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The continental hydrosystems of wetlands play fundamental socio-economic and environmental roles in all aquatic environments. These ecosystems, when located at the interface between surface and groundwater, such as oxbows, are of crucial importance in regulating water and nutrient flows. They help control water quality and provide ideal habitats for often fragile species. The transfer of contaminants into the different compartments of the groundwater-wetland-river continuum is difficult to characterize because they are most often of different types and origins within the same hydrosystem. The objective of this study is to characterize water quality and water exchange using a multi-tracer approach combining monthly hydrochemical monitoring, isotopic characterization of NO 3 − molecules (δ18O NO3 and δ15N NO3) and concentration of chemical micropollutant particles. This methodology is applied to a fluvial annex of the Allier River, the Auzon oxbow hydrosystem, subject to moderate environmental and anthropogenic pressure (low level of industrialization and urbanization, mixed conventional farming). Nitrate (NO 3 −) and phosphate (PO 4 3−) concentrations do not behave in the same way over time: NO 3 − has a seasonal dynamic, whereas phosphates are disconnected from the hydrological regime. Some subsystems of the Auzon oxbow are undergoing denitrification, demonstrating the importance of preserving these environments for their nutrient regulation potential. As for chemical micropollutants and PO 4 3−, the low overall concentration of these two contaminants, coupled with the high dilution potential of the Auzon oxbow hydrosystem, means that average concentrations remain within acceptable standards for surface waters. Based on these results, the Auzon hydrosystem is maintaining good ecological quality despite nutrient flows from multiple sources. The multi-tracer approach used in this study demonstrates its effectiveness in determining the origin of nutrients, and it could be applied to other studies in contexts where environmental and societal pressures are significantly higher. • Nitrates derive from agricultural practice while phosphates result from human activities. • Dynamic of NO 3 − is seasonal in surface water, and more sporadic for PO 4 3-. • Denitrification processes take place in alluvial aquifers and in riparian wetlands. [ABSTRACT FROM AUTHOR]

Résumé Introduction Les mycétomes sont des affections cutanées infectieuses rares causées par des agents de nature fongique ou bactérienne. Elles siègent préférentiellement sur les extrémités. Nous rapportons ici un cas original de mycétome polyfistulisé chez un commerçant camerounais. Observation Une masse cutanée polyfistulisée était reçue au laboratoire d’anatomopathologie. Elle provenait d’un commerçant de 30 ans, sans antécédents particuliers, vivant à Yaoundé qui avait été vu en consultation pour une lésion de la plante du pied apparue plusieurs mois auparavant. Cette lésion, au départ se serait présentée sous la forme d’un nodule dur et indolore qui aurait par la suite fistulisé à la peau. Ces faits cliniques ne permettant d’évoquer un diagnostic certain, on avait procédé à une exérèse chirurgicale de cette masse et une analyse anatomopathologique avait été requise. L’examen histopathologique usuel couplé à des colorations spéciales avait révélé le diagnostic de mycétome d’étiologie fongique. Discussion Cette observation décrit un cas original de mycétome d’origine fongique non suspecté cliniquement, survenu chez un commerçant camerounais, vivant en milieu urbain et en dehors de toute zone d’endémicité de mycétome. Ce cas pour lequel le diagnostic était posé en histologie confirme l’apport indéniable de l’anatomopathologie au diagnostic de certitude. À notre connaissance, et selon les données disponibles, c’est la première fois qu’un mycétome soit décrit en milieu urbain au Cameroun. Summary Background Mycetoma are rare cutaneous affections caused by pathogens such as fungi or bacteria. They settle preferentially on limb extremities. We are going to talk about an original case of mycetoma in a young Cameroonian trader. Observation A cutaneous mass with multiple draining sinuses was received at the anatomy and cytopathology laboratory. That mass was from a 30-year-old male trader, with no particular medical history and living in Yaounde, who was received for a lesion at the sole of the foot, which appeared some months before. This lesion started like a tough and painless nodule, which later showed draining sinuses to the skin. The surgical resection of the tissue mass was performed. The histopathological analysis with special staining procedures, which was later on performed, revealed mycetoma caused by fungi. Discussion This observation describes an original case of fungal mycetoma, which occured in a Cameroonian trader living in an urban milieu away from any mycetoma endemic zone. This case confirms the undeniable or undisputable contribution of histopathology in diagnosis of certainty. To our knowledge and according to available data, it is a premiere to find a case of mycetoma described in an urban milieu in Cameroon. [ABSTRACT FROM AUTHOR]

The anthropogenic emissions of Pt to the environment have increased significantly over the past decades, especially after the introduction of the catalytic converters in motor vehicles. In order to check whether this is affecting the levels of this trace metal on living organisms, time-series analysis of freeze-dried soft tissue material of wild mussels ( Mytilus galloprovincialis ) covering the period from 1991 to 2001 and collected at an urban beach in the city of Vigo (NW Iberian Peninsula) was conducted. Concentrations ranged from 0.30 to 0.68 ng g − 1 with an average concentration of 0.47 ± 0.10 ng g − 1 ( n = 21); these concentrations were higher than those obtained for samples collected at a control location away from anthropogenic pressure (0.31 ± 0.10 ng g − 1 ; n = 5). Platinum concentrations followed a statistically significant temporal trend (at the 0.020 level), and the excess of Pt in mussels over the 1991–2011 period compared to the control location were correlated with the European Pt autocatalyst demand ( p = 0.0006) and, especially, the car sales in Spain ( p = 0.0001). A bioaccumulation factor of ~ 5 · 10 3 was derived, which is greater than those previously calculated for Pt from exposure experiments, but 1–2 orders of magnitude lower than other trace elements (e.g. Zn, Cu, Pb, Cd). [ABSTRACT FROM AUTHOR]

Abstract: The Water Framework Directive requires the development of biological tools which can act as early-warning indicators of a sudden increase (accidental pollution) or decrease (recovery due to prevention) of the chemical status of aquatic systems. River biofilms, which respond quickly to modifications of environmental parameters and also play a key part in the functioning of aquatic ecosystems, are therefore good candidates to monitor an increase or a decrease of water pollution. In the present study, we investigated the biological response of biofilms transplanted either upstream (recovery) or downstream (deterioration of exposure levels) the urban area of Paris (France). Both modifications of Cu community tolerance levels and of global bacterial and eukaryotic community structure using automated ribosomal intergenic spacer analysis (ARISA) fingerprints were examined 15 and 30 days after the transplantation. Cu tolerance levels of the heterotrophic component of biofilms were assessed using a short-term toxicity test based on β-glucosidase (heterotrophic) activity. Cu tolerance increased for biofilms transplanted upstream to downstream Paris (5-fold increase on day 30) and conversely decreased for biofilms transplanted downstream to upstream (8-fold decrease on day 30). ARISA fingerprints revealed that bacterial and eukaryotic community structures of transplanted biofilms were closer to the structures of biofilms from the transplantation sites (or sites with similar contamination levels) than to biofilms from their sites of origin. Statistical analysis of the data confirmed that the key factor explaining biofilm Cu tolerance levels is the sampling site and not the site of origin. It also showed that Cu tolerance levels are related to the global urban contamination (both metals and nutrients). The study shows that biofilms adapt fast to modifications of their surroundings. In particular, community tolerance varies quickly and reflects the new exposure levels only 15 days after transplantation. Those results support the use of biofilms as reliable early-warning indicators of diffuse urban contamination. [Copyright &y& Elsevier]

The feasibility of reducing children’s exposure to lead (Pb) polluted soil in New Orleans is tested. Childcare centers (median = 48 children) are often located in former residences. The extent of soil Pb was determined by selecting centers in both the core and outlying areas. The initial 558 mg/kg median soil Pb (range 14–3692 mg/kg) decreased to median 4.1 mg/kg (range 2.2–26.1 mg/kg) after intervention with geotextile covered by 15 cm of river alluvium. Pb loading decreased from a median of 4887 μg/m2 (454 μg/ft2) range 603–56650 μg/m2 (56–5263 μg/ft2) to a median of 398 μg/m2 (37 μg/ft2) range 86–980 μg/m2 (8–91 μg/ft2). Multi-Response Permutation Procedures indicate similar (P-values = 0.160–0.231) soil Pb at childcare centers compared to soil Pb of nearby residential communities. At ∼$100 per child, soil Pb and surface loading were reduced within hours, advancing an upstream intervention conceptualization about Pb exposure prevention. [Copyright &y& Elsevier]

Abstract: Isolated mollusk shells and crustacean exoskeletons adsorb from waters almost twice their weight of Pb in a few minutes. Likewise, the chitin-based sorbents of animal and fungal origin adsorb U and transuranium elements: some are manufactured commercially in a form suitable for high flow-rates. Supported viable Trichoderma harzianum is quite effective in collecting microcrystals of U oxides. Chitosan as well can induce deposition of mixed U oxides, to the point that the final material contains a prevailing inorganic component. Metal-reducing bacteria also offer good performances. These data are exploitable for preventing pollution in civilian operations: the pollution case of Colonie, NY, is discussed in the light of the high toxicity of uranium. The disappointing results of the programs aimed at the collection of uranium from seawater with the aid of synthetic poly(amidoamine) induce to envisage that chitin/chitosan-bearing materials might be involved in the future exploitation of the marine uranium resources. [ABSTRACT FROM AUTHOR]

Abstract: The impact on a population from an event resulting in dispersal and deposition of radionuclides in an urban area could be significant, in terms of both the number of people affected and the economic costs of recovery. The use of computer models for assessment of urban contamination situations and remedial options enables the evaluation of a variety of situations or alternative recovery strategies in contexts of preparedness or decision-making. At present a number of models and modelling approaches are available for different purposes. This paper summarizes the available modelling approaches, approaches for modelling countermeasure effectiveness, and current sources of information on parameters related to countermeasure effectiveness. Countermeasure information must be applied with careful thought as to its applicability for the specific situation being modelled. Much of the current information base comes from the Chernobyl experience and would not be applicable for all types of situations. [Copyright &y& Elsevier]

Abstract: The Urban Remediation Working Group of the International Atomic Energy Agency''s EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the second of two modelling exercises. This exercise was based on a hypothetical dispersal of radioactivity in an urban area from a radiological dispersal device, with reference surface contamination at selected sites used as the primary input information. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a “no action” situation (with no remedial measures) and for selected countermeasures. The exercise provided an opportunity for comparison of three modelling approaches, as well as a comparison of the predicted effectiveness of various countermeasures in terms of their short-term and long-term effects on predicted doses to humans. [Copyright &y& Elsevier]

Abstract: This study reports the degree of heavy metal pollution (Cr, Cu, Ni, Pb, Zn and V) in 135 urban topsoil samples from the metropolitan area of Mexico City. Pollution indices (PI) were calculated to identify the metal accumulation with respect to the background values. The levels of heavy metals in the analyzed samples show a wide range of variation. Lead, Zn and Cu are the elements most enriched in the analyzed area, presenting pollution indexes of up to 23.8, 21.6 and 12.4, respectively. Geochemical maps were produced to assess the spatial distribution of pollution index. It is concluded that emissions from vehicles may be the major source of Pb urban contamination; furthermore, other small or large factories are possible sources for soil pollution (Cu, Zn). The concentration of Cr, Ni, and V in most of the analyzed samples do not appear to reach pollution levels. The assessment of the soil environmental quality in the metropolitan area Mexico City in terms of PI can be used as the basis for a regular monitoring program for implementing suitable pollution control measures. [Copyright &y& Elsevier]

Abstract: The Urban Remediation Working Group of the International Atomic Energy Agency''s EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the first of two modelling exercises, which was based on Chernobyl fallout data in the town of Pripyat, Ukraine. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces and radionuclides, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a “no action” situation (with no remedial measures) and for selected countermeasures. The exercise provided a valuable opportunity to compare modelling approaches and parameter values, as well as to compare the predicted effectiveness of various countermeasures with respect to short-term and long-term reduction of predicted doses to people. [Copyright &y& Elsevier]

Abstract: The Urban Remediation Working Group of the International Atomic Energy Agency''s Environmental Modelling for Radiation Safety (EMRAS) programme was established to improve modelling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group''s activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful. [Copyright &y& Elsevier]

Recent investigations in Russia have emphasised the significance of dose contributions from contamination on urban streets and roof pavings, and, typically to a lesser extent, walls in the urban environment. The crucial factor determining the magnitude of these contributions is the retention of the contamination by the different types of urban surface. Since the Chernobyl accident, a series of long-term field studies has been carried out on urban streets, walls and roofs, to examine the weathering processes of 137Cs on the various surface types. The derived time-functions are applied to estimate resultant long-term doses to inhabitants of an urban centre. The paper highlights the effect on caesium retention of surface material characteristics. [Copyright &y& Elsevier]

This study aims to evaluate the impacts of the activation of a hypothetical radiological dispersal device (RDD) on the urban critical infrastructure (health facilities and public transport). A densely populated urban region was chosen as a scenery. Additionally, the influence of local environmental factors in the post-detonation process was verified. The source term was Cs-137 due to its mobility in the environment and relative ease of access. The approach used for the evaluation of the consequences was a computer simulation by Gaussian modeling. The HotSpot Health Physics Codes software was applied in conjunction with the RESRAD-RDD software. The results suggest that there is a strong influence of the local atmospheric stability classes (Pasquill-Gifford classes) on both the total equivalent effective dose (TEDE) and soil contamination. Consequently, the impacts on critical urban infrastructure follow the same trend. The method used for comparing the simulated and reference limits was the proportional ratio. All calculated values for radioactive contamination were divided by the reference value adopted by the RESRAD-RDD model for urban critical infrastructure. The results indicate that the information compiled is useful to support the decision-making process, although it is not sufficient to provide care and support for longer periods than those considered in the initial response phase. • Urban critical infrastructure are severely impacted by the RDD. • Atmospheric stability strongly influences TEDE in the first hours. • Codes approaching together may provide better support to decision. [ABSTRACT FROM AUTHOR]

Data on chlorophenoxy herbicides (CPHs) in drinking water from China are scarce. This study was designed to describe the occurrence of CPHs in drinking water in China. In June 2019, drinking water samples including 789 tap water and 95 groundwater samples were collected from 31 provinces in mainland China and Hong Kong. Raw source, treated, and tap water samples (n = 20, 20, and 170, respectively) in Wuhan, Central China were also analyzed. 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) were found in 71.2% and 74.9% of the samples nationwide, respectively. The cumulative concentration of CPHs (ΣCPHs) in tap water in China was up to 125 ng/L (median: 1.38 ng/L), and regional variations were found for ΣCPHs. The highest median ΣCPHs (3.95 ng/L) was found in Northeast China, followed by Central (3.40), South (2.71), East (2.43), Southwest (1.58), North (0.42), and Northwest China (0.30). The median ΣCPHs in groundwater was approximately five times lower than that in tap water. In addition, ΣCPHs were found in all the raw source water samples collected in Wuhan, Central China (median: 6.69 ng/L, range: 2.66–43.1 ng/L). The removal of 2,4-D and MCPA during conventional drinking water treatment was not efficient, removing approximately 0.91% and 17.4%, respectively. In a water plant with advanced treatment, they were efficiently removed. Seasonal variations were found in ΣCPHs in tap water from Wuhan, with the highest found in July (median: 21.2 ng/L), and the lowest in October (1.96 ng/L). The intake of CPHs via water ingestion was estimated as below 5 ng/kg-bw/day, much lower than the reference doses for 2,4-D (5 μg/kg-bw/day) and MCPA (4 μg/kg-bw/day). This is the first study to demonstrate the fate of CPHs during drinking water treatment and seasonal variations of CPHs in water from Wuhan, China. Moreover, this study provides an overview of ΣCPHs in tap water for many areas in China. Unlabelled Image • The highest median ΣCPHs was found in Northeast China. • MCPA was higher than 2,4-D in water from Wuhan and many other cities. • The highest ΣCPHs were observed in July, and the lowest in October. • Higher ΣCPHs were found in surface water derived tap water than in groundwater. [ABSTRACT FROM AUTHOR]