Agent Name

Lead

CAS Number

7439-92-1

Formula

Pb

Major Category

Metals

Synonyms

Plumbum; [NIOSH] Lead and inorganic compounds, as Pb; [ACGIH]

Category

Lead Compounds, Inorganic

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]

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; In a 2003 survey of industries using lead in New Jersey, 83% of lead was used to make automotive batteries. The second highest use was metal production (primary and scrap recycling). The third was cable and wire production. The fourth was making leaded compounds in plastics, pastes, and caulks. [PMID 17558800] The highest proportion of adults with high blood leads are employed in manufacturing (72%), construction (14%), and mining (6%). Nonoccupational exposures account for 4% of high blood leads (shooting firearms, remodeling, painting, retained bullets, and lead casting. [Reference #2]

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] Heavy lead exposure causes anemia; Lead inhibits hemoglobin synthesis (ALAD and other enzymes), and also shortens lifespan of RBCs with resulting hemolysis. [Nordberg, p. 621] Exposure to high air concentrations of lead can precipitate hemolytic anemia. [LaDou, p. 213] 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.

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]

Reference Link

ATSDR Case Studies - Lead Toxicity

Exposure Assessment
BEI

Lead in blood = 30 ug/100 ml; sampling time not critical;

Skin Designation (ACGIH)

Insufficient data

Bioaccumulates

Yes

TLV (ACGIH)

0.05 mg/m3, as Pb

Excerpts from Documentation for IDLHs

Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for lead compounds.

Explanatory Notes

Melting Point = 621 degrees F;

Half Life

Blood: 1-3 months; whole body: 5 years; [TDR, p. 790]

Reference Link

Adult Blood Lead Epidemiology and Surveillance United States, 20082009

Adverse Effects
Nephrotoxin

Yes

Reproductive Toxin

Yes

Neurotoxin

Motor Neuropathy

Hepatotoxin

Hepatotoxin, Secondary

IARC Carcinogen

Probable Carcinogen

NTP Carcinogen

Anticipated Human Carcinogen

ACGIH Carcinogen

Confirmed Animal

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: