Heavy Metals'' with ``Potentially Toxic Elements'
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5 Heavy Metals As Endocrine-Disrupting Chemicals
5 Heavy Metals as Endocrine-Disrupting Chemicals Cheryl A. Dyer, PHD CONTENTS 1 Introduction 2 Arsenic 3 Cadmium 4 Lead 5 Mercury 6 Uranium 7 Conclusions 1. INTRODUCTION Heavy metals are present in our environment as they formed during the earth’s birth. Their increased dispersal is a function of their usefulness during our growing dependence on industrial modification and manipulation of our environment (1,2). There is no consensus chemical definition of a heavy metal. Within the periodic table, they comprise a block of all the metals in Groups 3–16 that are in periods 4 and greater. These elements acquired the name heavy metals because they all have high densities, >5 g/cm3 (2). Their role as putative endocrine-disrupting chemicals is due to their chemistry and not their density. Their popular use in our industrial world is due to their physical, chemical, or in the case of uranium, radioactive properties. Because of the reactivity of heavy metals, small or trace amounts of elements such as iron, copper, manganese, and zinc are important in biologic processes, but at higher concentrations they often are toxic. Previous studies have demonstrated that some organic molecules, predominantly those containing phenolic or ring structures, may exhibit estrogenic mimicry through actions on the estrogen receptor. These xenoestrogens typically are non-steroidal organic chemicals released into the environment through agricultural spraying, indus- trial activities, urban waste and/or consumer products that include organochlorine pesticides, polychlorinated biphenyls, bisphenol A, phthalates, alkylphenols, and parabens (1). This definition of xenoestrogens needs to be extended, as recent investi- gations have yielded the paradoxical observation that heavy metals mimic the biologic From: Endocrine-Disrupting Chemicals: From Basic Research to Clinical Practice Edited by: A. -
The Periodic Electronegativity Table
The Periodic Electronegativity Table Jan C. A. Boeyens Unit for Advanced Study, University of Pretoria, South Africa Reprint requests to J. C. A. Boeyens. E-mail: [email protected] Z. Naturforsch. 2008, 63b, 199 – 209; received October 16, 2007 The origins and development of the electronegativity concept as an empirical construct are briefly examined, emphasizing the confusion that exists over the appropriate units in which to express this quantity. It is shown how to relate the most reliable of the empirical scales to the theoretical definition of electronegativity in terms of the quantum potential and ionization radius of the atomic valence state. The theory reflects not only the periodicity of the empirical scales, but also accounts for the related thermochemical data and serves as a basis for the calculation of interatomic interaction within molecules. The intuitive theory that relates electronegativity to the average of ionization energy and electron affinity is elucidated for the first time and used to estimate the electron affinities of those elements for which no experimental measurement is possible. Key words: Valence State, Quantum Potential, Ionization Radius Introduction electronegative elements used to be distinguished tra- ditionally [1]. Electronegativity, apart from being the most useful This theoretical notion, in one form or the other, has theoretical concept that guides the practising chemist, survived into the present, where, as will be shown, it is also the most bothersome to quantify from first prin- provides a precise definition of electronegativity. Elec- ciples. In historical context the concept developed in a tronegativity scales that fail to reflect the periodicity of natural way from the early distinction between antag- the L-M curve will be considered inappropriate. -
An Alternate Graphical Representation of Periodic Table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt
An Alternate Graphical Representation of Periodic table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt. Ltd, Hyderabad, India. [email protected] Abstract Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2) SU(2) group. IUPAC, the governing body in Chemistry, doesn‟t approve any periodic table as a standard periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as „Circular form of Periodic table‟. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables. 1. Introduction The profoundness of inherent symmetry in nature can be seen at different depths of atomic scales. Periodic table symbolizes one such elegant symmetry existing within the atomic structure of chemical elements. This so called „symmetry‟ within the atomic structures has been widely studied from different prospects and over the last hundreds years more than 700 different graphical representations of Periodic tables have emerged [1]. Each graphical representation of chemical elements attempted to portray certain symmetries in form of columns, rows, spirals, dimensions etc. Out of all the graphical representations, the rectangular form of periodic table (also referred as Long form of periodic table or Modern periodic table) has gained wide acceptance. -
Tracing Contamination Sources in Soils with Cu and Zn Isotopic Ratios Z Fekiacova, S Cornu, S Pichat
Tracing contamination sources in soils with Cu and Zn isotopic ratios Z Fekiacova, S Cornu, S Pichat To cite this version: Z Fekiacova, S Cornu, S Pichat. Tracing contamination sources in soils with Cu and Zn isotopic ratios. Science of the Total Environment, Elsevier, 2015, 517, pp.96-105. 10.1016/j.scitotenv.2015.02.046. hal-01466186 HAL Id: hal-01466186 https://hal.archives-ouvertes.fr/hal-01466186 Submitted on 19 Mar 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Tracing contamination sources in soils with Cu and Zn isotopic ratios Fekiacova, Z.1, Cornu, S.1, Pichat, S.2 1 INRA, UR 1119 Géochimie des Sols et des Eaux, F-13100 Aix en Provence, France 2 Laboratoire de Géologie de Lyon (LGL-TPE), Ecole Normale Supérieure de Lyon, CNRS, UMR 5276, 69007 Lyon, France Abstract Copper (Cu) and zinc (Zn) are naturally present and ubiquitous in soils and are im- portant micronutrients. Human activities contribute to the input of these metals to soils in dif- ferent chemical forms, which can sometimes reach a toxic level for soil organisms and plants. Isotopic signatures could be used to trace sources of anthropogenic Cu and Zn pollution. -
Health Concerns of Heavy Metals (Pb; Cd; Hg) and Metalloids (As)
Health concerns of the heavy metals and metalloids Chris Cooksey • Toxicity - acute and chronic • Arsenic • Mercury • Lead • Cadmium Toxicity - acute and chronic Acute - LD50 Trevan, J. W., 'The error of determination of toxicity', Proc. Royal Soc., 1927, 101B, 483-514 LD50 (rat, oral) mg/kg CdS 7080 NaCl 3000 As 763 HgCl 210 NaF 52 Tl2SO4 16 NaCN 6.4 HgCl2 1 Hodge and Sterner Scale (1943) Toxicity Commonly used term LD50 (rat, oral) Rating 1 Extremely Toxic <=1 2 Highly Toxic 1 - 50 3 Moderately Toxic 50 - 500 4 Slightly Toxic 500 - 5000 5 Practically Non-toxic 5000 - 15000 6 Relatively Harmless >15000 GHS - CLP LD50 Category <=5 1 Danger 5 - 50 2 Danger 50 - 300 3 Danger 300 - 2000 4 Warning Globally Harmonised System of Classification and Labelling and Packaging of Chemicals CLP-Regulation (EC) No 1272/2008 Toxicity - acute and chronic Chronic The long-term effect of sub-lethal exposure • Toxicity - acute and chronic • Arsenic • Mercury • Lead • Cadmium Arsenic • Pesticide o Inheritance powder • Taxidermy • Herbicide o Agent Blue • Pigments • Therapeutic uses Inorganic arsenic poisoning kills by allosteric inhibition of essential metabolic enzymes, leading to death from multi- system organ failure. Arsenicosis - chronic arsenic poisoning. Arsenic LD50 rat oral mg/kg 10000 1000 LD50 100 10 1 Arsine Arsenic acid Trimethylarsine Emerald green ArsenicArsenious trisulfide oxideSodium arsenite MethanearsonicDimethylarsinic acid acid Arsenic poisoning by volatile arsenic compounds from mouldy wall paper in damp rooms • Gmelin (1839) toxic mould gas • Selmi (1874) AsH3 • Basedow (1846) cacodyl oxide • Gosio (1893) alkyl arsine • Biginelli (1893) Et2AsH • Klason (1914) Et2AsO • Challenger (1933) Me3As • McBride & Wolfe (1971) Me2AsH or is it really true ? William R. -
The Development of the Periodic Table and Its Consequences Citation: J
Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1. -
Removal of Heavy Metals from Aqueous Solution by Zeolite in Competitive Sorption System
International Journal of Environmental Science and Development, Vol. 3, No. 4, August 2012 Removal of Heavy Metals from Aqueous Solution by Zeolite in Competitive Sorption System Sabry M. Shaheen, Aly S. Derbalah, and Farahat S. Moghanm rich volcanic rocks (tuff) with fresh water in playa lakes or Abstract—In this study, the sorption behaviour of natural by seawater [5]. (clinoptilolite) zeolites with respect to cadmium (Cd), copper The structures of zeolites consist of three-dimensional (Cu), nickel (Ni), lead (Pb) and zinc (Zn) has been studied in frameworks of SiO and AlO tetrahedra. The aluminum ion order to consider its application to purity metal finishing 4 4 wastewaters. The batch method has been employed, using is small enough to occupy the position in the center of the competitive sorption system with metal concentrations in tetrahedron of four oxygen atoms, and the isomorphous 4+ 3+ solution ranging from 50 to 300 mg/l. The percentage sorption replacement of Si by Al produces a negative charge in and distribution coefficients (Kd) were determined for the the lattice. The net negative charge is balanced by the sorption system as a function of metal concentration. In exchangeable cation (sodium, potassium, or calcium). These addition lability of the sorbed metals was estimated by DTPA cations are exchangeable with certain cations in solutions extraction following their sorption. The results showed that Freundlich model described satisfactorily sorption of all such as lead, cadmium, zinc, and manganese [6]. The fact metals. Zeolite sorbed around 32, 75, 28, 99, and 59 % of the that zeolite exchangeable ions are relatively innocuous added Cd, Cu, Ni, Pb and Zn metal concentrations (sodium, calcium, and potassium ions) makes them respectively. -
TEK 8.5C: Periodic Table
Name: Teacher: Pd. Date: TEK 8.5C: Periodic Table TEK 8.5C: Interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements. Elements and the Periodic Table An element is a substance that cannot be separated into simpler substances by physical or chemical means. An element is already in its simplest form. The smallest piece of an element that still has the properties of that element is called an atom. An element is a pure substance, containing only one kind of atom. The Periodic Table of Elements is a list of all the elements that have been discovered and named, with each element listed in its own element square. Elements are represented on the Periodic Table by a one or two letter symbol, and its name, atomic number and atomic mass. The Periodic Table & Atomic Structure The elements are listed on the Periodic Table in atomic number order, starting at the upper left corner and then moving from the left to right and top to bottom, just as the words of a paragraph are read. The element’s atomic number is based on the number of protons in each atom of that element. In electrically neutral atoms, the atomic number also represents the number of electrons in each atom of that element. For example, the atomic number for neon (Ne) is 10, which means that each atom of neon has 10 protons and 10 electrons. Magnesium (Mg) has an atomic number of 12, which means it has 12 protons and 12 electrons. -
Heavy Metals Toxicity. Int J Health Sci Res
International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571 Review Article Heavy Metals Toxicity Shikha Bathla, Tanu Jain Research Scholar, Department of Food and Nutrition, Punjab Agricultural University, Ludhiana-141004. Corresponding Author: Shikha Bathla Received: 15/02/2016 Revised: 13/04/2016 Accepted: 18/04/2016 ABSTRACT A heavy metal is a member of a loosely defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed based on density, atomic number or atomic weight, and some on chemical properties. Heavy metal toxicity can result in damaged central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys, liver, and other vital organs. Long- term exposure may result in slowly progressing physical, muscular, and neurological degenerative diseases. Exposure to toxic or heavy metals comes from many sources like in fish, chicken, vegetables, vaccinations, dental fillings and deodorants. Remedies to combat heavy metal toxicity can be to adopt the practice of kitchen gardening and also to ensure plethora supply of antioxidant includes fruits and vegetables in the diet Increase intake of miso soup (made from soya) and garlic and regular exercise and brisk walking. Increase intake of water to detoxify the harmful effect of heavy metals. Use of lead free paints and avoids carrying metal accessories. Key words: heavy metals, lead, selenium, mercury, silicon. INTRODUCTION in body with ligands containing oxygen Metals occurrence in the (OH, -COO,-OPO3H, >C=O) sulphur (-SH, environment has become a concern because -S-S-), and nitrogen (-NH and >NH) and the globe is experiencing a silent epidemic affect the body by interaction with essential of environmental poisoning, from the ever metals, formation of metal protein complex, increasing amounts of metals released into age and stage of development, lifestyle the biosphere. -
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. -
Novel Thin-Film Polymeric Materials for the Detection of Heavy Metals
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Available online at www.sciencedirect.com Procedia Engineering 47 ( 2012 ) 322 – 325 Proc. Eurosensors XXVI, September 9-12, 2012, Kraków, Poland Novel Thin-Film Polymeric Materials for the Detection of Heavy Metals H. Ikena, D. Kirsanovb,c, A. Leginb,c and M.J. Schöninga,d,* a Institute of Nano- and Biotechnologies (INB), FH Aachen, Jülich Campus, Germany b Sensor Systems, LLC, St. Petersburg, Russia c Laboratory of Chemical Sensors, St. Petersburg University, St. Petersburg, Russia d Peter Grünberg Institute (PGI-8), Research Centre Jülich GmbH, Jülich, Germany Abstract A variety of transition metals, e.g., copper, zinc, cadmium, lead, etc. are widely used in industry as components for wires, coatings, alloys, batteries, paints and so on. The inevitable presence of transition metals in industrial processes implies the ambition of developing a proper analytical technique for their adequate monitoring. Most of these elements, especially lead and cadmium, are acutely toxic for biological organisms. Quantitative determination of these metals at low activity levels in different environmental and industrial samples is therefore a vital task. A promising approach to achieve an at-side or on-line monitoring on a miniaturized and cost efficient way is the combination of a common potentiometric sensor array with heavy metal-sensitive thin-film materials, like chalcogenide glasses and polymeric materials, respectively. © 20122012 The Published Authors. by Published Elsevier by Ltd. Elsevier Ltd. Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o. -
FS Heavy Metals and Metalloids Final
DETOX Program Fact Sheet – Heavy Metals and Metalloids DETOX Program Hazardous Substances Fact Sheet Heavy Metals and Metalloids 1 DETOX Program Fact Sheet – Heavy Metals and Metalloids Content 1 Background .................................................................................................................... 3 2 Definition ........................................................................................................................ 3 3 Legal Aspects ................................................................................................................. 4 4 Hazardous Properties and Exposure .............................................................................. 4 4.1 Hazardous Properties .............................................................................................. 4 4.2 Exposure ................................................................................................................. 5 5 Sources for Heavy Metals and Metalloids in production of textiles .................................. 6 6 Alternative and Substitute Substances ........................................................................... 7 2 DETOX Program Fact Sheet – Heavy Metals and Metalloids 1 Background Heavy metals and metalloids are constituents of specific dyes and pigments, tanning chemicals for leather, catalysts in fiber production, printing pastes, as part of flame retardants and many more. They can also be found in natural fibers due to absorption by plants through soil or from fertilizers. Metals