ABSTRACT
The contamination of surface and subsurface environments via the anthropogenic and natural input of heavy metals has established the need to investigate and comprehend metal-soil interactions. The pathways for heavy metal introduction into soil and aquatic environments are numerous, and include the land application of sewage sludge and municipal composts, mine wastes, dredged materials, fly ash, and atmospheric deposits.1
In addition to these anthropogenic sources, heavy metals can be introduced to soils naturally as reaction products via the dissolution of metal-bearing minerals that are found in concentrated deposits. Of a thousand Superfund sites named in the U.S. Environmental Protection Agency’s National Priority List of 1986, 40% were reported to have elevated levels of heavy metals relative to background levels.2 The fate and mobility of these metals in soils and sediments are of concern because of potential bioaccumulation, food chain magnification, degradation of vegetation, and human exposure.3
