Record Display for the EPA National Library Catalog
RECORD NUMBER: 9 OF 55| Main Title | Comparison of static-replacement and flow-through bioassays using duckweed 'Lemna gibba' G-3 / | |||||||||||||||||||||
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| Author | Davis, John A. | |||||||||||||||||||||
| CORP Author | Breedlove Associates, Inc., Gainesville, FL.;Environmental Protection Agency, Washington, DC. Office of Pesticides and Toxic Substances. | |||||||||||||||||||||
| Publisher | U.S. Environmental Protection Agency, Office of Pesticides and Toxic Substances, available from NTIS, | |||||||||||||||||||||
| Year Published | 1981 | |||||||||||||||||||||
| Report Number | EPA 560/6-81-003; EPA-68-01-5776 | |||||||||||||||||||||
| Stock Number | PB81-187650 | |||||||||||||||||||||
| OCLC Number | 18439092 | |||||||||||||||||||||
| Subjects | Lemna--Analysis ; Duckweeds ; Lemnaceae | |||||||||||||||||||||
| Additional Subjects | Toxicology ; Bioassay ; Comparison ; Mortality ; Reproduction(Biology) ; Data processing ; Cost analysis ; Cresols ; Chlorine organic compounds ; Ethylene glycol ; Duckweed ; Lemna gibba ; Toxic substances ; Water pollution effects(Animals) ; Copper sulfate ; TCP 2-4-6 herbicide ; Phenol/trichloro ; Phthalic acid/bis(ethylhexyl-ester) | |||||||||||||||||||||
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| Collation | xi, 92 p. ; ill. : 28 cm. | |||||||||||||||||||||
| Abstract | Static-replacement and flow-through tests were conducted using CuSO4.5H2O, 2,4,6-trichlorophenol, and o-cresol to determine if they gave similar LC50's and EC50's for duckweed, Lemna gibba G-3. Static-replacement tests also were conducted using ethylene glycol and di(2-ethylhexyl) phthalate. Mortality, reproduction, dry weight, and root length were used to measure effect levels of the toxicants. LC50's and EC50's were calculated using quadratic regression with log transformation of the independent variable (concentration) and with several different transformations for the dependent variables. ANOVA's were used to test for differences between the two types of tests, tests within types, and replicates within tests. A procedure also was provided for estimating the number of tests and replicates necessary to obtain confidence limits within a given percentage of the mean. Mortality and reproduction produced the best results. The highest variation occurred among tests, regardless of type, and the smallest variation was generally within tests (i.e. among replicates). Therefore, the best allocation of resources would be to replicate static-replacement tests in time, using four replicates per test. |
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| Notes | "EPA 560/6-81-003, PB81-187650." "January, 1981." |
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| Contents Notes | Static-replacement and flow-through tests were conducted using CuSOb4s ยจ 5Hb2sO, 2,4,6-trichlorphenol, and o-cresol to determine if they gave similar LC50's and EC50's for duckweed, Lemna gibba G-3. Static-replacement tests also were conducted using ethylene glycol and di(2-ethylhexyl)phthalate. Mortality, reprotduction, dry weight, and root length were used to measure effect levels of the toxicants. LC50's and EC50's were calculated using quadratic regression with log transformation of the independent variable (concentration) and with the following transformations for the dependent variables: arc sin square root of the proportion (p) of dead to total fronds on Day 7 (mortality), a log function yielding a growth rate constant K (reproduction), logb10s dry weight and arc sin square root of the ratio of dry weight to control weight (dry weight), and logb10s of root length. ANOVA's were used to test for differences between the two types of tests, tests within types, and replicates within tests. A procedure also was provided for estimating the number of tests and replicates necessary to obtain confidence limits within a given percentage of the mean. |