Effects of Nuclear Radiation on Human Beings
Unstable nuclei give rise to radioactive isotopes. Although there is a general belief that these isotopes are because of human activities quite a number occur naturally. Most of the radiations that we receive on earth have natural sources. The cosmic rays originate from space and other radioactive isotopes and we expose ourselves to daily. The most significant aspects of these radiations are their ability to transmit energy in terms of waves. The various forms of radiations include the visible light, radio waves and microwaves, which do not have to carry with them enough energy to ionize.
Ionizing radiations are the ones, which are associated with nuclear radiations. This means they carry with them enough energy to ionize gases. The interfacial processes induced by these radiations are of fundamental scientific research and technological concerns. When the energy waves travel across a multiphase body excitation and ionization occurs. The implications of radiation in each phase are based on the level of interaction between the different layers. When the dimensions of a layer are small, interfacial energy transfer occurs.
The first means of energy transfer is through the hole, which can lose its excess energy hence, etherealize then localize in a trap state inside the particular particle causing a recombination of the carriers. The technological relevant aspect of this process is the ability to preferentially regulate the radiolytic processes as well manipulation of the point of occurrence.
An atom contains a nucleus composed of protons and neutrons surrounded by a cloud of electrons orbiting it. The characteristics of an element are determined by its atomic number, which represents the number of protons in the nucleus. The atomic weight of an element is the total sum of protons and neutrons. Isotopes of elements have the same number of protons but different numbers of neutrons and hence they differ in atomic in atomic weight and similar in physical and chemical characteristics. The study of effects of the radiations on organisms and the measurement of radiations is known as dosimetry. It is extremely beneficial in policy making regarding the establishment of research centers dealing with radioactive materials as well as energy generation reactors being used in the world (Bodansky, 96).
Unstable nuclides are known to be radioactive that is they emit radiations as they decay over time. Over 60 of this can be found in nature. They can be broadly categorized as primordial which were in existence before the earth was created, cosmogenic which have been formed a result of cosmic-ray interactions and human produced. These naturally occurring nuclides include radium, uranium and potassium-40. Potassium-40 is the most common since it is in every human being. They emit nuclear radiation in three different particles, which include alpha particles, which are produced from the radioactive decay of exceptionally heavy elements such as uranium.
With their relative size being that of a helium atom and electrical charge from the two protons, they can travel only a remarkably short distance within any object. Alpha particles can even be stopped by small sheet of material. Secondly, there are beta particles, which are electrons that arise due to transformation of a neutron contained in a nucleus of an atom to a proton. Since they are lighter than the alpha particles, they can travel up to five meters in air. Below is an equation representing the emission?
60Co 60Ni + 0 e
27 28 -1
Thirdly, there are the gamma rays, which are electromagnetic radiation. They are emitted from the nucleus of a radioactive atom that is in an excited state. They travel at the speed of light and they penetrate long distances in the air and can traverse some materials such as lead. Radionuclides are symbolized based on the element and atomic weight they have. In the case of alpha particles, they are represented by He-2, which is the weight of helium, and uranium can be written as U-235 (Timberlake, 26).
Radioactivity cannot be recognized by any human senses and it is detected through distinct detectors. The fact that it is not human-detectable makes it extremely dangerous since someone may never know he or she is exposed until consequences occur. Some of the instruments used to detect radioactivity include but not limited to electroscopes, ionizing chambers, Wilson cloud chamber, the Geiger Muller tube and spinthariscope. Some building materials also contain radioactive elements in them. The common materials such as granite, cement and sand stone contain small levels of uranium, thorium and potassium.
Since cosmic radiations are present around the earth from space, their effects are felt and have no matter. Cosmic radiations can be grouped into two primary and secondary. The primary cosmic radiations are composed of protons, which have exceptionally high-energy content. Majority of these radiations interact with the atmosphere and never make it to the earth’s surface. This is because the earth’s magnetic fields and the atmosphere act as a barrier (Timberlake, 28). Ones these interactions with the atmosphere occur the new radiations are what are called secondary cosmic radiations. The interaction between the upper atmosphere and them produces radioactive nutrides. The common cosmogenic nuclides include carbon-14, tritium-3 and beryllium-7.
Nuclear Fission and Fusion
The two fundamental processes involving the nuclei of atoms can be broadly categorized as fission, which is the splitting of nuclei, and fusion, which is the combining of different nuclei. This nuclei process can generate enormous amounts of energy without producing greenhouse gases. There currently more than 400 reactors in the world in about 30 countries producing a fifth of the worlds electric power.
The process used in these reactors is nuclear fission because nowhere in the world has fusion reactions been commercially used for generation of energy. This is due to the complexity nature of the reactors required. Currently, only research concerning the possibility of the process being used commercially is being done. An example of a fission process that produces a lot of energy is uranium (Timberlake, 20). The equation of the process of breaking up the large nuclei is shown below.
235U + 1n 139Ba + 94Kr + 3 1n + energy
92 0 56 36 0
Producing radioactive isotopes involves the bombardment of atoms. A good example is shown
Below : a cobalt atom giving a manganese radioisotope.
59Co + 1n = 27 56Mn + 4H e = 27
27 0 25 2
The time that the radiation of an isotope falls to a half of its initial level is known as half-life.
The increased use of nuclear fission energy as well as other human activities that expose as to these radiations guidelines and policies is to ensure safety for all. Doses to human beings of these radiations should be kept as low as possible, but since small exposures from accidents, building materials or procedures involving the radionuclides then measures of safety should be in place. Concentrations of natural radionuclides may vary from place to place hence different kinds of safeguards. In medicine, appropriate programs for health workers involved with nuclear medicine are properly trained and periodic review of the procedures done.
A radiation protection programmed is being implemented all over the world in the health facilities. Since radiographs are essential in medicine for diagnosis, treatment planning and monitoring of treatment they are widely accepted. The magnitude of dosage should not exceed the threshold at any particular instant when an x-ray is done. For any x-ray, examination to be done justification of the same must be done by qualified medical practitioner.
Occupational exposure should be always contained to not more than 20 msv per year. In order to ensure these additional dose constraints should be put in place. The measure includes putting up shields that are more concrete. Otherwise, there are long-term risks of leukemia from low-level exposure. Restricting the use of certain building materials will avoid some tragic results.
Practical and periodic investigations should be done in these premises. The main radiation sources should be identified and a unit in charge of radiation protection put in place. Workers of such installations should have radiation work permits with a requirement to demonstrate adequate radiation safety knowledge. Medical surveillance and radiation worker personal protective equipment are compulsory. A written action program for keeping the dose low must be available for audit by the government on demand. Planned extensive repairs in prone areas must first be examined and special arrangements made.
Bodansky, David. Nuclear Energy: Principles, Practices, and Prospects .Woodbury, NY: AIP Press,1996
Timberlake, Karen. Basic Chemistry. New York: NY. Prentice Hall.2008