Radioactivity

 INTRODUCTION TO RADIOACTIVITY

Radiation is basically energy that travels either in the form of waves (Electromagnetic radiation) or in the form of fast-moving particles (particulate radiation). One source of radiation is the spontaneous decay of the nucleus of an atom by the emission of particles (alpha or beta) and is usually also followed by EM (x-ray or gamma) emission as well. Electromagnetic radiation ranges from high energy to low energy and can be Ionizing or Non Ionizing depending on the energy. Fast-movng particles are all ionising.

Ionizing radiation is a very high energy radiation that has the capacity to break chemical bonds leading to the ionization of atoms that come into contact with it. The three types of Ionizing radiation from radioactivity are alpha, beta and gamma rays. Alpha and beta decay come into the category of Particulate radiation which involves high-speed, tiny particles that have both mass and energy. Unstable nuclei of radioactive atoms (polonium, radium and uranium), disintegrate and release particles which could be alpha particles (2 protons and 2 neutrons –helium nucleus) or beta particles. Beta particles are fast-moving electrons which can penetrate deeper and further than alpha particles can. Both, however, can be hazardous if ingested but usually are harmless superficially as they cannot expose the internal tissues to radiation through physical barriers like clothing and skin. Gamma rays often accompany alpha and beta particles during decay and are high energy forms of radiation. Unlike the particles though, Gamma rays have the most energy, are extremely penetrating, and can infiltrate tissue and kill living cells, which is why they are used in cancer treatments to destroy malignant cancerous cells. X-rays essentially are similar to gamma rays but originate externally from the nucleus (change in electron structure of atoms) whereas gamma rays come from the nucleus itself. This is why X-Rays are usually produced by machines and aren’t as penetrating as gamma rays are.

Radioactivity has made great advances in the medical world and assists physicians in diagnosis of diseases, therapy and research. In fact, it has its own specialized field which is referred to as: Nuclear Medicine. Examples of some techniques used by doctors to look inside the body (using a combination of detectors, radioactive substances and computers) are Positron emission tomography (PET), Single photon emission computed tomography (SPECT), cardiovascular imaging and Bone scanning. Other techniques incorporating radioactive substances into medicine include the detection of: tumors, aneurysms (weak spots in blood vessel walls), and irregular or inadequate blood flow to various tissues, blood cell disorders and inadequate functioning of organs, such as thyroid and pulmonary function deficiencies. Besides all these positive benefits, we cannot overlook the negative consequences and ‘side=effects’ of the exposure to radioactive substances and the effect it has on our bodies. Some cells can be adversely affected by radiation causing them to multiply quickly at different rates. Being overexposed to ionizing radiation in particular can cause mutations in the genes of your DNA which can lead to birth defects. An example is the bombing of Hiroshima and Nagasaki and the numerous birth defects still present in the generation to this day because of the extreme exposure to the radiation from the explosion. Additionally it can also lead to the raised risk of cancer, burns, and ‘radiation sickness’.

Therefore, we should limit the exposure to radioactive materials in our everyday lives while simultaneously appreciating the many benefits it provides us in the medical field. The possibilities of diagnosing and treating more and more patients with the help of radioactivity, is increasing every day and has become an innovation worth looking into.

REFERENCES: http://www.infoplease.com/encyclopedia/science/radioactivity-radioactive-decay.html http://www.science20.com/nonpragmatic_engineer/introduction_radiation-77286 http://science.howstuffworks.com/radiation3.htm http://science.howstuffworks.com/nuclear-medicine3.htm http://www.youtube.com/watch?v=TJgc28csgV0