Accession Number : ADA292666

Title :   Environmental Effects of Dredging. New Technique for Sediment/Organism Equilibrium Partitioning Studies.

Descriptive Note : Technical notes,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Personal Author(s) : McFarland, Victor A. ; Feldhaus, Jane ; Ace, Louis N. ; Brannon, James M.

PDF Url : ADA292666

Report Date : DEC 1992

Pagination or Media Count : 11

Abstract : Equilibrium partitioning (EqP) studies on bioaccumulation of organic chemicals in aquatic organisms typically require long-term exposures. In the case of highly hydrophobic neutral organic chemicals, such as polychiorinated biphenyls (PCBs), dioxins, and dibenzofurans, exposures of up to 6 months have been used (Pruell and others 1990). During long-term laboratory exposures, changes can occur in the condition of both organism and sediment. Sediments can be depleted of the bioavailable fraction of chemical, thereby reducing exposure. Nutrient quality and amount may decline and sublethal toxicity may occur, affecting the health of organisms and causing loss of lipids. Metabolic degradation of bioaccumulating chemicals may occur in long-term exposures, reducing bioaccumulation. Induction of metabolizing enzymes caused by the chemical under investigation or by other chemicals in the sediment may exacerbate this effect. Growth during the exposure period can dilute tissue concentrations causing reduced apparent bioaccumulation. Spawning and other seasonal changes also affect bioaccumulation (Lee and others 1989).

Descriptors :   *CONTAMINATION, *AQUATIC ORGANISMS, *DREDGING, *SEDIMENTS, CHEMICALS, NEUTRAL, HEALTH, TOXICITY, ENZYMES, LIPIDS, NUTRIENTS, ENVIRONMENTAL IMPACT, QUALITY, LETHALITY, LOSSES, HYDROPHOBIC PROPERTIES, CATABOLISM, DIOXINS, BIPHENYL.

Subject Categories : Biology
      Civil Engineering
      Solid Wastes Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE