Types, frequencies, and burden of nonspecific adverse events of drugs: analysis of randomized placebo-controlled clinical trials.

PURPOSE: Scarce studies analyzing adverse event (AE) data from randomized placebo-controlled clinical trials (RPCCTs) of selected illnesses suggested that a substantial proportion of collected AEs are unrelated to the drug taken. This study analyzed the nonspecific AEs occurring with active-drug exposure in RPCCTs for a large range of medical conditions. METHODS: Randomized placebo-controlled clinical trials published in five prominent medical journals during 2006-2012 were searched. Only trials that evaluated orally or parenterally administered active drugs versus placebo in a head-to-head setting were selected. For AEs reported from ≥10 RPCCTs, Pearson's correlation coefficients (r) were calculated to determine the relationship between AE rates in placebo and active-drug recipients. Random-effects meta-analyses were used to compute proportions of nonspecific AEs, which were truncated at a maximum of 100%, in active-drug recipients. RESULTS: We included 231 trials addressing various medical domains or healthy participants. For the 88 analyzed AE variables, AE rates for placebo and active-drug recipients were in general strongly correlated (r > 0.50) or very strongly correlated (r > 0.80). The pooled proportions of nonspecific AEs for the active-drug recipients were 96.8% (95%CI: 95.5-98.1) for any AEs, 100% (97.9-100) for serious AEs, and 77.7% (72.7-83.2) for drug-related AEs. Results were similar for individual medical domains and healthy participants. The pooled proportion of nonspecificity of 82 system organ class and individual AE types ranged from 38% to 100%. CONCLUSION: The large proportion of nonspecific AEs reported in active-drug recipients of RPCCTs, including serious and drug-related AEs, highlights the limitations of clinical trial data to determine the tolerability of drugs. Copyright © 2017 John Wiley & Sons, Ltd.

Behavior of PAH/mineral associations during thermodesorption: impact for the determination of mineral retention properties towards PAHs.

Polycyclic aromatic hydrocarbons (PAHs) associated with two minerals (silica sand and bentonite) presenting opposite retention properties were analyzed with a thermodesorption (Td)-GC-MS coupling in order to validate this technique as a new and rapid way to evaluate the solid sorption properties. Two analysis modes were used, evolved gas analysis (EGA) and Td with cryo-trap. EGA allowed a real-time monitoring of the compounds desorbed during a temperature program and gave a first screening of the samples while Td gave more precise indications on compound abundances for selected temperature ranges. When associated with silica sand, PAHs were released at relatively low temperatures (<300 °C) close to corresponding boiling point, whereas for the PAH/bentonite mixture, PAHs were desorbed at much higher temperatures; they were also present in much lower abundance and were associated with mono-aromatic compounds. With bentonite, the PAH abundances decreased and the mono-aromatics increased with the increasing PAH molecular weight. These results indicated a clear PAH retention by the bentonite due to polymerization, followed by a thermal cracking at higher temperatures. The Td-GC-MS was proven to efficiently underline differences in retention properties of two minerals, and this study highlights the great potential of this technique to evaluate compound/matrix bond strength and interaction.

Stability of an extemporaneously prepared bleomycin-lidocaine-epinephrine intradermal admixture used in dermatology.

INTRODUCTION: Bleomycin (0.75 g/L)-lidocaine (3.5 g/L)-epinephrine (3.5 mg/L) admixture (BLE) is indicated for keloids treatment. Effect of short-term storage, influence of BLE components and temperature on efficacy and chemical compatibility of bleomycin were studied. METHODS: The stability study of BLE was conducted in polypropylene infusion bags at 4℃ and 22℃ over a period of 7 days versus bleomycin diluted alone in normal saline and stored in the same conditions. Active Bleomycin fractions, bleomycin A2 (BA2) and bleomycin B2 (BB2) and inactive demethylbleomycin A2 (DBA2) were analyzed by a validated stability-indicating HPLC method. RESULTS AND DISCUSSION: BA2 and BB2 remained stable for up to 7 days, in both types of bleomycin preparations, whatever the temperature (<10% loss of the initial peak response). In BLE, DBA2 fraction (2.2% at T0) decreased with time. Less degradation was noted with refrigeration (remained % at day 7: 0.86 ± 0.06% at 4℃ versus 0.43 ± 0.02% at 22℃; p = 0.0004). A degradation product (DP) was observed. More significant percentage (of the total of bleomycin fractions) was reached at room temperature (at day 7, 0.97 ± 0.03% at 4℃ versus 1.41 ± 0.06% at 22℃, p = 0.0004). DP attained an identification threshold of 0.5% between the third and fourth days at 4℃ and between the first and the second days at 22℃. CONCLUSION: A maximum of three days storage at 4℃ and only one day at 22℃ was approved for BLE.

Effect of polycyclic aromatic compounds (PAH & Polar-PAC) availability on their ecotoxicity towards terrestrial organisms.

The exposure of terrestrial organisms to soils freshly contaminated by polycyclic aromatic compounds (PACs, including PAHs and polar-PACs) is known to cause significant toxicity effects. However, historically contaminated soils, such as former coking plant soils, usually induce a limited toxic impact, due to the "aging" phenomenon which is the result of several processes causing a reduction of PAC availability over time. For a better understanding of these behaviors, this study aimed to compare the toxic responses of terrestrial organisms exposed to aged contaminated soils and their counterparts submitted to a moderate heating process applied to increase PAC availability. Two aged "raw" soils (limited PAC availability) were selected for their representativeness of former industrial soils in terms of PAC contamination. These soils were submitted either to moderate heating (expected PAC availability increase) or solvent-extraction (expected PAC removal). Physico-chemical parameters, contamination levels and availability were determined for these three soil modalities. Additionally, standardized limit bioassays on plants and earthworms were performed to assess soil ecotoxicity. The findings demonstrated that historically contaminated soils exposed to moderate heating induced the highest ecotoxic responses from terrestrial organisms. Heating increased PAC (bio)availability, without modifying any other soil physico-chemical properties. These results pointed out the importance of considering the contamination availability parameter in risk evaluation and also provide a possible tool for protective long-term risk assessment.

An experimental multi-method approach to better characterize the LNAPL fate in soil under fluctuating groundwater levels.

Light-Non-Aqueous phase liquids (LNAPLs) are important soil contamination sources, and groundwater fluctuations may significantly affect their migration and release. However, the risk assessment remains complex due to the continuous three-phase fluid redistribution caused by water table level variations. Hence, monitoring methods must be improved to integrate better the LNAPL multi-compound and multi-phase aspects tied to the groundwater level dynamics. For this purpose, a lysimetric contaminated soil column (2 m3) combining in-situ monitoring (electrical permittivity, soil moisture, temperature, pH, Eh), direct water and gas sampling and analyses (GC/MS-TQD, µGC) in monitoring well, gas collection chambers, and suction probes) were developed. This experiment assesses in an integrated way how controlled rainfalls and water table fluctuation patterns may affect LNAPL vertical soil saturation distribution and release. Coupling these methods permitted the investigation of the effects of rainwater infiltration and water table level fluctuation on contaminated soil oxygen turnover, LNAPL contaminants' soil distribution and remobilization towards the dissolved and the gaseous phase, and the estimate of the LNAPL source attenuation rate. Hence, 7.5% of the contamination was remobilized towards the dissolved and gaseous phase after 120 days. During the experiment, groundwater level variations were responsible for the free LNAPL soil spreading and trapping, modifying dissolved LNAPL concentrations. Nevertheless, part of the dissolved contamination was rapidly biodegraded, leaving only the most bio-resistant components in water. This result highlights the importance of developing new experimental devices designed to assess the effect of climate-related parameters on LNAPL fate at contaminated sites.

Efficient organic carbon burial in the Bengal fan sustained by the Himalayan erosional system.

Continental erosion controls atmospheric carbon dioxide levels on geological timescales through silicate weathering, riverine transport and subsequent burial of organic carbon in oceanic sediments. The efficiency of organic carbon deposition in sedimentary basins is however limited by the organic carbon load capacity of the sediments and organic carbon oxidation in continental margins. At the global scale, previous studies have suggested that about 70 per cent of riverine organic carbon is returned to the atmosphere, such as in the Amazon basin. Here we present a comprehensive organic carbon budget for the Himalayan erosional system, including source rocks, river sediments and marine sediments buried in the Bengal fan. We show that organic carbon export is controlled by sediment properties, and that oxidative loss is negligible during transport and deposition to the ocean. Our results indicate that 70 to 85 per cent of the organic carbon is recent organic matter captured during transport, which serves as a net sink for atmospheric carbon dioxide. The amount of organic carbon deposited in the Bengal basin represents about 10 to 20 per cent of the total terrestrial organic carbon buried in oceanic sediments. High erosion rates in the Himalayas generate high sedimentation rates and low oxygen availability in the Bay of Bengal that sustain the observed extreme organic carbon burial efficiency. Active orogenic systems generate enhanced physical erosion and the resulting organic carbon burial buffers atmospheric carbon dioxide levels, thereby exerting a negative feedback on climate over geological timescales.

Functional redundancy in response to runoff input upholds microbial community in hydrocarbon-contaminated land-sea continuum.

An experimental approach mimicking the land-sea continuum in microcosms was developed in order to determine the effect of the terrigenous inputs by soil runoff on the microbial functional potential in hydrocarbon (HC) contaminated marine coastal sediment. We hypothesized that the coalescent event increases the functional potential of microbial communities in marine coastal sediments, influencing the fate of HC in marine coastal ecosystems. The microbial functional potential including the HC degradation ability was assessed by DNA-array to compare the sediment receiving or not terrigenous inputs. The removal of HC and the functional gene richness in sediment was unchanged with the terrigenous inputs. However, the gene variants (GVs) composition was modified indicating functional redundancy. In addition, functional indicators including GVs related to sulfite reduction, denitrification and polyaromatic degradation were identified in higher proportion in sediment receiving terrigenous inputs. The terrigenous inputs modified the functional co-occurrence networks, showing a reorganization of the GVs associations with an increase of the network complexity. Different keystone GVs ensuring similar functions were identified in networks with or without terrigenous inputs, further confirming functional redundancy. We argue that functional redundancy maintains the structure of microbial community in hydrocarbon-contaminated land-sea continuum mixing zone. Our results provide helpful functional information for the monitoring and management of coastal environment affected by human land-based activities.

Taxonomic and functional trait-based approaches suggest that aerobic and anaerobic soil microorganisms allow the natural attenuation of oil from natural seeps.

Natural attenuation, involving microbial adaptation, helps mitigating the effect of oil contamination of surface soils. We hypothesized that in soils under fluctuating conditions and receiving oil from seeps, aerobic and anaerobic bacteria as well as fungi could coexist to efficiently degrade hydrocarbons and prevent the spread of pollution. Microbial community diversity was studied in soil longitudinal and depth gradients contaminated with petroleum seeps for at least a century. Hydrocarbon contamination was high just next to the petroleum seeps but this level drastically lowered from 2 m distance and beyond. Fungal abundance and alpha-diversity indices were constant along the gradients. Bacterial abundance was constant but alpha-diversity indices were lower next to the oil seeps. Hydrocarbon contamination was the main driver of microbial community assemblage. 281 bacterial OTUs were identified as indicator taxa, tolerant to hydrocarbon, potentially involved in hydrocarbon-degradation or benefiting from the degradation by-products. These taxa belonging to lineages of aerobic and anaerobic bacteria, have specific functional traits indicating the development of a complex community adapted to the biodegradation of petroleum hydrocarbons and to fluctuating conditions. Fungi are less impacted by oil contamination but few taxa should contribute to the metabolic complementary within the microbial consortia forming an efficient barrier against petroleum dissemination.

Handle Matrix Rank Deficiency, Noise, and Interferences in 3D Emission-Excitation Matrices: Effective Truncated Singular-Value Decomposition in Chemometrics Applied to the Analysis of Polycyclic Aromatic Compounds.

The characterization of organic compounds in polluted matrices by eco-friendly three-dimensional (3D) fluorescence spectroscopy coupled with chemometric algorithms constitutes a powerful alternative to the separation techniques conventionally used. However, the systematic presence of Rayleigh and Raman scattering signals in the excitation-emission matrices (EEMs) complicates the spectral decomposition via PARAllel FACtor analysis (PARAFAC) due to the nontrilinear structure of these signals. Likewise, the specific problem of selectivity in spectroscopy for unexpected chemical components in a complex sample may render its chemical interpretation difficult at first glance. The relevant chemical information can then be complicated to extract, especially if the raw data is noisy. There are several strategies to overcome these drawbacks, but weaknesses remain. As a consequence, a new alternative method is proposed to handle these interferences, the noise, and the rank deficiencies in the data and applied for the characterization of polycyclic aromatic compound (PAC) mixtures. It is based on effective truncated singular-value decomposition (MT-SVD) that does not require any prior knowledge of the raw data. The algorithm provides a valuable estimation of the global rank to choose on complex samples where selectivity problems are observed. It is a real alternative compared to other existing methods applied to the fluorescence matrix to filter the signal from noise or light scattering effects. The first exploratory results of the proposed algorithm are promising to handle matrix rank deficiencies as well as the effects of noise and light scattering on complex PAC mixtures.

A critical review of the influence of groundwater level fluctuations and temperature on LNAPL contaminations in the context of climate change.

The intergovernmental panel on climate change (IPCC) predicts significant changes in precipitation patterns, an increase in temperature, and groundwater level variations by 2100. These changes are expected to alter light non-aqueous phase liquid (LNAPL) impacts since groundwater level fluctuations and temperature are known to influence both the mobility and release of LNAPL compounds to air and groundwater. Knowledge of these potential effects is currently dispersed in the literature, hindering a clear vision of the processes at play. This review aims to synthesize and discuss the possible effects of the increase in temperature and groundwater level fluctuations on the behavior of LNAPL and its components in a climate change context. In summary, a higher amplitude of groundwater table variations and higher temperatures will probably increase biodegradation processes, the LNAPL mobility, and spreading across the smear zone, favoring the release of LNAPL compounds to the atmosphere and groundwater but decreasing the LNAPL mass and its longevity. Outcomes will, nevertheless, vary greatly across arid, cold, or humid coastal environments, where different effects of climate change are expected. The effects of the climate change factors linked to soil heterogeneities, local conditions, and weathering processes will govern LNAPL behavior and need to be further clarified.

Permanganate oxidation of polycyclic aromatic compounds (PAHs and polar PACs): column experiments with DNAPL at residual saturation.

Permanganate is an oxidant usually applied for in situ soil remediation due to its persistence underground. It has already shown great efficiency for dense nonaqueous phase liquid (DNAPL) degradation under batch experiment conditions. In the present study, experimental permanganate oxidation of a DNAPL - coal tar - sampled in the groundwater of a former coking plant was carried out in a glass bead column. Several glass bead columns were spiked with coal tar using the drainage-imbibition method to mimic on-site pollution spread at residual saturation as best as possible. The leaching of organic pollutants was monitored as the columns were flushed by successive sequences: successive injections of hot water, permanganate solution for oxidation, and ambient temperature water, completed by two injections of a tracer before and after oxidation. Sixteen conventional US-EPA PAHs and selected polar PACs were analyzed in the DNAPL remaining in the columns at the end of the experiment and in the particles collected at several steps of the flushing sequences. Permanganate oxidation of the pollutants was rapidly limited by interfacial aging of the DNAPL drops. Moreover, at the applied flow rate chosen to be representative of in situ injections and groundwater velocities, the reaction time was not sufficient to reach high degradation yields but induced the formation and the leaching of oxygenated PACs.

Root exudates modify bacterial diversity of phenanthrene degraders in PAH-polluted soil but not phenanthrene degradation rates.

To determine whether the diversity of phenanthrene-degrading bacteria in an aged polycyclic aromatic hydrocarbon (PAH) contaminated soil is affected by the addition of plant root exudates, DNA stable isotope probing (SIP) was used. Microcosms of soil with and without addition of ryegrass exudates and with ¹³C-labelled phenanthrene (PHE) were monitored over 12 days. PHE degradation was slightly delayed in the presence of added exudate after 4 days of incubation. After 12 days, 68% of added PHE disappeared both with and without exudate. Carbon balance using isotopic analyses indicated that a part of the ¹³C-PHE was not totally mineralized as ¹³CO2 but unidentified ¹³C-compounds (i.e. ¹³C-PHE or ¹³C-labelled metabolites) were trapped into the soil matrix. Temporal thermal gradient gel electrophoresis (TTGE) analyses of 16S rRNA genes were performed on recovered ¹³C-enriched DNA fractions. 16S rRNA gene banding showed the impact of root exudates on diversity of PHE-degrading bacteria. With PHE as a fresh sole carbon source, Pseudoxanthomonas sp. and Microbacterium sp. were the major PHE degraders, while in the presence of exudates, Pseudomonas sp. and Arthrobacter sp. were favoured. These two different PHE-degrading bacterial populations were also distinguished through detection of PAH-ring hydroxylating dioxygenase (PAH-RHD(α)) genes by real-time PCR. Root exudates favoured the development of a higher diversity of bacteria and increased the abundance of bacteria containing known PAH-RHD(α) genes.

Low-temperature, mineral-catalyzed air oxidation: a possible new pathway for PAH stabilization in sediments and soils.

Reactivity of polycyclic aromatic hydrocarbons (PAHs) in the subsurface is of importance to environmental assessment, as they constitute a highly toxic hazard. Understanding their reactivity in the long term in natural recovering systems is thus a key issue. This article describes an experimental investigation on the air oxidation of fluoranthene (a PAH abundant in natural systems polluted by industrial coal use) at 100°C on different mineral substrates commonly found in soils and sediments (quartz sand, limestone, and clay). Results demonstrate that fluoranthene is readily oxidized in the presence of limestone and clay, leading to the formation of high molecular weight compounds and a carbonaceous residue as end product especially for clay experiments. As demonstrated elsewhere, the experimental conditions used permitted the reproduction of the geochemical pathway of organic matter observed under natural conditions. It is therefore suggested that low-temperature, mineral-catalyzed air oxidation is a mechanism relevant to the stabilization of PAHs in sediments and soils.

Totally implantable port management: impact of positive pressure during needle withdrawal on catheter tip occlusion (an experimental study).

BACKGROUND: Totally implanted ports (TIP) have become a standard part of patient care, providing long-term central venous access for treatment administration and other procedures. Despite overall the safety and effectiveness of TIP, complications still occur. Negative pressure created during needle withdrawal induces blood reflux and subsequent catheter occlusion. Application of positive pressure during needle withdrawal is thought to largely prevent such reflux, but supporting data are limited. PURPOSE OF RESEARCH: To quantify the role of positive pressure, using a test model designed to simulate physiological conditions. METHODS: Reflux associated with needle withdrawal with and without applied positive pressure was tested using various TIP models from different manufacturers mounted on a specially designed test bench. In addition to the presence or absence of positive pressure during needle withdrawal, study variables comprised of needle type (safety and standard), needle gauge and port septum diameter. RESULTS: Application of positive pressure during needle withdrawal reduced the incidence of reflux during needle withdrawal by nearly 80% (22% vs. 99%, p<0.001). When reflux did occur, the mean residual volume was half that observed without positive pressure. In the absence of positive pressure, mean reflux increased with septum diameter and needle gauge to a statistically significant extent. None of these variables significantly affected reflux in the context of needle withdrawal under positive pressure. CONCLUSION: The results of this study support the use of positive pressure during needle withdrawal to prevent blood reflux potentially leading to catheter tip occlusion.

FerrateVI oxidation of polycyclic aromatic compounds (PAHs and polar PACs) on DNAPL-spiked sand: degradation efficiency and oxygenated by-product formation compared to conventional oxidants.

In situ chemical oxidations are known to remediate PAH contaminations in groundwater and soils. In this study, batch-scale oxidations aim to compare the PAC (polycyclic aromatic compound) degradation of three oxidation processes traditionally applied for soil treatment: permanganate, heat-activated persulfate (60 °C) and Fenton-like activated by magnetite, to results obtained with ferrates (FeVI). Widely studied for water treatments, ferrates are efficient on a wide range of pollutants with the advantage of producing nontoxic ferric sludge after reaction. However, fewer works focus on their action on soil, especially on semi-industrial grade ferrates (compatible with field application). Oxidations were carried out on sand spiked with dense non-aqueous phase liquid (DNAPL) sampled in the groundwater of a former coking plant. Conventional 16 US-EPA PAHs and polar PACs were monitored, especially potential oxygenated by-products that can be more harmful than parent-PAHs. After seven reaction days, only the Fenton-like showed limited degradation. Highest efficiencies were obtained for heat-activated persulfate with no O-PAC ketones formed. Permanganate gave important degradation, but ketones were generated in large amount. The tested ferrates not only gave slightly lower yields due to their auto-decomposition but also induced O-PAC ketone production, suggesting a reactional pathway dominated by oxidoreductive electron transfer, rather than a radical one.

Influence of vegetation on the in situ bacterial community and polycyclic aromatic hydrocarbon (PAH) degraders in aged PAH-contaminated or thermal-desorption-treated soil.

The polycyclic aromatic hydrocarbon (PAH) contamination, bacterial community, and PAH-degrading bacteria were monitored in aged PAH-contaminated soil (Neuves-Maisons [NM] soil; with a mean of 1,915 mg of 16 PAHs.kg(-1) of soil dry weight) and in the same soil previously treated by thermal desorption (TD soil; with a mean of 106 mg of 16 PAHs.kg(-1) of soil dry weight). This study was conducted in situ for 2 years using experimental plots of the two soils. NM soil was colonized by spontaneous vegetation (NM-SV), planted with Medicago sativa (NM-Ms), or left as bare soil (NM-BS), and the TD soil was planted with Medicago sativa (TD-Ms). The bacterial community density, structure, and diversity were estimated by real-time PCR quantification of the 16S rRNA gene copy number, temporal thermal gradient gel electrophoresis fingerprinting, and band sequencing, respectively. The density of the bacterial community increased the first year during stabilization of the system and stayed constant in the NM soil, while it continued to increase in the TD soil during the second year. The bacterial community structure diverged among all the plot types after 2 years on site. In the NM-BS plots, the bacterial community was represented mainly by Betaproteobacteria and Gammaproteobacteria. The presence of vegetation (NM-SV and NM-Ms) in the NM soil favored the development of a wider range of bacterial phyla (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Verrucomicrobia, Actinobacteria, Firmicutes, and Chloroflexi) that, for the most part, were not closely related to known bacterial representatives. Moreover, under the influence of the same plant, the bacterial community that developed in the TD-Ms was represented by different bacterial species (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Actinobacteria) than that in the NM-Ms. During the 2 years of monitoring, the PAH concentration did not evolve significantly. The abundance of gram-negative (GN) and gram-positive (GP) PAH-degrading bacteria was estimated by real-time PCR quantification of specific functional genes encoding the alpha subunit of PAH-ring hydroxylating dioxygenase (PAH-RHD(alpha)). The percentage of the PAH-RHD(alpha) GN bacterial genes relative to 16S rRNA gene density decreased with time in all the plots. The GP PAH-RHD(alpha) bacterial gene proportion decreased in the NM-BS plots but stayed constant or increased under vegetation influence (NM-SV, NM-Ms, and TD-Ms).

Fenton-like and potassium permanganate oxidations of PAH-contaminated soils: Impact of oxidant doses on PAH and polar PAC (polycyclic aromatic compound) behavior.

Potassium permanganate and Fenton-like oxidations were applied on two PAH-contaminated soils collected on former coking plant and gas plant sites. The impact of oxidant dose on the polycyclic aromatic compound (PAC) evolution, including 16 US-EPA PAHs, 11 oxygenated- and 4 nitrogen heterocyclic-PACs (O- and N-PACs) was studied for both treatments. The content of extractable organic matter and PACs was determined prior and after oxidation. Overall, permanganate treatment was more efficient than Fenton-like to decrease the PAH content, this latter being limited by the contamination availability. However, permanganate treatment resulted in incomplete PAH degradation, leading to the formation of O-PACs, that was limited with the application of higher dose. It underlines the importance of the dose and the oxidant type in the selection of oxidation parameters for remediation purpose, as improper use of oxidant can lead to the accumulation of oxidation by-products that could be as toxic as the parent compounds.

Aging as the main factor controlling PAH and polar-PAC (polycyclic aromatic compound) release mechanisms in historically coal-tar-contaminated soils.

In industrial sites, historically contaminated by coal tar (abandoned coking and manufactured gas plants), other families of organic pollutants than the 16 PAHs (polycyclic aromatic hydrocarbons) classified by the US-EPA can occur and induce potential risk for groundwater resources. Polar PACs (polycyclic aromatic compounds), especially oxygenated and nitrogenated PACs (O-PACs and N-PACs), are present in the initial pollution and can also be generated over time (i.e., O-PACs). Their aqueous solubilities are much greater than those of the PAHs. For these reasons, we need to increase our knowledge on polar PACs in order to better predict their behavior and the potential on-site risk. Batch leaching tests were carried out under various conditions of temperature, ionic strength, and availability of pollutants to determine the mechanisms and key parameters controlling their release. The results show a release of low-molecular-weight PAHs and polar PACs mainly by dissolution, while higher molecular weight PAHs are mainly released in association with colloids. Aging mainly controls the former mechanism, and ionic strength mainly controls the latter. Temperature increased both dissolution and colloidal mobilization. The Raoult law predicts the PAC equilibrium concentration for soils presenting high pollutant availability, but this law overestimates PAC concentration in aged soils (low pollutant availability). This is mainly due to limitation of PAC diffusion within coal-tar particles with aging. The most soluble PACs (especially polar PACs) are the most sensitive to aging. For better prediction of the PAC behavior in soils and water resources management, aging needs to be taken into account.

Quantitative multimolecular marker approach to investigate the spatial variability of the transfer of pollution from the Fensch River to the Moselle River (France).

The lipidic fraction from 8 sediments sampled at the confluence between the Fensch River (FR) and the Moselle River (MR) have been analyzed by gas chromatography-mass spectrometry (GC-MS) in order to investigate the transfer of organic micropollutants from the FR to the MR. Molecular markers have been quantified and classified into five categories: natural, petrogenic, pyrogenic and sewage water markers and non-specific molecules. This classification coupled with the quantification of the molecules allows the comparison between anthropogenic and natural inputs and the source apportionment of anthropogenic molecules that are not covalently bound to sedimentary organic macromolecules. The transfer and the fate of organic micropollutants in river sediments seem to be controlled by the water flow. Low water flow conditions induce the settling of fine particles, which could limit the biodegradation. This leads to the preservation of the original anthropogenic fingerprint that is rich in low molecular weight molecules. In high water flow conditions, sediments are mainly composed of coarse particles, limiting the preservation of organic matter, which leads to a persistent anthropogenic fingerprint, mainly composed of high molecular weight compounds.

Evolution of the source apportionment of the lipidic fraction from sediments along the Fensch River, France: a multimolecular approach.

The Fensch River (FR) is one of the most contaminated rivers in France due to the population density and the concentration of industrial activities in this small watershed area. From upstream to downstream, the organic matter extracted from sediments has been analyzed by gas chromatography-mass spectrometry and molecules have been quantified and classified into natural, petrogenic, pyrogenic and sewage water (SW) markers. Upstream the river, anthropogenic molecules are already predominant and represent 87.1% of the molecules quantified. This proportion increases from upstream to downstream and rises to 96.8% at the confluence of the FR with the Moselle River. In the upper part of the FR the contamination is mainly due to human waste (coprostanol: 36.44 microg/g; 42.1% of anthropogenic markers). In the lower part, the contribution of SW markers decreases from 42.1 to 2.4% and the proportion of pyrogenic molecules increases from 29.6 to 59.6%. The major sources of pyrogenic organic matter have been determined by calculation of specific ratios on polycyclic aromatic hydrocarbons and by comparison with reported data. Coal tar, road runoff and atmospheric depositions of urban particles seem to be the major pyrogenic sources. Along the river, the proportion of petrogenic molecules remains constant and those molecules seem to be mainly inherited from road runoff, in the upper part of the FR. Industrial lubricants that occur in steel plant sludge are an additional source in the lower part of the river.