periodically re-registered. Because a significant number of new and 

 registered pesticides may contaminate aquatic ecosystems, chronic or 

 partial chronic tests provide an important intermediate measure of relative 

 hazard between simple acute toxicity tests and costly experimental field 

 trials. Within practical limits such studies can be adapted to include 

 simulation of various general aquatic habitats, and timing and concentra- 

 tion of exposures can be controlled to approximate proposed or recommended 

 uses. In addition, chronic test systems offer a unique opportunity to con- 

 duct concurrent or parallel studies of residue dynamics and physiological, 

 biochemical, and pathological effects that can be linked to growth and re- 

 productive effects in primary chronic tests. 



SUMMARY 



Requirements for registration, re-registration, and classification of 

 pesticides for general or restricted use were published recently by the EPA. 

 If the pesticide is intended for outdoor uses, data must generally be sub- 

 mitted that permit evaluation of hazards to non-target animals, including 

 fish and wildlife. Depth of these evaluations depends on proposed patterns 

 of use, environmental chemistry characteristics, and nature of the hazard 

 to humans, domestic animals, and non-target animals. Data to support regis- 

 tration can be obtained from acute and chronic or partial chronic toxicity 

 studies, simulated field tests, or field monitoring and observation, as des- 

 cribed in the extensive registration guidelines recently proposed by EPA. 

 Chronic testing techniques and apparatus, with controllable light and 

 temperature, offer versatile systems for investigating effects of pesti- 

 cides and other contaminants on fish according to daily and seasonal 

 periodicity and simulated pesticide-use patterns. 



REFERENCES 



Day, K. 1973. Toxicology of pesticides: Recent advances. Environ. Res. 

 6: 202-243. 



Fowler, D.L., and J.N. Mahan. 1973. The pesticide review. Agricultural 

 Stabilization and Conservation Service, U.S. Dep. Agric, Washington, 

 D.C. 60 p. 



Grant, B.F., and R.A. Schoettger. 1972. The impact of organochlorine 



contaminants on physiologic functions in fish. Proc. Tech. Sess. 18th 

 Ann. Meeting Inst. Environ. Sci . , New York City. p. 245-250. 



Henderson, C, W.L. Johnson, and A. Inglis. 1969. Organochlorine 



insecticide residues in fish (National Pesticide Monitoring Program). 

 Pest. Monit. J. 3: 145-171. 



Johnson, D.W. 1968. Pesticides and fishes--a review of selected litera- 

 ture. Trans. Am. Fish. Soc. 97: 398-424. 



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