Search results for "Toxicity tests"
showing 10 items of 141 documents
Evaluation of the effects of titanium dioxide and aluminum oxide nanoparticles through tarsal contact exposure in the model insect Oncopeltus fasciat…
2019
Abstract Despite the increasing presence of metal nanoparticles in the biosphere as a consequence of their widespread use, knowledge about the impact of these nanoparticles on fauna, ecosystems and human health is far from completion. This is especially true for terrestrial invertebrates. Insects are environmentally exposed to nanoparticles by several ways, the ectopic contact being one of the most probable. The model insect Oncopeltus fasciatus, has been used in the present work for testing toxicity of nanoparticles present in a surface. Adverse effects of TiO2 nanoparticles and Al2O3 in nanoparticulated or bulk form on mortality, reproductive and embryonic developmental parameters have be…
Screening of physical–chemical methods for removal of organic material, nitrogen and toxicity from low strength landfill leachates
2002
Physical-chemical methods have been suggested for the treatment of low strength municipal landfill leachates. Therefore, applicability of nanofiltration and air stripping were screened in laboratory-scale for the removal of organic matter, ammonia, and toxicity from low strength leachates (NH4-N 74-220 mg/l, chemical oxygen demand (COD) 190-920 mg O2/l, EC50 = 2-17% for Raphidocelis subcapitata). Ozonation was studied as well, but with the emphasis on enhancing biodegradability of leachates. Nanofiltration (25 degrees C) removed 52-66% of COD and 27-50% of ammonia, the latter indicating that ammonia may in part have been present as ammonium salt complexes. Biological pretreatment enhanced t…
Effect of the lipid regulator Gemfibrozil in the Cladocera Daphnia magna at different temperatures.
2016
ABSTRACTIn the present study, an ecotoxicological approach to the evaluation of Gemfibrozil (GEM) as an emerging organic pollutant was done. In order to assess its toxicity, tests were conducted using the cladocera Daphnia magna. Experiments were carried out at 22°C and 28°C. EC50, feeding behavior, and chronic toxicity tests (21 days) were evaluated in D. magna exposed to GEM as well as cholesterol levels at 21-day chronic exposure. D. magna GEM EC50 values (24 h) in our experimental conditions were 148.75 and 116.24 mg L−1 at 22°C and 28°C, respectively. Test concentrations of 0.1, 0.5, 1.0, 5.0 and 7.5 mg L−1 were selected for subacute and chronic experiments. Subacute short-term test (f…
Phytotoxicity of low-weight carboxylic acids.
2011
Abstract Presence of low-weight carboxylic acids (LWCAs) can be the reason for phytotoxicity of green manures, treated bio-waste or digestates from biogas production applied to soils. As the phytotoxic concentrations of LWCA are poorly known, this work presents data on six acids (C 1 C 6 : formic, acetic, propionic, butyric, valeric, and caproic). Phytotoxicity was measured in acute (72 or 120 h) and subchronic (21 d) assays for seed germination, seedling elongation, and plant growth for garden cress Lepidium sativum and ryegrass Lolium multiflorum . The dose–response relationship was modeled using Weibull model. Results showed a trend that toxicity of LWCA increases with the length of the …
Acute, chronic and sublethal effects of the herbicide propanil on Daphnia magna.
2003
Acute and chronic toxicity tests with propanil were conducted on Daphnia magna. The 24 and 48 h LC50 were 43.74 and 5.01 mg/l respectively. Chronic toxicity tests were carried out using sublethal propanil concentrations (0.07, 0.10, 0.21 and 0.55 mg/l) during 21 days. The effect of propanil on survival, reproduction and growth of D. magna organisms was monitored. The parameters used to evaluate herbicide effect on reproduction were: mean total young ones per female, mean brood size, time to first reproduction, mean number broods per female and intrinsic rate of natural increase (r). Survival and growth (body length) were also determined after 21 days of exposure to the herbicide. Reproducti…
Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET) bottles: A source of controversy review…
2012
A declaration of conformity according to European regulation No. 10/2011 is required to ensure the safety of plastic materials in contact with foodstuffs. This regulation established a positive list of substances that are authorized for use in plastic materials. Some compounds are subject to restrictions and/or specifications according to their toxicological data. Despite this, the analysis of PET reveals some non-intentionally added substances (NIAS) produced by authorized initial reactants and additives. Genotoxic and estrogenic activities in PET-bottled water have been reported. Chemical mixtures in bottled water have been suggested as the source of these toxicological effects. Furthermo…
Disturbances in energy metabolism of Daphnia magna after exposure to tebuconazole.
2008
Abstract This study was conducted to investigate the change of some biochemical parameters in the aquatic invertebrate Daphnia magna following exposure to the fungicide tebuconazole and to determine the most sensitive biomarker among the ones tested in this species. Four biochemical biomarkers (protein, glycogen, lipids and caloric content) were correlated with feeding behaviour studies of D. magna after fungicide exposure. Juveniles of D. magna were exposed to four sublethal concentrations of tebuconazole (0.41, 0.52, 0.71 and 1.14 mg L−1) for 5 d. Daphnid samples were taken from each test and control group at 24, 48, 72, 96 and 120 h after the start of the experiment. Tebuconazole EC50 va…
Biochemical stress response in tetradifon exposed Daphnia magna and its relationship to individual growth and reproduction
2009
Abstract Environmental risk assessment of chemicals toxicity requires the use of costly and labor-intensive chronic data and short-term tests provide additional information. Energy budget is used by the animals for their growth, reproduction, and metabolism and it is reduced in case of toxic stress. Tetradifon acaricide is frequently used in the European Mediterranean region and it is implicated in aquatic environmental pollution. Previous studies showed that the EC50-24 h of tetradifon on Daphnia magna was 8.92 mg/L. Based on that, D. magna were exposed to sublethal tetradifon concentrations of 0.10, 0.18, 0.22 and 0.44 mg/L for five days in order to investigate their effect on intermediat…
Quantitative genetic analysis of Cry1Ab tolerance in Ostrinia nubilalis Spanish populations
2013
30 p.-2 fig.-3 tab.
Mycotoxins: Toxicology, Identification and Control
2021
The evaluation of the presence of mycotoxins in different matrices is achieved through different analytical tools (including quantitative or qualitative determinations) [...]