Radionuclides (Including Radon, Radium and Uranium)
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What Is Radon?
Biology Unit Radon Alert INVESTIGATION 3 WHAT IS RADON? INTRODUCTION Radon is a naturally occurring radioactive gas. It is formed by the radioactive breakdown of radium, and is found in soils just about everywhere. You cannot see it, taste it, or smell it. It is continuously formed in rocks and soils and escapes into the atmosphere. In some cases, it makes its way into homes, builds up to high concentrations in indoor air, and can become a health hazard. Although there are several different isotopes of radon, the one that is of greatest concern as a potential Radioactivity - the spontaneous human health threat is called radon-222. Radon-222 is emission of energy by certain (radio- formed naturally during a chain of radioactive disintegra- active) atoms, resulting in a change tion reactions (decay series). The decay series begins from one element to another or one when uranium-238 decays. Uranium is widely distrib- isotope to another. The energy can uted in rocks and soils throughout the earth’s crust. It has be in the form of alpha or beta par- a half-life of 4.5 billion years, which means a very slow ticles and gamma rays. breakdown. The decay series is shown schematically in Figure 1. There are eight different elements and 15 different isotopes in the series, beginning with uranium- 238 and ending with lead-206. New elements formed by radioactive disintegration reactions are called decay products. Thus, radium-226 is one of the decay products of uranium-238. Polonium-218 and lead-214 are decay products of radon-222. -
Of the Periodic Table
of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use. -
How Do Radioactive Materials Move Through the Environment to People?
5. How Do Radioactive Materials Move Through the Environment to People? aturally occurring radioactive materials Radionuclides can be removed from the air in Nare present in our environment and in several ways. Particles settle out of the our bodies. We are, therefore, continuously atmosphere if air currents cannot keep them exposed to radiation from radioactive atoms suspended. Rain or snow can also remove (radionuclides). Radionuclides released to them. the environment as a result of human When these particles are removed from the activities add to that exposure. atmosphere, they may land in water, on soil, or Radiation is energy emitted when a on the surfaces of living and non-living things. radionuclide decays. It can affect living tissue The particles may return to the atmosphere by only when the energy is absorbed in that resuspension, which occurs when wind or tissue. Radionuclides can be hazardous to some other natural or human activity living tissue when they are inside an organism generates clouds of dust containing radionu- where radiation released can be immediately clides. absorbed. They may also be hazardous when they are outside of the organism but close ➤ Water enough for some radiation to be absorbed by Radionuclides can come into contact with the tissue. water in several ways. They may be deposited Radionuclides move through the environ- from the air (as described above). They may ment and into the body through many also be released to the water from the ground different pathways. Understanding these through erosion, seepage, or human activities pathways makes it possible to take actions to such as mining or release of radioactive block or avoid exposure to radiation. -
Keeping Your Home Safe from RADON
Keeping Your Home Safe From RADON 800-662-9278 | Michigan.gov/radon 08/2019 What is Radon? Radon is a colorless and odorless gas that comes from the soil. The gas can accumulate in our home and in the air we breathe. Radon gas decays into fine particles that are radioactive. When inhaled, these fine particles can damage the lung. Exposure to radon over a long period of time can lead to lung cancer. It is estimated that 21,000 people die each year in the United States from lung cancer due to radon exposure. A radon test is the only way to know how much radon is in your home. Radon can be reduced with a mitigation system. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has created this guide to explain: • How radon accumulates in homes • The health risks of radon exposure • How to test your home for radon • What to do if your home has high radon • Radon policies C Keeping Your Home Safe From Radon Table of Contents Where Does Radon Come From? ............................................. 1 Radon in Michigan ....................................................................... 1 Percentage of Elevated Radon Test Results by County ......... 2 Is There a Safe Level of Radon? ............................................... 3 Radon Health Risks ..................................................................... 4 How Radon Enters the Home ..................................................... 6 Radon Pathways ........................................................................... 7 Radon Testing ............................................................................ -
Uranium Fact Sheet
Fact Sheet Adopted: December 2018 Health Physics Society Specialists in Radiation Safety 1 Uranium What is uranium? Uranium is a naturally occurring metallic element that has been present in the Earth’s crust since formation of the planet. Like many other minerals, uranium was deposited on land by volcanic action, dissolved by rainfall, and in some places, carried into underground formations. In some cases, geochemical conditions resulted in its concentration into “ore bodies.” Uranium is a common element in Earth’s crust (soil, rock) and in seawater and groundwater. Uranium has 92 protons in its nucleus. The isotope2 238U has 146 neutrons, for a total atomic weight of approximately 238, making it the highest atomic weight of any naturally occurring element. It is not the most dense of elements, but its density is almost twice that of lead. Uranium is radioactive and in nature has three primary isotopes with different numbers of neutrons. Natural uranium, 238U, constitutes over 99% of the total mass or weight, with 0.72% 235U, and a very small amount of 234U. An unstable nucleus that emits some form of radiation is defined as radioactive. The emitted radiation is called radioactivity, which in this case is ionizing radiation—meaning it can interact with other atoms to create charged atoms known as ions. Uranium emits alpha particles, which are ejected from the nucleus of the unstable uranium atom. When an atom emits radiation such as alpha or beta particles or photons such as x rays or gamma rays, the material is said to be undergoing radioactive decay (also called radioactive transformation). -
12 Natural Isotopes of Elements Other Than H, C, O
12 NATURAL ISOTOPES OF ELEMENTS OTHER THAN H, C, O In this chapter we are dealing with the less common applications of natural isotopes. Our discussions will be restricted to their origin and isotopic abundances and the main characteristics. Only brief indications are given about possible applications. More details are presented in the other volumes of this series. A few isotopes are mentioned only briefly, as they are of little relevance to water studies. Based on their half-life, the isotopes concerned can be subdivided: 1) stable isotopes of some elements (He, Li, B, N, S, Cl), of which the abundance variations point to certain geochemical and hydrogeological processes, and which can be applied as tracers in the hydrological systems, 2) radioactive isotopes with half-lives exceeding the age of the universe (232Th, 235U, 238U), 3) radioactive isotopes with shorter half-lives, mainly daughter nuclides of the previous catagory of isotopes, 4) radioactive isotopes with shorter half-lives that are of cosmogenic origin, i.e. that are being produced in the atmosphere by interactions of cosmic radiation particles with atmospheric molecules (7Be, 10Be, 26Al, 32Si, 36Cl, 36Ar, 39Ar, 81Kr, 85Kr, 129I) (Lal and Peters, 1967). The isotopes can also be distinguished by their chemical characteristics: 1) the isotopes of noble gases (He, Ar, Kr) play an important role, because of their solubility in water and because of their chemically inert and thus conservative character. Table 12.1 gives the solubility values in water (data from Benson and Krause, 1976); the table also contains the atmospheric concentrations (Andrews, 1992: error in his Eq.4, where Ti/(T1) should read (Ti/T)1); 2) another category consists of the isotopes of elements that are only slightly soluble and have very low concentrations in water under moderate conditions (Be, Al). -
6.2.43A Radiation-Dominated Model of the Universe
6 BIG BANG COSMOLOGY – THE EVOLVING UNIVERSE 6.2.43A radiation-dominated model of the Universe R We have just seen that in the early Universe, the dominant energy density is that due to the radiation within the Universe. The Friedmann equation that was described in Chapter 5 (Box 5.4) can be solved for such conditions and the way in which the scale factor varies with time for such a model is shown in Figure 6.7. One important feature of such a model is that the scale factor varies in the following way: R(t) ∝ t1/2 (6.17) 0 t −4 Because the energy density of radiation is dominant for times when R(t)/R(t0) < 10 , all cosmological models which start at t = 0 with R(0) = 0, will go through a phase Figure 6.73The evolution of the that is well described by this radiation-dominated model. Thus we are in the rather scale factor with time in a remarkable position that regardless of which type of cosmological model best cosmological model in which the dominant contribution to the describes the Universe at the present, we can be reasonably confident that we energy density arises from the know how the scale factor varied with time in the first few tens of thousands of radiation within the Universe years of the big bang. (i.e. during the radiation-dominated However, the temperature of the background radiation varies with scale factor era). according to T(t) ∝ 1/R(t) (Equation 6.6). It follows that during the radiation- dominated era the temperature of the background radiation varies with time according to T(t) ∝ t −1/2 (6.18) This describes how temperature changes with time in an expanding universe where the energy density of radiation is the dominant component. -
1 Introduction
1 Introduction WHO commissions reviews and undertakes health risk assessments associated with exposure to potentially hazardous physical, chemical and biological agents in the home, work place and environment. This monograph on the chemical and radiological hazards associated with exposure to depleted uranium is one such assessment. The purpose of this monograph is to provide generic information on any risks to health from depleted uranium from all avenues of exposure to the body and from any activity where human exposure could likely occur. Such activities include those involved with fabrication and use of DU products in industrial, commercial and military settings. While this monograph is primarily on DU, reference is also made to the health effects and behaviour of uranium, since uranium acts on body organs and tissues in the same way as DU and the results and conclusions from uranium studies are considered to be broadly applicable to DU. However, in the case of effects due to ionizing radiation, DU is less radioactive than uranium. This review is structured as broadly indicated in Figure 1.1, with individual chapters focussing on the identification of environmental and man-made sources of uranium and DU, exposure pathways and scenarios, likely chemical and radiological hazards and where data is available commenting on exposure-response relationships. HAZARD IDENTIFICATION PROPERTIES PHYSICAL CHEMICAL BIOLOGICAL DOSE RESPONSE RISK EVALUATION CHARACTERISATION BACKGROUND EXPOSURE LEVELS EXPOSURE ASSESSMENT Figure 1.1 Schematic diagram, depicting areas covered by this monograph. It is expected that the monograph could be used as a reference for health risk assessments in any application where DU is used and human exposure or contact could result. -
Recalling Radon's Recognition
in your element Recalling radon’s recognition Brett F. Thornton and Shawn C. Burdette look back at the discovery — and the many different names — of element 86. n 1899, Pierre and Marie Curie noted an Thoron, unlike radon, requires no such “induced radioactivity” — left behind by clarification, and 220Rn is routinely called Iradium, distinct from its own radioactivity. thoron today. Thoron is far easier to say Ernest Rutherford and Robert B. Owens also than ‘radon-two-twenty’, perhaps explaining reported that year on a radioactive substance why the annual count of scientific papers 220 ( Rn, t1/2 = 55.6 s) emitted by thorium, which mentioning thoron has increased over twenty- they called emanation. In 1900, Friedrich fold since thoron was ‘disallowed’ in 1957. Dorn realized that the Curies had observed a Distinguishing between 222Rn (the 222 220 unique substance ( Rn, t1/2 = 3.8 d), similar isotope called ‘radon’) and Rn (thoron) is to emanation. In 1904, André-Louis Debierne not of idle linguistic and historic interest. 222 found a third radioactive particle; this one © SUPERSTOCK/ALAMY Rn can persist indoors, whereas the short- 219 produced from actinium ( Rn, t1/2 = 4 s). lived thoron cannot. Not all home radon These were at first regarded as elements and actinon (An) for the three isotopes; detectors (pictured) are sensitive to thoron, and became colloquially known as thorium names suggested by Elliott Q. Adams. and thoron-sensitive detectors must be emanation, radium emanation and actinium An official statement on a name for all placed with care because thoron does not emanation, but today we recognize them three isotopes — that is, a name for the travel far from its source. -
PE1128 Radiation Exposure in Medical Imaging
Radiation Exposure in Medical Imaging This handout answers questions about radiation exposure and what Seattle Children’s Hospital is doing to keep your child safe. Medical imaging uses machines and techniques to provide valuable information about your child’s health. It plays an important role in helping your doctor make the correct diagnosis. Some of these machines use radiation to get these images. We are all exposed to small amounts of radiation in normal daily life from soil, rocks, air, water and even some of the foods we eat. This is called background radiation. The amount of background radiation that you are exposed to depends on where you live and varies throughout the country. The average person in the United States receives about 3 milli-Sieverts (mSv) per year from background radiation. A mSv is a unit of measurement for radiation, like an inch is a unit of length. Which medical MRI and ultrasound do not use ionizing (high-energy) radiation to make imaging exams images. MRI uses magnets and radio waves, and ultrasound uses sound waves. use radiation? Diagnostic An X-ray is a form of energy that can pass through your child’s bones and Radiography tissues to create an image. The image created is called a radiograph, sometimes referred to as an “X-ray.” X-rays are used to detect and diagnose conditions in the body. CT scan A CT (computed tomography) scan, sometimes called a “CAT scan,” uses X-rays, special equipment, and computers to make pictures that provide a multidimensional view of a body part. -
General Terms for Radiation Studies: Dose Reconstruction Epidemiology Risk Assessment 1999
General Terms for Radiation Studies: Dose Reconstruction Epidemiology Risk Assessment 1999 Absorbed dose (A measure of potential damage to tissue): The Bias In epidemiology, this term does not refer to an opinion or amount of energy deposited by ionizing radiation in a unit mass point of view. Bias is the result of some systematic flaw in the of tissue. Expressed in units of joule per kilogram (J/kg), which design of a study, the collection of data, or in the analysis of is given the special name Agray@ (Gy). The traditional unit of data. Bias is not a chance occurrence. absorbed dose is the rad (100 rad equal 1 Gy). Biological plausibility When study results are credible and Alpha particle (ionizing radiation): A particle emitted from the believable in terms of current scientific biological knowledge. nucleus of some radioactive atoms when they decay. An alpha Birth defect An abnormality of structure, function or body particle is essentially a helium atom nucleus. It generally carries metabolism present at birth that may result in a physical and (or) more energy than gamma or beta radiation, and deposits that mental disability or is fatal. energy very quickly while passing through tissue. Alpha particles cannot penetrate the outer, dead layer of skin. Cancer A collective term for malignant tumors. (See “tumor,” Therefore, they do not cause damage to living tissue when and “malignant”). outside the body. When inhaled or ingested, however, alpha particles are especially damaging because they transfer relatively Carcinogen An agent or substance that can cause cancer. large amounts of ionizing energy to living cells. -
What Is Electromagnetic Radiation?
WHATHAT ISIS ELELECTRT R OMAGNETICOMAGNETIC RADIAADIATITIONON? MEET A PLANETARY SCIENTIST — Dr. Carlé Pieters, Brown University How are radio waves, visible light, and X-rays similar? They are all types of electromagnetic radiation. All three travel — radiate — What do you do? and are made or detected by electronic (or magnetic) sensors, like a T.V., a digital camera, or a dentist’s X-ray machine. Types of electromagnetic radiation with which we are most familiar include ultraviolet light (causing sunburn), infrared light (in remote controls), and microwaves (in ovens). Electromagnetic radiation is made of electromagnetic waves. It is classified by the distance from the crest of one wave to the crest of the next — the wavelength. These waves can be thousands of miles long, like radiowaves, or smaller than an atom, like gamma rays! Collectively, these wavelengths make a spectrum — the electromagnetic spectrum. The shorter the wavelength, the more energetic the electromagnetic radiation. Radio waves, including microwaves, have long wavelengths and relatively low energy levels. Visible light, ultraviolet rays, X-rays, and gamma rays have shorter wavelengths and correspondingly higher levels of energy. The wavelengths of ultraviolet light, X-rays, and gamma rays are short enough to interact with human tissue and even alter DNA. What have you investigated on the Moon? Radiation Cosmic and Ultraviolet Visible Infrared Type X-Rays Microwaves and Radio Waves Gamma Rays Light Light Light 0.01 10 400 700 1 million nanometers nanometers nanometers nanometers nanometers Relative Why should we return to the Moon? Size tip of atomic atom molecule bacterium butterflyastronaut buildings nucleus a pin (you!) WHATHAT ISIS REFLECTANCEEFLECTANCE SPECPECTRTROSCOPYOSCOPY? If someone wants to become a scientist, what should they do? Spectroscopy is the study of the electromagnetic radiation emitted, absorbed, or reflected by an object.