Workplace lead-exposed

The public and, more particularly, industrial workers in workplaces, are exposed to different kinds and forms of toxic chemical substances—for instance, solids, liquids, gases, vapors, dusts, fumes, hbers, and mists. How a chemical substance gets into the body and its effect on health depend on the form or the physical properties of the candidate chemical substance. Welding fumes are a complex mixture of metallic oxides, silicates, and fluorides. Many kinds of occupations, such as welding, cutting, and allied processes, produce fumes and gases, leading to serious health effects on workers. 

Workplaces that expose workers to asbestos, tremolite, anthophyllite, and actinolite dust vinyl chloride acrylonitrile inorganic arsenic lead benzene ethylene oxide 4,4 -methylenedianiline formaldehyde cadmium 1,3-butadiene and methylene chloride are covered by appropriate 1910 standards. 

Information on occupational exposure to lead is obtained primarily from the National Occupational Exposure Survey (NOES) and industry surveys of workers. While occupational exposure is widespread, environmental monitoring data on levels of exposure in many occupations are not available. OSHA has established a permissible exposure limit (PEL) for lead of 50 pg/m3 for workplace air (OSHA 1991). NIOSH has estimated that more than 1 million American workers were occupationally exposed to inorganic lead in more than 100 occupations (NIOSH 1977a, 1978a). According to NOES, conducted by NIOSH between 1980 and 1983, an estimated 25,169 employees were exposed to tetraethyl lead (not used in gasoline since December 31, 1995) approximately 57,000 employees were exposed to various lead oxides mostly in non-ferrous foundries, lead smelters, and battery plants 3,902 employees were exposed to lead chloride and 576,579 employees were exposed to some other form of lead in the workplace in 1980 (NIOSH 1990). Workers who operate and maintain solid waste incinerators are also exposed to air lead levels as high as 2,500 pg/m3 (Malkin 1992). 

Triebig G, Weitle D, Valentin H. 1984. Investigations on neurotoxicity of chemical substances at the workplace V. Determination of the motor and sensory nerve conduction velocity in persons occupationally exposed to lead. Int Arch Occup Environ Health 53 189-204. 

Dermal exposure to chemicals is one of the leading causes of job-related illness as reported by the National Institutes for Occupational Safety and Health. As jet fuel is the primary occupational exposure of military and aviation industry personnel, there is elevated concern regarding JP-8 dermal exposures in the workplace. Several anecdotal reports confirm that persons exposed to jet fuel experience itching or burning skin, skin redness or rash, skin dryness or dermatitis, skin lesions or weeping, or skin sensitization [32,33,34], yet little is known regarding possible systemic effects following dermal exposure. 

Probably the greatest concern in the workplaces is solvent exposure from cleaning agents or chemical processes. Farmers and pesticide workers can also be exposed to compounds clearly designed to affect the nervous system. The outdoor environment can contain elevated levels of a number of persistent chemicals that can adversely affect the nervous system, such as lead, mercury, and chlorinated pesticides. 

Many individuals who depend on television and radio for information probably believe that working in a chemical plant is a hazardous occupation. This myth is exposed by facts from the Bureau of Labor Statistics chemical plant employees enjoy one of the safest occupations. With all the federal pressures on the chemical industry to reduce injuries even further, it is astonishing that the second leading cause of death for the entire U.S. workplace was homicide in 1995. 

The highest exposures occur occupationally. The National Occupational Hazard Survey conducted by the National Institute for Occupational Safety and Health from 1972 through 1974 concluded that some 2.5 million workers could be exposed to chromium and its compounds in the workplace. The National Occupational Exposure Survey conducted a decade later from 1981 through 1983 estimated a total of almost 200 000 workers were exposed to hexavalent chromium compounds (barium chromate, calcium chromate, chromium trioxide, lead chromate, strontium chromate, and zinc chromate). Occupational exposure occurs primarily from stainless steel production and welding, chromate production, chrome plating, ferrochrome alloys, chrome pigment and tanning industries. 

More commonly, selenium enters the air from burning coal or oil. Much of the selenium in air is attached to fly ash and to suspended particles. The elemental selenium that may be present in fossil fuels forms selenium dioxide when burned. Selenium dioxide can then form selenious acid with water or sweat. Selenium anhydride is released during the heating of copper, lead, and zinc ores when there is selenium in them. Hydrogen selenide breaks up rapidly in air to form elemental selenium and water, thus eliminating the danger from this compound for most people, except those who are exposed to it in their workplace. 

People may also be exposed to selenium from industrial sources. Humans are normally not exposed to large amounts of selenium in the air, unless selenium dust or volatile selenium compounds are formed in their workplace. Occupations in which humans may be exposed to selenium in the air are the metal industries, selenium-recovery processes, paint manufacturing, and special trades. Selenium dioxide and elemental selenium can be released into the air during the burning of coal and oil. In addition, irrigation runoff may cause high levels of selenium in fresh water and can lead to high concentrations in some of the fish and birds that live there. 

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