Biomedical subjects

Tatjana Tisler

Publications and source records attributed to Tatjana Tisler.

6 recordsLinked to original sources

PubMed2006

Evaluation of point and diffuse sources of nutrients in a river basin on base of monitoring data.

The methodology of materials accounting is presented and applied to developing nutrient balance (nitrogen and phosphorus) in a river basin. The method is based on the balance principle: inputs and outputs of each nitrogen and phosphorus related sub-systems were balanced. The application of the methodology strategies was illustrated by means of a case study of the Krka river, Slovenia. Different pathways of emission to surface waters were taken into account: WWTP discharges, direct discharges, erosion/runoff and baseflow. Total annual emission into the river Krka was estimated to be 362 tonnes N/year and 73.3 tonnes P/year. The main sources of nitrogen are diffuse sources, emitted via baseflow (52%). Other important sources are effluents from WWTP, which account for 36% of total emissions. Other sources like erosion and direct discharges to surface water (animal manure, industry, households) are of lower magnitude. Erosion is main source of phosphorus emission (55% of total emission), WWTP effluents account for 37% of total emission, while other sources are less important. Besides reduction of point sources by means of wastewater collection and implementation of nutrient removal technology, managing agricultural nitrogen and phosphorus to protect water quality should become a major challenge in the Krka river basin.

Environmental Monitoring↗

PubMed2006

The applicability of acetylcholinesterase and glutathione S-transferase in Daphnia magna toxicity test.

The most commonly used toxicity test worldwide is the acute Daphnia magna test. The relevance of acetylcholinesterase (AChE) and glutathione S-transferase (GST) activity in D. magna exposed to chromium, cadmium, and diazinon was evaluated in connection with this standard test. We found no link between enzyme activities and immobility. Concentrations of Cr(6+) up to 280 microg/L had no effect on AChE and GST activities, while 20% immobility was observed. At concentrations of 20-25 microg/L of Cd(2+) AChE activity was increased by about 50%. The effect of diazinon on both enzymes was insignificant up to concentrations that caused 27% immobility. Consequently, while the use of AChE and GST activities is recommended when the mode of action of chemicals is studied, the value of these biomarkers in routine acute toxicity tests is limited because the relationship between enzyme activities and immobility of D. magna exposed to different chemicals is unclear.

Acetylcholinesterase↗

PubMed2006

Abamectin in the aquatic environment.

Abamectin, widely used as a veterinary anthelmintic, medicine against a variety of animal parasites and insects, can runoff from the sites of application and becomes an aquatic pollutant. The aim of this study was to identify the toxicity of abamectin on bacteria, algae, daphnids, and fish. An extremely high toxicity of avermectin to the survival and reproduction of Daphnia magna was observed in 21-day exposure tests. Zebrafish and the algae Scenedesmus subspicatus are less sensitive to avermectin. The compound is expected to have adverse effects on the aquatic environment due to its high toxicity, even at very low concentrations, to daphnids and to fish.

Aliivibrio fischeri↗

PubMed2004

Toxicity potential of disinfection agent in tannery wastewater.

Wastewater from a tannery was investigated using chemical-specific analyses and assessment of the acute toxicity of the whole effluent over a 2-year period. The wastewater samples were overloaded with organic and inorganic compounds, and measured concentrations of the chemical parameters as well as dilution factors estimating acute toxicity, frequently exceeded the permissible limits for the discharge of wastewater from a tannery into the receiving stream. In the later part of the monitoring programme, the toxicity of the samples was significantly increased in comparison to the previous samples. The agent for hide disinfection was assumed to be the reason for the increased toxicity of the wastewater samples, and the extremely high acute and chronic toxicity of the agent to bacteria, algae, daphnids, and fish confirmed this suspicion. The most sensitive species was Daphnia magna; the 48 h EC50 was 0.70 x 10(-5)v/v% and the 21d IC25 was 0.40 x 10(-6)v/v% of the agent. After withdrawal of this highly toxic agent for hide disinfection from the technological process in the tannery, the toxicity of the wastewater declined to the previous level.

Animals↗

PubMed2003

Aquatic toxicity of selected chemicals as a basic criterion for environmental classification.

In order to protect public health and the environment, the EU legislation has proposed a classification of dangerous substances. Chemicals are classified according to physico-chemical as well as toxicological and ecotoxicological properties. Environmental classification is based on inherent harmful potential of a substance to organisms and on its environmental fate, that is, degradation and bioaccumulation potential. In this study, experimental data on acute and chronic toxicity to aquatic organisms and biodegradability and bioaccumulation data obtained from literature were used to classify arsenic (applied as As2O3), copper (applied as CuCl2), phenol and 1,4-butynediol. For this purpose, the "base set data" obtained from standardised test methods served as a convenient indicator of the inherent toxicity of tested chemicals. Additional data about environmentally relevant properties of arsenic and 1,4-butynediol could lead to a revision of present chemical classification and labelling.

Animals↗

PubMed2002

Hazard identification for 3,5-dichlorophenol in the aquatic environment.

The risk assessment of substances in various environmental compartments is essential for their proper, safe and environmentally friendly production, handling, use and final deposition or destruction. Hazard identification is an important part of risk assessment. The aim of our research was to present a methodology for the hazard identification of substances dangerous to the aquatic environment according to the 93/21/EEC Directive relating to the classification, packaging and labelling of dangerous substances, from the adverse effect assessment of chemicals in European Union. A battery of toxicity tests and biodegradability studies with 3,5-dichlorophenol were performed. The substance was classified as toxic to aquatic organisms with possible long-term adverse effects. The presented methodology assures reliable data for the classification and labelling of substances according to their harmful effect on aquatic biota, suitable for the competent authorities at the national and EU level.

Animals↗