Acute Toxicities of Organic Chemicals to Fathead Minnows (Pimephales promelas) Volume III

Abstract

Acute toxicity values for aquatic life continue to be useful for pre­liminary assessment of the potential for harm in the environment by chemicals. The end-point for an Lc50 (concentration of chemical necessary to kill 50 per­ cent of the test organisms in a specified time limit) is rigorous and defini­tive. This end-point lends itself well to comparative testing and is useful in preliminary screening for hazardous chemicals. The literature contains many papers dealing with acute toxicity to aquatic organisms. The Aquatic Information Retrieval (AQUIRE) data base, for example, presently contains information on approximately 4,600 chemicals using 2,245 test species (Anne Pilli, personal communication).1 These species include various fresh and saltwater organisms from fungi to fish. The Columbia National Fisheries Research Laboratory data base (Johnson and Finley, 1980) contains acute toxicity test results for 271 chemicals using 58 aquatic species of test organisms. The large data bases contain data gleaned from the literature and derived from diverse test conditions. In contrast, the data base presented here is derived using standardized conditions of chemical exposure and a single test species. (fathead minnow, Pimephales promelas) of a given age class (26 to 37 day old juveniles at start of exposures). All tests have been conducted using either Lake Superior water or water from the municipal supply for the City of Superior, Wisconsin, which is derived from wells beneath Lake Superior and is very similar in its natural chemical characteristics to Lake Superior water. Volume III adds 151 tests to the data base, bringing the total number of tests to 500 and the number of chemicals tested to 425. New chemical classes are contained in this volume which are not in Volumes I and II. Testing is still underway for many new chemicals and chemical classes. The results of these tests will be reported in future volumes.