title: Prospective Environmental Risk Assessment for Sediment-Bound Organic Chemicals: A Proposal for Tiered Effect Assessment.
abstract: A broadly accepted framework for prospective environmental risk assessment (ERA) of sediment-bound organic chemicals is currently lacking. Such a framework requires clear protection goals, evidence-based concepts that link exposure to effects and a transparent tiered-effect assessment. In this paper, we provide a tiered prospective sediment ERA procedure for organic chemicals in sediment, with a focus on the applicable European regulations and the underlying data requirements. Using the ecosystem services concept, we derived specific protection goals for ecosystem service providing units: microorganisms, benthic algae, sediment-rooted macrophytes, benthic invertebrates and benthic vertebrates. Triggers for sediment toxicity testing are discussed.We recommend a tiered approach (Tier 0 through Tier 3). Tier-0 is a cost-effective screening based on chronic water-exposure toxicity data for pelagic species and equilibrium partitioning. Tier-1 is based on spiked sediment laboratory toxicity tests with standard benthic test species and standardised test methods. If comparable chronic toxicity data for both standard and additional benthic test species are available, the Species Sensitivity Distribution (SSD) approach is a more viable Tier-2 option than the geometric mean approach. This paper includes criteria for accepting results of sediment-spiked single species toxicity tests in prospective ERA, and for the application of the SSD approach. We propose micro/mesocosm experiments with spiked sediment, to study colonisation success by benthic organisms, as a Tier-3 option. Ecological effect models can be used to supplement the experimental tiers. A strategy for unifying information from various tiers by experimental work and exposure-and effect modelling is provided.
authors.affiliation: Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, 47, 6700 AA, Wageningen, The Netherlands. noel.diepens@wur.nl.
authors.forename: Noël J
authors.initials: NJ
authors.lastname: Diepens
authors.affiliation: Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, 47, 6700 AA, Wageningen, The Netherlands.|IMARES, Institute for Marine Resources & Ecosystem Studies, Wageningen UR, 68, 1970 AB, IJmuiden, The Netherlands.
authors.forename: Albert A
authors.initials: AA
authors.lastname: Koelmans
authors.affiliation: Environmental Risk Assessment Team, Alterra, 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Baveco
authors.affiliation: Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, 47, 6700 AA, Wageningen, The Netherlands.|Environmental Risk Assessment Team, Alterra, 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van den Brink
authors.affiliation: IMARES, Institute for Marine Resources & Ecosystem Studies, Wageningen UR, 68, 1970 AB, IJmuiden, The Netherlands.
authors.forename: Martine J
authors.initials: MJ
authors.lastname: van den Heuvel-Greve
authors.affiliation: Environmental Risk Assessment Team, Alterra, 47, 6700 AA, Wageningen, The Netherlands.
authors.forename: Theo C M
authors.initials: TCM
authors.lastname: Brock
mesh_terms: D000818:Animals; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry*; D009930:Organic Chemicals / Q000633:toxicity*; D011446:Prospective Studies; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Benthic organisms; Exposure and effect modelling; Microcosms; Sediment ecotoxicology; Sediment-spiked toxicity tests; Species sensitivity distributions