Patty's Toxicology 

About: Patty's Toxicology is an academic journal. The journal publishes majorly in the area(s): Chemistry & Carcinogen. Over the lifetime, 118 publications have been published receiving 866 citations.

Occupational Ergonomics: Principles and Applications

Abstract: This chapter provides the basic principles that underlie the field of ergonomics and their application to some of the current issues of importance in the workplace. Sections 2 to 4 deal with the physiology of muscles; biomechanics; cellular responses to tissue, nerve, and joint injuries as they relate to cumulative trauma disorders; and common types of overuse syndromes. The remaining sections deal with applications of the principles to workplace ergonomic issues and proposed ergonomic regulations. The word “ergonomics” is made up of two Greek words, “ergo” meaning work and “nomas” meaning laws. The field of ergonomics is highly interdisciplinary. It applies principles from engineering, physiology, medicine, and psychology to the understanding of the interaction of humans with their workplace. The interaction of humans with their workplace may consist of identifying the relationship between job physical risk factors and physiological responses. For example, a specific ergonomic problem of paramount importance in the occupational health and safety is the issue of work-related musculoskeletal disorders (WMD). Some of these issues are discussed further in this chapter. The specific areas of application relevant for the field of ergonomics are defined and briefly explained. Activities that involve repetitive stress have effects that are extremely complicated. Adding internal or external forces to the body can, as described, alter bone, joints, ligaments, tendons, nerves, and muscles. Belief that a repetitive motion will result in an isolated nerve injury without affecting surrounding joints, ligaments, muscles, or tendons is likely to inhibit appropriate care and control of exposed individuals. Additional research is needed to further characterize changes that occur, and current approaches to recognizing, managing and preventing repetitive injuries must address all tissues in the involved area. Keywords: Principles; Ergonomics; Muscle; Skeletal system; Anthropometry; Biomechanics; Physiological effects; Stress strain; Tissue injury; Bone; Joints; Ligament; Tendon; Nerve; Upper extremity overuse; Carpal tunnel; Low back pain; Low back loads; Regulations; California standards; ANSI Z-365; Job analysis

Aromatic Amino and Nitro–Amino Compounds and Their Halogenated Derivatives

Abstract: Aromatic amines are organic compounds that contain at least one amino group attached directly to an aryl moiety. Aromatic amines represent one of the most important classes of industrial and environmental chemicals. Many aromatic amines have been shown to be potent carcinogens, mutagens, skin sensitizers, and/or hematotoxicants capable of inducing methemoglobinemia. Since the introduction of substituted anilines and naphthylamines as intermediates for the manufacture of azo dyes in the mid-1800s, aromatic amines have found numerous uses in various industries. Substantial worker exposure to aromatic amines with subsequent induction of bladder cancer occurred before preventive measures were instituted. Beyond occupational exposure, humans may also be exposed to aromatic amines through environmental sources. At least three carcinogenic aromatic amines (4-aminobiphenyl, 2-naphthylamine, and o-toluidine) have been detected in cigarette smoke. Many commonly used pharmaceuticals contain or are aromatic amines. Owing to their hazard potential, aromatic amines have been the subject of many biomonitoring studies, making them model compounds in molecular dosimetry and epidemiology studies. Since extensive information is available on the metabolic pathways and, to a lesser extent, the mechanism(s) of action, aromatic amines have also become targets for genetic polymorphism studies with ultimate goals of identifying susceptible subpopulations and designing of strategies for cancer prevention and intervention. The multifaceted interest in aromatic amines has continued to attract a tremendous amount of scientific studies and attention. Since the publication of the previous edition of Patty's on aromatic amines, many reviews and important research articles on aromatic amines and halogenated nitroaromatics have been published. In addition, a number of heterocyclic aromatic amines have attracted increasing attention as carcinogens of environmental significance. In this chapter, we present an overview of the aromatic amine class as a whole with emphasis on recent studies, followed by an updated description on individual chemicals grouped into eight subgroups of structurally related compounds. Keywords: Aromatic amino compounds; carcinogenicity; halogenated derivatives; hemoglobin binding; mechanism of action; methemoglobinemia; mutagenicity; nitro–amino compounds; skin sensitization; teratogenicity

Uranium and Thorium

Abstract: Uranium is a heavy, radioactive metal, the 92nd element in the periodic table, and a member of the actinide series. Its name and chemical symbol U are derived from the planet Uranus, discovered (1781) a few years before the element. A compound of uranium (uranium oxide) was discovered in the uranium ore pitchblende by M. H. Klaproth in 1789. Klaproth believed that he had isolated the element, but this was not achieved until 1841 when a French chemist, E. M. Peligot, reduced uranium tetrachloride with potassium in a platinum crucible to obtain elemental uranium. Uranium is not as rare as once believed. Widely distributed in the earth's crust, uranium occurs to the extent of about 0.0004%, making the metal more plentiful than mercury, antimony, or silver. Before World War II, uranium was of interest only to the chemists and physicists who studied the element as they would any other substance. With the advent of the nuclear age, uranium now occupies a key position in nuclear weapons and energy. The physical and chemical properties of uranium and some of its compounds are listed. To enhance its use in reactors and nuclear weapons, uranium undergoes an industrial enrichment process that increases the 235U content from 0.7% found naturally to a content between 2 and 90%. 235U is the only natural uranium isotope that can sustain the nuclear chain reaction required for reactors and weapons processes. No deposits of concentrated uranium ore have been discovered. As a result, uranium must be extracted from ores containing less than 0.1% U. Because it is necessary to use low-grade ores, substantial and complex processing of these ores is required to obtain pure uranium. Usually it is necessary to preconcentrate the ore by grinding and flotation or similar processes. Hazardous exposures in the uranium industry begin in the mining process. Hazards are of two types, chemical and radiological; of the two, radiation is the more dangerous. Effective ventilation control measures have reduced the radiation exposures in the larger mines, but far less satisfactory radiation-exposure conditions exist in small mines without the benefit of ventilation. In addition to the alpha-particle radiation hazard from uranium in the ore, the most hazardous elements are radon gas and its particulate daughters, RaA and RaC, all alpha emitters. Some mine waters are high in radon and thus are an additional exposure source and should not be used for wet drilling. In the mines some beta and gamma exposures from RaB, RaC, and Ra also occur but are of relatively minor importance. The chemical toxicity of uranium is similar to other heavy metals. Storage in the skeleton and excretion via the urine are accompanied by renal toxicity and are discussed. Hazards in milling uranium to produce a concentrate were thought to be relatively minor because a wet process was used. However, some chronic health effects, including nonmalignant respiratory disease and renal tubular biochemical abnormalities, have been documented in these workers and are discussed. A variety of both mandatory and voluntary health-based exposure limits for uranium are derived from both its chemical and radiological toxicity. Regulating bodies include international, national, and state organizations. Some of the pertinent regulations and guidelines on exposure limits are summarized here, but the reader is cautioned to consult other sources to ensure health protection and regulatory compliance. Uranium is unusual among the elements because it presents both chemical and radiological hazards. Thorium, the second element in the actinide series, exists in the earth's crust as an unstable, radioactive element that undergoes decay by alpha emission and gives rise to a series of short-lived daughter products that ends in a stable isotope of lead. Thorium is used as a source of atomic fuel, in the production of incandescent mantles, as an alloying element with magnesium, tungsten and nickel, and in the past was used as a diagnostic agent for systemic radiological studies. Thorium is primarily a radioactive hazard in humans; however, its chemical toxicity must also be considered. Keywords: Uranium; Uranium compounds; Thorium; Thorium compounds; Radon; Oxides; Nuclear fuel technology; Tissues; Smoking; Miners; Non-Miners; Uranium mines; Thorotrast; Depleted uranium; Uranium mills; Distribution

Esters of Aromatic Mono‐, Di‐, and Tricarboxylic Acids, Aromatic Diacids and Di‐, Tri‐, Or Polyalcohols

Abstract: The simple aliphatic esters of benzoic acid are liquids used as solvents, flavors, or perfumes. The arylbenzoate benzyl is used as a miticide or plasticizer. In general, these compounds have a low order of toxicity. The primary effect expected from ingestion of moderate amounts of benzoates is gastrointestinal irritation, gastric pain, nausea, and vomiting. Available data indicate a low order of skin absorbability, and the undiluted materials may be either slight or moderate skin irritants. In rabbits, the degree of skin irritation caused by alkyl benzoates increases with an increase in molecular weight. The salicylates are used as flavorants, perfumes, or analgesics. The most commonly used member of this class of compounds is methyl salicylate. Ingestion of relatively small quantities of methyl salicylate may cause severe, rapid-onset salicylate poisoning. The lower alkyl esters of p- or 4-hydroxybenzoic acid (C1 to C4), also named the methyl-, ethyl-, propyl-, and butyl parabens, are high-boiling liquids that decompose on heating. They are widely used in the food, cosmetic, and pharmaceutical industries as preservatives, bacteristats, and fungistats. Parabens also have been used therapeutically for the treatment of moniliasis, a Candida albicans infection. By the oral route, parabens are rapidly absorbed, metabolized, and excreted. The lower paraben homologues have low potential for acute or chronic systemic toxicity and are therefore approved as human food additives. The cinnamates (phenyl acrylates, phenylpropenoic acid esters) are mainly used as fragrances in the perfume industry. The cinnamates appear to have low to moderate toxicity in mammals. In humans, dermal exposure to allyl cinnamate may cause skin irritation. Some p-aminobenzoic acid (PABA) esters occur naturally, since the free compound, PABA, is an intricate part of the vitamin B complex and is utilized for its synthesis. PABA esters exhibit a low order of acute toxicity in experimental animals. In humans, cases of methemoglobinemia after topical benzocaine or procaine use have been reported. Sunscreen agents containing PABA esters may occasionally produce allergic photosensitization. The ortho-aminobenzoates (anthranilates) are less irritating and less likely to cause sensitization than the para-aminobenzoates, but have less therapeutic usefulness. They are used in some sunscreen lotions. Anthranilates have low toxicity potential. Long-chain fatty acids of glycerides may be replaced by one or more acetyl groups to produce mono-, di-, or triacetin. Acetins, propionates, and butyrates serve as food additives, solvents or plasticizers, and surface-active agents. Available evidence indicates that these agents exhibit a low order of toxicity. Normally, no irritant effects occur upon inhalation or direct dermal contact. The higher glycerides of fatty acids with odd-numbered carbon chains (C5 to C11) are found naturally in very small quantities in diverse organisms, and the even-numbered (C12 to C24) esters are common nutritional constituents. They are used as emulsifiers for foods, industrial raw materials, or nonacid detergent components. Some toxicity data are available for the C5 and C8 compounds. The even-numbered C12 to C18 glycerides are nontoxic. Little toxicological information is known about resorcinol esters compounds. Gallates are chemically trihydroxybenzoic acid esters. They serve generally as antioxidants, and the propyl, octyl, and dodecyl gallates have been approved as food additives. The gallates exhibit low acute and chronic toxicity in experimental animals. The bulk of evidence suggests that they are not carcinogenic or teratogenic. Oxalates, malonates, glutarates, and succinates are high-flash, high-boiling fluids. Oxalates and malonates are mainly used as solvents for resins or as chemical intermediates. The general industrial use of these materials has not been associated with any particular toxicity problem. Diethyl oxalate, which can exert typical local solvent and systemic effects, may present an exception. In humans, diethyl oxalate may cause irritation to skin and mucous membranes. Chemical and physical property data for alkyl and alkoxy adipates, azelates, and sebacates are summarized. These compounds are important chemical intermediates and are used extensively as plasticizers. Some of these agents are used in food packaging materials. They possess low acute toxicities, and their irritant effects on the skin and eye are very slight. Available evidence suggests that the lower alkyl adipates (dimethyl, diethyl, dibutyl) are reproductive and/or fetal toxicants. Maleic acid esters (cis-2-butenoates), fumarates (trans-2-butenoates), and itaconates have been utilized as plasticizers, raw materials for chemical syntheses, or preservatives for fats and oils. The esters of alkenyl dicarboxylic acids are of low acute toxicity. They have a tendency to cause skin or eye irritation in rabbits. Allergic dermatitis has occurred in humans exposed to dibutyl maleate. Subacute and chronic toxicity data for these compounds are limited. The aromatic ortho-dicarboxylic acid (phthalate) esters are among the most important industrial chemicals. They are used as plasticizers for a variety of plastics; those of C8 and above are used to add flexibility to PVC. They also are used with vinyl and cellulose resins to lend toughness and flexibility. They are commonly used in wire and cable coverings, moldings, vinyl consumer products, and medical devices. Some low-molecular-weight phthalate esters (e.g., methyl, ethyl, and butyl) are used as industrial solvents rather than as plasticizers. Occasionally, these low-molecular-weight phthalates have applications for consumer products such as ink and lacquer. Physically, phthalates occur mainly in liquid form with high boiling ranges and very low vapor pressures, with both contributing to the high stability of these materials. The biological responses to phthalate esters vary based on the alcohol side chain and the animal species tested. In general, phthalate esters have low potential for acute toxicity following oral, dermal, or inhalation exposure. They are nonirritating or slightly irritating to the skin and eyes, and they are not sensitizers. Keywords: Benzoates; Salicylates; Parabens; Hydroxybenzoates; Cinnamates; Aminobenzoates; Glycerol acetates; Acetins; Propionates; Butylates; Oxalates; Malonates; Succinates; Sulfosuccinates; Glutarates; Adipates; Azelates; Sebacates; Maleates; Fumarates; Itaconates; Phthalates; Glycolates; Trimellitates

Cyanides and Nitriles

Abstract: Cyanides are among the most acutely toxic of all industrial chemicals and are produced in large quantities and used in many different applications. However, they cause few serious accidents or deaths. This is partly because the word cyanide is synonymous with a highly poisonous substance and a certain amount of care in handling is thereby ensured. The cyanides and nitriles are a disparate group of substances characterized by the presence of a cyanide (CN) group in their molecular structure. The cyanide group consists of a carbon bonded to a nitrogen. In those cases where the cyanide group is readily available, their toxicity is likely to have similarity to hydrogen cyanide (HCN). The chemical and physical characteristics of the compound will affect the potential availability of the cyanide group and therefore the hazards associated with different chemical species. For purposes of the toxicologist, cyanides and nitriles can be classified into the following groups: The inorganic cyanides include (Group 1) hydrogen cyanide, cyanogen, simple salts of hydrogen cyanide that dissociate readily to release CN−1 ions (such as sodium, potassium, calcium, and ammonium cyanide); (Group 2) halogenated compounds such as cyanogen chloride or bromide; and (Group 3) simple and complex salts of hydrogen cyanide that do not dissociate readily to release CN−1 ions (such as cobalt cyanide trihydrate, cupric and cuprous cyanide, silver cyanide, and ferricyanide and ferrocyanide salts). The organic cyanides include (Group 4) cyanide glycosides produced by plants (such as amygdalin and linamarin); and (Group 5) nitriles [such as acetonitrile (methyl cyanide), acrylonitrile and isobutyronitrile]. Keywords: Cyanides; Nitriles; Bhopal; India; Methylisocyanate release