Thread: Lead warnings
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Old January 23, 2012, 05:18 PM   #1
warbirdlover
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Join Date: December 13, 2009
Location: central Wisconsin
Posts: 2,324
Lead warnings

Being a retired metallurgist I've had some experience with lead. It's commonly added to steel (usually bar stock) for machineability and also to brass, copper and bronze for the same reason. It makes the cutting tools cut like butter.

One of purchasing guys decided he'd help out the guys in the shop and told the casting company to double the lead in the bronze castings (without any concern for material strength etc).

I was talking to the owner of the foundry and he said he had to back off on the lead as his WHOLE workforce got severe lead poisoning from breathing the vapors. And this was a large foundry.

My point of this post is, when you guys are pouring lead, don't do it in a confined area and preferably use some kind of a mask. No kidding! If you don't realize how bad lead poisoning can be read this... The workers in the foundry all had these symptoms!

Quote:
Occupational Lead Poisoning

KEVIN C. STAUDINGER, M.D., M.P.H., Baptist Health Centers, Inc., Birmingham, Alabama

VICTOR S. ROTH, M.D., M.P.H., University of Alabama at Birmingham School of Medicine, Birmingham, Alabama

Am Fam Physician. 1998 Feb 15;57(4):719-726.

See related patient information handout on coronary artery disease, written by the authors of this article.


The continued occurrence of occupational lead overexposure and lead poisoning in the United States remains a serious problem despite awareness of its adverse health effects. Lead exposure is arguably the oldest known occupational health hazard. It is a particularly insidious hazard with the potential for causing irreversible health effects, including hypotension, central nervous system problems, anemia and diminished hearing acuity before it is clinically recognized. Scientific evidence of subclinical lead toxicity continues to accumulate, making further reduction in workplace exposure, regular screening, and earlier diagnosis and treatment of critical importance in the prevention of this occupational hazard. For the most part, the diagnosis of lead poisoning in the adult worker is based on the integration of data obtained from the history, a physical examination, laboratory tests and tests of specific organ function. A blood lead level of 40 μg per dL (1.95 μmol per L) or greater requires medical intervention; a level of 60 μg per dL (2.90 μmol per L) or three consecutive measurements averaging 50 μg per dL (2.40 μmol per L) or higher indicate the necessity for employee removal. The decision to initiate chelation therapy is not based on specific blood lead levels but depends on the severity of clinical symptoms.

Occupational lead poisoning has been a recognized health hazard for more than 2,000 years. Characteristic features of lead toxicity, including anemia, colic, neuropathy, nephropathy, sterility and coma, were noted by Hippocrates and Nikander in ancient times, as well as Ramazzini and Hamilton in the modern era.1 Physicians have gained an extensive understanding of the causes, the clinical presentations and the means of preventing lead poisoning. However, it remains one of the most important occupational and environmental health problems.2

Lead serves no useful biologic function in the human body. Over the past several years, concern has increased over the health effects of low-level lead exposure and the “normal” body burden of lead. In the occupational setting, the present “no-effect” level for lead exposure is currently being reevaluated as more sensitive measures of the physiologic effects of lead are made available through clinical investigations.3 Based on current knowledge of the health effects of lead in adults, the U.S. Public Health Service has declared a health objective for the year 2000: the elimination of all exposures that result in blood lead concentrations greater than 25 μg per dL (1.20 μmol per L) in workers.4

Occupational Exposure and the OSHA Lead Standard

Lead and lead compounds play a significant role in modern industry, with lead being the most widely used nonferrous metal.5 A wide variety of industrial populations is at risk of occupational exposure to lead (Table 1). According to estimates made by the National Institute of Occupational Safety and Health (NIOSH), more than 3 million workers in the United States are potentially exposed to lead in the workplace. Occupational exposure to lead in general industry is regulated by the 1978 Occupational Safety and Health Administration (OSHA) Lead Standard. The general industry standard specifies permissible limits on airborne lead exposure, as well as blood lead levels (Table 2). A construction standard, recently extended to cover workers in the construction industry, has slight differences in detail. However, enforcement of both standards is inadequate, and significant occupational exposure remains widespread.6

TABLE 1
Major Occupations and Industries Associated with Lead Overexposure
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Battery manufacturing




Chemical industry




Construction workers




Demolition workers




Firing-range instructors




Foundry workers




Gas-station attendants




Gasoline additives production




Jewelers




Lead miners




Lead smelters and refiners




Pigment manufacturing




Pipe fitters




Plastics industry




Pottery workers




Printers




Radiator repair




Rubber industry




Soldering of lead products




Solid waste production




Stained-glass makers




Welders
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