Introduction to ENVIRONMENTAL TOXICOLOGY Impacts of Chemicals Upon Ecological Systems - CHAPTER 2 ppsx

... LLC CHAPTER 2 A Framework for Environmental Toxicology Environmental toxicology can be simplified to the understanding of only three functions. These functions are presented in Figure 2. 1. ... effects of a toxicant can range over a variety of temporal scales, so can the nature of the input of the toxicant to the system (Figure 2. 5). Household or Figure...

Ngày tải lên: 10/08/2014, 20:20

... repeatable laboratory data to effects upon the systems that environmental toxi- cology tries to protect is often called the lab -to- field dilemma. Comparisons of laboratory data to field results ... Aquat. Toxicol. 22 : 12 9-1 44. © 1999 by CRC Press LLC One of the primary reasons for conducting any type of toxicity test is to rank chemicals as to their toxicity....

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... Environ. Toxicol. Chem. 11: 147 7-1 483. Sugiura, K. 19 92. A multispecies laboratory microcosm for screening ecotoxicological impacts of chemicals. Environ. Toxicol. Chem. 11: 121 7-1 22 6. U.S. Environmental ... components of the microcosm com- munity. The protocol requires two species of single-celled green algae or diatoms, one species of filamentous green alga, one speci...

Ngày tải lên: 10/08/2014, 20:20

... liver to 25 -hydroxy-D 3 . This is then converted in the kidney to 1 ,25 -dihydroxy-D 3 , the “hormone-like” substance that is the active form of the vitamin. The 25 -hydroxyla- tion of cholecalciferol ... . 90: 61 5-6 22 . Brown, V.M. 1968. The calculation of the acute toxicity of mixtures of poisons to rainbow trout. Wat. Res . 2: 72 3-7 33. Calabrese,...

Ngày tải lên: 10/08/2014, 20:20

... amounts to 15 to 25 mg/day and represents two-thirds of the total absorbed Pb. By contrast, about 20 to 40% of the inhaled Pb is absorbed, amounting to about 8 mg/day, or one-third of the total absorbed ... coordination. The relative toxicity of various compounds toward tissue depends on their relative ease of for- mation of the Hg 2+ ion. The biological half-life...

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... DFP, dichlorvos and dimethyl 2, 2 , 2- trichloro-1-n-butyryloxyethyl phosphonate (butonate). Catfish enzymes also were able to hydrolyze paraoxon and methyl 3-hydroxy-alpha-cronate, dimethyl phosphate ... Mn 2+ . Tt DFPase-1, Tt DFPase- 2, and Tt DFPase-3 are only stimulated 2 to 4 fold, and part of this increase may be due to contamination by the higher molecular weight Tt DFPas...

Ngày tải lên: 10/08/2014, 20:20

... of the Ecological Effects of Toxicants INTRODUCTION This chapter deals with perhaps the most difficult topic in environmental toxi- cology, how to measure and then evaluate the impact of toxicants ... vector. Consumption vector for species A. is the sum of the vectors for the rate of consumption of resource 1 and resource 2. The consump- tion vector determines the path...

Ngày tải lên: 10/08/2014, 20:20

... Relationship of toxicity data from one species to another or perhaps more often, class to class. Often only a 96-h green algal toxicity test is available to use as a representative of all photosynthetic ... curve for exposure of the biotic components of interest to the stressor. Dose and concen- tration probabilities are the typical units used in environmental toxicology....

Ngày tải lên: 10/08/2014, 20:20

... homogeneity of variance assumptions. pp. 19 2- 20 3 Appendix C Dunnett’s procedure. pp. 20 4 -2 15 Appendix D Bonferroni’s t-test. pp. 21 6 -2 20 Appendix E Steel’s many-one rank test. pp. 22 1 -2 24 Appendix ... (ERL-D-SOP- CTI-016), Chironomus tentans (ERL-D-SOP-CTI-015), and Lumbriculus variegatus (ERL-D-SOP-CTI-017), U.S. Environmental Protection Agency, Envi...

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... 3 80 92 Zürich ETH-Zentrum Switzerland E-mail: onder@ethz.ch ISBN 97 8-3 -6 4 2- 1 077 4-0 e-ISBN 97 8-3 -6 4 2- 1 077 5-7 DOI 10.1007/97 8-3 -6 4 2- 1 077 5-7 Library of Congress Control Number: 20 09940 323 c  20 10 ... bar preferred range of operation -1 5 -1 0 -5 0 5 -1 5 -1 0 -5 0 5 p cr start of injection [deg CA] start of injection [de...

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