The dangers of high level radiation have risen dramatically over the last half century. Over these years, we have discovered many uses of radioactive materials, and our subsequent use of these materials has soared. From nuclear weapons to nuclear power plants, the potential for damaging the ecosystem beyond repair has increased dramatically. Nuclear weapons tests, reactor accidents, and waste disposal have already created many problems for the entire world. Radiation can affect the entire planet in many ways; to better understand how radiation affects our world as a whole it is best to first know some background information on radiation and how it affects us individually.
There are many different kinds of radiation, much of which we are exposed to in our daily lives. Radiation can be in the form of electromagnetic waves, or as in high-speed subatomic particles. The electromagnetic spectrum includes radio waves, microwaves, infrared, visible light, ultra violet, x-rays and gamma ray radiation. Particle radiation includes alpha particles, beta particles, and neutrons; all these types of particles can be emitted from different radioactive isotopes.
Fortunately much of the radiation we are currently exposed to is harmless, or at least in moderate quantities. If radiation has enough energy to disrupt biological processes, it can be very harmful. Radiation can be classified as either ionizing or non-ionizing depending on how much energy it has. When the frequency of electromagnetic radiation is greater than 109 GHz, it has enough energy to rip electrons away from atoms. This turns the atom into an ion and the radiation is classified as ionizing. Ionizing radiation is very dangerous because it can cause cell death, damage DNA, and cause mutations such as cancer.
However, not only ionizing radiation can cause harm. At high levels, non-ionizing radiation such as ultraviolet and infrared light can also be very destructive. These high levels of non-ionizing radiation are produced at the beginning of a nuclear explosion. The massive amount of infrared light (heat) and ultraviolet light can even vaporize objects, and can cause severe burns depending on the distance to the explosion. Non-ionizing radiation is generally only dangerous when produced in massive amounts during the beginning of nuclear explosions, and the range of this radiation would be within sight of the explosion. Non-ionizing radiation does not pose as large a threat as ionizing radiation that can be emitted by nuclear fallout, which has no limited range.
Although there are many different sources of ionizing radiation, the biggest potential problem comes from our use of radioactive isotopes and our control over the disposal of waste material. Atoms are made up of protons, neutrons, and electrons. Protons give an atom the characteristics of an element; to be considered the same element atoms must have the same number of protons. What makes an atom an isotope of a certain element is if it has a different number of neutrons than the majority of other atoms from the same element. Isotopes are often unstable and radioactive; when they decay, radiation is emitted from the nuclear reaction.
Four common types of radiation emitted from radioactive isotopes during decay and nuclear reactions are in the form of electromagnetic waves such as gamma rays, and particles such as neutrons, alpha particles,and beta particles.
Alpha particles are the lowest energy of the three types. Alpha particles are composed of helium nuclei that are traveling extremely fast, although they are easier to protect against compared to beta and gamma radiation alpha particles can still kill cells and cause genetic damage.
Beta particles are higher in energy than alpha particles, but still do not have nearly as much energy as gamma ray and neutron radiation. Beta particles are simply free electrons traveling at high speeds. Because electrons are charged particles, beta radiation can also be shielded relatively easily.
Neutrons are dangerous because they are subatomic particles that have no charge, and therefore require very thick shielding to give protection against them. When neutrons strike atoms, nuclear reactions can occur. This can kill or severely damage living tissue.
Gamma rays are a very powerful form of ionizing radiation. Gamma rays can do large quantities of damage to living tissue, and are very hard to shield against.
The effects of ionizing radiation depend on the several factors. The level of radiation and the time exposed will determine how much of a dose the subject is exposed to. Type of radiation and how it is delivered to the body can also affect the outcome. Sicknesses from radiation are wide ranging, with symptoms occurring from instantaneous to many years after exposure depending on how much a person is exposed to. Although a person’s exposure to direct radiation may be very low from a nuclear explosion, the fallout from the explosion has a much larger area of influence. (Johns, et al)
Radiation that is from an external source is distributed through the body evenly, but internal radiation sources such as the inhalation or ingestion of radioactive particles can build up in specific areas and organs of the body. This buildup of radioactive material can pose a huge threat to the body. When radioactive isotopes are concentrated in certain organs it can lead to cancer and leukemia. Examples of organs prone to radiation buildup are the lungs, digestive tract, as well as the thyroid and bones. (Johns, et al)
A low exposure to radiation might not have any instantaneous effects. However, exposure to even low doses of radiation can increase the chance of leukemia and cancer.
We are all regularly exposed to low levels of radiation that is natural in our environment. This radiation can come from space, the sun, radioactive materials such as radon gas, and fallout from nuclear weapons testing and dumped waste. An exposure to radiation of 100 rem can bring about radiation sickness, and can have many symptoms. The effects of this level of exposure can lead to loss of hair, skin burns, nausea, vomiting, internal bleeding, and anemia from destruction of red blood cells. (Henderson) If the victim survives, there is a greater chance of having other future problems such as cancer and leukemia.
At 400 rem, the dosage is high enough that half of people subjected to this level of radiation will die in within 30 days. Sever symptoms of radiation sickness will cause the person exposed great pain and suffering before they die. Above this level of exposure, the chances of survival diminish even more rapidly. At 1,000 rem there is almost no chance of surviving because of the magnitude of damage done to the body.
Ionizing radiation could pose a huge problem in the future if our use of radioactive materials continues. Though the immediate radiation from events like nuclear explosions and reactor meltdowns are relatively limited in range, the range of fallout is not. Fallout can travel through the air for many thousands of miles and contaminate the world with radioactive particles and cause health risks for everyone. Even if the immediate effects of radiation may not be drastic, the long-term effects from damaged DNA and reproductive problems may compound and threaten not only humans but also every other form of life on the planet.