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International audience; Sediments play a critical role in biogeochemical cycling and in the maintenance of the biodiversity. They are natural sinks for many contaminants which can accumulate over time and impact exposed communities, thereby disturbing the functioning of aquatic ecosystems. However, knowledge about the functional effects of contaminants on benthic communities is scarce and there is a need of ecosystem functioning indicators of ecotoxicological impacts. In the present microcosm study, we assessed the individual and combined effects of Cu and As (40 mg kg dw-1 each, 21 days of exposure) on the capacity of natural micro- and macro-organism communities from an uncontaminated river sediment to consume and decompose particulate organic matter using the bait lamina method (ISO 18311) as well as artificial tablets consisting of cellulose, bran flakes and active coal embedded in an agar matrix. The sediment toxicity was also evaluated using the standardized ostracod toxicity test (ISO 14371:2012). The two tested substrates (i.e. bait lamina and artificial tablets) showed similar results with low effects of As on feeding activity and organic matter breakdown whereas Cu demonstrated a strongest functional effect. When the two metals were combined, a total functional inhibition was observed, whatever the kind of substrate. The ostracod toxicity test also showed high toxicity of Cu-spiked and mixture-spiked sediments and low toxicity of As-spiked sediments. Our results highlight the relevance of artificial organic matter substrates to assess the functional effects of contaminants on sediment micro- and macro-organism communities, opening new perspectives to assess the functional integrity of contaminated sediments.

Additional file 1. The 20th Annual Meeting of SETAC GLB took place September 7–10, 2015 in Zurich, Switzerland. The complete program and abstracts are available as Additional file 1.

Wood preservatives are biocidal products used to protect wood building materials from wooddestroying or wood-disfiguring organisms. Active ingredients such as metallic salts, quaternary ammonium salts, carbamates and azoles are frequently employed. Solid timber or wood based products are used for diverse service situations and are therefore classified according to different "Use Classes", as defined by the European standard EN 335: 2013. Situations for which wood product is above ground and exposed to the weather or in direct contact with ground are classified under use class 3 and 4, respectively. In this case, the chemical substances employed are likely to reach the soil compartment either by leaching from the treated wood surface or by direct contact between the wood and the soil. They may then pose a potential risk for the soil organisms, the essential functions they performed and thus for the soil ecosystem in general. Currently, the available toxicity data for terrestrial organisms regarding the active ingredients present in wood preservatives are still scarce. The aim of this project was to synthesize the available knowledge regarding the toxicity for terrestrial organisms of representative active ingredients contained in wood preservatives and authorized for use in Switzerland, and to provide missing data where necessary. Therefore, a market analysis was performed to determine the active ingredients the most frequently used (calculated as the number of entries of active ingredients registered in wood preservatives authorized in Switzerland) and present on the Swiss market. More than 60% of the number of entries of active ingredients were represented by only 4 substances, i.e. IPBC, Propiconazole, Permethrin, and Tebuconazole, all belonging to use class 3. Boric acid, quaternary ammonium salts and copper based salts represented more than 15% of the number of entries for use class 4. Four wood preservatives containing the selected active ingredients, either present as a single substance or in a mix, were chosen for the ecotoxicological evaluation. They contained: 1) IPBC, 2) Propiconazole, 3) Boric acid and Copper(II)hydroxide, with Chromium as fixing agent; referred to as "CuCrB" 4) Copper(II)carbonate-Copper(II)hydroxide, Didecylpolyoxethylammoniumborat (DPAB) and Boric acid; referred to as "Quats". A review of the toxicity data available for terrestrial organisms for the chosen active ingredients was made. Literature was also searched for mixture toxicity data regarding the active ingredient combinations present in the corresponding wood preservatives. The literature search showed a lack of information regarding the toxicity of IPBC, Propiconazole and DPAB for terrestrial organisms. Toxicity of Boric acid and Copper based salts was better documented but no information on mixture toxicity was found for the active ingredient combinations. Therefore, collembolan reproduction tests and earthworm avoidance tests were performed in order to determine effect concentrations, either for the single active substance or for the active ingredient mixture contained in the wood preservatives. For IPBC, similar range of toxicity were obtained for collembolans and earthworms, with EC50s of 40 mg a.i./kg d.w. and of 33 mg a.i./kg d.w., respectively. Earthworms seemed to be more sensitive to Propiconazole than collembolans with EC50s of 52 mg a.i./kg d.w. and 192 mg a.i./kg d.w., respectively. The 2 wood preservatives containing a mix of active ingredients showed a quite high toxicity for collembolans but even greater for earthworms taking into account that 2 or more active ingredients were present in the biocidal products. For CuCrB, EC50s of 239 mg/kg d.w. and of 11 mg/kg were found for collembolans and earthworms, respectively. For Quats, the EC50 was of 873 mg/kg for collembolans and of 47 mg/kg d.w. for earthworms. The toxicity data found in the literature for the individual active ingredients themselves were much greater than the corresponding concentrations of these substances present in the wood preservative for which a toxicity was observed. Leaching data in field situation for the selected active ingredients contained in wood preservatives are nearly unavailable and data on measured environmental soil concentrations were not found. This project will provide the basis for future studies aiming at characterizing the impact of wood preservatives on soil organisms in microcosms or in field conditions.

National audience; Le sédiment constitue un compartiment dynamique et essentiel dans les écosystèmes aquatiques. Il joue un rôle important pour de nombreux animaux et végétaux en tant qu’habitat ou site de ponte. Cependant, il présente la caractéristique d’adsorber des polluants, pouvant être toxiques pour les organismes, et agissant alors comme un réservoir et une source secondaire de contamination à long-terme. Sa surveillance est donc nécessaire pour protéger l’intégrité écologique des écosystèmes aquatiques.

In the past years, it has been observed that some compounds present in our environment can disturb the reproduction and development of animals like fishes, birds, or reptiles by interfering with their endocrine system. Indeed, these endocrine disrupting compounds (EDC) can mimic or antagonize the effects of hormones, alter the pattern of synthesis and metabolism of hormones or modify hormone receptor levels. These substances represent a risk for wildlife, and possibly for humans. Up to now, endocrine disruption was mainly evaluated for vertebrates and aquatic organisms and for oestrogeniclike substances. However, soil invertebrates, which play an important role in soil functioning, have rarely been considered. Moreover, as their endocrine system differs substantially from those of vertebrates (estrogens do not seem to regulate endocrine functions in invertebrates), other substances than can mimic invertebrate hormones should be taken into account. In this sense, insect growth regulators (IGR), which are third generation insecticides specially developed to interfere with insect endocrine system, are interesting compounds. These substances are supposed to have a high specificity for insect pest and a low toxicity for non-target organisms. In the first part of this study, the sublethal effects of six IGR (methoprene, fenoxycarb, precocene II, tebufenozide, hexaflumuron and teflubenzuron) were evaluated on the non-target soil arthropod Folsomia candida. The collembola F. candida represents an integral and beneficial part of the soil ecosystem. It is an euedaphic (subsurface) species which plays an important role in soil respiration and decomposition processes and is therefore vulnerable to the effects of soil contamination. This ecologically relevant organism is one of the most appropriate invertebrate test species for the assessment of environmental quality. It is recommended as test organism by the international standard ISO 11267. The 28-days reproduction tests conducted according to this protocol show that F. candida is affected by the chosen IGR. The most toxic compounds were the two chitin synthesis inhibitors, teflubenzuron and hexaflumuron, with an EC50 of 0.05 mg/kg (dw) for teflubenzuron and an EC50 of 0.6 mg/kg for hexaflumuron. These concentrations are probably environmentally relevant (toxicity/exposure ratios

Le sédiment constitue un compartiment dynamique et essentiel dans les écosystèmes aquatiques.Il joue un rôle important pour de nombreux animaux et végétaux en tant qu’habitat ou site de ponte. Cependant, il présente la caractéristique d’adsorber des polluants, pouvant être toxiques pour les organismes, et agissant alors comme un réservoir et une source secondaire de contamination à long-terme. Sa surveillance est donc nécessaire pour protéger l’intégrité écologique des écosystèmes aquatiques.

L’interprétation des résultats d’analyses chimiques d’échantillons environnementaux de sédiments nécessite l’accès à des valeurs de référence ou à des critères de qualité consensuels. Suite à notre publication dans Aqua & Gas 4/2012, des demandes de précisions nous ont été adressées concernant les critères de qualité des sédiments pour les polychlorobiphényles (PCBs). Ces pré- cisions sont données dans cet article, avec un tableau revisé qui résume les concentrations seuils d’effet TEC et les concentrations d’effet probable PEC pour huit métaux, la somme des PCBs ainsi que celle des hydrocarbures aromatiques polycycliques (HAPs) pour les sédiments d’eau douce.

A validation or adaptation of the TEC-PEC values for Switzerland is recommended before SQG can be implemented. Background concentrations can be established on a regional scale when a broad database is available, e.g. 5%-percentile of data. Else the FOREGS (Forum of the European Geology Surveys; www.gsf.fi/publ/foregsatlas) can be used as a rough indicator. A tiered approach that includes an initial comparison against TEC-PEC values and a subsequent consideration of background/natural metal concentrations can serve as a preliminary framework until SQG are implemented in Switzerland. Harmonisation of sampling and pre-treatment methods is required.

In the past years, it has been observed that some compounds present in our environment can disturb the reproduction and development of animals like fishes, birds, or reptiles by interfering with their endocrine system. Indeed, these endocrine disrupting compounds (EDC) can mimic or antagonize the effects of hormones, alter the pattern of synthesis and metabolism of hormones or modify hormone receptor levels. These substances represent a risk for wildlife, and possibly for humans. Up to now, endocrine disruption was mainly evaluated for vertebrates and aquatic organisms and for oestrogeniclike substances. However, soil invertebrates, which play an important role in soil functioning, have rarely been considered. Moreover, as their endocrine system differs substantially from those of vertebrates (estrogens do not seem to regulate endocrine functions in invertebrates), other substances than can mimic invertebrate hormones should be taken into account. In this sense, insect growth regulators (IGR), which are third generation insecticides specially developed to interfere with insect endocrine system, are interesting compounds. These substances are supposed to have a high specificity for insect pest and a low toxicity for non-target organisms. In the first part of this study, the sublethal effects of six IGR (methoprene, fenoxycarb, precocene II, tebufenozide, hexaflumuron and teflubenzuron) were evaluated on the non-target soil arthropod Folsomia candida. The collembola F. candida represents an integral and beneficial part of the soil ecosystem. It is an euedaphic (subsurface) species which plays an important role in soil respiration and decomposition processes and is therefore vulnerable to the effects of soil contamination. This ecologically relevant organism is one of the most appropriate invertebrate test species for the assessment of environmental quality. It is recommended as test organism by the international standard ISO 11267. The 28-days reproduction tests conducted according to this protocol show that F. candida is affected by the chosen IGR. The most toxic compounds were the two chitin synthesis inhibitors, teflubenzuron and hexaflumuron, with an EC50 of 0.05 mg/kg (dw) for teflubenzuron and an EC50 of 0.6 mg/kg for hexaflumuron. These concentrations are probably environmentally relevant (toxicity/exposure ratios