Chemical bioavailability in terrestrial environments
Date
2008
Authors
Naidu, R.
Bolan, N.S.
Megharaj, M.
Juhasz, A.L.
Gupta, S.K.
Clothier, B.E.
Schulin, R.
Editors
Hartemink, A.E.
McBratney, A.B.
Naidu, R.
McBratney, A.B.
Naidu, R.
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Book chapter
Citation
Source details - Title: Developments in soil science, 2008 / Hartemink, A.E., McBratney, A.B., Naidu, R. (ed./s), vol.32, pp.1-6
Statement of Responsibility
Conference Name
Abstract
This chapter discusses some basic concepts related to chemical bioavailability in terrestrial environments. Bioavailability refers to how much of a chemical is available to a living biota. The bioavailability of a chemical defines the relationship between the concentration of the chemical in the terrestrial environment and the level of the chemical that actually enters the receptor causing either positive or negative effect on the organism. Bioavailability is species-specific because the dose which reaches an organism's target organs or tissues, and results in a biological response, may vary among receptors. Chemical bioavailability is considered an important consideration in the environment because the availability of chemicals may be mitigated once the chemical comes in contact with the soil and sediment. For this reason, both fertility status of soils as well as risk assessment of contaminated sites requires quantification of chemical bioavailability much like any other parameter in a risk calculation. Concepts related to physicochemical factors influencing dissolution and precipitation into the mineral phase are introduced in this chapter. Precipitation is discussed as a commonly occurring process that controls the solubility of many elements including aluminum, iron, manganese, magnesium, and calcium. The sorption of a chemical onto soil that plays an important role in determining its bioaccessibility and subsequent bioavailability is also elaborated.