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.

Comparison of the uptake of polycyclic aromatic hydrocarbons and organochlorine pesticides by semipermeable membrane devices and caged fish (Carassius carassius) in Taihu Lake, China

“…One-com- partment models proposed by Huckins et al [14,17] can be used to derive most of these parameters. For example, the following model describes the first-order exponential uptake of HOCs by SPMDs and BMOs: …”

Estimation of the Uptake Rate Constants for Polycyclic Aromatic Hydrocarbons Accumulated by Semipermeable Membrane Devices and Triolein-Embedded Cellulose Acetate Membranes

“…In previous studies sampling rates of PSDs were usually estimated from the laboratory flow-through experiments (13,14,19). However, it is often difficult to maintain aqueous concentrations of chemicals sufficiently constant in a laboratory experiment.…”

Accurate quantification of freely dissolved organochlorine pesticides in water in the presence of dissolved organic matter using triolein-embedded cellulose acetate membrane

“…where t 1/2 is the first-order half-time of the uptake curve and a time of 4t 1/2 is needed to exceed 94% of steady-state concentrations [9]. If a matrix such as humic acid is present in the solution in a dissolved state, the uptake of the chemical by TECAM will be reduced due to the reduced freely dissolved fraction in the water phases, and considering that k u and k e are not affected by the presence of humic acid [14], Eq.…”

“…Several new techniques have been developed for this purpose in recent years and the triolein-containing semipermeable membrane device (SPMD) [6] and solid-phase microextraction (SPME) [7] are the two outstanding representatives among them. SPME was successfully used as an equilibrium sampling device owing to its relatively short equilibration time (hours to days) [8] and SPMD was generally used as an integrative sampler as it needs a long time to reach equilibrium (days to months) [9]. In aquatic systems where chemical concentrations often vary over time, it is particularly important to obtain time-weighted average (TWA) contaminant concentration as a fundamental part of the ecological risk assessment process.…”