UPTAKE, ACCUMULATION, ELIMINATION, AND BIODEGRADATION Appraisal 2,4-D does not persist in soil because of its rapid degradation. The physico-chemical properties of 2,4-D acid and its formulations have an important effect on its behaviour in environmental compartments. The bioavailability to, and uptake by, aquatic and terrestrial organisms is strongly influenced by the organic matter content of soils, microbiological activity, and by environmental conditions such as temperature and pH.
Laboratory studies Eliasson (1973) sprayed leaves of 3-year-old aspen (Populus tremens) with the butoxyethanol ester of 2,4-D at 0.5 kg acidequivalent/litre.
Bonner FW & Parke DV (1984) [Transmissibility to humans of test results with laboratory animals.] In: Merian E ed. Metalle in der Umwelt. Weinheim, VCH Verlagsgesellschaft, pp 195-207 (in German).
(1987) Acute toxicity handbook of chemicals to estuarineorganisms, Washington, DC, US Department of Commerce, NationalTechnical Information Service, 274 pp.
Brasch J & Geier J (1997) Patch test results in schoolchildren. Results from the Information Network of Departments of Dermatology (IVDK) and the German Contact Dermatitis Research Group (DKG). Contact Dermatitis, 37: 286-293.
Since the inception of the EHC Programme, the IPCS has organized meetings of scientists to establish lists of priority chemicals for subsequent evaluation. Such meetings have been held in Ispra, Italy, 1980; Oxford, United Kingdom, 1984; Berlin, Germany, 1987; and North Carolina, USA, 1995. The selection of chemicals has been based on the following criteria: the existence of scientific evidence that the substance presents a hazard to human health and/or the environment; the possible use, persistence, accumulation or degradation of the substance shows that there may be significant human or environmental exposure; the size and nature of populations at risk (both human and other species) and risks for the environment; international concern, i.e., the substance is of major interest to several countries; adequate data on the hazards are available.
Howe, The Institute of Terrestrial Ecology, Monks Wood Experimental Station, Huntingdon, United KingdomNOTE TO READERS OF THE CRITERIA DOCUMENTS Every effort has been made to present information in the criteriadocuments as accurately as possible without unduly delaying theirpublication.
Although the body's absorption of minerals depends in large part on theirsolubility, we must be very careful not to equate solubility of the salt containing amineral with absorption of that mineral. In the example with zinc and phytic aciddescribed above, the absorption of zinc decreases with phytic acid even though thesolubility of zinc sulfate is increased. This is because the zinc is not present as thefree ion in solution; rather it is bound to phytic acid and is therefore unavailable forabsorption by the body. One way to overcome the problem of poor zinc absorption due tophytic acid is to eat leavened, rather than unleavened bread. When yeast is used to makebread rise, it destroys the phytic acid, and so the Zn2+ ions remain free insolution to be absorbed by the body.
All individuals who as authors, consultants or advisers participate in the preparation of the EHC monograph must, in addition to serving in their personal capacity as scientists, inform the RO if at any time a conflict of interest, whether actual or potential, could be perceived in their work. They are required to sign a conflict of interest statement. Such a procedure ensures the transparency and probity of the process.
Magallona, Pesticide Toxicology and Chemistry Laboratory, University of the Philippines at Los Banos, College of Agriculture, Laguna, PhilippinesProfessor P.N.
All Participating Institutions are informed, through the EHC progress report, of the authors and institutions proposed for the drafting of the documents. A comprehensive file of all comments received on drafts of each EHC monograph is maintained and is available on request. The Chairpersons of Task Groups are briefed before each meeting on their role and responsibility in ensuring that these rules are followed.
The promotional homepage provides access to alarge body of research documenting the effects of Olestra consumption and how Olestraworks. This informative site also contains a search engine to locate information ofparticular interest.
The bioavailability to, and uptake by, aquatic and terrestrialorganisms is strongly influenced by the organic matter content ofsoils, microbiological activity, and by environmental conditions suchas temperature and pH.