82 thallium ← lead → bismuth Sn ↑ Pb ↓ Uuq Periodic Table - Extended Periodic Table General Name, Symbol, Number lead, Pb, 82 Chemical series Post-transition metals or poor metals Group, Period, Block 14, 6, p Appearance bluish gray Standard atomic weight 207. Thallium (ˈθæliəm is a Chemical element with the symbol Tl and Atomic number 81 Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Ununquadium (ˌjuːnənˈkwɒdiəm or /ˌʌnənˈkwɒdiəm/ is the temporary name of a radioactive Chemical element in the Periodic table that has the This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in Poor metals The Trivial name poor metals is sometimes applied to the Metallic elements in the P-block of the Periodic In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic History Carbon, Tin, and Lead, are a few of the elements well known in the ancient world - together with Sulfur, Iron, A period 6 element is one of the Chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides See also Electron configuration The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass 2(1)  g·mol−1 Electron configuration [Xe] 4f14 5d10 6s² 6p² Electrons per shell 2, 8, 18, 32, 18, 4 Physical properties Phase solid Density (near r.t.) 11. In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 34  g·cm−3 Liquid density at m.p. 10. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 66  g·cm−3 Melting point 600. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 61 K (327. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 46 °C, 621. The Celsius Temperature scale was previously known as the centigrade scale. 43 °F) Boiling point 2022 K (1749 °C, 3180 °F) Heat of fusion 4. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 77  kJ·mol−1 Heat of vaporization 179. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 5  kJ·mol−1 Specific heat capacity (25 °C) 26. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 650  J·mol−1·K−1 Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k at T(K) 978 1088 1229 1412 1660 2027 Atomic properties Crystal structure cubic face centered Oxidation states 4, 2 (Amphoteric oxide) Electronegativity 2. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 33 (Pauling scale) Ionization energies (more) 1st:  715. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively 6  kJ·mol−1 2nd:  1450. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material 5  kJ·mol−1 3rd:  3081. 5  kJ·mol−1 Atomic radius 180  pm Atomic radius (calc. Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth ) 154  pm Covalent radius 147  pm Van der Waals radius 202 pm Miscellaneous Magnetic ordering diamagnetic Electrical resistivity (20 °C) 208 n Ω·m Thermal conductivity (300 K) 35. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. Van der Waals Volume The van der Waals volume, V, also called the atomic volume or molecular volume, is the atomic property most directly In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Diamagnetism is the property of an object which causes it to create a magnetic field in opposition of an externally applied Magnetic field, thus causing a repulsive effect Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 3  W·m−1·K−1 Thermal expansion (25 °C) 28. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes 9  µm·m−1·K−1 Speed of sound (thin rod) (r.t.) (annealed) 1190  m·s−1 Young's modulus 16  GPa Shear modulus 5. Sound is a vibration that travels through an elastic medium as a Wave. Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear 6  GPa Bulk modulus 46  GPa Poisson ratio 0. Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 44 Mohs hardness 1. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5 Brinell hardness 38. The Brinell scale characterizes the indentation Hardness of materials through the scale of penetration of an indenter loaded on a material test-piece 3  MPa CAS registry number 7439-92-1 Selected isotopes Main article: Isotopes of lead iso NA half-life DM DE (MeV) DP 204Pb 1. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Lead ( Pb) has four stable Isotopes - 204Pb 206Pb 207Pb 208Pb and one common Radiogenic isotope Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide 4% >1. 4×1017 y Alpha 2. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle 186 200Hg 205Pb syn 1. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 53×107 y Epsilon 0. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the 051 205Tl 206Pb 24. Thallium (ˈθæliəm is a Chemical element with the symbol Tl and Atomic number 81 1% 206Pb is stable with 124 neutrons 207Pb 22. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 1% 207Pb is stable with 125 neutrons 208Pb 52. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 4% 208Pb is stable with 126 neutrons 210Pb trace 22. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A trace radioisotope is a Radioisotope that occurs naturally in trace amounts (i 3 y Alpha 3. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle 792 206Hg Beta 0. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 064 210Bi References

Lead pipe in Roman baths

Lead (pronounced /ˈlɛd/) is a transitional element with a symbol Pb (Latin: plumbum). Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 Recommended values for many properties of the elements together with various references are collected on these data pages Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Lead has the atomic number 82. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. For malleability in Cryptography, see Malleability (cryptography. Lead has a bluish white color when freshly cut, but tarnishes to a dull grayish color when it is exposed to air and is a shiny chrome silver when melted into a liquid. Lead is used in building construction, lead-acid batteries, bullets and shot, weights, and is part of solder, pewter, and fusible alloys. Lead-acid batteries, invented in 1859 by French Physicist Gaston Planté, are the oldest type of Rechargeable battery. A bullet is a solid Projectile propelled by a Firearm or Air gun and is normally made from metal (usually Lead) Lead shot is a collective term for small balls of Lead. It is used primarily as Projectiles in Shotguns but is also used for a variety of other purposes A solder is a fusible metal Alloy with a melting point or melting range of 90 to 450 ° C (200 to 840 ° F) used in a process called Pewter is a Metal Alloy, traditionally between 85 and 99 percent Tin, with the remainder consisting of Copper and Antimony, acting An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Lead has the highest atomic number of all stable elements, although the next element, bismuth, has a half-life so long (longer than the estimated age of the universe) it can be considered stable. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton A Stable element is a Chemical element with at least one naturally occurring Stable isotope. Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 Like mercury, another heavy metal, lead is a potent neurotoxin that accumulates in soft tissues and bone over time. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A neurotoxin is a Toxin that acts specifically on nerve cells ( Neurons, usually by interacting with Membrane proteins such as Ion channels

Notable characteristics

Lead has a dull luster and is a dense, ductile, very soft, highly malleable, bluish-white metal that has poor electrical conductivity. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Ductility is a mechanical property used to describe the extent to which materials can be deformed plastically or "stretched" into "wires" without Electrical conductivity or specific conductivity is a measure of a material's ability to conduct an Electric current. This true metal is highly resistant to corrosion, and because of this property, it is used to contain corrosive liquids (e. Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings g. sulfuric acid). Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Because lead is very malleable and resistant to corrosion it is extensively used in building construction e. g. external coverings of roofing joints. Lead can be toughened by adding a small amount of antimony or other metals to it. Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and It is a common misconception that lead has a zero Thomson effect. The thermoelectric effect is the direct conversion of temperature differences to electric Voltage and vice versa All lead, except ²⁰⁴Pb, is the end product of a complex radioactive decay (see isotopes of lead below). Lead is also poisonous. Lead poisoning (also known as saturnism, plumbism, or painter's colic) is a medical condition caused by increased levels of the metal Lead in

History

Lead has been commonly used for thousands of years because it is widespread, easy to extract and easy to work with. It is highly malleable and ductile as well as easy to smelt. Chemical reduction, or smelting, is a form of Extractive metallurgy. In the early Bronze Age, lead was used with antimony and arsenic. The term Bronze Age refers to a period in human cultural development when the most advanced Metalworking (at least in systematic and widespread use included techniques for Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and Arsenic (ˈɑrsənɪk is a Chemical element that has the symbol As and Atomic number of 33 Lead was mentioned in the Book of Exodus (15:10). Exodus ( Greek: έξοδος eksodos = "departure" is the second book of the Jewish Torah and of the Christian Old Testament.

A stylistic variation of the Alchemical symbol for lead, also used for the Blue Öyster Cult logo

In alchemy, lead was thought to be the oldest metal and was associated with the planet Saturn. Alchemic symbols, originally devised as part of the Protoscience of Alchemy, were used to denote some elements and some compounds until the 18th century Blue Öyster Cult is an American rock band formed in New York in 1967 and still active in 2008 Alchemy a part of the Occult Tradition is both a philosophy and a practice with an ultimately unknown aim involving the improvement of the alchemist as well as the making of Lead pipes that bear the insignia of Roman emperors are still in service and many Roman "pigs" (ingots) of lead figure in Derbyshire lead mining history and in the history of the industry in other English centres. This article details some of the history of Lead mining in Derbyshire, England. The Romans also used lead in molten form to secure iron pins that held together large limestone blocks in certain monumental buildings. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Lead's symbol Pb is an abbreviation of its Latin name plumbum for soft metals; originally it was plumbum nigrum, where plumbum candidum was tin. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 The English words "plumbing" and "plumb-bob" also derive from this Latin root. A plumb-bob or a plummet is a weight with a pointed tip on the bottom that is suspended from a string and used as a vertical reference line

Lead also refers collectively to the organic and inorganic compounds of lead, which are toxic. Lead poisoning was documented in ancient Rome, Greece, and China. Lead poisoning (also known as saturnism, plumbism, or painter's colic) is a medical condition caused by increased levels of the metal Lead in In the 20th century, the use of lead in paint pigments was sharply reduced because of the danger of lead poisoning, especially to children. For the drug referred to as "pigment" see Black tar heroin. ^[1][2][3] By the mid-1980s, a significant shift in lead end-use patterns had taken place. Much of this shift was a result of the U. S. lead consumers' compliance with environmental regulations that significantly reduced or eliminated the use of lead in non-battery products, including gasoline, paints, solders, and water systems. Lead use is being further curtailed by the European Union's RoHS directive. The Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment 2002/95/EC ( / commonly referred to as the Restriction of Hazardous Lead may still be found in harmful quantities in stoneware, vinyl (such as that used for tubing and the insulation of electrical cords), and brass manufactured in China. Between 2006 and 2007 many children's toys made in China were recalled, primarily due to lead in paint used to color the product.

Occurrence

Metallic lead does occur in nature, but it is rare. Lead is usually found in ore with zinc, silver and (most abundantly) copper, and is extracted together with these metals. Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 The main lead mineral is galena (PbS), which contains 86. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Galena is the natural mineral form of Lead sulfide. It is the most important Lead Ore mineral 6% lead. Other common varieties are cerussite (PbCO₃) and anglesite (PbSO₄). Cerussite (also known as lead carbonate or White lead ore) is a Mineral consisting of Lead Carbonate (PbCO3 Anglesite is a Lead Sulfate Mineral, PbSO4 It occurs as an oxidation product of primary lead sulfide ore Galena.

Sources of Lead

Top lead producing countries (2008) are Australia, China, USA, Peru, Canada, Mexico, Sweden, Morocco, South Africa and North Korea. ^[4]

Lead mining in Wales

Lead ore (galena) is found commonly in northeast Wales. The Northeast Wales Orefield was by far the most important source of lead and zinc in Wales and second in national importance only to the North Pennine Orefield. Lead mining dates back to at least Roman times and continued until well into the 20th century. Galena is present in steeply dipping fissure veins and in pipes and is in Mississippi Valley-type lead-zinc-fluorite and copper-dolomite associations. Carbonate-hosted lead-zinc ore deposits are important and highly valuable concentrations of lead and zinc sulfide Ores hosted within carbonate ( Limestone The mineralisation occurs in the upper parts of the Loggerheads and Cefn Mawr Formations of the Carboniferous Limestone. ^[5]

Processing of metal from ore

Lead ore

The principal ores of lead are galena (PbS), anglesite (PbSO₄) and cerussite (PbCO₃). Galena is the natural mineral form of Lead sulfide. It is the most important Lead Ore mineral Anglesite is a Lead Sulfate Mineral, PbSO4 It occurs as an oxidation product of primary lead sulfide ore Galena. Cerussite (also known as lead carbonate or White lead ore) is a Mineral consisting of Lead Carbonate (PbCO3 Most ores contain less than 10% lead, and ores containing as little as 3% lead can be economically exploited. Ores are crushed and concentrated by froth flotation typically to 70% or more. Froth flotation is a process for selectively separating Minerals from Gangue by taking advantage of differences in their Hydrophobicity. Sulfide ores are roasted, producing primarily lead oxide and a mixture of sulfates and silicates of lead and other metals contained in the ore. The term sulfide ( sulphide in British English) refers to several types of Chemical compounds containing Sulfur in its lowest Oxidation Roasting is a metallurgical process involving gas-solids reactions at elevated temperatures For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI ^[6]

Lead oxide from the roasting process is reduced in a coke-fired blast furnace. ^[7] This converts most of the lead to its metallic form. Three additional layers separate in the process and float to the top of the metallic lead. These are slag (silicates containing 1. Slag is the By-product of Smelting Ore to purify Metals They can be considered to be a mixture of metal Oxides however 5% lead), matte (sulfides containing 15% lead), and speiss (arsenides of iron and copper). Matte is a term used in the field of Pyrometallurgy given to the molten metal Sulfide phases typically formed during Smelting of Copper, Speiss is a molten phase consisting primarily of Iron arsenide that is commonly encountered in Lead Smelting operations These wastes contain concentrations of copper, zinc, cadmium, and bismuth that can be recovered economically, as can their content of unreduced lead. ^[6]

Metallic lead that results from the roasting and blast furnace processes still contains significant contaminants of arsenic, antimony, bismuth, zinc, copper, silver, and gold. The melt is treated in a reverberatory furnace with air, steam, and sulfur, which oxidizes the contaminants except silver, gold, and bismuth. A reverberatory furnace is a metallurgical or process Furnace that isolates the material being processed from contact with the Fuel, but not from contact The oxidized contaminants are removed by drossing, where they float to the top and are skimmed off. Dross is a Mass of Solid impurities floating on a molten metal ^[6][4]

Most lead ores contain significant concentrations of silver, resulting in the smelted metal also containing silver as a contaminant. Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Metallic silver as well as gold is removed and recovered economically by means of the Parkes process. The Parkes process is a Pyrometallurgical industrial process for removing Silver from Lead, during the production of bullion ^[8][6][4]

Desilvered lead is freed of bismuth according to the Betterton-Kroll process by treating it with metallic calcium and magnesium, which forms a bismuth dross that can be skimmed off. Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 The Betterton-Kroll process is an industrial process for removing Bismuth from Lead. ^[6][4]

Very pure lead can be obtained by processing smelted lead electolytically by means of the Betts process. The Betts electrolytic process is an industrial process for separating Lead and Bismuth. The process uses anodes of impure lead and cathodes of pure lead in an electrolyte of silica fluoride. ^[6][4]

Production and Recycling

Worldwide production and consumption of lead is increasing. Total annual production is about 8 million tonnes; about half is produced from recycled scrap. The main countries are Australia, China and the US, which account for more than half of primary production. The most common lead ore is galena or lead sulfide. ^[9]

• Annual Metal Production (2006): 7918 Thousand tonnes^[10]
• Annual Mine Production (2006): 3442 Thousand tonnes (lead content)

At current use rates, the supply of lead is estimated to run out in 42 years. ^[11] Environmental analyst, Lester Brown, however, has suggested lead could run out within 18 years based on an extrapolation of 2% growth per year. For the Canadian football player of the same name see Lester Brown (football player. ^[12] This may need to be reviewed to take account of renewed interest in recycling, and rapid progress in fuel cell technology. Recycling involves processing used materials into new products in order to prevent the waste of potentially useful materials reduce the consumption of fresh raw materials reduce A fuel cell is an electrochemical conversion device It produces electricity from Fuel (on the Anode side and an oxidant (on the

Isotopes

Main article: Isotopes of lead

Lead has seven isotopes in total (3 stable, 3 unstable 1 radiogenic). Lead ( Pb) has four stable Isotopes - 204Pb 206Pb 207Pb 208Pb and one common Radiogenic isotope Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides The 3 stable isotopes are ²⁰⁶Pb, ²⁰⁷Pb, & ²⁰⁸Pb, and the 3 unstable isotopes are ²⁰⁴Pb, ²⁰⁵Pb, & ²¹⁰Pb, along with one common radiogenic isotope ²⁰²Pb with a half-life of ~53,000 years. Half-Life (computer-game page here It's already listed in the disambiguation page

Health effects

Main article: Lead poisoning

Lead is a poisonous metal that can damage nervous connections (especially in young children) and cause blood and brain disorders. Lead poisoning (also known as saturnism, plumbism, or painter's colic) is a medical condition caused by increased levels of the metal Lead in Long term exposure to lead or its salts (especially soluble salts or the strong oxidant PbO₂) can cause nephropathy, and colic-like abdominal pains. Nephropathy refers to damage to or disease of the Kidney. An older term for this is nephrosis. "Cholic" redirects here For cholic acid see Cholic acid. The concern about lead's role in cognitive deficits in children has brought about widespread reduction in its use (lead exposure has been linked to schizophrenia). Schizophrenia ( from the Greek roots schizein (σχίζειν "to split" and phrēn Most cases of adult elevated blood lead levels are workplace-related. ^[13] High blood levels are associated with delayed puberty in girls. ^[14]

Older houses may still contain substantial amounts of lead paint. Lead paint is Paint containing Lead, a heavy metal, that is used as pigment with Lead(II chromate ( Pb[[Chromium Cr]] O4 White lead paint has been withdrawn from sale in industrialized countries, but the yellow lead chromate is still in use; for example, Holland Colours Holcolan Yellow. Lead(II chromate ( Pb[[Chromium Cr]] O4) is a Chemical compound. Old paint should not be stripped by sanding, as this produces inhalable dust.

Lead salts used in pottery glazes have on occasion caused poisoning, when acid drinks, such as fruit juices, have leached lead ions out of the glaze. It has been suggested that what was known as "Devon colic" arose from the use of lead-lined presses to extract apple juice in the manufacture of cider. Devon colic is an affliction caused by Lead poisoning which was suffered by the people of Devon during parts of the 17th and 18th centuries For the non-alcoholic beverage commonly known in the US as "cider" see Apple cider. Lead is considered to be particularly harmful for women's ability to reproduce. For that reason, many universities do not hand out lead-containing samples to women for instructional laboratory analyses. Lead acetate (also known as sugar of lead) was used by the Roman Empire as a sweetener for wine, and some consider this to be the cause of the dementia that affected many of the Roman Emperors. Lead(II acetate is a Chemical compound, a white crystalline substance with a Sweetish taste The Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial Dementia (from Latin de- "apart away" + Mens ( genitive mentis) "mind" is the progressive decline ^[15]

Lead as a soil contaminant is a widespread issue, since lead is present in natural deposits and may also enter soil through (leaded) gasoline leaks from underground storage tanks or through a wastestream of lead paint or lead grindings from certain industrial operations. Soil contamination is caused by the presence of man-made chemicals or other alteration in the natural soil environment An Underground Storage Tank (UST in United States environmental law, is a tank and any underground piping connected to the tank that has at least 10 percent of its

Biochemistry of lead poisoning

In the human body, lead inhibits α-aminolevulinate (ALA) dehydratase and ferrochelatase, preventing both porphobilinogen formation and the incorporation of iron into protoporphyrin IX, the final step in heme synthesis. Porphobilinogen (PBG is a Pyrrole involved in Porphyrin metabolism Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 In the metabolism of Porphyrin, protoporphyrin IX is created by the enzyme Protoporphyrinogen oxidase, and the enzyme Ferrochelatase converts it into A heme ( American English) or haem ( British English) is a Prosthetic group that consists of an Iron atom contained in the center of This causes ineffective heme synthesis and subsequent microcytic anemia. Microcytic Anaemia is a generic term for any type of anemia characterized by small red Blood cells The normal Mean corpuscular volume (abbreviated to MCV

Leaching of lead from metal surfaces

The Pourbaix diagram for lead in a non-complexing aqueous medium (eg perchloric acid / sodium hydroxide)[16]

The Pourbaix diagram for lead in citric acid/citrate[16]

It is clear from the Pourbaix diagram below that lead is more likely to corrode in a citrate medium than it is in a non-complexing medium. In Chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable ( equilibrium) phases of an aqueous electrochemical system Perchloric acid, HClO4 is an Oxoacid of Chlorine and is a colorless liquid soluble in water. In Chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable ( equilibrium) phases of an aqueous electrochemical system In Chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable ( equilibrium) phases of an aqueous electrochemical system The central part of the diagram shows that lead metal is more easy to oxidise in the citrate medium than it is in normal water.

In a Pourbaix diagram, the acidity is plotted on the x axis using the pH scale, while how oxidising/reducing nature of the system is plotted on the y axis in terms of volts relative to the standard hydrogen electrode. The standard hydrogen electrode (abbreviated SHE) also called normal hydrogen electrode ( NHE) is a Redox electrode which forms the basis of The diagram shows the form of the element which is most chemically stable at each point, it only comments on thermodynamics and it says nothing about the rate of change (kinetics). In Physics, thermodynamics (from the Greek θερμη therme meaning " Heat " and δυναμις dynamis meaning "

Descriptive chemistry

See also: Category:Lead compounds

Various oxidized forms of lead are easily reduced to the metal. An example is heating PbO with mild organic reducing agents such as glucose. A mixture of the oxide and the sulfide heated together without any reducing agent will also form the metal. ^[8]

2PbO + PbS   →   3 Pb + SO₂

Metallic lead is attacked only superficially by air, forming a thin layer of oxide that protects it from further oxidation. The metal is not attacked by sulfuric or hydrochloric acids. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water It does, however, dissolve in nitric acid with the evolution of nitric oxide gas to form dissolved Pb(NO₃)₂. Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and Nitric oxide or nitrogen monoxide is a Chemical compound with Chemical formula N[[Oxygen O]] Lead(II nitrate is an Inorganic compound with the Chemical formula Pb ( NO 32

3 Pb + 8 H⁺ + 8 NO₃^–   →   3 Pb²⁺ + 6 NO₃^– + 2 NO + 4H₂O

When heated with nitrates of alkali metals, metallic lead oxidizes to form PbO (also known as litharge), leaving the corresponding alkali nitrite. In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms Lead(II oxide is the Chemical compound with the formula Litharge is one of the natural mineral forms of Lead(II oxide, PbO The nitrite Ion is NO2− The anion is bent being Isoelectronic with O3. PbO is representative of lead's II oxidation state. It is soluble in nitric and acetic acids, from which solutions it is possible to precipitate halide, sulfate, chromate, carbonate (PbCO₃), and basic carbonate (Pb₃(OH)₂(CO₃)₂) salts of lead. Acetic acid, also known as ethanoic acid, is an organic chemical compound, giving Vinegar its sour taste A halide is a Binary compound, of which one part is a Halogen Atom and the other part is an element or radical that is less Lead (II sulfate ( sulphate in British English) (PbSO4 is a white crystal or powder Lead(II chromate ( Pb[[Chromium Cr]] O4) is a Chemical compound. Lead carbonate, is the chemical compound PbCO3 It is prepared industrially from Lead(II acetate and Carbon dioxide. The sulfide can also be precipitated from acetate solutions. Lead(II acetate is a Chemical compound, a white crystalline substance with a Sweetish taste These salts are all poorly soluble in water. Among the halides, the iodide is less soluble than the bromide, which, in turn, is less soluble than the chloride. ^[17]

The II oxide is also soluble in alkali hydroxide solutions to form the corresponding plumbite salt. Trends The alkali metals show a number of trends when moving down the group - for instance decreasing electronegativity increasing reactivity and decreasing melting and boiling In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen The plumbite Ion is Pb(OH3&minus or PbO2&minus There are plumbite compounds for example Sodium plumbite ^[8]

PbO + 2OH^– + H₂O   →   Pb(OH)₄^2–

Chlorination of plumbite solutions causes the formation of lead's IV oxidation state. Chlorination is the process of adding the element Chlorine to Water as a method of Water purification to make it fit for human consumption as

Pb(OH)₄^2– + Cl₂   →   PbO₂ + 2 Cl^– + 2 H₂O

Lead dioxide is representative of the IV state, and is a powerful oxidizing agent. Lead(IV oxide, PbO2 also plumbic oxide and lead dioxide, is an Oxide of Lead, with lead in Oxidation state +4 An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound The chloride of this oxidation state is formed only with difficulty and decomposes readily into the II chloride and chlorine gas. The bromide and iodide of IV lead are not known to exist. ^[17] Lead dioxide dissolves in alkali hydroxide solutions to form the corresponding plumbates. The plumbate Ion is PbO32&minus or Pb(OH62&minus A plumbate (compound is a compound containing this ion ^[8]

PbO₂ + 2 OH^– + 2 H₂O   →   Pb(OH)₆^2–

Lead also has an oxide that is a hybrid between the II and IV oxidation states. Red lead (also called minium) is Pb₃O₄. Red lead, also called minium, lead tetroxide or triplumbic tetroxide, is a bright red or orange Crystalline or Amorphous Pigment

Lead readily forms an equimolar alloy with sodium metal that reacts with alkyl halides to form organometallic compounds of lead such as tetraethyl lead. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 The haloalkanes (also known as halogenoalkanes or alkyl halides) are a group of Chemical compounds consisting of Alkanes such as Methane Organometallic chemistry is the study of Chemical compounds containing bonds between Carbon and a Metal. Tetra-ethyl lead, abbreviated TEL, is an organometallic compound with the formula ( CH3CH2)4 Pb. ^[18]

Chloride complexes

Diagram showing the forms of lead in chloride media^[16]

Lead(II) forms a series of complexes with chloride, the formation of which alters the corrosion chemistry of the lead. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus This will tend to limit the solubility of lead in saline media.

Equilibrium constants for aqueous lead chloride complexes at 25 °C[19]
Pb2+ + Cl– → PbCl+		K1 = 12. 59
PbCl+ + Cl− → PbCl20		K2 = 14. 45
PbCl20 + Cl− → PbCl3−		K3 = 3. 98 ×10−1
PbCl3− + Cl− → PbCl42−		K4 = 8. 92 × 10−2

Phase diagrams of solubilities

Plot showing aqueous concentration of dissolved Pb2+ as a function of SO42−[16]

Diagram for lead in sulfate media[16]

Lead(II) sulfate is poorly soluble, as can be seen in the following diagram showing addition of SO₄²⁻ to a solution containing 0. In Physical chemistry, Mineralogy, and Materials science, a phase diagram is a type of graph used to show the equilibrium conditions 1M of Pb²⁺. The pH of the solution is 4. 5, as above that, Pb²⁺ concentration can never reach 0. 1M due to the formation of Pb(OH)₂. Observe that Pb²⁺ solubility drops 10,000 fold as SO₄²⁻ reaches 0. 1M

Diagram showing the solubility of lead in chloride media. The lead concentrations are plotted as a function of the total chloride present. [16]

Pourbaix diagram for lead in chloride (0. In Chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable ( equilibrium) phases of an aqueous electrochemical system 1 M) media[16]

Here it can be seen that the addition of chloride can lower the solubility of lead, however in chloride rich media (such as aqua regia) the lead can become soluble again as anionic chlorocomplexes. Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution

The Pourbaix diagram on the right is for a moderate concentration (0. In Chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable ( equilibrium) phases of an aqueous electrochemical system 1 M) of chloride.

Applications

• Lead is a major constituent of the lead-acid battery used extensively in car batteries. Lead-acid batteries, invented in 1859 by French Physicist Gaston Planté, are the oldest type of Rechargeable battery.
• Lead is used as a coloring element in ceramic glazes, notably in the colors red and yellow. Glaze is a layer or coating of a Vitreous substance which has been fired to fuse to a ceramic object to color decorate strengthen or waterproof it
• Lead is used to form glazing bars for stained glass or other multi-lit windows. For the Blackford Oakes novel see Stained Glass (novel The term stained glass refers either to the material of coloured Glass or to the art The practice has become less common, not for danger but for stylistic reasons.
• Lead is used as projectiles for firearms and fishing sinkers because of its density, low cost compared to alternative products and ease of use due to relatively low melting point. A projectile is any object propelled through space by the exertion of a force which ceases after launch A firearm is a Tool that projects either single or multiple Projectiles at high velocity through a controlled explosion A sinker or a plummet is a Weight used in Fishing to force a lure / bait to sink more rapidly or to increase the distance that it may ^[20]
• Lead or "sheet-lead" is used as a sound deadening layer in such areas as wall, floor and ceiling design in sound studios where levels of airborne and mechanically produced sound are targeted for reduction or virtual elimination.
• Lead is used in some candles to treat the wick to ensure a longer, more even burn. Because of the dangers, European and North American manufacturers use more expensive alternatives such as zinc. ^[21]
• Lead is used as shielding from radiation, e. Lead shielding refers to the use of Lead as a form of Radiation protection to shield people or objects from Radiation. Image talkNew_radiation_symbol_ISO_21482svg for details --> Ionizing radiation g. in x-ray rooms. X-radiation (composed of X-rays) is a form of Electromagnetic radiation.
• Molten lead is used as a coolant, eg. A coolant is a fluid which flows through a device in order to prevent its overheating transferring the heat produced by the device to other devices that utilize or dissipate it for lead cooled fast reactors. The lead-cooled fast reactor is a Nuclear power Generation IV reactor that features a Fast neutron spectrum molten Lead or Lead-bismuth
• Lead glass is composed of 12-28% lead oxide. Glass consists of a network former typically Silica (SiO2 and network modifiers including alkali fluxes such as Potassium oxide or Sodium Lead(II oxide is the Chemical compound with the formula It changes the optical characteristics of the glass and reduces the transmission of radiation.
• Lead is the traditional base metal of organ pipes, mixed with varying amounts of tin to control the tone of the pipe. An organ pipe is a sound-producing element of the Pipe organ that resonates at a specific pitch when pressurized air (commonly referred to as wind Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50
• Lead is used as electrodes in the process of electrolysis. An electrode is an Electrical conductor used to make contact with a nonmetallic part of a circuit (e In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current
• Lead is used in solder for electronics, although this usage is being phased out by some countries to reduce the amount of environmentally unfriendly waste. A solder is a fusible metal Alloy with a melting point or melting range of 90 to 450 ° C (200 to 840 ° F) used in a process called
• Lead is used in high voltage power cables as sheathing material to prevent water diffusion into insulation.
• Lead is used for the ballast keel of sailboats. Ballast is used in Sailboats to provide moment to resist the lateral forces on the Sail. Its high weight-to-volume ratio allows it to counterbalance the heeling effect of wind on the sails while at the same time occupying a small volume and thus offering the least underwater resistance.
• Lead is added to brass to reduce machine tool wear. Brass is any Alloy of Copper and Zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties A machine tool is a powered mechanical device typically used to fabricate metal components of machines by Machining, which is the selective removal of metal
• Lead has many uses in the construction industry, e. g. lead sheets are used as roofing material, cladding, flashings, gutters and gutter joints, and on roof parapets. Detailed lead mouldings are used as decorative motifs used to fix lead sheet.
• Lead is frequently used in scuba diving weight belts to counteract the diver's natural buoyancy and that of his equipment. Scuba diving is swimming underwater, or taking part in another activity while using a Scuba set. Divers wear weighting systems, weight belts or weights, generally made of Lead, to counteract the Buoyancy of other Diving equipment
• Lead is often used to balance the wheels of a car; this use is being phased out in favor of other materials for environmental reasons. Tire Balance, also referred to as tire unbalance or imbalance describes the distribution of mass within an automobile Tire and/or the wheel to which it is attached
• Lead is still widely used in statues and sculptures.

Former applications

• Lead was used as a pigment in lead paint for white as well as yellow and red colors. Lead paint is Paint containing Lead, a heavy metal, that is used as pigment with Lead(II chromate ( Pb[[Chromium Cr]] O4 It was discontinued because of the dangers of lead poisoning. However, lead chromate is still in use. Lead(II chromate ( Pb[[Chromium Cr]] O4) is a Chemical compound.
• Lead was the hot metal used in hot metal typesetting. Hot metal typesetting (also called hot lead typesetting or simply hot metal) is a term used to encompass a range of different 19th century technologies to create
• Lead was used for plumbing in Ancient Rome. Plumbing, from the Latin plumbum for Lead, is the skilled trade of working with pipes, tubing and Plumbing fixtures for Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC
• Lead was used as a preservative for food and drink in Ancient Rome. Food preservation is the process of treating and handling Food in a way that preserves its edibility and nutrition value
• Lead was used for joining cast iron water pipes and used as a material for small diameter water pipes until the early 1970s.
• Tetraethyl lead was used in leaded fuels to reduce engine knocking; however, this is no longer common practice in the Western world due to health concerns. Tetra-ethyl lead, abbreviated TEL, is an organometallic compound with the formula ( CH3CH2)4 Pb. Knocking (also called knock, detonation or spark knock, pinking in UK English or pinging in US English in spark-ignition The term Western world, the West or the Occident ( Latin: occidens -sunset -west as distinct from the Orient) can have multiple meanings ^[22]
• Lead has been used to make "clubs" or bats more lethal by melting it into a hole drilled into the top
• Lead was used to make bullets for slings. A sling is a projectile Weapon typically used to throw a blunt Projectile such as a stone
• Lead was used as a component of toys. Due to toy safety regulations, this use has been stopped in the United States.
• Lead was used in car body filler, which was used in many custom cars in the 1940s–60s. A custom car is a passenger vehicle that has been modified in either of the following two ways Hence the term Leadsled. leadsled is a car from the 1950s or early 1960s that has had extensive customization done to the body
• Lead is a superconductor at 7. Superconductivity is a phenomenon occurring in certain Materials generally at very low Temperatures characterized by exactly zero electrical resistance 2 K and IBM tried to make a Josephson Effect Computer out of lead-alloy. The Josephson effect is the phenomenon of current flow across two weakly coupled Superconductors, separated by a very thin insulating barrier ^[23]

Contrary to popular belief, pencil "leads" have never been made from lead. The term comes from the Roman stylus, called the penicillus, which was made of lead. Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC ^[24] When the pencil originated as a wrapped graphite writing tool, the particular type of graphite being used was named plumbago (lit. The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. "act for lead"; "leadmocku").

Phrases

A "lead pipe cinch" is something that is absolutely certain. In the 19th century, a horse saddle was safe when it was well "cinched". The "lead pipe" qualifier is an obscure "intensifier". ^[25]

A "lead pencil" is a leftover term from when the original pencils were made from the only known deposit of graphite ever to be found in a pure, solid state, Grey Knotts in 16th century England. A pencil is a Writing or Drawing instrument consisting of a thin stick of Pigment (usually Graphite, but can also be coloured pigment or The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. Grey Knotts is a Fell in the English Lake District, it is situated one kilometre south of the B5289 road as it crosses the Honister Pass The new material was assumed to be a form of lead. Modern pencils use a marking core made of powdered, refined graphite mixed with clay, as has been the practice for centuries.

It is said that if one made a lead balloon, it would not fly. As lead is a very heavy element, it is presumed it will not fly. However, if one achieves the right size-to-weight ratio and uses helium instead of oxygen or air, a lead balloon could fly. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five This was tested by the MythBusters. MythBusters is a Popular science Television program produced by Australian firm Beyond Television Productions originally for the

Trivia

The band Led Zeppelin was originally called lead zeppelin. Led Zeppelin were Keith Moon and John Entwistle suggested that a possible supergroup containing themselves, Jimmy Page, and Jeff Beck would go down like a lead zeppelin, a term Entwistle used to describe a bad gig. ^[26] The group deliberately dropped the 'a' in Lead at the suggestion of their manager, Peter Grant, to prevent "thick Americans"^[27] from pronouncing it as "leed". Peter Grant, ( 5 April 1935 &ndash 21 November 1995) was an English Music manager. ^[28]

See also

• Adult Blood Lead Epidemiology and Surveillance
• Medical geology
• Plumbosolvency

References

Further reading

• Keisch, B. , Feller, R. L. , Levine, A. S. , and Edwards, R. R. : "Dating and Authenticating Works of Art by Measurement of Natural Alpha Emitters". In: Science, 155, No. 3767, p. 1238–1242, 1967.
• Keisch, B: "Dating Works of Art Through their Natural Radioactivity: Improvements and Applications". In: Science, 160, p. 413–415, 1968.
• Keisch, B: "Discriminating Radioactivity Measurements of Lead: New Tool for Authentication". In: Curator, 11, No. 1. , p. 41–52, 1968.

External links

• Case Studies in Environmental Medicine - Lead Toxicity
• ToxFAQs: Lead
• National Pollutant Inventory - Lead and compounds fact sheet
• WebElements.com - Lead
• The Lead Education and Abatement Design Group (Australia)
• International Lead & Zinc Study Group
• International Lead Management Center
• Lead Development Association International
• Do lead fishing sinkers threaten the environment? (from The Straight Dope)
• A Small Dose of Toxicology:Lead. The Straight Dope is a popular question-and-answer Newspaper column published in the Chicago Reader, syndicated in thirty Newspapers A Small Dose Of. . . . Retrieved on 7 April 2007.
• Lead. Los Alamos National Laboratory. Retrieved on 7 April 2007.
• NIST's X-Ray Mass Attenuation Coefficients - Lead. NIST. Retrieved on 7 April 2007.
• Jennifer B. McKim, Keith Sharon and William Heisel. "Scandal involving lead-laced Mexican candy being eaten by children in California", Orange Counter Register, 25-04-2004. Retrieved on 2007-04-07. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 529 - First draft of Corpus Juris Civilis (a fundamental work in Jurisprudence) is issued by Eastern Roman Emperor  
• Darshak Sanghavi, "Getting the Lead Out: If only it was as easy as recalling the Mattel toys", Slate magazine, August 21, 2007
• National Institute for Occupational Safety and Health - ABLES Page