title: Passive sampling methods for contaminated sediments: state of the science for organic contaminants.
abstract: This manuscript surveys the literature on passive sampler methods (PSMs) used in contaminated sediments to assess the chemical activity of organic contaminants. The chemical activity in turn dictates the reactivity and bioavailability of contaminants in sediment. Approaches to measure specific binding of compounds to sediment components, for example, amorphous carbon or specific types of reduced carbon, and the associated partition coefficients are difficult to determine, particularly for native sediment. Thus, the development of PSMs that represent the chemical activity of complex compound-sediment interactions, expressed as the freely dissolved contaminant concentration in porewater (Cfree ), offer a better proxy for endpoints of concern, such as reactivity, bioaccumulation, and toxicity. Passive sampling methods have estimated Cfree using both kinetic and equilibrium operating modes and used various polymers as the sorbing phase, for example, polydimethylsiloxane, polyethylene, and polyoxymethylene in various configurations, such as sheets, coated fibers, or vials containing thin films. These PSMs have been applied in laboratory exposures and field deployments covering a variety of spatial and temporal scales. A wide range of calibration conditions exist in the literature to estimate Cfree , but consensus values have not been established. The most critical criteria are the partition coefficient between water and the polymer phase and the equilibrium status of the sampler. In addition, the PSM must not appreciably deplete Cfree in the porewater. Some of the future challenges include establishing a standard approach for PSM measurements, correcting for nonequilibrium conditions, establishing guidance for selection and implementation of PSMs, and translating and applying data collected by PSMs.
authors.affiliation: Center for Fisheries, Aquaculture and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lydy
authors.forename: Peter F
authors.initials: PF
authors.lastname: Landrum
authors.forename: Amy Mp
authors.initials: AM
authors.lastname: Oen
authors.forename: Mayumi
authors.initials: M
authors.lastname: Allinson
authors.forename: Foppe
authors.initials: F
authors.lastname: Smedes
authors.forename: Amanda D
authors.initials: AD
authors.lastname: Harwood
authors.forename: Huizhen
authors.initials: H
authors.lastname: Li
authors.forename: Keith A
authors.initials: KA
authors.lastname: Maruya
authors.forename: Jingfu
authors.initials: J
authors.lastname: Liu
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D009930:Organic Chemicals / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Bioavailability; Freely dissolved aqueous concentration; Organic contaminants; Passive sampling methods; Sediment-associated contaminants