Recent decades have been marked by unprecendented environmental changes which threaten the integrity of freshwater systems and their ecological value. Although most of these changes can be attributed to human activities, disentagling natural and anthropogenic drivers remains a challenge. In this study, surface sediments from Lake Ighiel, a mid-altitude site in the Carpathian Mts (Romania) were investigated following high-resolution sedimentological, geochemical, environmental magnetic and diatom analyses supported by historical cartographic and documentary evidence. Our results suggest that between 1920 and 1960 the study area experienced no significant anthropogenic impact. An excellent correspondence is observed between lake proxy responses (e.g., growth of submerged macrophytes, high detrital input, shifts in diatom assemblages) and parameters tracking natural hydroclimate variability (e.g., temperature, NAO). This highlights a dominant natural hydroclimatic control on the lacustrine system. From 1960 however, the depositional regime shifted markedly from laminated to homogenous clays; since then geochemical and magnetic data document a trend of significant (and on-going) subsurface erosion across the catchment. This is paralleled by a shift in lake ecosystem conditions denoting a strong response to an intensified anthropogenic impact, mainly through forestry. An increase in detrital input and marked changes in the diatom community are observed over the last three decades, alongside accelerated sedimentation rates following enhanced grazing and deforestation in the catchment. Recent shifts in diatom assemblages may also reflect forcing from atmospheric nitrogen (N) deposition, a key recent drive of diatom community turnover in mountain lakes. In general, enhanced human pressure alongside intermittent hydroclimate forcing drastically altered the landscape around Lake Ighiel and thus, the sedimentation regime and the ecosystem's health. However, paleoenvironmental signals tracking natural hydroclimate variability are also clearly discernible in the proxy data. Our work illustrates the complex link between the drivers of catchment-scale impacts on one hand, and lake proxy responses on the other, highlighting the importance of an integrated historical and palaeolimnological approach to better assess lake system changes.

• MeSH
• dějiny 19. století MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• dusík analýza   MeSH
• ekosystém MeSH
• geologické sedimenty analýza   MeSH
• jezera * analýza   MeSH
• klimatické změny * dějiny   MeSH
• lidé MeSH
• monitorování životního prostředí MeSH
• nadmořská výška MeSH
• přírodní zdroje MeSH
• rozsivky MeSH
• zachování přírodních zdrojů MeSH
• Check Tag
• dějiny 19. století MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rumunsko MeSH

Seemingly empty spaces in various archaeological settings have left many unanswered questions. This paper focuses on the appearance, maintenance and possible function of a large empty area situated at the summit plateau of the Iron Age oppidum Bibracte in France. Multidisciplinary research of the infill of the ditch that delimited this area in the 1st century BC has provided evidence on the primary function and the formation processes of the structure itself, and for the reconstruction of the appearance, maintenance and function of the area it enclosed. The results allow us to gain insight into a variety of topics, including the role of trees, hygiene measures and waste management strategies at this urbanised hilltop centre. This paper demonstrates that multi-proxy analyses provide detailed insight into the function of archaeological features in a local environmental context and the potential of such approaches in archaeology.

• MeSH
• archeologie * metody   MeSH
• dějiny starověku MeSH
• geologické jevy MeSH
• geologické sedimenty analýza   MeSH
• lidé MeSH
• nakládání s odpady dějiny   MeSH
• radioaktivní datování metody   MeSH
• rozsivky klasifikace   MeSH
• stromy klasifikace   MeSH
• urbanizace dějiny   MeSH
• Check Tag
• dějiny starověku MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Francie MeSH

The freely dissolved concentration (Cfree) of hydrophobic organic chemicals in sediments and soils is considered the driver behind chemical bioavailability and, ultimately, toxic effects in benthic organisms. Therefore, quantifying Cfree, although challenging, is critical when assessing risks of contamination in field and spiked sediments and soils (e.g., when judging remediation necessity or interpreting results of toxicity assays performed for chemical safety assessments). Here, we provide a state-of-the-art passive sampling protocol for determining Cfree in sediment and soil samples. It represents an international consensus procedure, developed during a recent interlaboratory comparison study. The protocol describes the selection and preconditioning of the passive sampling polymer, critical incubation system component dimensions, equilibration and equilibrium condition confirmation, quantitative sampler extraction, quality assurance/control issues and final calculations of Cfree. The full procedure requires several weeks (depending on the sampler used) because of prolonged equilibration times. However, hands-on time, excluding chemical analysis, is approximately 3 d for a set of about 15 replicated samples.

• MeSH
• geologické sedimenty analýza   MeSH
• hydrofobní a hydrofilní interakce MeSH
• látky znečišťující půdu analýza   MeSH
• mikroextrakce na pevné fázi metody   MeSH
• půda chemie   MeSH
• znečištění životního prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (δ18O, δ13C) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (δ18Osw) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (δ18Osw), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low δ18Osw) versus Mediterranean (high δ18Osw) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.

• MeSH
• geologické sedimenty analýza   MeSH
• izotopy kyslíku analýza   MeSH
• klimatické změny * MeSH
• radioaktivní datování * MeSH
• stromy fyziologie   MeSH
• teplota MeSH
• zkameněliny * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Středomoří MeSH

Although pharmaceuticals are frequently studied contaminants, their fate in the environment is still not completely clear. During a one year study, a complex approach including water, sediment and fish sampling was used to describe the behaviour of pharmaceuticals and their metabolites (PTMs) in the environment. Eighteen pharmaceuticals and seven of their metabolites were determined in a pond used for the tertiary treatment of wastewater effluent. A liquid chromatography-tandem mass spectrometry method was applied to determine the PTMs concentrations in all matrices. Seasonal variations in concentrations were evaluated. The partitioning of contaminants between pond compartments was estimated by means of solid water distribution coefficients (Kd) and bioaccumulation factors (BAF) for the livers of fish. Kd values were almost stable throughout the year, which may be a sign of the continuous transport of PTMs between water and sediment under the experimental conditions. Almost all of the studied compounds, with exception of sertraline (BAF of 6200), were found to not be bioaccumulative in fish livers. The pond removal efficiency was calculated for all PTMs, and favourable conditions for natural pharmaceutical removal were proposed. Further aspects regarding fish pharmaceutical exposure need to be studied.

• MeSH
• chromatografie kapalinová MeSH
• geologické sedimenty analýza   MeSH
• léčivé přípravky MeSH
• odpadní voda analýza   MeSH
• roční období MeSH
• ryby metabolismus   MeSH
• voda analýza   MeSH
• vodní organismy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Detection of endocrine disrupting compounds in water and sediment samples has gained much importance since the evidence of their effects was reported in aquatic ecosystems in the 1990s. The aim of this review is to highlight the advances made in the field of in vitro analysis for the detection of hormonally active compounds with estrogenic, androgenic and progestogenic effects in water and sediment samples. In vitro assays have been developed from yeast, mammalian and in a few cases from fish cells. These assays are based either on the hormone-mediated proliferation of sensitive cell lines or on the hormone-mediated expression of reporter genes. In vitro assays in combination with various sample enrichment methods have been used with limits of detection as low as 0.0027 ng L-1 in water, and 0.0026 ng g-1 in sediments for estrogenicity, 0.1 ng L-1 in water, and 0.5 ng g-1 in sediments for androgenicity, and 5 ng L-1 in water for progestogenicity expressed as equivalent concentrations of standard reference compounds of 17β-estradiol, dihydrotestosterone and progesterone, respectively. The experimental results and limits of quantification, however, are influenced by the methods of sample collection, preparation, and individual laboratory practices.

• MeSH
• biotest metody   MeSH
• chemické látky znečišťující vodu analýza   toxicita   MeSH
• endokrinní disruptory analýza   toxicita   MeSH
• geologické sedimenty analýza   MeSH
• kultivované buňky MeSH
• lidé MeSH
• odběr biologického vzorku metody   MeSH
• odpadní voda analýza   MeSH
• pohlavní steroidní hormony analýza   toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Concentrations and fluxes of total and methylmercury were determined in surface sediments and associated with settling particles at two sites in Lake Geneva to evaluate the sources and dynamics of this toxic contaminant. Total mercury concentrations measured in settling particles were different throughout the seasons and were greatly influenced by the Rhone River particulate inputs. Total mercury concentrations closer to shore (NG2) ranged between 0.073 ± 0.001 and 0.27 ± 0.01 μg/g, and between 0.038 ± 0.001 and 0.214 ± 0.008 μg/g at a site deeper in the lake (NG3). Total mercury fluxes ranged between 0.144 ± 0.002 and 3.0 ± 0.1 μg/m2/day at NG2, and between 0.102 ± 0.008 and 1.32 ± 0.08 μg/m2/day at NG3. Combined results of concentrations and fluxes showed that total mercury concentrations in settling particles are related to the season and particle inputs from the Rhone River. Despite an observed decrease in total mercury fluxes from the coastal zone towards the open lake, NG3 (~ 3 km from the shoreline) was still affected by the coastal boundary, as compared to distal sites at the center of the lake. Thus, sediment focusing is not efficient enough to redistribute contaminant inputs originating from the coastal zones, to the lake center. Methylmercury concentrations in settling particles largely exceeded the concentrations found in sediments, and their fluxes did not show significant differences with relation to the distance from shore. The methylmercury found associated with settling particles would be related to the lake's internal production rather than the effect of transport from sediment resuspension.

• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• geologické sedimenty analýza   MeSH
• jezera analýza   chemie   MeSH
• methylortuťné sloučeniny analýza   MeSH
• monitorování životního prostředí MeSH
• řeky MeSH
• roční období MeSH
• rtuť analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Švýcarsko MeSH

Analysis of over 500 groundwater samples from throughout the Red River Delta indicates de-coupling of dissolved arsenic (As) and dissolved iron (Fe). Sorting of all data along the redox potentials suggests re-adsorption of As released initially from Mn(IV)-oxyhydroxides and later from Fe(III)-oxyhydroxides on remaining ferric phases at moderate redox levels. A gradually decreasing specific surface area available for re-adsorption of As probably plays a role as a consequence of limited reactivity of more crystalline phases such as goethite and hematite. At low redox levels, concentrations of Fe and phosphate decrease, but As concentrations keep increasing and most As is present as As(III) with limited adsorption affinity. Based on the results of speciation modeling, the water is supersaturated with respect to siderite and vivianite. A general conceptual model of As and Fe behavior is presented, suggesting that coupled behavior is possible in two geochemical "windows", i.e., 1: between saturation of remaining adsorption sites and the onset of siderite and vivianite precipitation, and 2: after the beginning of secondary sulfide phases precipitation and during methanogenesis. The de-coupling of As from Fe is common and has been observed at many sites around the world where As is released as a consequence of redox processes, e.g., in Bangladesh, West Bengal and Assam in India, the Mekong Delta in Cambodia and Vietnam, and Taiwan. The presented general conceptual model of de-coupling processes can be applied to the interpretation of As and Fe data, and, thus, it can help in the preparation of a site conceptual model which is a necessary prerequisite for reactive transport modeling.

• MeSH
• arsen analýza   MeSH
• chemické látky znečišťující vodu MeSH
• epidemiologické monitorování MeSH
• geologické sedimenty analýza   chemie   MeSH
• monitorování životního prostředí metody   MeSH
• oxidace-redukce MeSH
• řeky MeSH
• teoretické modely MeSH
• uhličitany MeSH
• železité sloučeniny analýza   MeSH
• železo analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Bangladéš MeSH
• Indie MeSH
• Kambodža MeSH
• Taiwan MeSH
• Vietnam MeSH

The contact assay measuring the inhibition of Arthrobacter globiformis dehydrogenase activity as an endpoint to evaluate the toxicity of solid samples was tested in an international ring-test to validate its performance for ISO standardization (ISO/CD 18187). This work reports the results of the ring-test involving 9 laboratories from six countries. At least 8 valid data sets were obtained for each sample and more than three quarters of the participants attained the validity criteria defined in the standard. The coefficient of variation within (CVr) and between (CVR) laboratories was generally on average <15% and <30% for negative and positive controls, respectively. Regarding solid samples, the laboratories provided a similar ranking of the samples based on their toxicity, despite some variation in the LOEC values. The logarithmic within-lab standard deviation <0.50 for soils and <0.25 for wastes evidenced a good repeatability. The between-lab variability assessed by a CVR <30%, minimum-maximum factor <4 and a reproducibility standard deviation (SDR) <0.13 for a great part of the solid samples, confirmed the test reproducibility. Overall, this assay proved to be robust, sensitive and feasible for routine use towards the quality assessment of soils and wastes.

• MeSH
• Arthrobacter enzymologie   MeSH
• biotest * MeSH
• dřevo analýza   MeSH
• geologické sedimenty analýza   MeSH
• hornictví MeSH
• hydrolasy metabolismus   MeSH
• laboratoře MeSH
• látky znečišťující půdu analýza   MeSH
• monitorování životního prostředí MeSH
• popel uhelný analýza   MeSH
• průmyslový odpad analýza   MeSH
• reprodukovatelnost výsledků MeSH
• sklo analýza   MeSH
• těžké kovy analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The freely dissolved concentration of persistent organic pollutants (POPs) is one of the most important parameters for risk assessment in aquatic environments, due to its proportionality to the chemical activity. Chemical activity difference represents the driving force for a spontaneous contaminant transport, such as water-aquatic biota or water-sediment. Freely dissolved concentrations in sediment pore water can be estimated from the concentrations in a partition-based passive sampler equilibrated in suspensions of contaminated sediment. Equilibration in the sediment/passive sampler system is slow, since concentrations of most POPs in the water phase, which is the main route for mass transfer, are very low. Adding methanol to sediment in suspension increases the POPs' solubility and, consequently, the permeability in the water phase. The resulting higher aqueous concentrations enhance POPs mass transfer up to three times for investigated POPs (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides) and shorten equilibrium attainment to less than 6 weeks. The addition of methanol to the aqueous phase up to a molar fraction of 0.2 changed the POPs equilibrium distribution ratio between sediment and passive sampler by less than a factor of two. As a result, the pore water concentrations of POPs, calculated from their amounts accumulated in a passive sampler, are affected by methanol addition not more than by the same factor.

• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• chlorované uhlovodíky analýza   MeSH
• geologické sedimenty analýza   MeSH
• methanol chemie   MeSH
• monitorování životního prostředí metody   MeSH
• pesticidy analýza   MeSH
• polychlorované bifenyly analýza   MeSH
• polycyklické aromatické uhlovodíky analýza   MeSH
• rozpustnost MeSH
• Publikační typ
• časopisecké články MeSH