0000000000247704
AUTHOR
Esko Martikainen
Toxicity of Dimethoate to Some Soil Animal Species in Different Soil Types
Toxicity of dimethoate (insecticide) to an earthworm (Aporrectodea caliginosa tuberculata), a collembola (Folsomia candida), and an enchytraeid worm (Enchytraeus crypticus/variatus) was studied in three different soil types (artificial soil, clayey soil, and humus sandy soil). Parameters measured were survival and biomass change of the earthworms and survival and reproduction of the collembolas and enchytraeids. The degradation of dimethoate was analyzed too. Toxic effects were observed at the concentrations of some mg/kg dry soil. The biomass reduction of the earthworms occurred at lower concentrations than reduction in survival. The collembolas were more susceptible to dimethoate than the…
A battery of toxicity tests as indicators of decontamination in composting oily waste.
Heterogeneous oily waste from an old dumping site was composted in three windrows constructed from different proportions of waste, sewage sludge, and bark. The objectives of this pilot study were to examine the usefulness of composting as a treatment method for this particular waste and to study decontamination in the composting process by using a battery of toxicity tests. Five samples from the windrow having intermediate oil concentrations were tested with toxicity tests based on microbes (Pseudomonas putida growth inhibition test, ToxiChromotest, MetPLATE, and three different modifications of a luminescent bacterial test), enzyme inhibition (reverse electron transport), plants (duckweed …
Effects of soil organic matter content and temperature on toxicity of dimethoate toFolsomia fimetaria(Collembola: Isotomiidae)
The purpose of these experiments was to study the effects of two major environmental factors, soil organic matter content (1.4–8.6%) and temperature (10–20°C), on chemical toxicity to a soil-dwelling collembolan Folsomia fimetaria. Dimethoate was used as a reference chemical. Effects on survival, reproduction, and juvenile size were investigated. Increasing soil organic matter content reduced toxicity significantly, but the differences disappeared when results were recalculated and expressed as soil pore-water concentrations. This supported the soil pore-water hypothesis. The effects of soil temperature were not so clear, because temperature affects not only the growth and reproduction of t…
Extractability of metals and ecotoxicity of soils from two old wood impregnation sites in Finland
Abstract Four metal-contaminated soil samples were classified using physical methods, extracted by selective extraction procedures and analyzed for chemical concentrations. De-ionized water, 0.01 mol/l barium chloride, 1 mol/l ammonium acetate and concentrated nitric acid were used as extraction solutions. Ecotoxicity of water extracts and soil samples was analyzed in order to describe the bioavailability of the contaminants. Samples from old wood impregnation plants contained high amounts of As, Cu, Cr and Zn, which originated from chromated copper arsenate, ammoniacal copper–zinc arsenate, and ammoniacal copper quaternary compound. Total As concentrations of the heavily contaminated sampl…
Effects of dimethoate and benomyl on soil organisms and soil processes – a microcosm study
Abstract Effects of two pesticides, dimethoate, an insecticide, and benomyl, a fungicide, applied singly or together, on soil organisms and plant growth were studied in microcosms containing agricultural soil and indigenous soil fauna together with introduced invertebrates and barley. Dimethoate reduced soil microarthropod populations and the reduction was stronger in the upper than in the lower soil layer. The collembolan community structure was affected by both pesticides. Populations of microarthropods in pesticide-treated microcosms recovered during the experiment but the community structures remained differentiated. Total numbers of enchytraeids and nematodes were not affected by eithe…
Temperature–Time Relationship in Collembolan Response to Chemical Exposure
Abstract Effects of temperature on chemical toxicity to a collembolan, Folsomia candida , in relation to time were studied in this experiment. Field soil was used as a test substrate. Collembolans were incubated at three different temperatures (+13, +16, and +19°C) and in two different dimethoate concentrations (1 and 3 mg/kg), clean soil serving as the control. Four destructive samplings were done at 2-week intervals. Dimethoate degradation was also analyzed. Dimethoate 1 mg/kg had a slight effect on both adult growth and reproduction, whereas 3 mg/kg was fatal to F. candida in the soil used. Toxic effects tended to last longer at low temperature than at high temperature, but the differenc…