Heavy metal

Description

An ambiguous term that has been defined as follows:

1) The most common definition is used for any metal with a specific gravity greater than 5.0. This includes Nickel, Lead, Zinc, Mercury, Arsenic, Manganese, Chromium, etc. These metals form water-insoluble salts that can accumulate in the environment. Of particular concern are the highly poisonous metals, such as lead, arsenic, and mercury.

2) Any metal with an atomic weight greater than sodium. This less common definition adds to the list some non-toxic metals such as Aluminum, Barium, Strontium, Titanium, etc.

Synonyms and Related Terms

metal pesado (Esp.); métal dense (Fr.;); Schwermetall (Deut.); metal denso (Port.)

Sources Checked for Data in Record

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998