Analytical and biological data to the environmental-toxicological behaviour of Verbutin pesticide.

Ecotoxicological characteristics of a new insecticide synergist, MBB-599 (proposed common name: Verbutin) was investigated. The studies included the determination of the hydrolysis, the biodegradability, the adsorption and desorption characteristics in soil and the effects on living systems (bacterium, alga, Daphnia, and fish) as well.

Evaluation of a Hungarian acaricide original molecule based on its environmental toxicological studies.

The results of the environmental toxicological investigations and their results of a new hungarian acaricide molecule (SZI-121) developed by the CHINOIN were summarized. The toxicological effects of the test item on different ecotoxicological test systems were investigated in the following tests: Bacterium, alga, and plant growth inhibition tests, acute immobilization and 21 days reproduction tests on Daphnia magna, acute fish test, closed bottle test, mobility, aerob degradation and adsorption/desorption tests on three different soils. No toxic effect was found in the bacterium, alga, plant growth inhibition and acute fish tests in the highest concentrations used. In the Daphnia immobilization test 0.14 mg/l LC50 value was established in the concentration range of 0.0128-40 mg/l applied. The test item showed similar characteristics as the reference item during the mobility test in soils, the adsorption/desorption study and the degradation investigations. In order to determine the environmental degradation rate further degradation investigations, as well as the nitrogen mineralization test and the model of concentration change in natural waters were performed.

Ecotoxicological experiences on Lemna minor test system.

Are plants generally less sensitive to toxicity than aquatic animals as indicated by some authors (1)? The use of phytotoxicity (higher plant) tests as a part of ecotoxicology is relatively underdeveloped. The objective of this study was to compare the results of the OECD Lemna Growth Inhibition Test with other mainly used test systems. Three toxicants were tested applying the Alga Growth Inhibition Test (Seleneastrum capricornutum), the Daphnia Immobilization Test (Daphnia magna) and the MICROTOX-test (Photobacterium phosphoreum). Duckweed plants were found to be sensitive to the chemicals tested, with nearly 100% inhibition of frond production occurring in the highest concentrations. The plants in some samples showed lesions (break up of the colony structure) and loss of green pigments (chlorosis), others showed localized dead tissues (necrosis). In addition to the morphological deviations (appearance) there is a wide range of characteristics to be observed on the test plants: number of fronds, number of plants, biomass, dry weight, mortality, CO2 and O2 exchange, concentration of chlorophyll a and chlorophyll b. It is consistent that the number of fronds is slightly more sensitive than or the same as the number of plants and that the biomass tend to be somewhat more tolerant than those for the number of plants (2). Applying the simplest way of observation, changes in the frond number were recorded. As Lemna minor show a characteristical sensitivity to the different kind of chemicals, it is a promising indicator of aquatic toxicity.