Agent Name

Radium

CAS Number

7440-14-4

Formula

Ra

Major Category

Physical/Radiation

Synonyms

Radium and compounds;

Category

Radionuclides

Description

Brilliant, white metal that blackens on exposure; Melting point = 700 degrees C. [Merck Index]

Sources/Uses

Used in cancer treatment and industrial radiography; [Merck Index]

Comments

In the first quarter of the 20th century, watch dial painters ingested small amounts of radium in the luminous paint. Mortality studies showed increased rates of bone-related cancers in these workers. [Sullivan, p. 757-8] There is sufficient evidence that ingestion of radium-228 causes bone sarcomas and that ingestion of radium-226 causes bone sarcomas and carcinomas of the paranasal sinuses and mastoid processes. [IARC] Most Important Radionuclide: Ra-226 Source: Decay product of U-238 decay series; Half-Life: 1600 years Effective Half-Life: 44 years Specific Activity: 1 Ci/gm Decay Mode: Alpha GI Absorption: 20% Lung Clearance Half-Time: Weeks Critical Organ: Bone Internal Toxicity: Very High Annual Limit on Intake: 0.0006 mCi Radiation Energy (MeV): Alpha 4.78 (95%); Gamma 0.186 (4%) + daughters; Radiation Accidents: Ingestion of 2 mCi of radium bromide resulted in death 4 years later; Two incidents of "Meltings of Radioactive Materials"; [See Glossary for references.] See "Radiation, ionizing."

Restricted

No longer used in luminous paints for watch dials;

Reference Link

Radium | Radiation Protection Program | US EPA

Exposure Assessment
Reference Link

ATSDR - ToxFAQs - Radium

Adverse Effects
IARC Carcinogen

Known Carcinogen

NTP Carcinogen

Human Carcinogen

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

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Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent: