A Crash Course In Radiation

If ever in a conversation the topic of radiation comes up your initial thoughts may be of mutants with three arms or nuclear weapons. However there is much more to radiation and radioactivity than this and this article’s aim is to act as a quick and simple guide.

What is Radiation?

In simple terms ‘radiation’ is a reference to the process by which one ‘body’ emits energy and it travels to be absorbed by another. Now, a ‘body’ can be anything from a light bulb to an atomic bomb but these emit very different types of radiation. 

Generally radiation can be divided into two broad categories: ionizing radiation and non-ionizing radiation.

‘Ionizing’ radiation is the type which can be dangerous to humans and other living organisms. It has the energy required to alter (or ionize) other bodies, such as organic cells, which can lead to cancer and mutation. Ionizing radiation is generally divided down into Alpha, Beta and Gamma radiation, which you may remember from those long science lessons at school. Another thing you may remember is the electromagnetic spectrum. Ionizing radiation tends to have short wavelengths and a high frequency on this.

On the other hand ‘non-ionizing’ radiation is any kind of radiation which simply does not have enough excess energy to alter other atoms. Types of radiation which fall under this category are light, heat (or thermal radiation) as well as other varieties like electromagnetic. Non-ionizing radiation tends to be the opposite of ionizing radiation on the electromagnetic spectrum, as you might expect really. They generally have longer waves and lower frequencies.

Radiation’s Uses

Radiation has a pretty bad write up really. All we tend to hear about are the harmful effects it has. Yet there are many beneficial uses for it. For example even ionizing radiation, which can be harmful, can be used beneficially. Gamma rays are often used by hospitals as an easy way of sterilising surgical equipment, as the rays kill bacteria off. They can even be used on fruit and vegetables to kill any mould and insects which may have attached themselves to it.

Gamma rays also have their uses in medicine. ‘Radiotherapy’ is cancer treatment which involves targeting cancerous cells with radiation. Because they are unable to repair themselves, while healthy cells are, this kills them off and saves patients having to undergo lengthy surgery.

Smoke alarms also make use of ionizing radiation. They contain a small amount of the radioactive substance Americium-241. This ionizes the air around it creating a small electric current. If smoke enters this circuit then it is broken, which causes the alarm to sound.

Carbon dating is also another use radiation has. Living organisms all have a certain amount of carbon in their bodies. When they die and stop taking in carbon that which is already in their bodies begins to decay at a stable rate. As a result this can be measured and used to work out how long ago a person or animal died; something highly useful in professions, like archaeology.

 So far all we’ve talked about is ionizing radiation but the non-ionizing types have their uses as well. For example lasers, which are concentrated light radiation, are used to cut metal and other materials in industrial construction.

Microwaves are another non-ionizing form of radiation which are highly useful. Without them heating up those ready meals would take a lot longer as you would be forced to use the thermal radiation of the oven, yet another type of radiation.  

So overall radiation has been given a bit of a bad reputation, which generally it doesn’t deserve.