ABSTRACT
The European Centre for Ecotoxicology and Toxicology of Chemicals proposes a tiered approach for the ecological risk assessment of endocrine disruptors, integrating exposure and hazard (effects) characterization. Exposure assessment for endocrine disruptors should direct specific tests for wildlife species, placing hazard data into a risk assessment context. Supplementing the suite of mammalian screens now under Organization for Economic Cooperation and Development (OECD) validation, high priority should be given to developing a fish screening assay for detecting endocrine activity in oviparous species. Taking into account both exposure characterization and alerts from endocrine screening, higher tier tests are also a priority for defining adverse effects. We propose that in vivo mammalian and fish assays provide a comprehensive screening battery for diverse hormonal functions (including androgen, estrogen, and thyroid hormone), whereas Amphibia should be considered at higher tiers if there are exposure concerns. Higher tier endocrine-disruptor testing should include fish development and fish reproduction tests, whereas a full life-cycle test could be subsequently used to refine aquatic risk assessments when necessary. For avian risk assessment, the new OECD Japanese quail reproduction test guideline provides a valuable basis for developing a test to detecting endocrine-mediated reproductive effects; this species could be used, where necessary, for an avian life-cycle test. For aquatic and terrestrial invertebrates, data from existing developmental and reproductive tests remain of high value for ecological risk assessment. High priority should be given to research into comparative endocrine physiology of invertebrates to support data extrapolation to this diverse fauna.
Subject(s)
Endocrine Glands/drug effects , Environmental Pollutants/toxicity , Amphibians , Animals , Animals, Wild , Ecosystem , Environmental Health , Environmental Monitoring/methods , Female , Fishes , Humans , Male , Mammals , Risk AssessmentABSTRACT
Two collaborative research projects were designed to develop and validate methods for determining the chronic effects of xenobiotics in freshwater ecosystems. The work reported here focuses on the development of methods for measuring effects on fish, invertebrates, and algae in outdoor artificial streams. 3,4-Dichloroaniline (3,4-DCA), has been used as a reference xenobiotic in two artificial stream experiments. The first used five stream channels: a control and treatments ranging from 70 to 2400 microg/liter. The second used eight stream channels--a control and treatments ranging from 0.45 to 4700 microg/liter and four coupled, 510-liter-capacity, downstream ponds-a control and treatments of 1.7, 37, and 820 microg/liter. Effects on the biota of the stream channels and the downstream ponds were examined using a range of sampling techniques and in situ toxicity tests.
