By Scott E. Belanger, Procter & Gamble
Animal Alternatives is an emerging discipline in environmental safety sciences. The historical emphasis on the development of non-animal testing methods for human safety is well known. The expectation is that large numbers of vertebrates (fish, amphibians, and birds) will be needed to satisfy the demand for environmental data accompanying large chemical management programs, such as the Organization for Economic Cooperation and Development (OECD) High Production Volume assessments, the Canadian categorization of the Domestic Substance List, and most recently the European Union REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) program (van der Jagt, et al., 2004).
A rapid increase in research interest and activity by environmental scientists is in motion to achieve the goals surrounding the 3Rs (replacement, reduction, and refinement) concept in environmental testing. A series of critical workshops and reports (Castano, et al., 2003; ECETOC, 2005) in the first half of the decade identified several fruitful areas for pursuit, which will be reviewed below with an almost exclusive eye on fish as the test organism.
Fish play a unique role in environmental safety sciences compared to other groups such as algae and invertebrates. This is due to their social and economic value, in addition to their key role in structuring aquatic ecosystems. Thus, fish are used as a test organism to understand acute and chronic toxicity of chemicals and effluent discharges; they form the basis of most assessments of environmental bioaccumulation of chemicals, and are a sentinel organism to assess endocrine disruption associated with environmentally dispersed chemicals. Numerous organizations have joined together to bring various research efforts into practical employment under existing national and international regulatory bodies to address these diverse endpoints. An additional facet of environmental assessment of contamination using fish is the fact that only a few species (< 20) can be cultured in the laboratory environment. These species have moderate to high sensitivity, and are used to model the more than 40,000 described species of fish from tropical to coldwater environments and freshwater to saltwater.
With this as background, the following are examples of programs where animal alternatives research is making a difference in fish testing:
OECD
- The OECD promulgated the Threshold Approach as an addendum to the OECD 203 Test Guideline (TG) for Acute Fish Toxicity: This test strategy is initially driven by knowledge of invertebrate and algal toxicity to establish an appropriate concentration to determine if fish are likely more or less sensitive. Jeram, et al. (2005) determined this approach could reduce fish use by 50-70% in REACH.
- The Fish Embryo Test is under evaluation and validation by an OECD expert group as a replacement to the fish acute toxicity test. Embryo and eleutheroembryo life stages are those in which the yolk sac is the sole source of food for the developing fish. Lammer, et al. (2009) demonstrated a near 1:1 relationship between the Fish Embryo Test and the OECD 203 TG for 5 of the most commonly used species. A validation program is being overseen by the European Centre for the Validation of Alternative Methods (ECVAM) and involves a collaboration of European and US laboratories representing industry, government, and academia.
- The goal for both of these methods is to retain at least the present level of certainty in environmental risk assessment, while reducing fish use or outright replacement.
European chemical industry efforts of European Chemical Industry Council Long-range Research Initiative (CEFIC LRI), European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC), and Environmental Risk Assessment and Management (ERASM)
- CELLSens Project to develop testing strategies incorporating cell-based assays: This initiative, consistent with recommendations from Castano, et al. (2003), has coordinated research from leading academic and research institutes across Europe. Detailed protocols are developed for a number of cell lines ranging from fish gill to liver and brain tissues. Strategic priority setting of chemicals to be assayed was outlined by Schirmer, et al. (2008).
- Tools to advance tiered testing strategies for bioaccumulation assessments has been the product of several years’ research by CEFIC, ECETOC, and ERASM. Notably, ILSI-HESI (International Life Sciences Institute-Health and Environmental Sciences Institute) has played an important strategy setting and coordinating role. New cellular and sub-cellular methods to understand biotransformation processes as a mitigating factor are in pre-validation with ECVAM as a partner organization (Weisbrod, et al., 2008).
In addition to the institutions and companies performing the actual research, several organizations are currently involved at various levels to assist these and other related environmental animal alternatives work. Among these are:
- ECVAM
- OECD Environmental Directorate
- ILSI-HESI
- SETAC (Society of Environmental Toxicology and Chemistry) Science Advisory Group on Environmental Animal Alternatives
- ECETOC
In the span of less than a decade, methods have already been elevated for consideration at OECD as draft or approved guidelines, or via ECVAM as validated methods. Much work remains to be done to provide the full breadth of endpoint coverage as well as consideration of amphibian and bird species. Another new challenge is the burgeoning interest in fish as models for higher vertebrates such as mammals used in human safety sciences. More is to be written on these fronts in the coming years.
References
Biography
©2009 Scott E. Belanger
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