Table of Contents
Radiation
Radiation may seem scary, but understanding it can help ease those fears. It can’t be seen, heard, tasted or touched, but it is a common occurrence in our every day lives. There are some risks to radiation, however, together we can demystify radiation, helping you to grasp how it works and were it comes from. Lets explore the facts and dispel misconceptions so you can navigate the world of radiation like a pro!
What is radiation?
Radiation is the emission or transmission of energy in the form of particles or waves through space or a material medium.
There are two main categories of radiation…
Electromagnetic Radiation
Electromagnetic Radiation
Particle Radiation
Particle Radiation
Where does radiation come from?
Radiation comes from a variety of different sources which we encounter in our everyday lives, both naturally occurring and man made. The amount can vary a lot depending on where we live and what we do.
Artificial Sources
- Medical Applications: X-rays and radiation therapy which uses controlled amounts of radiation for diagnostics and treatments.
- Nuclear Power: Nuclear reactors generate electricity through controlled nuclear reactions.
- Industrial/ Research: Various industries use radiation for purposes like sterilization and scientific research.
- Food: Some grains, vegetables and tea and coffee contain natural potassium. Also, depending on the source, water contains varying levels of radiation.
Natural Sources
- Cosmic Radiation: Radiation originating from space.
- Radioactive Decay: Naturally occurring elements decay and emit radiation in the process.
- Terrestrial Radiation: Radioactive materials in the Earth’s crust release radiation.
- Radon: Is naturally occurring. It comes from both the formation of the Earth’s crust and natural radioactive decay processes in rocks and soil.
Radon
Radon gas is the largest contributor to our average yearly radiation dosage, so what is radon?
Radon is a naturally occurring radioactive gas with no smell, colour, or taste. It comes from the natural decay of uranium, which is found in rocks, soil, and water. When Radon escapes from the ground into the air, it dilutes very quickly, the average outdoor radon level is between 5-15Bq per metre cubed. There are higher concentrations of radon in areas with less ventilation such as caves, mines and buildings. The concentration of radon can depend also on where you are in the country, the figure to the right shows a radon concentration map which was published by the British Geological Survey.
Understanding the Impact of Radiation on the Body:
Some types of radiation, like visible light and radio waves, are harmless to us. Most of us are exposed to them daily without even knowing! Some of these include Wi-Fi equipment and microwaves.
It is important to also discuss those that can cause harm. Ionizing radiation can damage cells in the body by breaking DNA. This can lead to various health issues from nausea to cancer, but keep in mind the level of harm that can be caused depends on many factors such as the dosage and type of radiation. A severe example of this is Acute Radiation Syndrome (ARS), if we are exposed to high doses of radiation in a short time, we can experience acute effects, such as nausea, vomiting, hair loss, skin burns, or organ failure. This can happen in rare and unfortunate situations such as accidents involving nuclear reactors.
This may be some scary information, but it is important to keep in mind that the average amount of radiation a person receives in a year as stated above is 2.7 mSv and the International Commission on Radiological Protection (ICRP) stipulate that annual limit of intake of a radioactive isotope for a reference ‘average’ man is 20mSv, almost 7 times that.
Radiation Uses
How do we detect radiation?
There are different ways of detecting radiation, depending on what kind of radiation it is and how much of it there is.
This is a device that uses a gas-filled tube to detect radiation. When radiation enters the tube, it makes the gas atoms lose electrons and become charged. This creates a small electric current that can be measured by a meter or a speaker. The more radiation there is, the more current and the louder the sound. Geiger counters can detect alpha, beta, and gamma radiation, but they cannot tell them apart.
This is a simple way of measuring how much radiation a person has been exposed to over time. It consists of a piece of photographic film inside a plastic holder with different windows made of metal or plastic. The film gets darker when it is exposed to radiation, and the windows block different types of radiation. By comparing the darkness of the film under different windows, one can estimate the amount and type of radiation received.
This is a device that shows the tracks of radiation in a cloud of water vapor. It consists of a sealed container with a cold bottom and a warm top. When alcohol is sprayed inside the container, it forms a cloud near the cold bottom. When radiation passes through the cloud, it ionizes the water molecules and makes them visible as thin trails. The shape and length of the trails depend on the type and energy of the radiation. Alpha particles make short and thick trails, while beta particles make long and thin trails.
This is a device that uses a special material that glows when it is hit by radiation. The material is called a scintillator, and it can be a solid, a liquid, or a gas. When radiation strikes the scintillator, it produces flashes of light that are detected by a photomultiplier tube or a photodiode. The number and intensity of the flashes indicate the amount and type of radiation.
This is a device that uses a gas-filled tube to detect radiation. When radiation enters the tube, it makes the gas atoms lose electrons and become charged. This creates a small electric current that can be measured by a meter or a speaker. The more radiation there is, the more current and the louder the sound. Geiger counters can detect alpha, beta, and gamma radiation, but they cannot tell them apart.
This is a simple way of measuring how much radiation a person has been exposed to over time. It consists of a piece of photographic film inside a plastic holder with different windows made of metal or plastic. The film gets darker when it is exposed to radiation, and the windows block different types of radiation. By comparing the darkness of the film under different windows, one can estimate the amount and type of radiation received.
This is a device that shows the tracks of radiation in a cloud of water vapor. It consists of a sealed container with a cold bottom and a warm top. When alcohol is sprayed inside the container, it forms a cloud near the cold bottom. When radiation passes through the cloud, it ionizes the water molecules and makes them visible as thin trails. The shape and length of the trails depend on the type and energy of the radiation. Alpha particles make short and thick trails, while beta particles make long and thin trails.
This is a device that uses a special material that glows when it is hit by radiation. The material is called a scintillator, and it can be a solid, a liquid, or a gas. When radiation strikes the scintillator, it produces flashes of light that are detected by a photomultiplier tube or a photodiode. The number and intensity of the flashes indicate the amount and type of radiation.
How can we keep radiation contained?
Different types of radiation can penetrate through different materials and to different depths. Ionizing radiation has lots of energy and when it passes through materials it can remove electrons from atoms.
Alpha particles have a large mass and slow speeds, this causes them to collide more frequently with other particles and lose energy sooner. So they can be stopped easily by paper and air.
Beta particles are very high speed electrons. Due to them having the same mass as orbital electrons their direction can be changed easily through collisions. Thus, the amount of energy they lose depends on the amount of particles they collide with and so they can be stopped by aluminium.
Gamma and Neutrons are both uncharged, thus these can only lose energy by being absorbed and can be stopped by lead and concrete respectively.
Using this knowledge, the nuclear industry designs buildings, structures, containers, shielding, and more in a way which reduces radiation to very low levels and therefore keeps people safe.
All of this is encompassed in a concept known as ALARP (As Low As Reasonably Practicable), site operators are committed to reducing exposure of personnel to ionising radiation and sites follow clear guidelines on how to reduce any hazards.
Rebecca Horrocks
UK Dosage Pie from
Radiation Protection Services – Ionising Radiation and you (ukhsa-protectionservices.org.uk)
Radon Concentration Map from
Updated radon map for Great Britain published – British Geological Survey (bgs.ac.uk)
Detailed Radon Information from
Uses of radiation from Uses Of Radiation | NRC.gov
