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Semipermeable membrane devices (SPMD) and polar organic chemical integrative samplers (POCIS) were exposed to a cocktail of organic chemicals using a flow-through system. Samplers were removed and analyzed every 7 d over a four-week period in order to determine sampling rates (Rs) for individual compounds. Prior to laboratory exposure, half of the samplers were allowed to foul naturally for six weeks, in order to examine differences in uptake due to fouling. The amount of fouling ranged from 0.2 to 2.8 g dry weight/dm2 for POCIS and 0.1 to 1.4 g dry weight/dm2 for SPMDs, and the pattern of accumulation was also different between them. The Rs values were determined by fitting curves to time course uptake data and also by using performance reference compounds (PRCs) for SPMDs. Sampling rates ranged from 2.7 to 14.2 L/d for SPMDs and 0.01 to 0.27 L/d for POCIS. Fouled SPMDs showed a reduction in Rs (<20%) for all but one compound, and there was a similar reduction in the release of PRCs. However, PRC-predicted R, values were overall somewhat higher than those from fitted curves. Uptake of alkylated phenols in POCIS was generally higher (up to 55%) in fouled samplers. The reason for this is not known, but is possibly due to some reduction in interactions with the membrane in fouled samplers. There was no overall pattern in the relationship of sampling rate differences with log Kow or over time for either sampler. Release of compounds from POCIS after a drop in exposure water concentrations provides some encouragement for the application of a PRC approach to polar passive samplers.

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The uptake characteristics of semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCISs) were examined for mono, di and tributyltin, triphenyltin, pyrene, benzo[a]pyrene, 4-tert-butylphenol, 4-n-nonylphenol, PCBs 77 and 153, PBDE 47, lindane, triclosan and DDT. Exposure in a flow through system continued for 28 days with samplers removed every 7 days in order to study the relevant uptake kinetics. Uptake remained linear for POCISs with sampling rates (Rs) of up to 0.2 L d(-1). For SPMDs uptake varied from linear to approaching equilibrium with Rs values of up to 14 L d(-1). 7 out of 9 results for SPMDs could be explained by an empirical model (nonylphenol and lindane were exceptions). None of the four organo-tin compounds studied were detected in POCISs and only tributyltin was accumulated significantly by SPMDs. The establishment of these sampling rates allows the calculation of time weighted water concentrations for several important contaminants. Using presented methods, sampling rates and exposure conditions, theoretical detection limits for selected compounds by SPMDs were between 11-68 pg L(-1), which is well below the environment quality standard proposed for those compounds that are included in the European Water Framework Directive.

Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized.