Alternative approaches to vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status

Abstract

Abstract-The need for alternative approaches to the use of vertebrate animals for hazard assessment of chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimized wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments has been banned; in other situations, the number of organisms tested has been dramatically reduced or the severity of the procedure refined. However, there is still a long way to go to achieve a complete replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is based not just on ethical considerations but also on reducing the cost of performing vertebrate ecotoxicity tests and in some cases on providing better information aimed at improving environmental risk assessments. The present Focus article provides an overview of the considerable advances that have been made toward alternative approaches for ecotoxicity assessments over the last few decades. Environ Toxicol Chem 2016;35:2637-2646. # 2016 SETAC

Differential uptake of and sensitivity to diphenhydramine in embryonic and larval zebrafish

“…To specifically test this hypothesis among developmental stages, the FET was extended from its initial 48 h duration to include hatching (48-72 h) and the eleutheroembryo stage (96 h) [17,28]. To specifically test this hypothesis among developmental stages, the FET was extended from its initial 48 h duration to include hatching (48-72 h) and the eleutheroembryo stage (96 h) [17,28].…”

“…We examined whether uptake of diphenhydramine differed across embryo-larval stages of zebrafish. To specifically test this hypothesis among developmental stages, the FET was extended from its initial 48 h duration to include hatching (48-72 h) and the eleutheroembryo stage (96 h) [17,28]. We further examined uptake during older stages of 7 to 11 and 14 to 18 dpf because relationships for differential chemical uptake among embryo and larval stages and associated toxicity responses of zebrafish are not understood.…”

“…Significant hurdles exist for the production of such toxicology data sets because traditional whole-organism studies are costly, time-intensive, use elevated numbers of individuals, and are low-throughput [3,4]. Despite appreciable advancements, challenges and opportunities remain regarding its applicability domain and the translatability of produced data [5][6][7][8][9][10]. Despite appreciable advancements, challenges and opportunities remain regarding its applicability domain and the translatability of produced data [5][6][7][8][9][10].…”

“…One emerging model that satisfies the 3 Rs (reduction, refinement, replacement) for animal research and overcomes many challenges posed by traditional whole-organism toxicity test methods is the embryonic fish testing method with zebrafish, Danio rerio (Organisation for Economic Co-operation and Development [OECD] test guideline 236). Despite appreciable advancements, challenges and opportunities remain regarding its applicability domain and the translatability of produced data [5][6][7][8][9][10].…”

An International Perspective on the Tools and Concepts for Effluent Toxicity Assessments in the Context of Animal Alternatives: Reduction in Vertebrate Use

“…Fish are used in a range of ecotoxicological investigations of effluents, including acute toxicity, chronic toxicity, bioaccumulation, endocrine disruption, and instream monitoring of ecological status. Over the last decade, various testing strategies to reduce the use of fish in aquatic toxicity tests have been discussed in the context of the European Union's Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) legislation (European Commission ) or more recently in a broader Organisation for Economic Co‐operation and Development context (Lillicrap et al ). With the advent of restrictions placed on the use of protected stages of fish for testing in the European Union (Halder et al ), methods are needed to prevent a significant shortfall in the assessment of the potential effects of effluents and chemical mixtures in the environment.…”