Download (.pdf) Toxicity effects of diflubenzuron, cypermethrin and diazinon on the development of the brine shrimp, Artemia salina and the sea urchin, Heliocidaris tuberculata
Simon Gartenstein, Rosanne G. Quinnell and Anthony W. D. Larkum. 2006. AUSTRALASIAN JOURNAL OF ECOTOXICOLOGY. Vol. 12, pp. 77-84.
The toxicity of diflubenzuron (DFB) on the brine shrimp, Artemia salina, and the sea urchin, Heliocidaris tuberculata,... more The toxicity of diflubenzuron (DFB) on the brine shrimp, Artemia salina, and the sea urchin, Heliocidaris tuberculata, was evaluated in the laboratory. DFB was toxic to A. salina embryos and larvae at 0.13 μg.L-1. The LC50 was 0.37 μg.L-1 for A. salina larvae after 48 h. Synergistic mortality effects after 48 h were found for the following combined insecticides: DFB and cypermethrin (LC20 + LC20 = LC85), DFB and diazinon (LC20 + LC20 = LC60) and cypermethrin and diazinon (LC20+LC20 = LC55). Antagonistic mortality effects to A. salina larvae occurred when DFB was combined with both cypermethrin and diazinon (LC20+LC20+ LC20 = LC40). We also show that DFB is toxic to the larvae of the sea urchin H. tuberculata at concentrations as low as 2.69 μg.L-1 during a 72 h EC50 experiment.
Combination of a higher-tier flow-through system and population modeling to assess the effects of time-variable exposure of isoproturon on the green algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata
Denis Weber, Dieter Schaefer, Michael Dorgerloh, Eric Bruns, Gerhard Goerlitz, Klaus Hammel, Thomas G. Preuss & Hans Toni Ratte
Environmental Toxicology and Chemistry, in press
A flow-through system was developed to investigate the effects of time-variable exposure of pesticides on algae. A... more A flow-through system was developed to investigate the effects of time-variable exposure of pesticides on algae. A recently developed algae population model was used for simulations supported and verified by laboratory experiments. Flow-through studies with Desmodesmus subspicatus and Pseudokirchneriella subcapitata under time-variable exposure to isoproturon were performed, in which the exposure patterns were based on the results of FOrum for Co-ordination of pesticide fate models and their USe (FOCUS) model calculations for typical exposure situations via run-off or drain flow. Different types of pulsed exposure events were realized, including a whole range of repeated pulsed and steep peaks as well as periods of constant exposure. Both species recovered quickly in terms of growth from short-term exposure and according to substance dissipation from the system. Even a peak at 10 times the maximum predicted environmental concentration of isoproturon, there were only transient effects on algae populations. No modified sensitivity or reduced growth was observed after repeated exposure. Model predictions of algal growth in the flow-through tests agreed well with the experimental data. The experimental boundary conditions and the physiological properties of the algae were used as the only model input. No calibration or parameter fitting was necessary. The combination of the flow-through experiments with the algae population model turned out to be a powerful tool for the assessment of pulsed exposure on algae. It allowed investigating the growth reduction and recovery potential of algae after complex exposure, which is not possible with standard laboratory experiments alone. The results of the combined approach confirm the beneficial use of population models as supporting tools in higher-tier risk assessments of pesticides.
Ecotoxicological effects on structure and function of aquatic and terrestrial ecosystems
by Claudia Vaj
PhD thesis: DoctorateinEnvironmentalSciences (XXIII Cycle). FacultyofMathematical,PhysicalandNaturalSciences, University ofMilano-Bicocca,Milano, Italy.
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Assessing, mapping and validating site-specific ecotoxicological risk for pesticide mixtures: A case study for small scale hot spots in aquatic and terrestrial …
by Claudia Vaj
Co-authored with Stefania Barmaz, Peter Borgen Sørensen, David Spurgeon and Marco Vighi, published on Ecotoxycology and environmental safety 74 (2011) 2156-2166.
Mixture toxicity is a real world problem and as such requires risk assessment solutions that can be applied within... more Mixture toxicity is a real world problem and as such requires risk assessment solutions that can be applied within different geographic regions, across different spatial scales and in situations where the quantity of data available for the assessment varies. Moreover, the need for site specific procedures for assessing ecotoxicological risk for non-target species in non-target ecosystems also has to be recognised. The work presented in the paper addresses the real world effects of pesticide mixtures on natural communities. Initially, the location of risk hotspots is theoretically estimated through exposure modelling and the use of available toxicity data to predict potential community effects. The concept of Concentration Addition (CA) is applied to describe responses resulting from exposure of multiple pesticides The developed and refined exposure models are georeferenced (GIS-based) and include environmental and physico-chemical parameters, and site specific information on pesticide usage and land use. As a test of the risk assessment framework, the procedures have been applied on a suitable study areas, notably the River Meolo basin (Northern Italy), a catchment characterised by intensive agriculture, as well as comparative area for some assessments. Within the studied areas, the risks for individual chemicals and complex mixtures have been assessed on aquatic and terrestrial aboveground and belowground communities. Results from ecological surveys have been used to validate these risk assessment model predictions. Value and limitation of the approaches are described and the possibilities for larger scale applications in risk assessment are also discussed.
Sensitivity assessment of freshwater macroinvertebrates to pesticides using biological traits
A. Ippolito, R. Todeschini, M. Vighi
Ecotoxicology
Volume 21, Number 2, March 2012, Pages 336–352
Assessing the sensitivity of different species to chemicals is one of the key points in predicting the effects of... more Assessing the sensitivity of different species to chemicals is one of the key points in predicting the effects of toxic compounds in the environment. Trait-based predicting methods have proved to be extremely efficient for assessing the sensitivity of macroinvertebrates toward compounds with non specific toxicity (narcotics). Nevertheless, predicting the sensitivity of organisms toward compounds with specific toxicity is much more complex, since it depends on the mode of action of the chemical. The aim of this work was to predict the sensitivity of several freshwater macroinvertebrates toward three classes of plant protection products: organophosphates, carbamates and pyrethroids. Two databases were built: one with sensitivity data (retrieved, evaluated and selected from the U.S. Environmental Protection Agency ECOTOX database) and the other with biological traits. Aside from the "traditional" traits usually considered in ecological analysis (i.e. body size, respiration technique, feeding habits, etc.), multivariate analysis was used to relate the sensitivity of organisms to some other characteristics which may be involved in the process of intoxication. Results confirmed that, besides traditional biological traits, related to uptake capability (e.g. body size and body shape) some traits more related to particular metabolic characteristics or patterns have a good predictive capacity on the sensitivity to these kinds of toxic substances. For example, behavioral complexity, assumed as an indicator of nervous system complexity, proved to be an important predictor of sensitivity towards these compounds. These results confirm the need for more complex traits to predict effects of highly specific substances. One key point for achieving a complete mechanistic understanding of the process is the choice of traits, whose role in the discrimination of sensitivity should be clearly interpretable, and not only statistically significant.
Lethal dose-effect correlations of chloride snow-melting agent on Euonymus japonicus
by ZhouYuan Li
LI Zhou-yuan1; ZHOU Jun-hui2; LIANG Ying-mei1*
1 College of Environmental Science and Engineering, Research Center for Water Pollution Source Control and Eco-Remediation, Beijing Forestry University, 100083, P. R. China;
2 College of Biological Sciences and Biotechnology, Beijing Forestry University, 100083, P. R. China.
(Accepted Mar.15, 2011)
Published @ Journal of Beijing Forestry University (2012) Vol. 34 (1) p 67-72
*Corresponding author: liangym812@126.com
To prevent severe pollution of inorganic snow-melting agents on greenery along urban roads, half lethal dose (LD50) of... more
To prevent severe pollution of inorganic snow-melting agents on greenery along urban roads, half lethal dose (LD50) of plant population was confirmed through stress simulation of chloride snow-melting agent on Euonymus japonicus, plant physiological change analysis, plant population lethality rate statistic and mathematic modeling analysis within a 30-day subacute toxicity test. Results indicated that a significant positive correlation in the early stage and a significant negative correlation in the later stage were observed between the total content of chlorophyll a and b in plants and cumulative dose of chloride snow-melting agent. The free L-proline content in plants and the dose of snow-melting agent were positively correlated during the whole period. No significant correlation in the initial stage, but a significant negative correlation in the later stage was observed between the soluble protein and the dose of snow-melting agent. The half lethal dose (LD50) of chloride snow-melting agent on E. japonicus is 5 kg/(L•m-2) within a 30-day period.
Key words: snow-melting agent; Euonymus japonicus; dose-effect correlation; LD50
Toxicokinetic-toxicodynamic modeling of quantal and graded sublethal endpoints: A brief discussion of concepts.
Ashauer R, Agatz A, Albert C, Ducrot V, Galic N, Hendriks J, Jager T, Kretschmann A, O'Connor I, Rubach MN, Nyman A-M, Schmitt W, Stadnicka J, van den Brink PJ, Preuss TG
Environmental Toxicology and Chemistry 30, 2519-2524
We report on the advantages and problems of using toxicokinetic-toxicodynamic (TKTD) models for the analysis,... more We report on the advantages and problems of using toxicokinetic-toxicodynamic (TKTD) models for the analysis, understanding, and simulation of sublethal effects. Only a few toxicodynamic approaches for sublethal effects are available. These differ in their effect mechanism and emphasis on linkages between endpoints. We discuss how the distinction between quantal and graded endpoints and the type of linkage between endpoints can guide model design and selection. Strengths and limitations of two main approaches and possible ways forward are outlined.
The Effects of Final Treated Effluent and In-Mill Waste Streams from a Canadian Thermomechanical Pulp and Paper Mill on Mummichog (Fundulus heteroclitus) Reproduction
Bosker T, Hewitt ML, Munkittrick KR, Melvin SD, and DL MacLatchy. 2009. Water Qual. Res. J. Can. 44(4):333-344.
The effect on fish reproduction of final treated effluent from a thermomechanical pulp mill in Saint John, New... more The effect on fish reproduction of final treated effluent from a thermomechanical pulp mill in Saint John, New Brunswick, Canada, was studied using mummichog (Fundulus heteroclitus), an endemic fish species of the Atlantic coast of North America. A 1997 artificial stream study at the same mill showed a reduction in gonad sizes in mummichog after a 28- day exposure to 3% final treated effluent. In 2005, we reevaluated final treated effluent, and conducted a toxicity source evaluation to identity waste stream sources within the mill that may cause reproductive effects. Relative to reference, no significant differences in gonad size, plasma levels of gonadal sex steroids, egg production, or stage of egg development were observed in fish exposed to 1, 3, 10, 30, and 100% final treated effluent or in-mill waste streams. Unlike the previous study in 1997, these data indicate a low potential for an effect of final effluent on fish reproduction. Since the 1997 study there were no major process changes that could explain the differences in the results. However, there was high variability in gonad size, egg production, and endocrine endpoints measured in the more recent test, which resulted in low power to detect differences. This has prompted research to refine the current reproductive test by optimizing study design.
An individualbased modeling approach for evaluation of endpoint sensitivity in harpacticoid copepod life cycle tests and optimization of test design
T.G. Preuss, M.Brinkmann, E. Lundström, B.E. Bengtsson, M. Breitholtz
In the present study, an individual-based model for Nitocra spinipes was developed and used to optimize the test... more In the present study, an individual-based model for Nitocra spinipes was developed and used to optimize the test design of a proposed Organisation for Economic Co-operation and Development test guideline for harpacticoid copepods. The variability between individuals was taken into account, based on measured data, leading to stochastic model output. Virtual experiments were performed with the model to analyze the endpoint sensitivity and the effect of number of replicates and inspection intervals on statistical power. The impact of mortality was evaluated; most sublethal effects could not be determined if the mortality was ≥70%. Most sensitive to mortality was the determination of effects on brood size, for which the statistical power was reduced at 10% mortality. Our simulations show that increasing the number of replicates from 72 to 96 or 144 has little impact on the statistical power, whereas 25 replicates disallow relevant endpoint detection. Furthermore, it was demonstrated that the proposed 1D inspection interval can be shifted to a 3D interval, without losing statistical power. It was demonstrated that developmental endpoints have a higher statistical power than reproductive endpoints in the current test design. The present study highlights the usefulness of individual-based models for optimizing the experimental design. The use of such models in the development of standard test guidelines will lead to a faster and less resource-demanding process.
Identification of realistic worst case aquatic macroinvertebrate species for prospective risk assessment using the trait concept
A. Gergs, S. Classen, U. Hommen & T.G. Preuss
Purpose
Approaches in environmental risk assessment for pesticides are becoming more and more realistic.... more
Purpose
Approaches in environmental risk assessment for pesticides are becoming more and more realistic. Thereby, risk assessment has to be protective in a way that no long-lasting (adverse) effects on populations will occur in the environment. Since this imperative includes species generally showing high population vulnerability due to their life history traits, prospective risk assessment should be based on realistic worst cases. Based on life history traits, the purpose of the current study was to verify whether a worst case combination of low potential for intrinsic recovery and low ability for recolonisation can be found in the field.
Methods
Combinations of traits related to dispersal ability and reproduction of macroinvertebrates were investigated using monitoring data from edge of field water bodies in Germany. The relative distribution of traits was analyzed across different agricultural regions and across sites of different potential for exposure to pesticides. Species were sorted in a tiered approach in order to gain a list of realistic worst case species.
Results
Life history traits were found equally distributed across different regions. Thereby, dispersal ability and voltinism were not randomly combined. Within the data analysed, low dispersal ability was found to be exclusive to semivoltine taxa. Owing to their appearance in reference sites, poor dispersal ability and a long time reproduction, three species were considered potentially worst case.
Conclusions
The trait approach was found to be suitable in comparing trait distributions within different regions and in compiling a list of critical taxa for consideration in environmental risk assessment.
Weight dependent bioaccumulation of a nonylphenol isomer in Daphnia magna
PREUSS, T.G.; TELSCHER, M.; RATTE, H.T.
Environ. Poll. 156: 1211-1217
Bioaccumulation is an important aspect for the fate and effects of xenobiotics in the environment. In this study we... more Bioaccumulation is an important aspect for the fate and effects of xenobiotics in the environment. In this study we used a radiolabeled nonylphenol isomer to investigate the bioconcentration in Daphnia magna at different ages. Apart from the total radioactivity we measured the metabolism of p353-NP in D. magna, to calculate the amount of p353-NP compared to total radioactivity found within the daphnids. Bioconcentration factors, based on wet weight, calculated from the rate constants for total radioactivity in neonates and adults were 4271 kg/l and 760 kg/l respectively, leading to a 5.6 deviance in bioconcentration. This deviance was even more pronounced, nearly one order of magnitude, for the p353-NP concentration with bioconcentration factors of 302 kg/l for neonates and 31 kg/l for adults. We were able to describe the bioconcentration for all daphnids by a weight-dependent one- compartment model. These results pointed out that it is not possible to compare bioconcentration experiments conducted with different substances and different sized daphnids. Additionally it was shown that it is not possible to describe the bioconcentration by measuring the total radioactivity. Metabolism of nonylphenol occurs at a very fast rate and bioconcentration is not triggered by the partition between two phases, but by metabolism. Discrimination between the two mechanisms was achieved using radiolabeled substances and a pseudo two-compartment model to describe metabolism and elimination by two rate constants which afterwards can be compared between different substances.
Some nonylphenol isomers show antiestrogenic potency in the MVLN cell assay
PREUSS, T.G.; GURER-ORHAN; MEERMAN, J.; RATTE H.T.
Toxicology in Vitro 24 (2010) 129–134
It has been shown that nonylphenol (NP) isomers vary in their estrogenic potency. These differences may be due to... more It has been shown that nonylphenol (NP) isomers vary in their estrogenic potency. These differences may be due to varieties in receptor affinity, receptor activation, or ctivation/deactivation of non-receptor mediated side paths of reporter gene translation. In the present study we investigated the underlying mechanism of the different estrogenic potency of seven nonylphenol isomers. An estrogen receptor binding assay was conducted with the human etrogen receptor alpha (hERa). Additionally we co-incubated the nonylphenol isomers with two concentrations of 17b-estradiol (E2) in the MVLN cell assay to measure the potency of the isomers to compete with E2. No significant differences were found between the nonylphenol isomer binding affinities for the hERa. The IC50 were in the range of 2.1–8.1 x 10-6 M and the binding affinity relative to estradiol (set to 1) were between 2.6 and 6.7 x 10-3. Only two test items (p353-NP and p-NP) were able to increase the estrogenic response of 100 pM estradiol. The response of the other isomers co-incubated with 100 pM E2 showed varying degrees of inhibition of the response in the MVLN reporter gene assay. Thus, it appears that all isomers bind to the ER but some are partial agonists while others are antagonists in the MVLN reporter gene assay.