Ecotoxicity parameter

As of 1981, when theEuropeanchemicalspolicy was implemented, theEuropean Union required the submission of base set test data for physiochemical, environmental fate, toxicological properties and health effects, and ecotoxicity parameters for new... 

The environmental fate and pathways and the ecotoxicity parameters implemented in the IUCLID database (Allanou et al. 1999) will be looked upon. These are ... 

The development of models incorporating biomarker assays to predict the effects of chemicals upon parameters related to r has obvious attractions from a scientific point of view and is preferable, in theory, to the crude use of ecotoxicity data currently employed in procedures for environmental risk assessment. However, the development of this approach would involve considerable investment in research, and might prove too complex and costly to be widely employed in environmental risk assessment. 

A few decades ago the range of chemical descriptors used was very limited. Let us take the example of Corwin Hansch s studies, in which he described the relationship between ecotoxicity and a series of parameters, including log P... 

In response to the concern expressed by the shellfish farmers operating in the Ebro River delta about the potential positive role of pesticides on the oyster and mussel mortalities observed in the area, our group, commissioned by and with the collaboration of the Catalan Water Agency (ACA), carried out a comprehensive study in which chemical and toxicity data were combined to assess potential toxic presures present in the delta. To this end, a combined approach scheme integrating the measurement of various general physicochemical parameters in water, quantitative chemical analysis of pesticides in water and biota, and ecotoxicity assays in water was applied to a series of samples collected at springtime (between mid-April and mid-June 2008) from six selected sites of the delta the two (northern and southern)... 

Over the last decade, much interest has been generated in monitoring environmental problems and associated risks of wastes, in particular, wastewaters generated by the pulp and paper industries. A major goal is to reassess the target pollutant levels and consider the use of risk-based discharge permit values rather than the absolute endpoint values. This risk-based approach requires analytical tools that can quantify the ecotoxic characteristics of discharges rather than the absolute concentration of specihc pollutants or the values of lumped pollution parameters such as BOD, COD, and so on. 

Helma, C., Eckl, P., Gottmann, E., Kassie, F., Rodinger, W., Steinkellner, EL, Windpassinger, C., Schulte-Hermann, R. and Knasmiiller, S. (1998) Genotoxic and ecotoxic effects of groundwaters and their relation to routinely measured chemical parameters, Environmental Science and Technology 32 (12), 1799-1805. 

This approach can be applied for substances rich in ecotoxicity data as well as for substances poor in ecotoxicity data. The prerequisite is knowledge of the soil parameter values influencing availability of the substance in the individual ecotoxicity tests. It is also important to be aware of the associated uncertainties of these data. 

Nendza M, Jackel H, Muller M, Giesreuschel A, Klein W. Estimation of exposure and ecotoxicity related parameters by computer based structure-property and structure-activity relationships. Toxicol Environ Chem 1993 40 57-69. 

Based on case studies, many countries have tried to develop similar indices where a number of toxicological parameters are integrated with the aim of quickly measuring the potential danger of the samples, particularly industrial effluents. The potential ecotoxic effects probe (PEEP) is one of the best known. It was developed in Canada as part of the St. Lawrence River Action Plan and was used to rank the impact of 50 industrial effluents discharged daily into the St. Lawrence River (Costan elal.. 1993). 

Van Straalen, N.M. and Kammenga, J.E. (1998) Assessment of ecotoxicity at the population level using demographic parameters. In Ecotoxicology, Schiiurmann, G. and Markert, B. (eds), pp. 621-644. John Wiley and Sons and Spektrum Akademischer Verlag, London. 

Instead of four similarities between Widuchowa samples (WD) in case of chemical pollution, ecotoxicological parameters without exception lead to incomparabilities between WD samples, thus indicating significant differences in their ecotoxicity. 

In contrast to the evaluations above where equivalence classes are a consequence of clustering results (instead of original parameter values samples obtain the values of cluster centres), here equivalence classes are a result of equivalent pattern concerning the three parameter groups (chemicals, ecotox. and biochemical tests). 

Aggregation to get three super indicators concerning environmental fate (FATE), ecotoxicity (ETOX), and chemical information (CHID) (Section Aggregation equal weight of environmental Parameters and Chemicals )... 

By this aggregation the aspects of fate, ecotoxicity and chemicals are maintained and kept separately for further analysis. This "thematic" aggregation can be interpreted as taking a more abstract level of consideration Not which specific fate parameter is important, but the whole concept of fate in comparison to other criteria. 

By their Code of Ethics ETAD member companies are required to provide a Material Safety Data Sheet (MSDS) that contains parameters relevant to the ecotoxicity (LCjo, EC50, elimination, COD, BOD for some categories of dyes the partition coefficient n-octanol/water is available). 

In another approach, with an aim to offer a realistic motive towards handling millions of databases and hundreds of descriptors for a fruitful structure-activity relationship (SAR), Putz and coworkers have proposed a unique QSAR model called spectral-SAR (S-SAR) [220], which considers the spectral norm in quantifying toxicity and reactivity with molecular structure. A handful of applications of the S-SAR algorithm in dealing with ecotoxicity, enzyme activity, and anticancer bioactivity are well established [221-227]. The S-SAR model coupled with Element Specific Influence Parameter (ESIP) formulations [228] are also utilized for predicting ecotoxicity measures. QSAR studies on the anti-HIV-1 activity of HEPT (l-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine) [229] and further studies involving the minimum topological difference (MTD) method [230, 231] are also reported [232]. 

The data-quality requirements for QSAR models relate to several aspects of the experimental procedure, data transformation and the selection of the appropriate test compounds. Only if the input data of a QSAR meet the highest quality standards may a sound model be derived. Because the accuracy of predictions can never be better than the variability of the respective measurements (usually 20% and more), validity assessment of the activity and effects data is crucial in QSAR derivations. The data should be generated by tests that are methodologically and mechanistically defined. The latter is not trivial for parameters such as biodegradability, soil sorption and ecotoxicity. With regard to the considerable variability of measurements, inter- and also intra-laboratory, the test results, especially when collected from different literature sources, should be critically evaluated with respect to ... 

The compounds subject to a QSAR analysis must differ sufficiently in activity to provide the basis for a representative model and to avoid the description of local phenomena. If the activity range is too narrow it may over-value the inherent variance in the experimental data, which may significantly exceed 20% for parameters such as soil sorption, bioconcentration and ecotoxicity. The difference in activity between compounds must therefore clearly exceed that among the replicated measurements for each of the test substances. Otherwise, the derived QSAR may show an artificial relationship between the compounds structure and the experimental scatter, but not the effects under investigation. 

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