Analyse statistique correlative de l'influence des proprietes des sols sur l'adsorption d'herbicides et insecticides

A statistical correlative study (simple and multiple) between 14 herbicides and insecticides and composition of 51 soil samples has been performed by considering top- and sub-soil horizons, separately. Results point out the suitability of these regression models as a predictive tool to determine quantitatively the adsorption of numerous pesticides in soils mainly the more soluble compounds.     

Effet de l'EDTA sur l'accumulation et l'elimination du mercure par la moule Mytilus edulis

The effect of the presence of the chelating agent EDTA on the uptake and loss of mercury from the whole soft parts of the common mussel Mytilus edulis were investigated under laboratory conditions. It is concluded that the EDTA significantly increased mercury accumulation throughout 18 days exposure. During the elimination period the loss rates of mercury by the presence of EDTA were less important than those obtained in natural sea-water.     

Repartition du virus poliomyelitique a l'interface eau de mer-sediment d'un systeme experimental

The distribution between sea water and sediment of a polio virus has been studied under an experimental system. Throughout 7 days of incubation, a significant statistical difference exist between the viral concentration of sea water in times T₀ and T₇ (P～0,99) and the viral concentration of sea water samples and sediments in times T₇ (P～0,95). this for any type of sediment.     

L'utilisation de souches de micro-organismes de collection pour l'etude de la biodegradabilite des pesticides

Use of Microbial strains from collection in the study of pesticide biodegradability. 5 different herbicides and 1 metabolite of herbicide were subjected to biodegradation by different microbial strains and simultaneously by soil suspensions.To take account of possible co-metabolisme a supplementary source of carbon was added in the culture media. Results were discussed.     

Microméthode de dosage simultané de l'alcool isopropylique et de son métabolite l'acétone

Simultaneous determination of Isopropyl Alcohol and Acetone prove to be necessary in cases of poisoning by this widely used alcohol. An aluminum capsule containing a sample of blood to be analyzed is introduced into a gas chromatograph equipped with a flameionization detector and a Carbowax 20 M - Chromosorb WHP column. Use of a small blood sample (0.50 μl) and high sensitivity of the method make it a selected procedure in the clinical diagosis of poisoning by Isopropyl Alcohol.     

Sensitized photodegradation of adsorbed polychlorobiphenyls (PCB's)

Polychlorobiphenyls (PCB's) adsorbed on silica gel or montmorillonite were degraded mainly to less chlorinated biphenyls by U.V. irradiation (λ = 254 nm). The photodegradation was considerably enhanced by adding triethylamine to the system. The sensitizing effect can be ascribed, like in solution, to the formation of a charge-transfer complex confirmed by fluorescence quenching experiments.     

Influence du volume d'inoculum dans la quantification des virus selon deux techniques comparees: Plages et N.P.P. utilisant un grand nombre d'inoculum par dilution

Viral particles can be quantified by two different titration methods which provided the same results: counting plates in solid medium and MPN method, using a large number of inocula for each dilution, in liquid medium. The accuracy of the two methods is a function of the volume of the inoculum used. The width of the confidence interval increases when the volume of the inoculum decreases.     

The role of laboratory testing in the United Kingdom's controls on dumping wastes at sea

The objective of the UK's pre-discharge controls under national legislation and the Conventions is taken to be the prevention of pollution from dumping. Laboratory tests have an essential role to play in assessing the polluting potential of a proposed discharge. Most emphasis is placed on toxicity tests to supplement basic physical and chemical data on the waste, and the results of these tests allow the possibility of acute toxic effects after discharge to be assessed. Longer term effects may arise from persistence or bioaccumulation potential in the waste. However, where tests are used to investigate such effects, care must be taken in the extrapolation of laboratory data to field conditions. The appropriate literature on the chemical components of the waste may often provide sufficient information on which to base decisions.Other essential components of an effective control programme are enforcement of regulations and monitoring of the effects of dumping. In the latter context examples are given of environmental effects which are nog capable of being adequately predicted on the basis of laboratory testing alone.