Introduction to ENVIRONMENTAL TOXICOLOGY Impacts of Chemicals Upon Ecological Systems - CHAPTER 11 doc

... 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 ... Relationship between two toxicity endpoints such as the NOAEL and the EC 50 . 3. Laboratory -to- field extrapolation — Relationship of the estimate of toxicity gath- ered...

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 ... sensitive to CHCl 3 . Death often results following their exposure to this chemical. The higher sensitivity of male mice to certain toxic chemicals may be due to...

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... 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 ... toxicants at ecological levels of organization. The chapter starts with an evaluation of methods and ends with a discussion of the responses of ecosystems to chemi...

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... in toxicant concentrations or interspecific inter- actions. The range of scales important in environmental toxicology range from the few angstroms of molecular interactions to the hundreds of ... responsible for © 1999 by CRC Press LLC CHAPTER 2 A Framework for Environmental Toxicology Environmental toxicology can be simplified to the understanding of only three fu...

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 ... variety of forms, from the dynamics of populations to the genetic sequence of mitochondria, it is necessary to be able to incorporate each of these types of data into...

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... Environ. Toxicol. Chem. 11: 147 7-1 483. Sugiura, K. 1992. A multispecies laboratory microcosm for screening ecotoxicological impacts of chemicals. Environ. Toxicol. Chem. 11: 121 7-1 226. 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 specie...

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 of...

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... able to hydrolyze 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, ... be the sites of toxic action, however. For example, lead is stored primarily in the bone, but acts mainly on the soft tissues of the body. If the storage site is not the site of toxic ac...

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... (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, Environmental Research Laboratory, ... Environmental Monitoring Systems Labo- ratory, Of ce of Research and Development, Cincinnati, OH, EPA 600/ 4-9 0/0027, pp. 4 4-6 9. USEPA. 1991b. Compendium of ERT Toxicity Testing...

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... 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: 2009940323 c  2010 Springer-Verlag ... 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 [d...

Ngày tải lên: 04/07/2014, 00:20