Mixtures of Chemical Pollutants at European Legislation Safety Concentrations: How Safe Are They?

The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentration

Mixtures of chemical pollutants at European legislation safety concentrations: how safe are they?

The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations

Toward the Development of Certified Reference Materials for Effective Biodiesel Testing - Part 2: Characterization and Value Assignment

A comprehensive feasibility study for the production of a biodiesel reference material for relevant specification parameters as provided in EN 142141 was launched because of insufficient knowledge available for most of the steps needed for the production of new biodiesel certified reference materials (CRMs). This paper summarizes the findings of this study for the characterization and final value assignment of a biodiesel reference material. Assigned values were calculated as the unweighted mean of the laboratory means of the accepted sets of results for each parameter. Uncertainties were estimated in compliance with the “Guide to the Expression of Uncertainty in Measurement” (GUM, ISO/IEC Guide 98-3:2008),2 including contributions from characterization, homogeneity, and stability studies. Of the 22 parameters considered overall, it could be shown that it would be feasible to prepare and certify reference material for 7 of them (ester, linolenic acid methyl ester, triacylglycerol, total glycerol, iodine value, oxidation stability, and acid value) with the approach taken thus far. For the remaining parameters, different problems were encountered. Although raising a considerable number of challenges, the development of a future biodiesel CRM for many parameters seems feasible. The provision of such a material would favor the building of a harmonized measurement system and, consequently, comparable analytical results.JRC.D.2-Reference material

Toward the Development of Certified Reference Materials for Effective Biodiesel Testing - Part 1: Processing, Homogeneity, and Stability

To address the current lack of certified reference materials (CRMs) for biodiesel analysis, the Institute for Reference Materials and Measurements (IRMM), Joint Research Centre (JRC), European Commission (EC), launched a comprehensive feasibility study on the production of biodiesel CRMs for relevant specification parameters as provided in EN 14214,1 the basis for defining product specifications and measurement methods for biodiesel in the European Union (EU). Laboratories need to be able to check the performance of their methods. This is also true for standardized methods, the use of which does not per se guarantee reliable results. Without underestimating the role and importance of other quality control tools, this paper is focused on aspects for the development of appropriate CRMs to be used for quality control in biodiesel analysis. Homogeneity and stability of a biodiesel material were investigated with dedicated studies. Of the 22 parameters considered overall, it could be shown that it would be feasible to produce a sufficiently homogeneous and stable material for 12 of them in a straightforward manner.JRC.D.2-Reference material

Anaerobic bioremediation of groundwater containing a mixture of 1,1,2,2-tetrachloroethane and chloroethenes

This study investigated the biotransformation pathways of 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA) in the presence of chloroethenes (i.e. tetrachloroethene, PCE; trichloroethene, TCE) in anaerobic microcosms constructed with subsurface soil and groundwater from a contaminated site. When amended with yeast extract, lactate, butyrate, or H-2 and acetate, 1,1,2,2-TeCA was initially dechlorinated via both hydrogen-olysis to 1,1,2-trichloroethane (1,1,2-TCA) (major pathway) and dichloroelimination to dichloroethenes (DCEs) (minor pathway), with both reactions occurring under sulfidogenic conditions. In the presence of only H-2, the hydrogenolysis of 1,1,2,2-TeCA to 1,1,2-TCA apparently required the presence of acetate to occur. Once formed, 1,1,2-TCA was degraded predominantly via dichloroelimination to vinyl chloride (VC). Ultimately, chloroethanes were converted to chloroethenes (mainly VC and DCEs) which persisted in the microcosms for very long periods along with PCE and TCE originally present in the groundwater. Hydrogenolysis of chloroethenes occurred only after highly reducing methanogenic conditions were established. However, substantial conversion to ethene (ETH) was observed only in microcosms amended with yeast extract (200 mg/l), suggesting that groundwater lacked some nutritional factors which were likely provided to dechlorinating microorganisms by this complex organic substrate. Bioaugmentation with an H-2-utilizing PCE-dechlorinating Dehalococcoides spp. -containing culture resulted in the conversion of 1,1,2,2-TeCA, PCE and TCE to ETH and VC. No chloroethanes accumulated during degradation suggesting that 1,1,2,2-TeCA was degraded through initial dichloroelimination into DCEs and then typical hydrogenolysis into ETH and VC

Assessment of natural or enhanced in situ bioremediation at a chlorinated solvent-contaminated aquifer in Italy: a microcosm study

A microcosm study was used to assess the potential for in situ natural or enhanced bioremediation at a chloroethane- (i.e., tetrachloroethane, TeCA) and chloroethene-contaminated (i.e., tetrachloroethene, PCE; trichloroethene, TCE) groundwater in Northern Italy. All the live microcosms were positive for dechlorination, indicating the presence of an active native dechlorinating population in the subsurface. All the tested electron donors (i.e., yeast extract, lactate, butyrate, hydrogen) promoted enhanced dechlorination of chlorinated contaminants. Lactate- and butyrate-amended microcosms performed the best, and also dechlorinated the solvents past cis-dichloroethene (cis-DCE). The microcosm bioaugmented with a PCE-dechlorinating mixed culture containing Dehalococcoides spp. dechlorinated groundwater contaminants to DCE, vinyl chloride (VC), and ethene (ETH). In conclusion, results from this microcosm study indicate the potential for enhancing full dechlorination at the contaminated site, through a proper addition of a suitable electron donor (e.g., lactate or butyrate) and/or through bioaugmentation with a Dehalococcoides-containing culture. (C) 2004 Elsevier Ltd. All rights reserved

Joint Research Project env08 “Traceable measurements for monitoring critical pollutants under the European Water Framework Directive (WFD) 2000/60/EC”

The Joint Research Project ENV08 “Traceable measurements for monitoring critical pollutants under the European Water Framework Directive (WFD) 2000/60/EC” is a multi-partner trans-national project within the targeted call “Environment” of the European Metrology Research Programme (EMRP). The EMRP represents a metrology-focused European programme of coordinated research and development that facilitates closer integration of national research programmes. ENV08 deals with the grand challenges for multidisciplinary metrology in environment meeting “the most urgent industrial and societal needs” as stated in the EMRP Outline 2008. The project aims to provide reference methods capable of analysing priority hazardous substances specified in the WFD at the proposed low environmental quality standard concentrations in the body of ground, surface and coastal waters. In addition, ENV08 will answer the need for accuracy and comparability of measurements for the end users capabilities assessment by developing concepts for reference materials. ENV08 is coordinated by BAM (Germany) and involves 14 European institutes. Five institutes work on the development of a validated measurement procedure for Polycyclic Aromatic Hydrocarbons (PAH) in whole water samples at a concentration level required by the EU Water Framework Directive (WFD)

The BIOREMA project - Part 2: International interlaboratory comparison for biodiesel test methods

The results of an interlaboratory comparison, using various measurement methods to carry out biodiesel testing, are presented and the findings are discussed. The interlaboratory comparison was organised within the framework of an EU-funded project called BIOREMA. A general overview of the project and results of an interlaboratory comparison on bioethanol are published as Part 1 and 2 of this series of papers. In the study presented here, reference values, provided by national metrology institutes and expert laboratories, were used for evaluating the results. Consensus values, derived from the results of all participants, were used to assess any bias between the results from the national metrology institutes and testing laboratories. The emphasis in this interlaboratory comparison was not the performance rating of the individual laboratories, but recognising and interpreting differences caused by the measurement methods applied. For most biodiesel parameters, a good agreement of measurement results was found among different methods, and between the consensus and reference values. The study material was a rapeseed oil fatty acid methyl ester, for which it was demonstrated that it is feasible to prepare and characterise reference materials for biodiesel with well-established reference values for many parameters.JRC.D.2-Standards for Innovation and sustainable Developmen