often differ from the measured risk. The risk of unfamiliar things (such as skydiving) and things that have an invisible effect (like ionising radiation) are often overestimated by people.
People who are worried about working with radioactive materials may turn down a job in any situation where radioactive materials are used whereas, in fact the real risk may be very different from the perceived risk, eg the risk that you think is there.
Nuclear radiation is invisible, and sounds threatening to many people. This makes the risk seem worse than something you can see, and which is more familiar. Many people do not realise that nuclear radiation has always been part of our environment.
Some people are afraid that irradiated food is itself radioactive, even though this is not true.