Passive sampling methods for contaminated sediments: Practical guidance for selection, calibration, and implementation

This article provides practical guidance on the use of passive sampling methods (PSMs) that target the freely dissolved concentration (C-free) for improved exposure assessment of hydrophobic organic chemicals in sediments. Primary considerations for selecting a PSM for a specific application include clear delineation of measurement goals for C-free, whether laboratory-based ex situ and/or field-based in situ application is desired, and ultimately which PSM is best-suited to fulfill the measurement objectives. Guidelines for proper calibration and validation of PSMs, including use of provisional values for polymer-water partition coefficients, determination of equilibrium status, and confirmation of nondepletive measurement conditions are defined. A hypothetical example is described to illustrate how the measurement of C-free afforded by PSMs reduces uncertainty in assessing narcotic toxicity for sediments contaminated with polycyclic aromatic hydrocarbons. The article concludes with a discussion of future research that will improve the quality and robustness of C-free measurements using PSMs, providing a sound scientific basis to support risk assessment and contaminated sediment management decisions. Integr Environ Assess Manag 2014;10:210-223. (c) 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.