title: Overview and comparison of lipid-containing semipermeable membrane devices and oysters (Crassostrea gigas) for assessing organic chemical exposure.
abstract: We performed 20-d, flow-through exposures of lipid-containing semipermeable membrane devices (SPMDs) and Pacific oysters (Crassostrea gigas) to three concentrations (nominally 10, 100, and 250 ng/L) of a diverse mixture of polycyclic aromatic hydrocarbons (PAHs). Exposure water was seawater free of particulates larger than 0.1 microm. The results of these controlled laboratory studies demonstrated that SPMDs and oysters concentrate the same chemicals but that the relative amounts accumulated are different. For oysters, the 20-d mean (across treatments) concentration factors (CFs) of test compounds with log Kow < or = 4.8 were much lower (4.0- to 20-fold lower) than those of the same compounds in SPMDs. In contrast, the 20-d CFs of PAHs with log Kow > or = 5.6 in oysters from the low-level treatment were higher than the corresponding CFs for SPMDs. The CFs of these compounds in oysters from the low-level treatment ranged from approximately 3.0- to 13-fold higher than those in oysters from the high-level treatment. This physiologically mediated difference in oyster CFs appears to be linked to active feeding in the low-level treatment and to apparent toxicity-induced cessation of feeding (i.e., valve closure) in the high-level treatment. Because CFs for these compounds in oysters were not independent of exposure concentrations, it follows that tissue levels were not proportional to exposure concentration. However, both sampling approaches have advantages and disadvantages, and the appropriateness of their use depends on the goals of a given study.
authors.affiliation: U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, Missouri 65201, USA. jhuckins@usgs.gov
authors.forename: James N
authors.initials: JN
authors.lastname: Huckins
authors.forename: Harry F
authors.initials: HF
authors.lastname: Prest
authors.forename: Jimmie D
authors.initials: JD
authors.lastname: Petty
authors.forename: Jon A
authors.initials: JA
authors.lastname: Lebo
authors.forename: Maureen M
authors.initials: MM
authors.lastname: Hodgins
authors.forename: Randal C
authors.initials: RC
authors.lastname: Clark
authors.forename: David A
authors.initials: DA
authors.lastname: Alvarez
authors.forename: William R
authors.initials: WR
authors.lastname: Gala
authors.forename: Alexis
authors.initials: A
authors.lastname: Steen
authors.forename: Robert
authors.initials: R
authors.lastname: Gale
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Ingersoll
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D005247:Feeding Behavior; D007700:Kinetics; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D009930:Organic Chemicals / Q000032:analysis*; D010125:Ostreidae / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D013048:Specimen Handling; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D008055:Lipids; D008567:Membranes, Artificial; D009930:Organic Chemicals; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical