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A method to evaluate the ecological risk of chemical mixtures in water bodies is here presented. In the first phase, the approach considered routine chemical monitoring data (MEC: measured environmental concentrations) obtained from the Italian National Institute for Environmental Protection and Research, which were georeferenced to a single coordinate system for each monitoring station. The overall mixture toxicity were then evaluated for three representative aquatic organisms (algae, Daphnia, fish) using the concentration addition model to combine exposure with ecotoxicological data (from different databases). A database management system was used to facilitate the creation, organisation, and management of the large datasets of this study. The outputs were obtained as GIS-based mixture risk maps and tables (listing the toxic unit of mixtures and individual substances) useful for further analysis. The method was applied to an Italian watershed (Adda River) as a case study. In the first phase, the mixture toxicity was calculated using two scenarios: best- and worst-case; wherein the former included only those compounds that were be detected, while the latter involved also substances with concentrations below the limit of quantification. The ratio between the two scenarios indicated the range within which mixture toxicity should ideally vary. The method demonstrates that these ratios were very small when the calculated toxicity using the best case indicated a potential risk and vice versa, indicating that the worst-case scenario could not be appropriate (extremely conservative). Consequently, in the successive phase, we focused exclusively on the best-case scenario. Finally, this approach allowed the priority mixture identification (those most likely occurring in the analysed water samples), algae as the organism at the highest risk, and the substances that contributed the most to the overall mixture toxicity (terbuthylazine and s-metolachlor for algae, and chlorpyrifos and chlorpyrifos-CH3 for Daphnia and fish).

The degradation and bioaccumulation of selected antibiotics such as the sulfonamide sulfamethoxazole (SMX) and the fluoroquinolones enrofloxacin (ENR) and ciprofloxacin (CIP) were investigated in soil microcosm experiments where Lactuca sativa was grown with manure or digestate (1%) and spiked with a mixture of the three antibiotics (7.5 mg/kg each). The soil, rhizosphere and leaf phyllosphere were sampled (at 0 and 46 days) from each microcosm to analyze the antibiotic concentrations, main resistance genes (sul1, sul2, qnrS, aac-(6')-Ib-crand qepA), the intI1and tnpA mobile genetic elements and the microbial community structure.Overall results showed that SMX and CIP decreased (70-85% and 55-79%, respectively), and ENR was quite persistent during the 46-day experiment. In plant presence, CIP and ENR were partially up-taken from soil to plant. In fact the bioaccumulation factors were1, with higher values in manure than digestate amended soils. The most abundant gene in soil was sul2 in digestate- and aac-(6')-Ib-cr in the manure-amended microcosms. In soil, neither sulfamethoxazole-resistance (sul1 and sul2), nor fluoroquinolone-resistance (aac-(6')-Ib-cr, qepA and qnrS) gene abundances were correlated with any antibiotic concentration. On the contrary, in lettuce leaves, the aac-(6')-Ib-cr gene was the most abundant, in accordance with the fluoroquinolone bioaccumulation. Finally, digestate stimulated a higher soil microbial biodiversity, introducing and promoting more bacterial genera associated with antibiotic degradation and involved in soil fertility and decreased fluoroquinolone bioaccumulation.

8 páginas.- 6 figuras.- 40 referencias, The risks of pollution by polycyclic aromatic hydrocarbons (PAHs) may increase in bioremediated soils as a result of the formation of toxic byproducts and the mobilization of pollutants associated to suspended colloids. In this study, we used the motile and chemotactic bacterium Pseudomonas putida G7 as an experimental model for examining the potential role of bacterial motility in the cometabolism and biosorption of pyrene in a porous medium. For this purpose, we conducted batch and column transport experiments with 14C-labelled pyrene loaded on silicone O-rings, which acted as a passive dosing system. In the batch experiments, we observed concentrations of the 14C-pyrene equivalents well above the equilibrium concentration observed in abiotic controls. This mobilization was attributed to biosorption and cometabolism processes occurring in parallel. HPLC quantification revealed pyrene concentrations well below the 14C-based quantifications by liquid scintillation, indicating pyrene transformation into water-soluble polar metabolites. The results from transport experiments in sand columns revealed that cometabolic-active, motile cells were capable of accessing a distant source of sorbed pyrene. Using the same experimental system, we also determined that salicylate-mobilized cells, inhibited for pyrene cometabolism, but mobilized due to their tactic behavior, were able to sorb the compound and mobilize it by biosorption. Our results indicate that motile bacteria active in bioremediation may contribute, through cometabolism and biosorption, to the risk associated to pollutant mobilization in soils. This research could be the starting point for the development of more efficient, low-risk bioremediation strategies of poorly bioavailable contaminants in soils. © 2020 Elsevier B.V., We thank the Spanish Ministry of Economy, Industry and Competitiveness (CGL2016-77497-R), the Andalusian Government (RNM 2337), and the European Commission (LIFE15 ENV/IT/000396). Joaquim Vila is a Serra Húnter Fellow (Generalitat de Catalunya).

The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component in most foaming agents used for mechanized tunneling excavation. The process produces huge amounts of soil debris that can have a potential impact on ecosystems. The lack of accurate information about SLES persistence in excavated soil has aroused increasing concern about how it is recycled. The objective of this study was to assess SLES biodegradability in two commercial foaming agents (P1 and P2). Microcosm experiments were performed with two different soils collected from a tunnel construction site and conditioned with P1 or P2 (85.0 or 83.0 mg kg −1 of SLES, respectively). At selected times soil samples were collected for assessing the SLES residual concentration using Pressured Liquid Extraction followed by methylene blue active substance analysis (MBAS). Simultaneously, soil microbial abundance (DAPI counts), viability (Live/Dead method), activity (dehydrogenase analysis) and phylogenetic structure (Fluorescent In Situ Hybridization) were evaluated. SLES halved faster in the silty-clay soil (6 d) than in the gravel in a clay-silty-sand matrix (8–9 days). At day 28 it was degraded in both soils. Its biodegradation was ascribed to the significant increase in Gamma-Proteobacteria. At this time, the spoil material can be considered as a by-product.

Sodium lauryl ether sulphate (SLES) is the anionic surfactant commonly utilized as the main synthetic chemical component in most foaming agents used in mechanized tunnelling. This produces huge amounts of soil debris which can contain residual concentrations of SLES. The absence of environmental quality standards for soil and water and the limited information about SLES persistence in real excavated soils do not facilitate any re-use of soil debris as by-products. The environmental risk assessment (ERA) of foaming agents containing SLES can be a valid tool for this purpose. In this study, an ERA analysis of SLES in 12 commercial formulations (cf) used for tunnelling excavation was performed. Various soils from different tunnel excavation sites were conditioned with the selected foaming agents containing SLES. Predicted or measured environmental concentrations (PECs, MECs) were determined and then compared with the Predicted No Effect Concentrations (PNECs) for both the terrestrial and aquatic compartments. The results indicate a reduction of the potential risk over time for these ecosystems, with differences depending on both the commercial foaming formulation and the spoil material characteristics. However, because potential threats to the natural environment cannot be excluded, some risk management and mitigation actions are discussed.

Reliable stable indicators are very important for assessing soil quality. This paper compares the dynamics of microbial parameters in two different soils (rich/poor in organic carbon), contaminated in laboratory experiments with an equal dose of heavy metals (HMs) after 30 and 90 days. For this purpose, the changes in the number, biomass, and taxonomic structure of bacterial and fungal communities were assessed in microcosm experiments using an organic carbon–rich ordinary chernozem (Ch-humus-rich soil) and a depleted carbon agrozem (Ag-humus-poor soil), spiked with high concentrations of a zinc, lead, and copper solution (1100 Zn + 660 Cu + 650 Pb mg per kg soil). At the 30th and 90th day from HM contamination, soil samples were collected for analyzing microbial community lipid markers by gas chromatography-mass spectrometry. The results show how both biomass and taxonomic structure of the bacterial and fungal communities analyzed were differently sensitive to HM contamination, depending on the type of soil. The Ag-humus-poor soil microbial community was significantly affected by the HM pollution with an increase in both fungi and bacteria and inside the latter several species changed their percentages. Differently, the Ch-humus-rich soil microbial community was not influenced by the HM addition. However, the negative impact of HM can manifest itself over time, so the microbial structure and its functioning cannot represent accurate indicators of the quality of all soil types. The results show that microbial characteristics should be taken into account only in a comprehensive assessment of soil quality in accordance with ISO 19,204:2017—soil quality TRIAD approach. This approach to environmental risk assessment combines biological data (from bioassay and ecological observations) with chemical analysis.

The anionic surfactant SLES (sodium lauryl ether sulfate) is an emerging contaminant, being the main component of foaming agents that are increasingly used by the tunnel construction industry. To fill the gap of knowledge about the potential SLES toxicity on plants, acute and chronic effects were assessed under controlled conditions. The acute ecotoxicological test was performed on Lepidum sativum L. (cress) and Zea mays L. (maize). Germination of both species was not affected by SLES in soil, even at concentrations (1200 mg kg−1) more than twice higher than the maximum realistic values found in contaminated debris, thus confirming the low acute SLES toxicity on terrestrial plants. The root elongation of the more sensitive species (cress) was instead reduced at the highest SLES concentration. In the chronic phytotoxicity experiment, photosynthesis of maize was downregulated, and the photosynthetic performance (PITOT) significantly reduced already under realistic exposures (360 mg kg−1), owing to the SLES ability to interfere with water and/or nutrients uptake by roots. However, such reduction was transient, likely due to the rapid biodegradation of the surfactant by the soil microbial community. Indeed, SLES amount decreased in soil more than 90% of the initial concentration in only 11 days. A significant reduction of the maximum photosynthetic capacity (Pnmax) was still evident at the end of the experiment, suggesting the persistence of negative SLES effects on plant growth and productivity. Overall results, although confirming the low phytotoxicity and high biodegradability of SLES in natural soils, highlight the importance of considering both acute and nonlethal stress effects to evaluate the environmental compatibility of soil containing SLES residues.

Huge amounts of soil debris are produced during the underground excavation with Earth Pressure Balance-Tunnel Boring Machines (EPB-TBM). Soil debris may contain residual concentrations of the anionic surfactant sodium lauryl ether sulphate (SLES), the main component in some foaming agents used as excavation additives. The reuse of this debris or its discharge as waste is a critical environmental question in construction engineering. There are only few studies on ecotoxicological effects on soil debris coming from a real excavation site. The aim of this study was to evaluate the ecotoxicity of two deep soils, with different lithological compositions, conditioned with three foaming agents. In some cases, lime was added to the soil. The soils were placed in mesocosms (1 m3) to simulate the temporary storage of the soil debris at a construction site. At fixed times, soil sub-samples were collected and ecotoxicological tests on terrestrial organisms (Lepidium sativum, Eisenia foetida) and an assessment of SLES concentration were performed with soils and aqueous elutriates produced from them. Results showed that at day 28, a SLES reduction was observed in both the soil and aqueous elutriates, with various rates of decrease. The differences were due to different soil lithological compositions and foaming agent products composition. In general, the two soils were not suitable for both plant growth and earthworm reproduction, but in Soil 1 the earthworm mortality was very low, except when lime was added. Tests with soil elutriates showed that 7 days after conditioning no toxic effect was found for the organisms tested.

Alkylethoxysulfate (AES) surfactants are the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Huge amounts of soil debris are produced during the excavation process and their possible re-use as by-products (e.g. land covering) or discharge as waste is a critical question in civil engineering. There can be an environmental impact from the potential ecotoxicity of the residual chemical mixture occurring in the foam-conditioned excavated soil. Chemical analyses are not able on their own to assess the potential hazards for the ecosystem ascribable to inadequate management of this kind of conditioned soil. Ecotoxicological tests, on the other hand, provide useful overall information about the potential effects of conditioned debris on soil and aquatic biota, including synergic ones, whether or not there is a detailed knowledge of the chemical composition of all the components of the commercial foaming products. In this context, the objective of this work was to evaluate the overall ecotoxicity of excavated soil conditioned with two common foaming products containing sodium lauryl ether sulphate (SLES) as the main component, in order to verify their possible re-use as by-products. For this purpose, two soils with different geopedological characteristics were conditioned with the commercial foaming agents at the concentrations utilised for mechanized tunnelling and then used for microcosm laboratory experiments. Soil sub-samples were collected at different times (0, 7, 14, 28 days) of incubation and soil elutriates were produced to assess the effects of the foaming agents on five test species (Pseudokirchneriella subcapitata, Daphnia magna, Danio rerio, Vibrio fischeri and Lepidium sativum). The results of the tests were then compared with SLES residual concentrations in the elutriates, determined with the MBAS (methylene blue active substances) spectrophotometric method. Finally, the data were combined in a battery index, which proved effective at evaluating the overall ecotoxicity in a real-life situation of two different excavated soils conditioned with the two products analysed.

The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Its use during the excavation processes can result in either the subsequent possible re-use of the huge amount of soil debris as by-products (e.g. land covering) or its discharge as waste. Currently, there are neither SLES soil threshold limits in European legislation, nor comprehensive studies on the environmental risk for soil ecosystems in these exposure scenarios. In this context, the present paper reviews the available data on the intrinsic characteristics of persistence and the ecotoxicological effects of the anionic surfactant SLES. Although SLES is generally reported to be biodegradable in standard tests, with degradation rates between 7 h and 30 days, depending on the initial conditions, data on its biodegradation in environmental studies are quite scarce. Consequently, assessing SLES biodegradation rates in field conditions is crucial for evaluating if in residual concentrations (typically in the range 40–500 mg/kg in excavated soils) it can or not be a potential hazard for terrestrial and water organisms. Laboratory ecotoxicological tests pointed out detrimental effects of SLES for aquatic organisms, while data on the terrestrial species are rather poor so far and further studies at the expected environmental concentrations are necessary. Finally, the review reports the main analytical methods available for detecting anionic surfactants in solid matrices and the future research needed to improve knowledge on the possible environmental risks posed by the use of SLES in foaming agents for mechanized tunnelling.

There is a growing concern about the simultaneous presence in the environment of different kinds of pollutants, because of the possible synergic or additive effects of chemical mixtures on ecosystems. Chlorpyrifos (CPF) is an organophosphate insecticide extensively used in agricultural practices. The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of several commercial products, including foaming agents used in underground mechanised excavation. Both compounds are produced and sold in high amounts worldwide and can be found in the environment as soil contaminants. The persistence of SLES and CPF in agricultural soils and their possible effects on the natural microbial community was evaluated in microcosms. The experimental set consisted of soil samples containing the autochthonous microbial community and treated with only SLES (70 mg/kg), only CPF (2 mg/kg) or with a mix of both compounds. Control microcosms (without the contaminants) were also performed. Soil samples were collected over the experimental period (0, 7, 14, 21 and 28 days) and analysed for CPF, SLES and the main metabolite of CPF (3, 5, 6-trichloropyridinol, TCP). The half-life time (DT50) of each parent compound was estimated in all experimental conditions. At the same time, the abundance, activity and structure of the microbial community were also evaluated. The results showed that the co-presence of SLES and CPF did not substantially affect their persistence in soil (DT50 of 11 and 9 days with co-presence and 13 and 10 days, respectively, when alone); however, in the presence of SLES, a higher amount of the metabolite TCP was found. Interestingly, some differences were found in the bacterial community structure, abundance and activity among the various conditions.

BACKGROUND: The Monviso clone previously tested successfully to remediate a lindane‐contaminated soil in central Italy was then applied in a historically heavy metal contaminated area in southern Italy. RESULTS: The results obtained at 900 days from the poplar planting showed a strong decrease below Italian national legal limits (D.Lgs 152/06) for most heavy metals (HMs). The highest reduction of HM concentrations was observed in soil samples collected near the trunk (25 cm distant from poplar) and in the rhizosphere. The values of the HM bioaccumulation factor (BAF, considering roots and leaves) and of the translocation factor (TF) suggest that poplar trees were able to phytostabilize HMs. The soil organic carbon content increased compared to the previous sampling in all plots planted. The highest values were observed for the rhizosphere soils of each target tree, while the phosphorous available strongly decreased. Microbial results showed an overall increase in cell viability, dehydrogenase activity and microbial abundance of some bacterial groups. CONCLUSION: Overall results showed that the poplar‐based phytoremediation strategy was able to promote the phytostabilization of the HMs and to improve the soil quality in terms of both organic carbon content and microbial community structure and activity. © 2019 Society of Chemical Industry

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent organic pollutants generated exclusively from human sources and found in the environment as several congeners (e.g. Apirolio, produced in Italy and used for electrical transformers). To evaluate the ability of the natural microbial community of historically PCB-contaminated soil to transform or degrade PCBs after fresh contamination through the addition of Apirolio, a microcosm experiment was conducted in a greenhouse for approximately 8 months. Compost and Medicago sativa (alfalfa) were additionally used in the microcosms to stimulate microbial PCB degradation. Chemical analyses were performed to evaluate PCB concentrations in the soil and plant tissue. Changes in the microbial community under the different experimental conditions were evaluated in terms of total abundance, viability, diversity, and activity. Interestingly, the addition of Apirolio did not negatively affect the microbial community but did stimulate the degradation of the freshly added PCBs. The plant and compost copresence did not substantially increase PCB degradation, but it increased the microbial abundance and activity and the occurrence of ?-Proteobacteria and fungi.

The Water Framework Directive (WFD) regulates freshwater and coastal water quality assessment in Europe. Chemical and ecological water quality status is based on measurements of chemical pollutants in water and biota together with other indicators such as temperature, nutrients, species compositions (phytoplankton, microalgae, benthos and fish) and hydromorphological conditions. However, in the current strategy a link between the chemical and the ecological status is missing. In the present WFD, no microbiological indicators are foreseen for integrating the different anthropogenic pressures, including mixtures of chemicals, nutrients and temperature changes, to provide a holistic view of the freshwater ecosystem water quality. The main aim of this work was to evaluate if natural microbial populations can be valuable indicators of multiple stressors (e.g. chemical pollutants, temperature, nutrients etc.) to guide preventive and remediation actions by water authorities. A preliminary survey was conducted to identify four sites reflecting a contamination gradient from the source to the mouth of a river suitable to the objectives of the European Marie Curie project, MicroCoKit. The River Tiber (Italy) was selected as a pilot case study to investigate the correlation between bacteria taxa and the chemical status of the river. The main physicochemical parameters, inorganic elements, organic pollutants and natural microbial community composition were assessed at four selected sites corresponding to pristine, agricultural, industrial and urban areas for three consecutive years. The overall chemical results indicated a correspondence between different groups of contaminants and the main contamination sources at the selected sampling points. Phylogenetic analysis of the microbial community analyzed by Fluorescence In Situ Hybridization method (FISH) revealed differences among the four sampling sites which could reflect an adaptive bacterial response to the different anthropogenic pressures.

The application of anaerobically digested cattle manure on agricultural land for both improving its quality and recycling a farm waste is an increasingly frequent practice in line with the circular economy. However, knowledge on the potential risk of spreading antibiotic resistance through this specific practice is quite scarce. The antibiotic sulfamethoxazole (SMX) is one of the most heavily prescribed in veterinary medicine. In this study, SMX dissipation and the possible effects on natural microorganisms were investigated in a soil amended with an anaerobically digested cattle manure produced from a biogas plant inside a livestock farm. Microcosm experiments were performed using amended soil treated with SMX (20 mg/kg soil). During the experimental time (61 days), soil samples were analysed for SMX and N4-acetylsulfamethoxazole, microbial abundance, activity and structure. Furthermore, the prevalence of the intI1 gene was also determined. The overall results showed that, although there was an initial negative effect on microbial abundance, SMX halved in about 7 days in the digestate-amended soil. The intI1 gene found in both the digestate and amended soil suggested that the use of anaerobically digested cattle manure as fertilizer can be a source of antibiotic resistant bacteria (ARBs) and genes (ARGs) in agroecosystems.

Remediation of polluted soils using phytoremediation techniques is an effective strategy. However, the use of the biomass from these soils for energy purposes may raise efficiency and pollution emission problems and there is currently little research on this issue. In this work, the main results of a fluidized-bed gasification treatment conducted on poplar biomass pruning residues from a multi-contaminated area are presented. The samples were collected from an experimental site in which a plant-assisted bioremediation (PABR) technology has been applied since 2013 to reduce the soil heavy metal (HM) and polychlorinated biphenyl (PCB) contents. The main goal of this study was to identify the specific treatment necessary, in addition to conventional tar reforming, for trapping possible residues of HMs and PCBs in ashes during the gasification process. In our study, we demonstrate that gasification of contaminated biomass coming from PABR (where contaminant residues are concentrated mainly in the roots and are insignificant in the shoots) produces syngas whose characteristics are similar to those obtained using non-contaminated biomass. The results showed that contaminant concentrations in the prunings were negligible; the total amount of PCBs was 1.63 ng/g, while HMs ranged from 0.01 to 0.70 mg/kg, except for Cu and Zn (∼20 mg/kg). Furthermore, the presence in the biomass of Ca and traces of other metals showed a possible catalytic effect with an improvement in the tar conversion in the gasifier leading to a reduction of 5–10% in tar content. The overall results suggest that a specific treatment for pollutant capture is necessary only when the roots, the part of the plants where these contaminants are concentrated, are sampled and used for the gasification process. Although energy from biomass produced on a contaminated site is currently considered waste and involves disposal costs, this paper shows that the poplar biomass grown on a multi-contaminated soil can be used for energy purposes without any impact on the environment.

Sulfamethoxazole and ciprofloxacin are among the most prescribed antibiotics and are frequently detected in surface water ecosystems. The aim of this study was to assess the role of a riverine natural microbial community in sulfamethoxazole (SMX) degradation in presence and absence of ciprofloxacin (CIP). River samples were collected from a stretch of the Tiber River highly impacted by human pressure. An experimental set up was performed varying some abiotic (dark/UV-light) and biotic (presence/absence of microorganisms) conditions that can affect antibiotic degradation. The residual concentrations of SMX and CIP were measured (HPLC-MS or HPLC-UV/FLD) and the effects on the natural microbial community were assessed in terms of microbial number (N. live cells/mL) and structure (Fluorescence In Situ Hybridization - FISH). Finally, the occurrence of the antibiotic resistance sul1 gene was also verified using quantitative PCR (qPCR). In 28 days, in the presence of both UV-light and microorganisms SMX disappeared (

Pharmaceuticals as environmental contaminants have received a lot of interest over the past decade but, for several pharmaceuticals, relatively little is known about their occurrence in European surface waters. Benzodiazepines, a class of pharmaceuticals with anxiolytic properties, have received interest due to their behavioral modifying effect on exposed biota. In this study, our results show the presence of one or more benzodiazepine(s) in 86% of the analyzed surface water samples (n = 138) from 30 rivers, representing seven larger European catchments. Of the 13 benzodiazepines included in the study, we detected 9, which together showed median and mean concentrations (of the results above limit of quantification) of 5.4 and 9.6 ng L−1, respectively. Four benzodiazepines (oxazepam, temazepam, clobazam, and bromazepam) were the most commonly detected. In particular, oxazepam had the highest frequency of detection (85%) and a maximum concentration of 61 ng L−1. Temazepam and clobazam were found in 26% (maximum concentration of 39 ng L−1) and 14% (maximum concentration of 11 ng L−1) of the samples analyzed, respectively. Finally, bromazepam was found only in Germany and in 16 out of total 138 samples (12%), with a maximum concentration of 320 ng L−1. This study clearly shows that benzodiazepines are common micro-contaminants of the largest European river systems at ng L−1 levels. Although these concentrations are more than a magnitude lower than those reported to have effective effects on exposed biota, environmental effects cannot be excluded considering the possibility of additive and sub-lethal effects.

12 páginas, 5 figuras.-- The original publication is available at www.springerlink.com, The herbicide terbuthylazine is widely used within the EU; however, its frequent detection in surface and groundwater, together with its intrinsic toxicological properties, may pose a risk both for human and environmental health. Organic amendments have recently been proposed as a possible herbicide sorbent in soil, in order to limit herbicide movement from soil to water. The environmental fate of terbuthylazine depends not only in its mobility but also in its persistence. The latter is directly dependent on microbial degradation. For this reason, the effects of pine and oak residues on terbuthylazine soil microbial community functioning and on the potential of this community for terbuthylazine degradation were studied. For this purpose, degradation kinetics, soil dehydrogenase activity and the number of live bacteria were assessed in a clay loam soil treated with terbuthylazine and either amended with pine or oak wood or unamended (sterilised and non-sterilised). At day 65, 85%of the herbicide applied still persisted in the sterile soil, 73 % in the pine-amended one and 63 % in the oak-amended and unamended ones. Pine residues increased the sorption of terbuthylazine to soil and hampered microbial degradation owing to its high terbuthylazine sorption capacity and a decrease in the bioavailability of the herbicide. On the contrary, in the presence of oak residues, the herbicide sorption did not increase significantly. The overall results confirm the active role of the soil microbial community in terbuthylazine degradation in amended and unamended soils and in a liquid enrichment culture performed using an aliquot of the same soil as the inoculum. In this clay loamsoil, in the absence of amendments, the herbicide was found to be quite persistent (t1/2>95 days), while in the enrichment culture, the same natural soil bacterial community was able to halve terbuthylazine in 24 days. The high terbuthylazine persistence in this soil was presumably ascribable to its texture and in particular to the mineralogy of the clay fraction., This work was funded by the CSIC/CNR Bilateral Agreement ‘Adsorption and degradation of pesticides in soils modified with low cost biomaterials: Study of the microbial communities responsible for the biodegradation’ (project reference 2006IT0022).

The antiviral drug Tamiflu has received particular attention because of its recommended use against the influenza A H5N1 and H1N1 viruses. Given its resistance to degradation and its hydrophilicity the active metabolite, Oseltamivir Carboxylate (OC), is expected to enter the aquatic ecosystem from sewage treatment plants. In the present paper the bacterial community of surface water samples, treated with OC (1.5 mg L-1), was characterized by Fluorescence In Situ Hybridization (FISH) in microcosm experiments. The alpha-, beta- and gamma-Proteobacteria increased in OC-treated versus non-treated water samples during the incubation period, suggesting these bacterial groups had an active role in OC degradation.

The ability of soil and groundwater ecosystems to recover from chemical contamination is primarily dependent on the presence of a microbial community which has the ability to remove it. Nevertheless, there has been a little research into these communities because it is strictly dependent on methods capable of identifying and characterizing their community structure and functioning. The use of molecular methods makes it possible to overcome this kind of identification limitation. In this work, we applied the fluorescence in situ hybridization (FISH) method to different samples, such as soil and groundwater contaminated with s-triazine herbicides (simazine or terbuthylazine) and surface water treated with the pharmaceutical oseltamivir carboxylate (Tamiflu). We compared the bacterial community structure in the presence/absence of these xenobiotics. The use of 16S rRNA-targeted oligonucleotide probes, designed specifically for the main phylogenetic levels (Archaea, Bacteria, -, -, -, "-subdivision of Proteobacteria, Planctomycetes, Gram-positive bacteria with a high or low DNA GþC content, Cytophaga-Flavobacter-Bacteroides phylum, and sulfate-reducing bacteria), and a DAPI stain made it possible to assess the structure of the bacterial community and its changes in the presence of these xenobiotics in all the ecosystems studied.

This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI. On 3 October 2007, 40 participants with diverse expertise attended the workshop Tamiflu and the Environment: Implications of Use under Pandemic Conditions to assess the potential human health impact and environmental hazards associated with use of Tamiflu during an influenza pandemic. Based on the identification and risk-ranking of knowledge gaps, the consensus was that oseltamivir ethylester-phosphate (OE-P) and oseltamivir carboxylate (OC) were unlikely to pose an ecotoxicologic hazard to freshwater organisms. OC in river water might hasten the generation of OC-resistance in wildfowl, but this possibility seems less likely than the potential disruption that could be posed by OC and other pharmaceuticals to the operation of sewage treatment plants. The work-group members agreed on the following research priorities: a) available data on the ecotoxicology of OE-P and OC should be published; b) risk should be assessed for OC-contaminated river water generating OC-resistant viruses in wildfowl; c) sewage treatment plant functioning due to microbial inhibition by neuraminidase inhibitors and other antimicrobials used during a pandemic should be investigated; and d) realistic worst-case exposure scenarios should be developed. Additional modeling would be useful to identify localized areas within river catchments that might be prone to high pharmaceutical concentrations in sewage treatment plant effluent. Ongoing seasonal use of Tamiflu in Japan offers opportunities for researchers to assess how much OC enters and persists in the aquatic environment. Environmental Knowledge Transfer Network, the Worshipful Company of Water Conservators, and the Chartered Institution of Water & Environmental Management.

We propose a new approach to evaluate the natural attenuation capacity of soil by using fluorescence in situ hybridization (FISH). A specific oligonucleotide probe AtzB1 was designed based on the sequence data of the atzB gene involved in the hydrolytic deamination of s-triazines; this gene, located in a multiple copy plasmid was detected by the optimized FISH protocol. Two agricultural soils (Lodi and Henares) with a history of simazine treatments, and two natural soils (Soto and Monza), without previous exposure to simazine, were studied. AtzB1 probe-target cells were found only in the agricultural soils and, in a greater percentage, in the Lodi soil, compared to the Henares one. Moreover, the greatest percentage of AtzB1 probe-target cells in Lodi was accompanied by a greater mineralization rate, compared to the Henares soil. The FISH method used in this study was suitable for the detection of simazine-degrading bacteria and could be a useful indicator of the potential of soil bioremediation.

Polychlorobiphenyl (PCB) biodegradation was followed for 1 year in microcosms containing marine sediments collected from Mar Piccolo (Taranto, Italy) chronically contaminated by this class of hazardous compounds. The microcosms were performed under strictly anaerobic conditions with or without the addition of Dehalococcoides mccartyi, the main microorganism known to degrade PCBs through the anaerobic reductive dechlorination process. Thirty PCB congeners were monitored during the experiments revealing that the biodegradation occurred in all microcosms with a decrease in hepta-, hexa-, and penta-chlorobiphenyls (CBs) and a parallel increase in low chlorinated PCBs (tri-CBs and tetra-CBs). The concentrations of the most representative congeners detected in the original sediment, such as 245-245-CB and 2345-245-CB, and of the mixture 2356-34-CB+234-245-CB, decreased by 32.5, 23.8, and 46.7 %, respectively, after only 70 days of anaerobic incubation without any bioaugmentation treatment. Additionally, the structure and population dynamics of the microbial key players involved in the biodegradative process and of the entire mixed microbial community were accurately defined by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) in both the original sediment and during the operation of the microcosm. The reductive dehalogenase genes of D. mccartyi, specifically involved in PCB dechlorination, were also quantified using real-time PCR (qPCR). Our results demonstrated that the autochthonous microbial community living in the marine sediment, including D. mccartyi (6.32E+06 16S rRNA gene copy numbers g−1 sediment), was able to efficiently sustain the biodegradation of PCBs when controlled anaerobic conditions were imposed. © 2015, Springer-Verlag Berlin Heidelberg.

The need for comprehensive and reliable risk management of chemicals requires appropriate information, data integration, and sharing, as suggested in Europe by Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation. REACH requires more sharing of responsibilities among authorities, chemical manufacturers, importers, and users to manage the risks that chemicals can pose to human health and the environment throughout their life cycle. This has obviously enlarged the audience of people who could be interested in gathering this information. A major bottleneck is that information sources on chemicals are frequently sparsely distributed, collected, and managed by different institutions, with different aims, resulting in several practical problems. This article describes the conceptual design and implementation of a free online access database (DESC) as an integrated information system on chemical substances in compliance with the REACH regulation. An interdisciplinary approach was applied by involving several experts from different disciplines (ecotoxicologists, chemists, information technology specialists, regulators). DESC contains relevant environmental and toxicological data (physico-chemical and ecotoxicological data, inclusion in priority lists, current classification and labeling, etc.) on more than 651 chemicals, which can be easily consulted by people with different degrees of expertise interested in knowing the risk from exposure to chemicals and their safe use. © 2013 Copyright Taylor and Francis Group, LLC.

In this work the degradation of the herbicides metolachlor, diuron, monuron and of the metabolites 2-ethyl-6-methylaniline (EMA), and 3,4-dichloroaniline (DCA) was assessed in laboratory experiments on microbiologically active and sterilized soils. Their leaching potentials were calculated, using Gustafson's equation, by determining their mobility (as Koc) and persistence (expressed as DT50). Lysimeter experiments were also conducted to assess the actual leaching of the studied herbicides in a cereal crop tillage area vulnerable to groundwater contamination. The data obtained from the field were compared to the laboratory results. Moreover, some compounds of particular concern were searched for in the groundwater located near the experimental area in order to evaluate actual contamination and to test the reliability of the leaching potential. The GUS index, computed on data from microbiologically active soil, shows monuron as a leacher compound, EMA and DCA as non-leachers, metolachlor and diuron as transient ones. The presence of metolachlor in the groundwater monitored, even at concentrations up to 0.1 μg/l, confirms the possibility that transient compounds can be leached if microbial activity has not completely occurred in active surface soil.

The present work aims at evaluating the ability of the River Tiber natural microbial community to degrade naproxen in water samples collected downstream from a wastewater treatment plant. For this purpose, different water microcosms were set up (microbiologically active vs sterile ones) and treated with naproxen (100 μg/L) alone or in the co-presence of gemfibrozil in order to evaluate if the co-presence of the latter had an influence on naproxen degradation. The experiment was performed in the autumn and was compared with the same experimental set performed in spring of the same year to highlight if seasonal differences in the river water influenced the naproxen degradation. Pharmaceutical concentrations and microbial analysis (total cell number, viability, and microbial community composition) were performed at different times in the degradation experiments. The overall results show that the natural microbial community in the river water had a key role in the naproxen degradation. In fact, although there was a transient negative effect on the natural microbial community in all the experiments (3 h after adding the pharmaceutical), the latter was able to degrade naproxen within about 40 days. On the contrary, no decrease in the pharmaceutical concentration was observed in the sterile river water. Moreover, the co-presence of the two drugs lengthened the naproxen lag phase. As regards the natural microbial community composition detected by Fluorescence in situ Hybridization, Alpha and Gamma-Proteobacteria increased when the pharmaceutical halved, suggesting their role in the degradation. This study shows that with the concentration studied, naproxen was degraded by the natural microbial populations collected from a river chronically contaminated by this pharmaceutical.

On 3 October 2007, 40 participants with diverse expertise attended the workshop Tamiflu and the Environment: Implications of Use under Pandemic Conditions to assess the potential human health impact and environmental hazards associated with use of Tamiflu during an influenza pandemic. Based on the identification and risk-ranking of knowledge gaps, the consensus was that oseltamivir ethylester-phosphate (OE-P) and oseltamivir carboxylate (OC) were unlikely to pose an ecotoxicologic hazard to freshwater organisms. OC in river water might hasten the generation of OCresistance in wildfowl, but this possibility seems less likely than the potential disruption that could be posed by OC and other pharmaceuticals to the operation of sewage treatment plants. The workgroup members agreed on the following research priorities: a) available data on the ecotoxicology of OE-P and OC should be published; b) risk should be assessed for OC-contaminated river water generating OC-resistant viruses in wildfowl; c) sewage treatment plant functioning due to microbial inhibition by neuraminidase inhibitors and other antimicrobials used during a pandemic should be investigated; and d) realistic worst-case exposure scenarios should be developed. Additional modeling would be useful to identify localized areas within river catchments that might be prone to high pharmaceutical concentrations in sewage treatment plant effluent. Ongoing seasonal use of Tamiflu in Japan offers opportunities for researchers to assess how much OC enters and persists in the aquatic environment.

Global change, in particular climate change, will affect agriculture worldwide in many ways: increased drought or flooding amplitude and frequency, variable temperature increases, loss of natural depuration of waters, soil erosion, loss of soil carbon content, invasion by alien species, increased pest events, changes in plant phenology, increased sensitivity of crops to stress and diseases etc. (Fisher et al. 2005; Howden et al. 2007). These anticipated or even already occurring stresses raise concerns about the sustainability of production and the ability of agriculture to feed human populations. All these changes could lead to an increased use of pesticides (Kattwinkel et al. 2011). Moreover, demographic pressure continues to rise, in particular in tropical and sub-tropical regions, where greater threats to agriculture and food sustainability are anticipated by the Intergovernmental Panel on Climate Change (IPCC) (Easterling et al. 2007). These trends will certainly lead to mounting conflicts involving water uses (irrigation versus drinking water production or freshwater ecosystem maintenance, sanitation etc.) and food production. This appeals to an “ecologically intensive agriculture” (Griffon 2006), i.e. a sustainable agriculture providing ecosystem services more efficiently than today and causing fewer adverse impacts on the environment and water resources. With EU Directive 2009/128/EC (EC 2009a) enforcement, requesting Member States to adopt action plans aiming to reduce risks and impacts related to pesticide uses, there will be a focus in the public and political debates in Europe on achieving a more sustainable use of pesticides. This should consequently lead to a reduction of the risks or impacts of pesticides on the environment. In Europe, there is currently a strong focus on source (including dose) reduction. This approach may nevertheless be too restrictive if the goal is to reduce the agriculture footprint while maintaining or increasing yield. Depending on the chemical properties of pesticides as well as environmental factors, decreasing the amounts of pesticides applied to crops will not automatically produce a decrease in the risk to non-target species or water supply. How could society meet the challenge of the forthcoming climate change? What adaptations should be envisaged for agriculture/pesticide risk management (RM)? These changes will probably have a profound effect on agricultural systems (crop selection, farming practices etc.) and to a lesser extent influence the fate and effects of chemicals (Schiedek et al. 2007). These questions have been addressed by two European research networks, namely Euraqua (the European Network of Freshwater Research Organisations, http://www.euraqua.org/) and PEER (Partnership for European Environmental Research, http://www.peer.eu/), which organised a workshop aiming to identify research needs and strategies induced by these questions in October 2011 in Montpellier, France. The workshop's specific goals were to (1) discuss the pesticide risk assessment (RA) approach, its limitations (e.g. spatial scale and multi-stress situations), the connections between different policies (pesticide regulation and Water Framework Directive), the use of models, (2) review integrated practices and innovative technologies which could or are intended to reduce pesticides' environmental impacts and (3) contribute to the future research and development agenda. This review summarises the workshop discussions.

A bacterial strain (FPA1) capable of using terbuthylazine, simazine, atrazine, 2-hydroxysimazine, deethylatrazine, isopropylamine or ethylamine as its sole carbon source was isolated from a shallow aquifer chronically contaminated with s -triazine herbicides. Based on its 16S rDNA sequence analysis, the strain FPA1 was identified as Rhodococcus wratislaviensis . The disappearance time of 50% of the initial terbuthylazine concentration in the presence of this strain (DT 50 ) was 62 days. This strain was also able to mineralise the [U-ring 14 C] triazine-ring, albeit at a slow rate. A 16S rRNA target oligonucleotide probe (RhLu) was designed, and the FISH protocol was optimised, in order to detect R. wratislaviensis in s- triazine-contaminated sites. The RhLu probe gave a positive signal (expressed as % of total DAPI-positive cells) in both the groundwater (2.19 ± 0.41%) and soil (2.10 ± 0.96%) samples analysed. Using the RhLu probe, R. wratislaviensis can be readily detected, and its population dynamics can be easily monitored, in soil and in water ecosystems contaminated with s -triazine. To the best of our knowledge, this is the first report showing the isolation, from groundwater, of a bacterial strain able to degrade s -triazines.

Numerous studies have documented that a wide number of pharmaceuticals used in human and veterinary medicine have the potential to enter the aquatic ecosystem. The antiviral prodrug oseltamivir phosphate has received recent attention with regard to its possible use against the highly pathogenic H5N1 virus. This preliminary laboratory study investigated the persistence of the active antiviral drug, oseltamivir carboxylate (OSC), in water samples taken from an irrigation canal. After an initial rapid decrease, OSC concentrations slowly decreased during the remaining incubation period. Approximately 65% of the initial OSC amount remained in water at the end of the 36-day incubation period. A small amount of OSC was lost both from sterilized water and from sterilized water/sediment samples, suggesting a significant role for microbial degradation. Stimulating microbial processes by the addition of sediments resulted in reduced OSC persistence. Presence of OSC (1.5 mgmL1) did not significantly affect the metabolic potential of the water microbial population, estimated by glyphosate and metolachlor mineralization. In contrast, OSC caused an initial transient decrease in the size of the indigenous microbial population of water samples.

The environmental fate of herbicides can be studied at different levels: in the lab with disturbed or undisturbed soil columns or in the field with suction cup lysimeters or soil enclosure lysimeters. A field lysimeter experiment with 10 soil enclosures was performed to evaluate the mass balance in different environmental compartments of the phenylurea herbicides diuron [3-(3,4-diclorophenyl)-1,1-dimethyl-urea] and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. After application on the agricultural soil, the herbicides were searched for in soil, pore water, and air samples. Soil and water samples were collected at different depths of the soil profile and analyzed to determine residual concentrations of both the parent compounds and of their main transformation products, to verify their persistence and their leaching capacity. Air volatilization was calculated using the theoretical profile shape method. The herbicides were detected only in the surface layer (0-10 cm) of soil. In this layer, diuron was reduced to 50% of its initial concentration at the end of the experiment, while linuron was still 70% present after 245 d. The main metabolites detected were DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] and DCA (3,4-dichloroaniline). In soil pore water, diuron and linuron were detected at depths of 20 and 40 cm, although in very low concentrations. Therefore the leaching of these herbicides was quite low in this experiment. Moreover, volatilization losses were inconsequential. The calculated total mass balance showed a high persistence of linuron and diuron in the soil, a low mobility in soil pore water (less than 0.5% in leachate water), and a negligible volatilization effect. The application of the Pesticide Leaching Model (PELMO) showed similar low mobility of the chemicals in soil and water, but overestimated their volatilization and their degradation to the metabolite DCPMU. In conclusion, the use of soil enclosure lysimeters proved to be a good experimental design for studying mobility and transport processes of herbicides in field conditions.