Ecotoxicity testing

With improvements in scientific knowledge and related technology, there is an expectation that more environmentally friendly pesticides will continue to be introduced, and that ecotoxicity testing procedures will become more sophisticated. There is much interest in the introduction of better testing procedures that work to more ecologically relevant end points than the lethal toxicity tests that are still widely used. Such a development should be consistent with the aims of organizations such as FRAME and ECVAM, which seek to reduce toxicity testing with animals. Mechanistic biomarker assays have the potential to be an important part of... 

Walker, C.H. (2006). Ecotoxicity testing of chemicals with particular reference to pesticides. Pest Management Science 62, 571-583. 

One of the most simple in application and an accessible test-object for biotesting are Infusorians. Incentive motives for the infusorians use in ecotoxic testing are the following [1, 2] ... 

Freshwater media based on the OECD 203 ecotoxicity testing medium for fish and daphnia have been used in all T/DP testing of metals, metal compounds and alloys in the pH range 6-8.5 to date. However, the composition of a marine medium is also given in the T/DP section of the GHS, and by implication, a method for marine T/D testing is open for development and validation. While not currently required for REACH dossiers, T/D data in marine media and attendant classification proposals may be required in the future for marine shipping. 

Stevens, C. Annelein, R. B. Ecotoxicity Testing Challenges of Organosilicon Materials. In The Handbook of Environmental Chemistry Vol. 3 Antropogenic Compounds, Part H Chandra, G., Ed. Springer Berlin, 1997 Chapter 4, pp 83-103. 

ThermoWood is not resistant to exterior weathering and the colour will gradually change to the grey that is characteristic of outdoor exposed wood. In addition, exposure in exterior conditions results in the formation of small cracks on the surface of uncoated wood. Unpigmented or low-build stain coatings do not protect the surface of the wood, but solvent-borne alkyds and water-borne acrylic paints have been found to exhibit better performance than on unmodified wood. VOC emissions from the heat-treated wood are lower compared to unmodified wood and the compositions of the emissions differ. The level of emissions is lower when the wood is treated at a higher temperature. Emissions of terpenes are reduced to very low levels, and the VOC content is dominated by furfural, hexanal and acetic acid (treated at 180 °C), and by acetic acid (treated at 230 °C). ThermoWood passes ecotoxicity tests. 

Kapanen, A. Itavaara, M. Ecotoxicity tests for compost applications. Ecotox. Environ. Safe. 2001, 49, 1-16. 

Bentley, A. Atkinson, A. Jezek, J. Rawson, D.M. Whole cell biosensors - electrochemical and optical approaches to ecotoxicity testing. Toxicol, in Vitro 2001, 15, 469-475. 

Tsvetnenko, Y. and Evans, L. (2002) Improved approaches to ecotoxicity testing of petroleum products. Mar. Pollut. Bull., 45, 148-156. 

Aquatic ecotoxicology evaluates the probability of an adverse impact of a substance on the aquatic environment at the present as well as in the future, considering the total flow into the system (Klein, 1999). It encompasses laboratory ecotoxicity tests on appropriate test organisms to explore relationships between exposure and effect under controlled conditions as well as studies of the effects of substances or effluents under a variety of ecological conditions in complex field ecosystems (Chapman, 1995). 

Standardized ecotoxicity tests (bioassays) have been developed and optimized over the last few years and encompass the effects on bacteria, daphnia and fish (DIN 38 412, parts 30, 31 and 34). These tests are designed to assess the toxicity on aquatic organisms. They are quick to perform, easy to handle and comparatively inexpensive, with the goal of allowing the toxicity of a complex water matrix to be estimated. However, they use pre-concentration steps so that it is possible that not all byproducts are recovered (which itself is hard to prove). 

Chapman J C (1995) The Role of Ecotoxicity Testing in Assessing Water Quality, Australian Journal of Ecology, 20(1) 20-27. 

Botanical tests would be evaluated using similar criteria as those used on other ecotoxicity tests. 

Babich, H. and Borenfieund, E. (1987) Cultured fish cells for the ecotoxicity testing of aquatic pollutants,... 

Baer, K.N., Ziegenfiiss, M.C., Banks, S.D. and Ling, Z. (1999) Suitability of high-hardness COMBO medium for ecotoxicity testing using algae, daphnids, and fish, Bulletin of Environmental Contamination and Toxicology 63 (3), 289-296. 

Isnard, P., Flammarion, P., Roman, G., Babut, M., Bastien, P., Bintein, S., Essermeant, L., Ferard, J.F., Gallotti-Schmitt, S., Saouter, E., Saroli, M., Thiebaud, H., Tomassone, R. and Vindimian, E. (2001) Statitical analysis of regulatory ecotoxicity tests, Chemosphere 45, 659-669. 

Pablos, V., Fernandez, C., Valdovinos, C., Castano, A., Munoz, M.J. and Tarazona, J.V. (1996) Use of ecotoxicity tests as biological detectors of toxic chemicals in the environmental analysis of complex sewages, Toxicology Letters 88 (Supplement 1), 82-82. 

In the WASTOXHAS procedure, ecotoxicity testing of leachate samples obtained at different liquid-to-solid ratios (or at different times of release) aims at measuring effects on species representing various levels of biological organization (see Section 5.4) as a function of dilution rate while controls without leachate are used as reference. In order to express results in a synthetic form, raw data obtained from concentration-response curves are transformed into a summary criterion corresponding to a specific measurement endpoint (e.g., EC5o, ECX, NOEC, LOEC, etc.) for each test (Fig. 3). 

For the BA waste, even if sensitivity ranking of ecotoxicity tests is similar, the evolution of ecotoxic hazard potential of the leachate fluxes was different between the two approaches. In the field, the ecotoxic hazard potential of leachate fluxes decreased, whereas it increased for the laboratory column study. The column approach tends to overestimate the long-term ecotoxic hazard potential of BA leachate fluxes generated in the field. This overestimation of the long-term ecotoxic hazard potential of leachate fluxes generated in the field may indicate that relevant factors such as 1) residence time of water in the waste, 2) the continuous or discontinuous watering of the waste and/or 3) the physico-chemical characteristics of the water used for obtaining leachates were not considered in the column approach. 

Table 9. Downward-flow column study and field scale study - Comparison of the two procedures based on the sensitivity responses of ecotoxicity tests and on the corresponding waste PEEP index values (see Section 5.6 for the detail of calculations) for a municipal solid waste incinerator bottom ash (BA) and a slag from a second smelting of lead (2SL) at different liquid-to-solid ratios (L/S).

Waste Procedure L/S ratio Sensitivity of ecotoxicity tests Waste PEEP index value Waste PEEP trend... 

Ai t-Ai ssa, S., Pandard, P., Magaud, H., Arrigo, A.P., Thybaud, E. and Porcher, J.M. (2003) Evaluation of in vitro hsp70 induction test for toxicity assessment of complex mixtures comparison with chemical analyses and ecotoxicity tests, Ecotoxicology and Environmental Safety 54, 92-104. 

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