Specifying the Dimensions of Aquatic Life Benchmark Values in Clear, Complete, and Justified Problem Formulations

Abstract

Nations that develop water quality benchmark values have relied primarily on standard data and methods. However, experience with chemicals such as Se, ammonia, and tributyltin has shown that standard methods do not adequately address some taxa, modes of exposure, and effects. Development of benchmark values that are protective requires an explicit description of the issues, a problem formulation. In particular, the assessment endpoints and other dimensions should be specified for each chemical so that the necessary data will be obtained and appropriate analyses will be performed. Assessment endpoints specify the entity and attribute to be protected. In addition, the level of protection, including the magnitude of effect and the proportion effected, is specified. Magnitude and proportion are included because they are used to calculate the benchmark concentration. If uncertainty is considered in the benchmark, the proportion of the uncertainty distribution that is protected should be specified. Because effects are related to the duration of exposure and time for recovery, temporal dimensions should be specified. Clearly described exposure metrics are also needed because the relevant exposure parameter is not always total aqueous concentration. Finally, the benchmark may be applicable to particular geographic or climatological areas, water chemistries, taxa, or habitat types. Considering and justifying all the dimensions is likely to result in protective and more easily communicated benchmarks. Integr Environ Assess Manag 2018;14:631-638. Published 2018. This article is a US Government work and is in the public domain in the USA.

Establishing Chronic Toxicity Effect Levels for Zebrafish (Danio rerio) Exposed to Perfluorooctane Sulfonate

“…The apical endpoints of survival, growth, and reproduction that are the focus of our review are typically used for regulatory screening criteria, providing quantitative benchmarks for decision‐making purposes at contaminated sites or point source evaluations (Conder et al, 2020; Environment and Climate Change Canada, 2018; Environment Protection Authority Victoria, 2017; National Institute for Public Health and the Environment [RIVM], 2010; Suter, 2018; USEPA, 2022). Studies evaluating any (or all) of these endpoints were selected if the exposure to PFOS was continuous and for a duration of at least 14 days because short‐term/acute studies in fish are generally considered to be less than 14 days in duration (Organisation for Economic Co‐operation and Development, 2012).…”

A Critical Review of Amphibian Per- and Polyfluoroalkyl Substance Ecotoxicity Research Studies: Identification of Screening Levels in Water and Other Useful Resources for Site-Specific Ecological Risk Assessments

“…A variety of biological effects were evaluated in the reviewed studies; however, this review focused on apical subacute, subchronic, or chronic responses on survival, growth, and development that are biologically relevant and assumed to cause population level effects. These endpoints are typically used for regulatory screening levels and decision-making purposes at contaminated sites (Conder et al, 2020;Environmental and Climate Change Canada, 2018;Environment Protection Authority of Victoria, Australia, 2016;National Institute for Public Health and the Environment, 2010;Suter, 2018;USEPA, 2022aUSEPA, , 2022b. Identification of dose-response relationships was considered in deriving no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) values in each dataset, following USEPA (2000) guidelines.…”