Ebook Current occupational and environmental medicine (5/E): Part 2
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Ebook Current occupational and environmental medicine (5/E): Part 2
Section IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2ls have resulted in their extensive use in industry. These naturally occurring materials have long been recognized for their ability to impart a variety of valuable characteristics to finished goods. Metals are used in the construction, automotive, aerospace, electronics, glass, and other manufactur Ebook Current occupational and environmental medicine (5/E): Part 2ing industries. Metals are major sources of pigments and stabilizers for paints and plastics. Metals are also used as catalysts and intermediates in tEbook Current occupational and environmental medicine (5/E): Part 2
he chemical and pharmaceutical industries. Metals may be emitted as contaminants or by-products from industrial operations and power generation, and tSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2They also may be bound to organic materials, altering their physical characteristics and potential toxicity. Some compounds, such as hydrides and carbonyls, are highly toxic and may be formed accidentally when the parent metal reacts with acids. Metals may be altered by burning and smelting or after Ebook Current occupational and environmental medicine (5/E): Part 2 uptake by biologic systems. The chemical structure of the metal or organometallic compound alters absorption, distribution, and toxicity.Metals exertEbook Current occupational and environmental medicine (5/E): Part 2
biologic effects chiefly through the formation of stable complexes with sulfhydryl groups, altering the structure and function of many proteins and eSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2 serve no recognized biologic purpose, raising public health concerns owing to their ubiquitous presence in living organisms. Understanding and eliminating health risks from low-level background exposures remains a top priority in environmental health.General population exposure to many metals is re Ebook Current occupational and environmental medicine (5/E): Part 2lated primarily to air,water, and food contamination. Background exposures vary considerably around the world owing to natural occurrence in soil andEbook Current occupational and environmental medicine (5/E): Part 2
groundwater, as well as pollution from industrial operations, automotive exhaust, and power generation. Familiarity with the potential health effects Section IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2TOXICITYAcute toxicity usually occurs after ingestion of metal-containing compounds or inhalation of high concentrations of metal dusts or fumes. These can arise from improperly ventilated burning or welding operations or from unexpected chemical reactions. Home remodeling activities can generate du Ebook Current occupational and environmental medicine (5/E): Part 2st from paint pigments, particularly lead. This and ingestion of paint chips (pica) are important causes of childhood poisoning. Familiarity with theEbook Current occupational and environmental medicine (5/E): Part 2
symptoms of acute heavy metal poisoning, along with an awareness of the potential sources of exposure, is critical for rapid detection and treatment. Section IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2effects of low-level exposure to metals indicates that physiologic alterations occur at levels that have been considered sale previously. The evidence for neurotoxicity, circulatory effects, nephrotoxicity, reproductive toxicity, and carcinogenicity at low levels of exposure continues to grow. Regul Ebook Current occupational and environmental medicine (5/E): Part 2atory agencies must consider these factors as they devise exposure standards that provide adequate margins of safety in protecting long-term populatioEbook Current occupational and environmental medicine (5/E): Part 2
n health, rhe challenge for physicians is to differentiate global public health issues from specific clinical concerns in individual patients.ARSENICESection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2onary dysfunction (prolonged QT interval, arrhythmias, congestive cardiomyopathy, non-cardiogenic pulmonary edema)•Anemia and leukopenia•Sensorimotor peripheral neuropathy►Chronic Effects•Constitutional (fatigue, malaise)•Anemia and leukopenia•Hyperkeratosis and hyperpigmentation•Sensorimotor periph Ebook Current occupational and environmental medicine (5/E): Part 2eral neuropathy•Peripheral vascular disease•Cancer of the skin, lung, and bladderGeneral ConsiderationsArsenic is a naturally occurring metalloid thatEbook Current occupational and environmental medicine (5/E): Part 2
occurs in a variety of chemical forms and valence states. The elemental form, which seldom exists in nature and is of low solubility, is a rare causeSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2s. Trivalent forms generally have greater acute toxicity than the pentavalent species, but in vivo interconversion may occur, and compounds of both valences are capable of exerting a similar pattern of acute and chronic intoxication. Organoarsenicals, which occur naturally and in many synthetic form Ebook Current occupational and environmental medicine (5/E): Part 2s, vary widely in their toxicological attributes, from the virtually nontoxic natural compound arsenobetaine widely encountered in seafood, to the higEbook Current occupational and environmental medicine (5/E): Part 2
hly toxic vesicant warfare agent lewisite (dichloro [2-chlorovinyl] arsine). Arsine, a hydride gas (AsH3) is a potent hemolytic agent.UseArsenic is usSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2mbers and utility poles); its widespread former use as a preservative for residential lumber was voluntarily discontinued in 2003. Arsenic is used a minor constituent of metal alloys, such as the hardening of lead in battery grids, bearings, and ammunition, and in the manufacture of certain types of Ebook Current occupational and environmental medicine (5/E): Part 2 glass. With the exception of monosodium methanearsonate (MSMA) as an herbicide, virtually all the domestic use of arsenic as a pesticide or herbicideEbook Current occupational and environmental medicine (5/E): Part 2
has been discontinued. High purity arsenic is used in the manufacture of gallium arsenide chips and circuit boards incorporated in products in the elSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2y. Phenylarsenic compounds are used as feed additives for poultry and swine, and poultry litter marketed as a soil amendment may contain low levels of soluble arsenic. Inorganic arsenic is occasionally encountered in folk remedies and tonics, particularly some of Asian origin.Occupational & Environm Ebook Current occupational and environmental medicine (5/E): Part 2ental ExposureOccupational exposure to arsenic may occur in the smelting of lead, copper, gold, and other nonferrous metals. Readily volatilized arsenEbook Current occupational and environmental medicine (5/E): Part 2
ic trioxide is concentrated in flue dust and can be condensed and recovered in a cooling chamber. Furnace and flue maintenance operations carry risk oSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metal Ebook Current occupational and environmental medicine (5/E): Part 2oelectronics and glass industries, workers may be exposed to arsenic from source materials, finished products, or maintenance operations. Arsine gas is used in semiconductor manufacturing and also may be formed accidentally when compounds or products containing inorganic arsenic come in contact with Ebook Current occupational and environmental medicine (5/E): Part 2 hydrogen or reducing agents in aqueous solution.Section IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metalSection IV. Occupational and Environmental Exposures30MetalsRichard Lewis, MD, MPH Michael J. Kosnett, MD, MPHThe diverse physical properties of metalGọi ngay
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