Simulating synergism or antagonism in binary mixtures with different modeling approaches - A case study focused on the effect of disinfection by-products on algal growth.

This paper aims to test several modeling approaches for predicting toxicity of binary mixtures with potential synergy and antagonism. The approach based on the construction of isoboles was first tested and criticized. In contrast to conventional approaches, and in order to be mathematically consistent with the additivity assumptions, non-linear isoboles have been constructed.

Sub-lethal toxicity of five disinfection by-products on microalgae determined by flow cytometry - Lines of evidence for adverse outcome pathways.

Standardised tests are often used to determine the ecotoxicity of chemicals and focus mainly on one or a few generic endpoints (e.g. mortality, growth), but information on the sub-cellular processes leading to these effects remain usually partial or missing.

Inter-laboratory validation of an ISO test method for measuring enzyme activities in soil samples using colorimetric substrates.

The evaluation of soil quality requires the use of robust methods to assess biologically based indicators. Among them, enzyme activities are used for several decades, but there is a clear need to update their measurement methods for routine use, in combining feasibility, accuracy, and reliability. To this end, the platform Biochem-Env optimized a miniaturized method to measure enzyme activities in soils using colorimetric substrates in micro-well plates.

Nanopharmaceuticals (Au-NPs) after use: Experiences with a complex higher tier test design simulating environmental fate and effect.

The current environmental hazard assessment is based on the testing of the pristine substance. However, it cannot be excluded that (nano)pharmaceuticals are excreted into sewage during the use phase followed by entry into wastewater treatment plants (WWTPs). Sorption to sewage sludge or release via effluent can result in modified ecotoxicological effects which possibly can only be detected with a modified test approach.

Evaluation of the OECD QSAR toolbox automatic workflow for the prediction of the acute toxicity of organic chemicals to fathead minnow.

Regulatory frameworks require information on acute fish toxicity to ensure environmental protection. The experimental assessment of this property relies on a substantial number of fish to be tested and it is in conflict with the current drive to replace in vivo testing. For this reason, alternatives to in vivo testing have been proposed during the past years.

Enhancing the Antioxidant Activity of Technical Lignins by Combining Solvent Fractionation and Ionic-Liquid Treatment.

A grass soda technical lignin (PB1000) underwent a process combining solvent fractionation and treatment with an ionic liquid (IL), and a comprehensive investigation of the structural modifications was performed by using high-performance size-exclusion chromatography, P NMR spectroscopy, thioacidolysis, and GC-MS. Three fractions with distinct reactivity were recovered from successive ethyl acetate (EA), butanone, and methanol extractions. In parallel, a fraction deprived of EA extractives was obtained.

Cigarette butts: A small but hazardous waste, according to European regulation.

The emergence of companies collecting cigarette butts (CB) leads to a new waste stream, exclusively made of butts, whereas they were previously mixed with household and municipal waste. In order to conclude on the classification of this new stream, according to the Waste Framework Directive, three cigarette butts samples were analyzed and submitted to ecotoxicological tests. Hazard properties HP 4 (irritant - skin irritation and eye damage), HP 5 (specific target organ toxicity/aspiration toxicity), HP 6 (acute toxicity), HP 7 (carcinogenic), HP 8 (corrosive), HP 10 (toxic for reproduction), HP 11 (mutagenic) and HP 13 (sensitising) have been assessed by calculation, thanks to the analytical results.

A bacterium-based contact assay for evaluating the quality of solid samples-Results from an international ring-test.

The contact assay measuring the inhibition of Arthrobacter globiformis dehydrogenase activity as an endpoint to evaluate the toxicity of solid samples was tested in an international ring-test to validate its performance for ISO standardization (ISO/CD 18187). This work reports the results of the ring-test involving 9 laboratories from six countries. At least 8 valid data sets were obtained for each sample and more than three quarters of the participants attained the validity criteria defined in the standard.

Comprehensive Insights into the Thermal Stability, Biodegradability, and Combustion Chemistry of Pyrrolidinium-Based Ionic Liquids.

The use of ionic liquids (ILs) as advanced electrolyte components in electrochemical energy-storage devices is one of the most appealing and emerging options. However, although ILs are hailed as safer and eco-friendly electrolytes, to overcome the limitations imposed by the highly volatile/combustible carbonate-based electrolytes, full-scale and precise appraisal of their overall safety levels under abuse conditions still needs to be fully addressed. With the aim of providing this level of information on the thermal and chemical stabilities, as well as actual fire hazards, herein, a detailed investigation of the short- and long-term thermal stabilities, biodegradability, and combustion behavior of various pyrrolidinium-based ILs, with different alkyl chain lengths, counteranions, and cations, as well as the effect of doping with lithium salts, is described.

Results from a round robin test for the ecotoxicological evaluation of construction products using two leaching tests and an aquatic test battery.

A European round robin test according to ISO 5725-2 was conceptually prepared, realised, and evaluated. The aim was to determine the inter-laboratory variability of the overall process for the ecotoxicological characterization of construction products in eluates and bioassays. To this end, two construction products BAM-G1 (granulate) and HSR-2 (roof sealing sheet), both made of EPDM polymers (rubber), were selected.

Validation of a two-generational reproduction test in Daphnia magna: An interlaboratory exercise.

Effects observed within one generation disregard potential detrimental effects that may appear across generations. Previously we have developed a two generation Daphnia magna reproduction test using the OECD TG 211 protocol with a few amendments, including initiating the second generation with third brood neonates produced from first generation individuals. Here we showed the results of an inter-laboratory calibration exercise among 12 partners that aimed to test the robustness and consistency of a two generation Daphnia magna reproduction test.

Evaluation of the extraction efficiency for the Hypoaspis aculeifer reproduction test in the context of soil quality assessment.

The standardized bioassay using the predatory mite Hypoaspis aculeifer (TG 226; as reported by OECD 2008) has already proven its usefulness for the assessment of chemicals. While included in the regulatory assessment scheme of pesticides as a non-target arthropod, it has still been rarely used for the assessment of soils or complex matrices of unknown quality. For such an objective, the extraction of both adults and juveniles from soil is a necessary and crucial step to get reliable data, but may be influenced by the characteristics of the tested soils or matrices.

Bioassay battery interlaboratory investigation of emerging contaminants in spiked water extracts - Towards the implementation of bioanalytical monitoring tools in water quality assessment and monitoring.

Bioassays are particularly useful tools to link the chemical and ecological assessments in water quality monitoring. Different methods cover a broad range of toxicity mechanisms in diverse organisms, and account for risks posed by non-target compounds and mixtures. Many tests are already applied in chemical and waste assessments, and stakeholders from the science-police interface have recommended their integration in regulatory water quality monitoring.

Adapting OECD Aquatic Toxicity Tests for Use with Manufactured Nanomaterials: Key Issues and Consensus Recommendations.

The unique or enhanced properties of manufactured nanomaterials (MNs) suggest that their use in nanoenabled products will continue to increase. This will result in increased potential for human and environmental exposure to MNs during manufacturing, use, and disposal of nanoenabled products. Scientifically based risk assessment for MNs necessitates the development of reproducible, standardized hazard testing methods such as those provided by the Organisation of Economic Cooperation and Development (OECD).

Exploration of Daphnia behavioral effect profiles induced by a broad range of toxicants with different modes of action.

Behavior is increasingly reported as a sensitive and early indicator of toxicant stress in aquatic organisms. However, the systematic understanding of behavioral effects and comparisons between effect profiles is hampered because the available studies are limited to few chemicals and differ in the exposure conditions and effect parameters examined. The aims of the present study were 1) to explore behavioral responses of Daphnia magna exposed to different toxicants, 2) to compare behavioral effect profiles with regard to chemical modes of action, and 3) to determine the sensitivity and response time of behavioral parameters in a new multi-cell exposure system named Multi-DaphTrack compared with currently utilized tests.

Ecotoxicological assessment of organic wastes spread on land: Towards a proposal of a suitable test battery.

The land spreading of organic wastes in agriculture is a common practice in Europe, under the regulation of the Directive 86/278/EEC. One of the objectives of this Directive is to prevent harmful effects of organic wastes on soil, plants and animals. Despite this regulatory framework, there is still a lack of harmonized ecotoxicological test strategy to assess the environmental hazard of such wastes.

The use of soil mites in ecotoxicology: a review.

Mites, and especially soil-inhabiting ones, have been less studied than the other invertebrates used in bio-assays for the assessment of soil quality and the hazards of chemicals, although these organisms are included in the regulatory assessment scheme of pesticides. The recent advances in the development of test methods for soil mites groups have provided more information on their sensitivities towards chemicals, which needs to be presented for a more robust assessment of the current trends in soil mite ecotoxicology. Moreover, interestingly mite is the only taxa for which test methods were developed and standardized on predatory organisms.

Soil genotoxicity assessment--results of an interlaboratory study on the Vicia micronucleus assay in the context of ISO standardization.

The Vicia micronucleus assay was standardized in an international protocol, ISO 29200, "Assessment of genotoxic effects on higher plants-Vicia faba micronucleus test," for soil or soil materials (e.g., compost, sludge, sediment, waste, and fertilizing materials).

Inter-laboratory trial of a standardized sediment contact test with the aquatic plant Myriophyllum aquaticum (ISO 16191).

A whole-sediment toxicity test with Myriophyllum aquaticum has been developed by the German Federal Institute of Hydrology and standardized within the International Organization for Standardization (ISO; ISO 16191). An international ring-test was performed to evaluate the precision of the test method. Four sediments (artificial, natural) were tested.

Ecotoxicity of non-aged and aged CeO2 nanomaterials towards freshwater microalgae.

The ecotoxicity of artificially alterated cerium dioxide nanoparticles (nano-CeO2) suspensions was determined using the freshwater microalgae growth inhibition test. The agglomeration or aggregation state of the alterated suspensions was followed because it represents one of the obvious modifications when nanoparticles reached the environment. In addition, its influence on the ecotoxicity of nanoparticles is currently not well-addressed.

Improvement of the Caenorhabditis elegans growth and reproduction test to assess the ecotoxicity of soils and complex matrices.

A growth and reproduction test using the nematode Caenorhabditis elegans was recently standardized by the International Organization for Standardization (ISO). Performing the ISO 10872 protocol (2010) revealed some drawbacks when applied to soil or soil mixed with complex matrices. The authors propose some modifications to the current protocol to normalize the test conditions.

Proposal for a "Harmonized" strategy for the assessment of the HP 14 property.

In Europe, the decision whether waste is hazardous or not is based on 15 properties, among them the HP 14 property ("ecotoxic": waste that presents or may present immediate or delayed risks for 1 or more sectors of the environment). This document describes a strategy for assessing the HP 14 property, based on a combination of 2 approaches: the summation of classified compounds in the waste carried out according to the regulation on Classification, Labeling and Packaging (CLP) of substances and mixtures and the usage of the results of biotests performed on waste eluates and solid wastes. The proposal is based mainly on recommendations of a European ring test carried out in 2007, the work performed in the CEN/TC 292/WG 7 standardization working group, and the results of various research projects regarding the ecotoxicological characterization of waste carried out mainly in France and Germany.

Standardisation of methods in soil microbiology: progress and challenges.

A plethora of methods have been developed over the few last decades to enable a better understanding of the ecology of soil microbial communities and their roles in soil functioning. However, there is generally considerable variation (both subtle and more extensive) in the actual realisation of these methods, and limited efforts have been devoted to their standardisation, despite this being crucial to underpin data comparison and integration. Ensuring comparable data across studies through standardisation is arguably best-practice, as well as necessary to effectively meet the objectives of various schemas, which require assessment of the consequences of the global change and intensification of human activities on the functioning of the soil ecosystem and its biological diversity.

Exploring an ecotoxicity database with the OECD (Q)SAR Toolbox and DRAGON descriptors in order to prioritise testing on algae, daphnids, and fish.

The European regulation on chemicals (REACh) places emphasis on reduction of systematic toxicity testing, thus fostering development of alternative methods. Consequently, we analysed acute toxicity data gathered by the Japanese Ministry of Environment for three species belonging to three different trophic levels (i.e.