Standard Methods for the Examination of Water and Wastewater Part 8000 TOXICITY 8010 INTRODUCTION*#(1) 8010 A. General Discussion 1. Uses of Toxicity Tests Toxicity tests are desirable in water quality evaluations because chemical and physical tests alone are not sufficient to assess potential effects on aquatic biota.1-3 For example, the effects of chemical interactions and the influence of complex matrices on toxicity cannot be determined from chemical tests alone. Different species of aquatic organisms are not equally susceptible to the same toxic substances nor are organisms equally susceptible throughout the life cycle. Even previous exposure to toxicants can alter susceptibility. In addition, organisms of the same species can respond differently to the same level of a toxicant from time to time, even when all other variables are held constant. Toxicity tests are useful for a variety of purposes that include determining: (a) suitability of environmental conditions for aquatic life, (b) favorable and unfavorable environmental factors, such as DO, pH, temperature, salinity, or turbidity, (c) effect of environmental factors on waste toxicity, (d) toxicity of wastes to a test species, (e) relative sensitivity of aquatic organisms to an effluent or toxicant, (f) amount and type of waste treatment needed to meet water pollution control requirements, (g) effectiveness of waste treatment methods, (h) permissible effluent discharge rates, and (i) compliance with water quality standards, effluent requirements, and discharge permits. In such regulatory assessments, use toxicity test data in conjunction with receiving-water and site-specific discharge data on volumes, dilution rates, and exposure times and concentrations. 2. Test Procedures There is a need to use correct terminology (see Section 8010B, Terminology), and environmentally relevant test procedures to meet regulatory, legal, and research objectives.3-8 The procedures given below allow measurement of biological responses to known and unknown concentrations of materials in both fresh and saline waters. These toxicity tests are applicable to routine monitoring requirements as well as research needs. Refer to Part 9000 for microbiological methods and Part 10000 for field and other types of biological laboratory methods for water quality evaluations. Refer to Section 10900 for identification aids for aquatic organisms. Reasonable uniformity of procedures and of data presentation is essential. The use of standardized methods described below will ensure adequate uniformity, reproducibility, and © Copyright 1999 by American Public Health Association, American Water Works Association, Water Environment Federation Standard Methods for the Examination of Water and Wastewater general usefulness of results without interfering unduly with the adaptability of the tests to local circumstances. Quality assurance practices for toxicity test methods include all aspects of the test that affect the quality of the data. These include sampling and handling, source and condition of test organisms, performance of reference toxicant tests, and the test procedures themselves. Quality assurance/quality control guidelines are available for single compound testing and general laboratory practices9 and for effluent evaluations in technical guidance manuals for conducting acute and short-term chronic toxicity tests with effluents.10-12 3. References 1. U.S. ENVIRONMENTAL PROTECTION AGENCY. 1991. Technical Support Document for Water Quality-Based Control. EPA-505/2-90-001 (PB91-127415), Off. Water, U.S. Environmental Protection Agency, Washington, D.C. 2. U.S. ENVIRONMENTAL PROTECTION AGENCY. 1987. Permit Writer’s Guide to Water Quality-Based Permitting for Toxic Pollutants. Off. Water, U.S. Environmental Protection Agency, Washington, D.C. 3. GROTHE, D.R., K.L. DICKSON & D.K. REED-JUDKINS, eds. 1996. Whole Effluent Toxicity Testing: An Evaluation of Methods and Prediction of Receiving System Impacts. SETAC Pellston Workshop on Whole Effluent Toxicity, Sept. 16-25, 1995, Pellston, Mich. SETAC Press, Pensacola, Fla. 4. AMERICAN SOCIETY FOR TESTING AND MATERIALS. 1996. 1996 Annual Book of ASTM Standards, Section 11, Water and Environment Technology. Volume 11.04 Pesticides; Resources Recovery; Hazardous Substances and Oil Spill Responses; Waste Disposal; Biological Effects. American Soc. Testing & Materials, W. Conshohocken, Pa. 5. ORGANIZATION FOR ECONOMIC COOPERATION AND DEVELOPMENT. 1981. OECD Guidelines for Testing of Chemicals. Organization for Economic Cooperation and Development, Paris, France. 6. BERGMAN, H., R. KIMERLE & A.W. MAKI, eds. 1985. Environmental Hazard Assessment of Effluents. Pergamon Press, Inc., Elmsford, N.Y. 7. AMERICAN SOCIETY FOR TESTING AND MATERIALS. 1997. Standard Guide for Conducting Acute Toxicity Tests on Aqueous Effluents with Fishes, Macroinvertebrates, and Amphibians. ASTM -1192-97, American Soc. Testing & Materials, W. Conshohocken, Pa. 8. AMERICAN SOCIETY FOR TESTING AND MATERIALS. 1997. Standard Guide for Conducting Acute Toxicity Tests with Fishes, Macroinvertebrates, and Amphibians. ASTM E 729-96, American Soc. Testing & Materials, W. Conshohocken, Pa. 9. U.S. ENVIRONMENTAL PROTECTION AGENCY. 1987. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA); Good Laboratory Practice Standards. Proposed Rule. 40 CFR Part 160; Federal Register 52:48920. 10. WEBER, C.I., ed. 1993. Methods for Measuring the Acute Toxicity of Effluents and Receiving Water to Freshwater and Marine Organisms, 4th ed. EPA-600/4-90-027F, © Copyright 1999 by American Public Health Association, American Water Works Association, Water Environment Federation Standard Methods for the Examination of Water and Wastewater Environmental Monitoring Systems Lab., U.S. Environmental Protection Agency, Cincinnati, Ohio. 11. KLEMM, D.J., G.E. MORRISON, T.J. NORBERG-KING, W.H. PELTIER & M.A. HEBER, eds. 1994. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, 2nd ed. EPA-600/4-91-003, Environmental Monitoring and Support Lab., U.S. Environmental Protection Agency, Cincinnati, Ohio. 12. LEWIS, P.A., D.J. KLEMM, J.M. LAZORCHAK, T.J. NORBERG-KING, W.H. PELTIER & M.A. HEBER, eds. 1994. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwaters Organisms, 3rd ed. EPA-600/4-91-002, Environmental Monitoring Systems Lab., U.S. Environmental Protection Agency, Cincinnati, Ohio. 4. Bibliography RAND, G.M. & S.R. PETROCELLI, eds. 1985. Fundamentals of Aquatic Toxicology. Methods and Applications. Hemisphere, New York, N.Y. KLAASON, C.D., M.O. AMDUR & J. DOULL, eds. 1986. Casarett and Doull’s Toxicology, 3rd ed. Macmillan, New York, N.Y. 8010 B. Terminology An aquatic toxicity test is a procedure in which the responses of aquatic organisms are used to detect or measure the presence or effect of one or more substances, wastes, or environmental factors, alone or in combination. 1. General Terms Acclimate—to accustom test organisms to different environmental conditions, such as temperature, light, and water quality. Response—the measured biological effect of the variable tested. In acute toxicity tests the response usually is death or immobilization. In plant toxicity tests, the response can be death, growth inhibition, or reproductive inhibition. In biostimulation tests, the response is biomass increase. Control—treatment in a toxicity test that duplicates all the conditions of the exposure treatment but contains no test material. Range-finding test—preliminary test designed to establish approximate toxicity of a solution. Test design incorporates multiple, widely spaced, concentrations with single replicates; exposure is usually 8 to 24 h. Screening test—toxicity test to determine if an impact is likely to be observed; test design incorporates one concentration, multiple replicates, exposure 24 to 96 h. Definitive test—toxicity test designed to establish concentration at which a particular end point occurs. Exposures for these tests are longer than for screening or range-finding tests, © Copyright 1999 by American Public Health Association, American Water Works Association, Water Environment Federation Standard Methods for the Examination of Water and Wastewater incorporating multiple concentrations at closer intervals and multiple replicates. 2. Toxicity Terms Dose—amount of toxicant that enters the organism. Dose and concentration are not interchangeable. Toxicity—potential or capacity of a test material to cause adverse effects on living organisms, generally a poison or mixture of poisons. Toxicity is a result of dose or exposure concentration and exposure time, modified by variables such as temperature, chemical form, and availability. Exposure time—time of exposure of test organism to test solution. Acute toxicity—relatively short-term lethal or other effect, usually defined as occurring within 4 d for fish and macroinvertebrates and shorter times (2 d) for organisms with shorter life spans. Chronic toxicity—toxicity involving a stimulus that lingers or continues for a relatively long period of time, often one-tenth of the life span or more. ‘‘Chronic’’ should be considered a relative term depending on the life span of an organism. A chronic toxic effect can be measured in terms of reduced growth, reduced reproduction, etc., in addition to lethality. Lethal concentration (LCP)—toxicant concentration estimated to produce death in a specified proportion (P) of test organisms. Usually defined