Humic substances reduce bioavailability and toxicity of contaminants

Conference · Thu Jan 01 00:00:00 EST 1987

OSTI ID:6497530

McCarthy, J F

The role of humic substances in the aquatic environment on the availability and toxicity of organic and inorganic contaminants is reviewed. Organic contaminants associated with humics appear to be essentially unavailable for uptake by amphipods, daphnids, and fish. Acute toxicity of these compounds is also diminished proportionally. Since the affinity of organic solutes for binding to humics is related to their hydrophobicity, the effect of humics is significant only for compounds with octanol-water partition coefficients >10/sup 4/. In most cases, association of toxic metals with humics reduces the uptake and toxic effects of the contaminants. However, complex interactions among the toxicants, humic ligands, other transition metals and major cations in solution, and the carrier proteins on biological membranes make it difficult to generalize and predict any reduction in accumulation and toxicity of metals. Humic substances may have secondary effects on uptake and accumulation of toxicants by biota through their role in altering the transport and fate of pollutants.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6497530
• Report Number(s): CONF-870410-24; ON: DE87009816
• Resource Relation: Conference: 193. national meeting of the American Chemical Society, Denver, CO, USA, 5 Apr 1987; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
54 ENVIRONMENTAL SCIENCES
HUMIC ACIDS
CHEMICAL PROPERTIES
TOXIC MATERIALS
BIOLOGICAL AVAILABILITY
AQUATIC ECOSYSTEMS
INORGANIC COMPOUNDS
METALS
ORGANIC COMPOUNDS
RESPONSE MODIFYING FACTORS
UPTAKE
ECOSYSTEMS
ELEMENTS
MATERIALS
ORGANIC ACIDS
560300* - Chemicals Metabolism & Toxicology
510200 - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)