Radiation is something many people don’t know much about. Radiation is in fact everywhere, you just can’t see it – well, most of it that is, and the kind you can see, you can’t see all that well. Most people have a general idea of what it might be, and might even know a few examples of how it manifests itself – such as from a microwave or x-ray.
With the recent threat of nuclear disaster here in Japan, sparked from the damage inflicted by the massive earthquake and subsequent tsunami, many people have no doubt been caught not knowing as much as they would have liked about nuclear radiation effects, types of radiation, and what a “safe” radiation dose amounts to .
But before we can understand what makes radiation so potentially harmful, we have to understand what it is and where it comes from. There are two main types of radiation: ionizing radiation and non-ionizing radiation. Ionizing radiation is what we’re looking for here, and it is the kind of radiation that turns atoms into ions, or atoms with uneven amounts of protons and electrons medium radiator cover .
“So What Exactly is Ionizing Radiation?”
Ionizing radiation is simply radiation that has the energy-capacity to ionize atoms, and is often the sole form of radiation implied when speaking of radiation. The ionizing of an atom occurs when ionizing radiation collides with an atom, “knocking out” an electron and causing an uneven amount of electrons and protons. This leaves the atom with a net positive charge – also called a cation.
Conversely, a net negative charge occurs when an atom gains an electron due to a free electron that is energetic enough to literally force its way into an atom, also called an anion. These two processes are the basis of ionization. Alpha particles, beta particles, neutrons, x-rays, gamma rays, and cosmic rays are all examples of ionizing radiation.
Now that we understand the process of ionization and what ionizing radiation is, we can uncover its potential dangers. As simple as this may sound, the adverse physical effects of radiation are caused by the alteration of atoms by this ionization process to the point of manifesting physical symptoms, such as cell death, genetic mutations, cancer, and ultimately, even death.
“Where does this ionizing radiation come from?”
Think of ionizing radiation as invisible particles or waves of energy that are emitted from either radioactive atoms or radiation-producing machines such as nuclear reactors. Radioactive atoms, also called radioisotopes or radionuclides, are atoms with an unstable nucleus and are therefore experiencing radioactive decay at a rate expressed by its half-life.
During radioactive decay, the atom emits ionizing radiation in the form of gamma rays and/or subatomic particles. However, the amount of ionizing radiation emitted from most naturally occurring radioactive decay is within safe limits. Nuclear reactors on the other hand, are responsible for the perpetual emission of large amounts of ionizing radiation via nuclear fission.
Of course, this radiation is contained within the housing structure so long as it does what it’s supposed to. – Which is exactly the point in question! If something happens that is outside the control and foresight of engineers, such as earthquakes, and other natural disasters, and the radiation is somehow allowed to leak out – or God forbid, flood out – there will be a major disaster.
The ionizing radiation in the form of radioisotopes such as iodine-131 and caesium -137 will then be dispersed by the wind which will carry them far and wide. The lifespan of a radioisotope is determined by its half-life, therefore you can say that the amount of damage it can inflict is partially based on its half-life. Iodine-131 for example, only has a half-life of about 8 days, whereas caesium-137 has a half-life of about 30 years.
But half-life is not the only factor involved in determining potential danger and its extent. As the half-life decreases, the amount of ionizing radiation emitted per unit of time increases. So although the time during which it’s doing damage is shorter, it’s also more concentrated and intense. Another factor is the atomic mass of the radioisotope.