| Agent Name |
Lead |
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| CAS Number |
7439-92-1 |
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| Formula |
Pb |
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| Major Category |
Metals |
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| Synonyms |
Plumbum; [NIOSH] |
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| Category |
Elements, Metallic |
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| Description |
A heavy, ductile, soft, gray solid; Inorganic lead includes lead oxides, metallic lead, and lead salts (including organic salts such as lead soaps but excluding lead arsenate). [NIOSH] |
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| Sources/Uses |
MINING OR SMELTING: Produce lead fume by primary or secondary smelting--includes brass, copper, and lead foundries and scrap metal recycling operations; MANUFACTURING: Lead-acid battery; crystal glass; lead joints/babbitt; pewter; fishing weights; leaded or stained glass; paint and ink; leaded plastics; ammunition; electronic components (ceramic coated capacitors and resistors); electrical components using fritted glass; lead pipe, sheet, solder, type metal, cable shielding, or anodes; ceramics (mix glaze & fire kiln); mix and weigh lead powders; USING: Weld, cut, braze, grind, sand or blast old paint: houses and buildings (painted before 1978); bridges; ships; steel towers; water, petroleum or underground tanks; Produce lead fume or dust by heating, machining, or spraying lead products; radiator repair; firing ranges; |
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| Comments |
At blood lead levels above 90 ug/dl, poisoning can cause acute lead encephalopathy. Peripheral neuropathy results from levels above 60 ug/dl, and nerve conduction delays have been measured at levels as low as 30 ug/dl. [ACGIH: BEI Documentation] Exposure to high air concentrations of lead can precipitate hemolytic anemia. [LaDou, p. 217] At blood levels above 50-60 ug/dl, suppression of heme synthesis causes anemia. [Rom, p. 978] Lead-exposed workers may develop proximal renal tubular damage and progressive renal insufficiency. [Rom, p. 966] Lead can produce slight hepatic injury in experimental animals. [Zimmerman, p. 419] There is strong positive data associating lead exposure with spontaneous abortions and prematurity in pregnant women, neurological dysfunction in children and decreased sperm counts in men. [ATSDR Case Studies #29] The OSHA standard requires periodic determination of blood lead in workers exposed at or above action level (30 ug/m3) for more than 30 days per year. [ATSDR ToxProfiles] About 90% of pre-1940 homes contain lead-based paints, while about 60% of 1960-1979 homes contain significant amounts of lead in paint. The use of lead piping and lead solder in plumbing has been prohibited since 1986. [Coluccio VM. Lead-Based Paint Hazards. Wiley, John & Sons; 1997, p. 8-15] Inorganic lead compounds are probable human carcinogens. Organic lead compounds are not classifiable. [IARC] In contrast to inorganic lead, organic compounds are absorbed readily through the skin and into the CNS. [Sullivan, p. 979] Tetraethyl & tetramethyl lead (CAS # 78-00-2 & 75-74-1) are covered separately. |
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| Restricted |
Organic lead was added to gasoline in the US until January 1996. Lead allowable in US paint was reduced to 1% in 1971 and to 0.006% in 1977. [ATSDR Case Studies, Lead Toxicity] |
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| Reference Link |
ATSDR - Index, Lead Toxicity Case Study |
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| Exposure Assessment |
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| BEI |
Lead in blood = 30 ug/100 ml; sampling time not critical; |
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| Skin Designation (ACGIH) |
No |
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| Bioaccumulates |
Yes |
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| TLV (ACGIH) |
0.05 mg/m3 |
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| PEL (OSHA) |
0.05 mg/m3 |
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| IDLH (NIOSH) |
100 mg/m3 |
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| Excerpts from Documentation for IDLHs |
Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for lead compounds. |
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| Explanatory Notes |
Melting Point = 621 degrees F; |
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| Half Life |
Blood: 1-3 months; whole body: 5 years; [TDR, p. 790] |
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| Reference Link |
ATSDR - ToxFAQs - Lead |
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| Adverse Effects |
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| Anemia |
Anemia, Hemolytic |
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| Neurotoxin |
Motor Neuropathy |
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| Hepatotoxin |
Hepatotoxin, Secondary |
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| Nephrotoxin |
Yes |
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| Reproductive Toxin |
Yes |
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| IARC Carcinogen |
Probable Carcinogen |
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| Links to Other NLM Databases |
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| Health Studies |
Human Health Effects from Hazardous Substances Data Bank: LEAD, ELEMENTAL
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