Composition of balanced diet and RDA for. Diet for disease states. Renal Function Tests. Commercial applications Study of the photostability of 18 sunscreens in creams by measuring the SPF in vitro. The target of this research was to evaluate. Today's Stock Market News and Analysis. CLOSEXPlease confirm your selection. You have selected to change your default setting for the Quote Search. This will now be your default target page. Are you sure you want to change your settings? Toxicity of chemicals (Part 1), principles and methods for evaluating the (EHC 6, 1. INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY. ENVIRONMENTAL HEALTH CRITERIA 6. PRINCIPLES AND METHODS FOR EVALUATING THETOXICITY OF CHEMICALSPART I. This report contains the collective views of an international group of. United Nations Environment Programme, the International. Labour Organisation, or the World Health Organization. All rights reserved. The designations. Secretariat of the World Health Organization concerning the legal. The. mention of specific companies or of certain manufacturers' products. World. Health Organization in preference to others of a similar nature that. Errors and omissions excepted, the names of. SOME GENERAL ASPECTS OF TOXICITY EVALUATION1. Introduction. 1. 1. Defining toxicity, hazard, risk, and related terms. Laboratory testing. Toxicological field studies. Ecotoxicology. 1. Priorities in the selection of chemicals for. The extent of toxicity testing required. Dose- effect and dose- response relationship. Effect and response. Dose- effect and dose- response curves. Toxic effects due to a combination of chemicals. Interpretation of laboratory data. Distinction between adverse and nonadverse effects. Threshold: practical and theoretical considerations. Extrapolation of animal data to man. Species differences and related factors. David Nelsen July 12, 2012. Peter, another excellent post. I don’t think anyone was on the edge of their seats with regard to the outcome, but it was good for the. Q.1- Discuss the mechanism of digestion and absorption of fructose. Answer-Fructose exists in foods as either a monosaccharide (free fructose) or as a unit of a. XI board exam preparation program is available NOW for the subjects of Mathematics, Physics, Chemistry, Biology and English. It is available for purchase as a. Safety factors. 1. Low- dose extrapolation. Other methods of extrapolation. Human data. 1. 4. Ethical considerations. Need for human investigations. The use of toxicological data in establishing environmental. Environmental health standards. Assessment of health risk and evaluation of. An example of toxicological information used in. Limitations of safety evaluation. FACTORS INFLUENCING THE DESIGN OF TOXICITY STUDIES2. Introduction. 2. 2. Chemical and physical properties. General considerations. Physicochemical properties and the design of. Impurities. 2. 3. Probable routes of exposure. General considerations. Specific variables related to route of exposure. Rate of absorption. Site of action. 2. Biotransformation. Species. 2. 3. 2. Unintended route. Special tests related to route. Selection and care of animals. General considerations. Animal variables. Selection of species. Animal models representing special. Cyclic variations in function or response. Environmental variables. Temperature. 2. 4. Caging. 2. 4. 4. 3 Diet and nutritional status. Statistical considerations. Nature of effects. Reversible and irreversible effects. Functional versus morphological changes. Dynamic aspects of predictive toxicology. Traditional versus new techniques. Toxicity of chemical analogues. Relation between site of metabolism and site of. In vitro test systems. ACUTE, SUBACUTE, AND CHRONIC TOXICITY TESTS3. Introduction. 3. 2. General nature of test procedures. Housing, diet, and clinical examination of test. Acute toxicity tests. Underlying principles. Experimental design. Selection of species. Selection of doses. Method of administration. Postmortem examination. Repeated high- dose studies. Subacute and chronic toxicity tests. Underlying principles. Experimental design. Selection of species and duration of. Selection of doses. Method of administration. Biochemical organ function tests. Physiological measurements. Metabolic studies. Haematological information. Postmortem examination. Controls. 3. 4. 3. Alternative approaches in chronic toxicity. Perinatal exposure. Use of nonrodent species. Evaluation and interpretation of the results of toxicity. CHEMOBIOKINETICS AND METABOLISM4. Introduction. 4. 2. Absorption. 4. 2. General principles. Absorption from the lungs. Absorption from the skin. Gastrointestinal absorption. Distribution. 4. 4. Binding. 4. 4. 1. Plasma- protein binding. Tissue binding. 4. Excretion. 4. 5. 1. Renal excretion. 4. Biliary excretion. Enterohepatic circulation. Other routes of excretion. Metabolic transformation. Mechanism of metabolic transformation. Microsomal, mixed- function oxidations. Conjugation reactions. Extramicrosomal metabolic transformations. Nonenzymatic reactions. Species variability. Enzyme induction and inhibition. Metabolic saturation. Experimental design. Chemobiokinetics. One- compartment open model. Two compartment/multicompartment open systems. Repeated administration or repeated exposure. Kinetics of nonlinear or saturable systems. Linear and nonlinear one compartment open- model kinetics of. T). 4. 1. 0. Linear chemobiokinetics used to assess potential for. TCDD). 5. MORPHOLOGICAL STUDIES5. Introduction. 5. 2. General recommendations. Gross observations. Autopsy techniques. Rat, mouse, guineapig, rabbit, monkey. Carnivores, swine. Selection, preservation, preparation, and storage of. Selection of tissues. Oral toxicity tests. Inhalation toxicity studies. Dermal toxicity studies. Special studies. 5. Preservation of tissues. Immersion. 5. 5. 2. Inflation. 5. 5. 3. Perfusion. 5. 6. Trimming. Histological techniques. Special techniques. Enzyme histochemistry. Autoradiography. 5. Immunofluorescence and immunoenzyme techniques. Electron microscopy. Microscopic examination. Number of animals and number of organs and tissues. Description of the lesions. Presentation, evaluation, and interpretation of. INHALATION EXPOSURE6. Introduction. 6. 2. Need for inhalation studies. Fate of inhaled materials. Nature of aerosols. Deposition. 6. 3. Clearance. 6. 4. Dose in inhalation studies. Choice of species. Anatomical differences. Physiological considerations. Disease and susceptibility states. Duration of exposure. Intermittent versus continuous exposure. Inhalation systems. Facilities required. Static systems. 6. Dynamic systems. 6. Typical whole- body systems. Construction materials. Engineering requirements. Special systems. 6. Isolation units. 6. Head and nose exposures. Instantaneous exposure systems. Variables to monitor. Human exposure facilities. Contaminant generation and characterization. Generation of vapours. Particle generators. Heterogeneous aerosols. Monitoring contaminant concentrations. Vapour sampling. 6. Particulate sampling. Other methods of respiratory tract exposure. In vivo exposures. In vitro exposures. Biological end- points and interpretation of changes in. Morphological changes. Functional changes. Measurement of respiratory frequency. Measurement of mechanics of respiration. Biochemical end- points. Other end- points in inhalation studies. CARCINOGENICITY AND MUTAGENICITY7. Introduction. 7. 2. Carcinogenicity. 7. Long- term bioassays. Species, strain, and sex selection, and. Route of administration. Inception and duration of tests. Dose- level and frequency of exposure. Combined treatment and cocarcinogenesis. Positive and untreated controls. Test material. 7. Survey of animals, necropsy, and. Short- term tests (rapid screening tests). Metabolic activation, reaction with DNA. DNA repair. 7. 2. In vitro neoplastic transformation of. Mutagenicity tests. Submammalian assay systems. Mammalian somatic cells. Host and tissue- (microsome) mediated. Correlation between short- and long- term bioassays. Significance of experimental testing for assessing. Heritable mutations. Whole- animal tests. Monitoring of human populations. Significance of tests for heritable mutations. NOTE TO READERS OF THE CRITERIA DOCUMENTS. While every effort has been made to present information in the. In the interest of all users of the environmental. Division of Environmental Health, World Health. Organization, Geneva, Switzerland, in order that they may be included. In many WHO Member States, this has resulted. Toxicologists have. The differences are. This has. resulted, in the last 2. WHO, 1. 95. 7, 1. WHO, 1. 96. 6, 1. WHO, 1. 96. 7b). mutagenicity, and carcinogenicity (WHO, 1. WHO. 1. 97. 3, 1. WHO, 1. 97. 5c), and on the methods used. WHO, 1. 97. 7). Several symposia have also been organized, to. USSR for establishing. WHO, 1. 97. 5d, 1. IARC, 1. 97. 6). All these. Harmonization of toxicological and epidemiological. WHO Environmental Health. Criteria Programme (WHO, 1. Member States and the United Nations Environment Programme. UNEP), while a very recent (1. World Health Assembly resolution. WHA3. 0. 4. 7 requested the Director- General . This situation is likely to continue for some. It is unrealistic and perhaps not really desirable at present. However, it is not. The underlying objectives are the same. Similarly, the basic. More than 5. 0 distinguished. Organization and. In addition, there was valuable support for the project. WHO collaborating centres at: the Institute of Hygiene and. Occupational Health, Sofia, Bulgaria; the National Institute of Public. Health, Bilthoven, Netherlands; the Department of Environmental. Hygiene, The Karolinska Institute, Stockholm, Sweden; the National. Institute of Environmental Health Sciences, Research Triangle Park. North Carolina, USA; and the Sysin Institute of General and Communal. Hygiene, Moscow, USSR. While aiming at agreement on purely scientific issues. This explains a certain unevenness in. However, WHO and. UNEP recently initiated another project that aims at internationally. Until this project is completed, it is. The reader is therefore warned to be wary. If it should also stimulate the exchange of knowledge and. The. first part contains the broad principles and more general aspects of. Part 2 systematically covers some more specialized. The WHO Secretariat. Meeting of the Main Authors in Geneva (2. July to 1 August. Scientific Group in Lyons (1 to 5 December 1. Dr M. El Batawi, Chief, Occupational Healtha. Dr H. Bartsch, Unit of Chemical Carcinogenesis, IARC, Lyonsb. Dr J. Copplestone, Vector Biology and Controlb; Dr F. Lu. Chief, Food Additivesb; Dr R. Montesano, Unit of Chemical. Carcinogenesis, IARC, Lyonsa,b; Dr H. Nakajima, Drug Evaluation and. Monitoringa; Dr M. Vandekar, Vector Biology and Controla; and. Dr G. Vettorazzi, Food Additivesa. Vouk, Chief, Control of. Environmental Pollution and Hazards was the Secretary of the Geneva. Dr L. Tomatis, Chief, Unit of Chemical Carcinogenesis. IARC, Lyons, and Dr Vouk were the Joint Secretaries of the Scientific. Group at Lyons. Representatives of other organizations who were. Dr M. Marcus (US Environmental. Protection Agency)a; Dr W.
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