Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Different household insecticide applications via two electric vaporizers emitting transfluthrin were realized in a full-scale experimental room under controlled air exchange rate conditions. On-line high-time resolved measurements of the gas-phase concentrations of the active substance during and immediately after the spreading periods were performed with a High Sensitivity Proton-Transfer-Reaction Mass Spectrometer (HS-PTR-MS). Experimental and modelled data from the ConsExpo 4.0 software were also compared to evaluate the sources of differences. Different application scenarios were also compared. Averaged inhaled concentrations over 1h, 1week, and 5months were estimated to be 8.3, 1.8, and 1.8μg.m(-3), respectively. Corresponding margins of exposures range from 1000 to 10,000, claiming for the absence of effect. Dermal and dust ingestion pathways, although roughly estimated, seems being non-negligible. This claims for a more in-depth integrated risk assessment.
ISSN: 0160-4120

hal-00875320
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00875320
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00875320/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00875320/file/Transfluthrin-indoor-accepted.pdf
DOI : 10.1016/j.envint.2013.07.011

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Lead in homes is a well-known source of childhood lead exposure, which is still of concern due to the health effects of low lead doses. This study aims to describe lead contamination in the homes of children aged 6 months to 6 years in France (without overseas). Between October 2008 and August 2009, 484 housing units were investigated. Lead in tap water and total and leachable lead levels from floor dust, outdoor soils and paint chips were measured. X-ray fluorescence measurements were carried out on non-metallic and metallic substrates. Nationwide results are provided. The indoor floor dust lead (PbD) geometric mean (GM) was 8.8 μg/m² (0.8 μg/ft²) and 6.8 μg/m² (0.6 μg/ft²) for total and leachable lead respectively; 0.21% of homes had an indoor PbD loading above 430.5 μg/m² (40 μg/ft²). The outdoor play area concentration GM was 33.5 mg/kg and 21.7 mg/kg in total and leachable lead respectively; 1.4% of concentrations were higher than or equal to 400 mg/kg. Outdoor floor PbD GM was 44.4 μg/m² (4.1 μg/ft²) that was approximately 3.2 times higher than the GM of indoor PbD. Lead-based paint (LBP) was present in 25% of dwellings, LBP on only non-metallic substrates was present in 19% of homes and on metallic substrates in 10% of dwellings. The GM of lead concentrations in tap water was below 1 μg/L; 58% of concentrations were lower than 1 μg/L and 2.9% were higher than or equal to 10 μg/L. The age cut-off for homes with lead would be 1974 for paint and 1993 for indoor floor dust. This study provides, for the first time, a look at the state of lead contamination to which children are exposed in French housing. Moreover, it provides policy makers an estimate of the number of French dwellings sheltering children where abatement should be conducted.
ISSN: 0013-9351

hal-00732138
https://hal.archives-ouvertes.fr/hal-00732138
DOI : 10.1016/j.envres.2012.04.005
PUBMED : 22551852

Éditeur(s) : HAL CCSD Ocean Drilling Programm
Résumé : This paper provides a summary of postcruise scientific results from Ocean Drilling Program (ODP) Leg 209 available to date, building upon shipboard observations and syntheses summarized in the Leg 209 Initial Results volume. During Leg 209, 19 holes were drilled at 8 sites along the Mid-Atlantic Ridge from 14°43´ to 15°44´N, mainly in residual mantle peridotite intruded by gabbroic rocks, in order to understand the tectonic and structural processes responsible for formation of oceanic lithosphere with abundant residual peridotite exposed on the seafloor coupled with a relatively low proportion of volcanic rocks. Based on proportions of recovered lithologies, the entire area may be underlain by mantle peridotite with ~20%–40% gabbroic intrusions and impregnations. Impregnated peridotites with olivine + two pyroxenes + plagioclase + spinel that apparently formed in equilibrium probably record crystallization from primitive mid-ocean-ridge basalt at pressures of 0.5–0.6 GPa. Metamorphic equilibria record isobaric cooling to ~1100°C at this pressure. Thus, the conductively cooled thermal boundary layer beneath the Mid-Atlantic Ridge in this region is >15 km thick. Combined crystallization and reaction with residual peridotite formed a series of impregnated peridotites recording increasing Na content at nearly constant Mg#; this process could explain some of the variation in fractionation-corrected Na (e.g., Na = 8.0) observed in mid-ocean-ridge basalts. Clinopyroxene textures and compositions record such impregnation processes, and they are particularly well documented for Site 1274. Other Leg 209 gabbroic rocks formed from extensive crystallization of highly evolved melts, indicating that a substantial proportion of melt entering the thermal boundary layer crystallizes entirely beneath the seafloor, with no volcanic equivalent. Alteration of peridotites occurred over a range of temperatures and is the result of three distinct processes: rock-dominated serpentinization with formation of brucite in olivine-rich lithologies, fluid-dominated serpentinization with formation of magnetite and no brucite, and fluid-dominated talc alteration with addition of SiO2 as well as H2O and oxygen. The latter two processes also exhibit detectable trace element metasomatism that is distinct in its character from the igneous impregnation described in the previous paragraph. Microstructures show that most residual peridotites were not ductilely deformed at temperatures less than ~1200°C. Structural and paleomagnetic data require tectonic rotations of relatively undeformed blocks; some rotations probably exceeded 60° around nearly horizontal axes parallel to the rift axis. Rotations occurred along several generations of high-temperature mylonitic shear zones extending deeper than 15 km depth and numerous faults at lower temperature. Early formed shear zones and faults were passively rotated around later features; such a process could have produced low-angle fault surfaces without slip on low-angle faults. This region provides end-member examples of processes that are common at many or most slow-spreading ridges. Osmium isotope ratios indicate an ancient history of depletion for residual peridotites from the 14°–16°N region along the Mid-Atlantic Ridge. Though depleted Os isotope ratios in peridotite have been reported elsewhere along the global ridge system, the values from this region are among the most depleted. In general, Os isotope ratios from mid-ocean-ridge basalts are systematically more radiogenic than Os isotope ratios from ridge peridotite samples, suggesting a polygenetic heterogeneous source for mid-ocean-ridge basalts. Geochemical studies of zircons from Leg 209 gabbroic rocks and impregnated peridotites, together with other ridge and arc-related zircons, indicate that ridge zircons have systematically lower fractionation-corrected U and Th concentrations compared to arc zircons. This observation provides a tool for interpreting the tectonic provenance of ancient detrital zircons and indicates an arclike provenance for Hadean detrital zircons. Geobiological studies and aerobiological studies were also undertaken during Leg 209. The geobiological work found no measurable microbial enhancement of olivine dissolution rate, possibly because the samples from Leg 209 were sterile. The aerobiological study determined that dust from North Africa, collected from the derrick of the JOIDES Resolution during Leg 209, contains a variety of abundant microorganisms.
Proceedings ODP, scientific results, 209

hal-00407966
https://hal.archives-ouvertes.fr/hal-00407966
DOI : 10.2973/odp.proc.sr.209.001.2007

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
We report trace element analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of metal grains from nine different CR chondrites, distinguishing grains from chondrule interior ("interior grains"), chondrule surficial shells ("margin grains"), and the matrix ("isolated grains"). Save for a few anomalous grains, Ninormalized trace element patterns are similar for all three petrographic settings, with largely unfractionated refractory siderophile elements and depleted volatile Au, Cu, Ag, S. All three types of grains are interpreted to derive from a common precursor approximated by the least-melted, fine-grained objects in CR chondrites. This also excludes recondensation of metal vapor as the origin of the bulk of margin grains. The metal precursors were presumably formed by incomplete condensation, with evidence for high-temperature isolation of refractory platinum-group-element (PGE)-rich condensates before mixing with lower temperature PGE-depleted condensates. The rounded shape of the Ni-rich, interior grains shows that they were molten and that they equilibrated with silicates upon slow cooling (1-100 K h 1), largely by oxidation/evaporation of Fe, hence their high Pd content, for example. We propose that Ni-poorer, amoeboid margin grains, often included in the pyroxene-rich periphery common to type I chondrules, result from less intense processing of a rim accreted onto the chondrule subsequent to the melting event recorded by the interior grains. This means either that there were two separate heating events, which formed olivine/ interior grains and pyroxene/margin grains, respectively, between which dust was accreted around the chondrule, or that there was a single high-temperature event, of which the chondrule margin records a late "quenching phase," in which case dust accreted onto chondrules while they were molten. In the latter case, high dust concentrations in the chondrule-forming region (at least three orders of magnitude above minimum mass solar nebula models) are indicated.
ISSN: 1086-9379

hal-01003975
https://hal.archives-ouvertes.fr/hal-01003975
DOI : 10.1111/maps.12212

Éditeur(s) : HAL CCSD
Résumé : Molds are common contaminants in indoor environments. Health effects associated with these microscopic fungi are multiple, including irritations, allergic reactions, infections and toxicity. Depending on the exposure level and the vulnerability of the populations, fungi may represent different public health risks. For example, damp and moldy dwellings are associated with chronic, respiratory diseases such as asthma and allergic rhinitis. However, the lack of valid tools for accurately measuring the environmental fungal exposure is one of the main challenges to better understanding the role of fungal products and particles in human health. In this thesis, diverse sampling techniques and analytical methods were evaluated for measuring the fungal contamination in the air, on surfaces and in settled dust. A quantitative PCR-based index was notably tested and compared with other approaches to assess fungal exposure in dwellings. By collecting and analyzing settled floor dust, this index successfully distinguished between contaminated and non-contaminated homes in Brittany, France. Quantitative PCR and this index are promising techniques for fungal exposure assessment in indoor environments. Further validation of these methods may lead to disease prevention approaches, particularly for vulnerable populations.
Les moisissures sont des micro-organismes présents dans tous les environnements intérieurs. Les effets sur la santé associés à ces champignons microscopiques sont multiples : irritations, réactions immunoallergiques, infections et effets toxiques. Selon le niveau d'exposition et la vulnérabilité des populations, les moisissures peuvent représenter des risques plus ou moins importants pour la santé publique. Les logements humides et moisis ont par exemple été associés à des maladies chroniques respiratoires telles que l'asthme et les rhinites allergiques. Cependant, le manque d'outils valides permettant d'évaluer quantitativement l'exposition fongique environnementale constitue une des principales difficultés pour mieux appréhender le rôle des particules et des composés fongiques sur la santé humaine. Lors de ce travail de thèse, diverses techniques d'échantillonnage et méthodes d'analyses ont été évaluées afin de mesurer la contamination fongique de l'air, des surfaces et des poussières. Un indice moléculaire basé sur la technique de PCR quantitative a notamment été testé et comparé à d'autres approches pour mesurer l'exposition fongique dans des logements. Après analyse des poussières domestiques collectées au sol, cet indice a permis de discriminer les habitats avec ou sans moisissures visibles. La quantification de groupes fongiques par PCR quantitative s'avère une technique prometteuse pour la mesure de l'exposition aux moisissures dans les environnements intérieurs. Outre le développement et la validation d'outils de mesure, une démarche globale de prévention du risque fongique semble nécessaire, particulièrement chez les populations vulnérables.
https://tel.archives-ouvertes.fr/tel-00768444

Droits : info:eu-repo/semantics/OpenAccess
tel-00768444
https://tel.archives-ouvertes.fr/tel-00768444
https://tel.archives-ouvertes.fr/tel-00768444/document
https://tel.archives-ouvertes.fr/tel-00768444/file/MA_heust_Delphine.pdf

Éditeur(s) : Amer Geophysical Union
Résumé : In this study, we undertook a reconnaissance study of sediments provenance in the Gulf of Lions focusing over the last 16 ka. We used geochemical and isotopic tracers to determine the source of sediments and give insight into the weathering conditions prevailing. Sediments samples were selected both onshore and offshore from the western, eastern, and central part of the Gulf of Lions. We analyzed bulk sediments, coarse and fine silt, and clay fractions. Elemental and Nd isotope compositions appeared to differ from one grain size fraction to another one. These are interpreted in terms of zircon addition in the coarse silt fraction for the elemental concentrations and variable sources influences for the Nd isotope compositions. Our results indicate that sediments in the Gulf of Lions mainly originated from the Rhone River watershed although a contribution of Saharan dust is seen in one sample. Influence of Pyrenean small rivers is minor in these samples. Some Sr isotope compositions shifts are interpreted as reflecting variable amounts of chemical weathering that are consistent with published paleoclimatic reconstructions.
Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2011-08 , Vol. 12 , N. Q08006 , P. 20 p.

Droits : 2011 by the American Geophysical Union
http://archimer.ifremer.fr/doc/00043/15376/12734.pdf
DOI:10.1029/2011GC003523
http://archimer.ifremer.fr/doc/00043/15376/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The active collision zone around Taiwan orogen receives a variety of sedimentary inputs, including terrigenous flux from Taiwan and Chinese rivers, oceanic currents and atmospheric dust. In order to determine the present-day respective contributions of these different sources, we analysed the Pb and Sr isotopic compositions of late Quaternary sediments accumulated offshore east Taiwan. Samples from the Taiwan Coastal Range (andesites, sandstones, conglomerate and Peinan River terraces and suspended loads) have also been analysed to constrain the mean Taiwan isotopic signature. Mixing lines between the different sources of material indicate that the core located in the Okinawa Trough represents a mixture of about 60% of Taiwan, 30% of Chinese Loess and 10% of Yangtze River contributions. The southernmost core, located close to Luzon Are, is influenced by Taiwan (60%) and volcanic material (40%). The Sr and Pb isotopic compositions of samples cored in the Manila Trench and in the Huatung Basin are strongly influenced by the Taiwan signature, while the Ryukyu Trench core samples point to significant but variable contributions of Chinese Loess and Yangtze River. This work also reports Zn isotopic variations in the silicate fraction of these marine core samples. The overall variation in Zn isotopic compositions (expressed as 666 Zn) is greater than 0.3 per mil (parts per thousand) for an analytical precision of +/- 0.05 parts per thousand. The Zn isotopic signal for most of the marine core samples is similar to the literature data measured on sedimentary material, except for the Manila Trench core samples and the older sample from the Huatung Basin: they present values heavier by 0.2-0.3 parts per thousand, close to those obtained on all Taiwan rocks and Peinan River particulates. These results show: 1- the particular characteristics of Taiwan Zn isotopic compositions on a large scale; and: 2- the possible use of Zn isotopes as a tracer of material sources.
ISSN: 0009-2541

hal-00412214
https://hal.archives-ouvertes.fr/hal-00412214
DOI : 10.1016/j.chemgeo.2007.10.024

Éditeur(s) : HAL CCSD
Résumé : International audience
Multiple chemicals are emitted in residential accommodation. Aggregate Daily Doses (ADD) (ng/kg-bw/d) were estimated for 32 semivolatile organic compounds (SVOCs) of different chemical families that are frequently detected in French dwellings in both air and settled dust. Daily doses were determined using steady-state models for the population, categorized into 11 age groups covering birth to age 30. Three routes of exposure were taken into account: dust ingestion, inhalation (gaseous and particulate phases) and dermal contact with the gaseous phase of air. Contamination levels were preferentially retrieved from large, nationwide representative datasets. A two-dimensional probabilistic approach was used to assess parametric uncertainty and identify the most influential factors. For children aged 2 to 3 years, ADD estimates spanned orders of magnitude, with median values ranging from 8.7 pg/kg-bw/d for 2,2′,3,4,4′-pentabromodiphenylether (BDE 85) to 1.3 μg/kg-bw/d for di-isobutyl phthalate (DiBP). Inhalation, ingestion and dermal pathway contributed at varying levels, and depending on compound, air was the dominant medium for 28 of the 32 compounds (either by inhalation or dermal contact). Indoor exposure estimate variance was mainly driven by indoor contamination variability, and secondarily by uncertainty in physical and chemical parameters. These findings lend support to the call for cumulative risk assessment of indoor SVOCs. © 2017 Elsevier Ltd
ISSN: 01604120

hal-01616433
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616433
DOI : 10.1016/j.envint.2017.08.024
PUBMED : 28950160

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
PURPOSE: Dairy farming is a risk factor for the development of chronic obstructive pulmonary disease (COPD). We assessed the prevalence of farming-induced COPD (FI-COPD) using a new screening device, and we analyzed symptoms and occupational risk factors. METHODS: We performed on-site screening study of bronchial obstruction using an electronic mini-spirometer (EMS) on an entire population of dairy farmers (n = 147) from two villages in Brittany, France. Suspected bronchial obstruction (FEV1/FEV6 <0.8) was confirmed with standardized lung function tests (FEV1/FVC ≤0.7). We assessed past medical histories, respiratory symptoms, and occupational tasks of subjects with bronchial obstruction; asthmatics were defined as atopic and/or reversible; smoking-induced COPD patients were defined as non-reversible, non-atopic with smoking histories (≥5 PY); and FI-COPD patients were defined as non-reversible, non-atopic, and non-smokers. RESULTS: Using the EMS, 30.6% (n = 45) of dairy farmers were suspected of bronchial obstruction and underwent standardized spirometry. The FEV1/FEV6 ratio and FEV1/FVC ratio were in good agreement (r² = 0.66, P < 0.0001). The prevalence of confirmed bronchial obstruction was 9.5% (n = 14), which included 4 asthmatics, 3 smoking-induced COPD subjects, and 7 FI-COPD subjects. All the COPD patients were GOLD Stage II, and none were aware of their respiratory disease. Foddering duration was significantly higher in FI-COPD subjects compared with non-obstructive subjects, with 44 versus 17 min/day, respectively. CONCLUSIONS: The EMS was a convenient mean of screening for bronchial obstruction, especially in on-site settings, and allowed us to diagnose FI-COPD in a non-spontaneously complaining dairy farmer population. Foddering was considered a significant risk factor.
ISSN: 0340-0131

hal-00872929
https://hal.archives-ouvertes.fr/hal-00872929
DOI : 10.1007/s00420-011-0708-6
PUBMED : 21986906

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Particle/gas and dust/gas partition coefficients (Kp and Kd) are two key parameters that address the partitioning of semi-volatile organic compounds (SVOCs) between gas-phase, airborne particles, and settled dust in indoor environment. A number of empirical equations to calculate the values of Kp and Kd have been reported in the literature. Therefore, the difficulty lies in the selection of a specific empirical equation in a given situation. In this study, we retrieved from the literature 38 empirical equations for calculating Kp and Kd values from the SVOC saturation vapor pressure and octanol/air partition coefficient. These values were calculated for 72 SVOCs: 9 phthalates, 9 polybrominated diphenyl ethers (PBDEs), 11 polychlorinated biphenyls (PCBs), 22 biocides, 14 polycyclic aromatic hydrocarbons (PAHs), 3 alkylphenols, 2 synthetic musks, tributylphosphate, and bisphenol A. The mean and median values of log10 Kp or log10 Kd for most SVOCs were of the same order of magnitude. The distribution of log10 Kp values was fitted to either a normal distribution (for 27 SVOCs) or a log-normal distribution (for 45 SVOCs). This work provides a reference distribution of the log10 Kp for 72 SVOCs, and its use may reduce the bias associated with the selection of a specific value or equation
ISSN: 0045-6535

hal-01295671
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01295671
DOI : 10.1016/j.chemosphere.2016.03.007
PUBMED : 27016817

Éditeur(s) : HAL CCSD
Résumé : 38 pages
Rapport
The Chicxulub impact crater, México, is unique. It is the only known terrestrial impact structure that has been directly linked to a mass extinction event and the only terrestrial impact with a global ejecta layer. Of the three largest impact structures on Earth, Chicxulub is the best preserved. Chicxulub is also the only known terrestrial impact structure with an intact, unequivocal topographic peak ring. Chicxulub’s role in the Cretaceous/Paleogene (K-Pg) mass extinction and its exceptional state of preservation make it an important natural laboratory for the study of both large impact crater formation on Earth and other planets and the effects of large impacts on the Earth’s environment and ecology. Our understanding of the impact process is far from complete, and despite more than 30 years of intense debate, we are still striving to answer the question as to why this impact was so catastrophic.During International Ocean Discovery Program (IODP) Expedition 364, Paleogene sediments and lithologies that make up the Chicxulub peak ring were cored to investigate (1) the nature and formational mechanism of peak rings, (2) how rocks are weakened during large impacts, (3) the nature and extent of post-impact hydrothermal circulation, (4) the deep biosphere and habitability of the peak ring, and (5) the recovery of life in a sterile zone. Other key targets included sampling the transition through a rare midlatitude section that might include Eocene and Paleocene hyperthermals and/or the Paleocene/Eocene Thermal Maximum (PETM); the composition and character of the impact breccias, melt rocks, and peak-ring rocks; the sedimentology and stratigraphy of the Paleocene–Eocene Chicxulub impact basin infill; the chronology of the peak-ring rocks; and any observations from the core that may help us constrain the volume of dust and climatically active gases released into the stratosphere by this impact. Petrophysical property measurements on the core and wireline logs acquired during Expedition 364 will be used to calibrate geophysical models, including seismic reflection and potential field data, and the integration of all the data will calibrate impact crater models for crater formation and environmental effects. The proposed drilling directly contributes to IODP Science Plan goals:Climate and Ocean Change: How resilient is the ocean to chemical perturbations? The Chicxulub impact represents an external forcing event that caused a 75% level mass extinction. The impact basin may also record key hyperthermals within the Paleogene.Biosphere Frontiers: What are the origin, composition, and global significance of subseafloor communities? What are the limits of life in the subseafloor? How sensitive are ecosystems and biodiversity to environmental change? Impact craters can create habitats for subsurface life, and Chicxulub may provide information on potential habitats for life, including extremophiles, on the early Earth and other planetary bodies. Paleontological and geochemical studies at ground zero will document how large impacts affect ecosystems and effects on biodiversity.Earth Connections/Earth in Motion: What are the composition, structure and dynamics of Earth’s upper mantle? What mechanisms control the occurrence of destructive earthquakes, landslides, and tsunami? Mantle uplift in response to impacts provides insight into dynamics that differ between Earth and other rocky planets. Impacts generate earthquakes, landslides, and tsunami, and scales that generally exceed plate tectonic processes yield insight into effects, the geologic record, and potential hazards.IODP Expedition 364 was a Mission Specific Platform expedition to obtain subseabed samples and downhole logging measurements from the sedimentary cover sequence and peak ring of the Chicxulub impact crater. A single borehole was drilled into the Chicxulub impact crater on the Yucatán continental shelf, recovering core from 505.7 to 1334.73 m below seafloor with ~99% core recovery and acquiring downhole logs for the entire depth.
International Ocean Discovery Program

hal-01639520
https://hal.archives-ouvertes.fr/hal-01639520
DOI : 10.14379/iodp.pr.364.2017

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Humans are exposed to a large number of contaminants, many of which may have similar health effects. This paper presents a framework for identifying pollutants to be included in a cumulative risk assessment approach. To account for the possibility of simultaneous exposure to chemicals with common toxic modes of action, the first step of the traditional risk assessment process, i.e. hazard identification, is structured in three sub-steps: (1a) Identification of pollutants people are exposed to, (1b) identification of effects and mechanisms of action of these pollutants, (1c) grouping of pollutants according to similarity of their mechanism of action and health effects. Based on this exposure-based grouping we can derive "multi-pollutant" toxicity reference values, in the "dose-response assessment" step. The approach proposed in this work is original in that it is based on real exposures instead of a limited number of pollutants from a unique chemical family, as traditionally performed. This framework is illustrated by the case study of semi-volatile organic compounds in French dwellings, providing insights into practical considerations regarding the accuracy of the available toxicological information. This case study illustrates the value of the exposure-based approach as opposed to the traditional cumulative framework, in which chemicals with similar health effects were not always included in the same chemical class.
ISSN: 0013-9351

hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00982315/file/An_exposure-based_framework_for_grouping_pollutants_accepted.pdf
DOI : 10.1016/j.envres.2014.01.007

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : Reconstruction of Northern African monsoon between 6.2 and 4.9 Ma and possible relationships with Late Miocene events. Mineralogical and geochemical investigations have been realized on ODP Site 659 in order to better understand the detrital sedimentation of the Cap Verde plateau and to reconstruct African monsoon intensity variations between 6.2 and 4.9 Ma. Time intervals corresponding to an intensification of the summer African monsoon rainfall are associated to a reduction of eolian input from the Sahara and an intensification of the African river input. The reflooding of the Mediterranean Sea at the end of the Messinian salinity crisis (MSC) (5.33 Ma) is correlated to a greater aridity in the Sahara.
ISSN: 1631-0713

hal-00412151
https://hal.archives-ouvertes.fr/hal-00412151
DOI : 10.1016/j.crte.2008.07.005

Éditeur(s) : Gauthier-Villars
Résumé : The dissolved Mn distribution on an oceanographic section along 50-degrees-W in the western North Atlantic shows decreasing concentrations in the offshore direction in the surface layer and with depth at the deep water stations. Leachable particulate Mn concentrations are low in the open ocean surface waters and elevated at intermediate depths. Dissolved Al concentrations in the surface layer are higher in the open ocean than on the shelf and the vertical distributions are characterized by surface maxima, a subsurface minimum at almost-equal-to 1 000 m and increasing concentrations in the deep waters. Leachable particulate Al concentrations are elevated on the shelf and in open ocean surface waters compared to the intermediate and deep waters. The Deep Western Boundary Current has high levels of dissolved Al and leachable particulate Mn and Al, and low levels of dissolved Mn. The distribution of dissolved Al is controlled primarily by inputs from atmospheric dust and removal onto biogenic particles. Both fluvial and atmospheric inputs affect dissolved Mn levels with removal occurring primarily by oxidation of Mn2+. The Al distribution is characterized by short residence times in shelf and surface waters and relatively constant distribution coefficients. The Mn distribution is characterized by longer surface water residence times, shorter deep water residence times, and more widely varying distribution coefficients than Al. Removal of Al by a surface adsorption mechanism and Mn by slower oxidation of Mn2+ are consistent with these observations. A model of Mn oxidation kinetics accurately predicts the intermediate depth leachable particulate Mn maximum.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1992 , Vol. 15 , N. 6 , P. 609-619

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00101/21186/18803.pdf
http://archimer.ifremer.fr/doc/00101/21186/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Environmental Relative Moldiness Index (ERMI) is a DNA-based metric developed to describe the fungal contamination in US dwellings. Our goal was to determine if the ERMI values in dwellings in north western France were correlated with other measures of fungal contamination. Dust and air samples were obtained from 40 dwellings and analyzed by quantitative PCR and/or by culturing. These dwellings were also inspected and the amount of visible fungal growth estimated in m(2). The ERMI values in these dwellings ranged from -2.7 to 28.8 and the fungal contamination estimates ranged from 0 to 20 m(2). The 40 dwellings were divided into those with a low (<6) or high (>8) ERMI values (n=20 in each). The average ERMI value was 15.70 for the high ERMI compared to 2.68 for the low ERMI dwellings. ERMI values were correlated (significant Kendall's tau values) with concentrations of fungi in air samples analyzed by QPCR or culturing. ERMI values were also correlated (significant Kendall's tau values) with the visible estimates of fungal contamination. Older dwellings were more likely to have higher ERMI values. These results suggest that the ERMI dust sample, which is quick and easy to collect, may be useful in making decisions about reducing fungal exposures in homes.
ISSN: 0048-9697

hal-00874733
https://hal.archives-ouvertes.fr/hal-00874733
DOI : 10.1016/j.scitotenv.2012.08.085
PUBMED : 23022719

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The Nile delta sedimentation constitutes a continuous high resolution (1.6 mm/year) record of Ethiopian African monsoon regime intensity. Multiproxy analyses performed on core MS27PT recovered in hemipelagic Nile sediment margin (<90 km outward of the Rosetta mouth of the Nile) allow the quantification of the Saharan aeolian dust and the Blue/White Nile River suspended matter frequency fluctuations during the last 21 cal. ka BP. The radiogenic Sr and Nd isotopes, clay mineralogy, bulk elemental composition and palynological analyses reveal large changes in source components, oscillating between a dominant aeolian Saharan contribution during the LGM and the Late Holocene (~4 to 2 cal. ka BP), a dominant Blue/Atbara Nile River contribution during the early Holocene (15 to 8.4 cal. ka BP) and a probable White Nile River contribution during the Middle Holocene (8.4 to 4 cal. ka BP). The following main features are highlighted: 1. The rapid shift from the LGM arid conditions to the African Humid Period (AHP) started at about 15 cal. ka BP. AHP extends until 8.4 cal. ka BP, and we suggest that the Ethiopian African Monsoon maximum between 12 and 8 cal. ka BP is responsible for a larger Blue/Atbara Nile sediment load and freshwater input into the Eastern Mediterranean Sea. 2. The transition between the AHP and the arid Late Holocene is gradual and occurs in two main phases between 8.4 and 6.5 cal. ka BP and 6.5 to 3.2 cal. ka BP. We suggest that the main rain belt shifted southward from 8.4 to ~4 cal. ka BP and was responsible for progressively reduced sediment load and freshwater input into the eastern Mediterranean Sea. 3. The aridification along the Nile catchments occurred from ~4 to 2 cal. ka BP. A dry period, which culminates at 3.2 cal. ka BP, and seems to coincide with a re-establishment of increased oceanic primary productivity in the western Mediterranean Sea. We postulate that the decrease in thermo-haline water Mediterranean circulation could be part of a response to huge volumes of fresh-water delivered principally by the Nile River from 12 to 8.4 cal. ka BP in the eastern Mediterranean. We propose that the large hydrological change in Ethiopian latitude could be a trigger for the 8.2 ka cooling event recorded in high latitude. Revel R., Colin C., Bernasconi S., Combourieu-Nebout N., Ducassou E., Grousset F.E., Rolland Y., Migeon S., Brunet P., Zhaa Y., Bosch D., Mascle J.,. "21,000 years of Ethiopian African moonsoon variability recorded in sediments of the western Nile deep sea fan", Regional Environmental Change,
ISSN: 1436-3798

hal-00836300
https://hal.archives-ouvertes.fr/hal-00836300

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
People spend a considerable amount of time indoors. As a result, exposure to indoor contaminants is of great concern, notably via settled dust ingestion in particular for infants and toddlers. This paper proposes a critical review on the organic contamination of settled house dust and human exposure over the past 10 years and focused on sources, contaminations and measurement methods (sampling, pretreatment, storage and analysis). As many compounds were identified, arises the question of which ones to consider. Sensitive and selective analytical methods for simultaneous determination of targeted substances should be developed and evaluated. Various methods were described for sampling and sample preparation. Harmonization and standardization are needed to enable comparison of results from similar studies. Finally, an integrated multipollutant and multicompartment (settled dust, suspended particles and air) approach appears essential in order to determine the extent of the threat to public health posed by indoor contaminants.
ISSN: 0013-936X

hal-00687396
https://hal.archives-ouvertes.fr/hal-00687396
DOI : 10.1021/es200925h
PUBMED : 21667945

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Our goal was to determine if the US Environmental Relative Moldiness Index (ERMI) scale might have application in France. Twenty homes in Brittany, north western region of France were classified by inspection as "Moldy" or "Non-Moldy". Dust and air samples were collected (MiTest sampler or Coriolis sampler, respectively) from each home and analyzed by quantitative polymerase chain reaction (QPCR) for the 36 fungi that make-up the ERMI. Inspection and ERMI values provided a consistent assessment for 90% of the homes. Two homes originally classified as "Non-Moldy" were found to fit better into the "Moldy" category based on the QPCR analysis and the ERMI. Dust and air samples analyzed by QPCR provided similar fungal contamination assessments. In conclusion, a metric like the ERMI describes mold burdens in homes on a continuum, as opposed to the frequently used dichotomous approach (moldy vs. non-moldy). Although a larger, random national sampling of French homes is needed, these results suggest that these same 36 fungi may be useful in creating an ERMI for France.
ISSN: 1438-4639

inserm-00817898
http://www.hal.inserm.fr/inserm-00817898
http://www.hal.inserm.fr/inserm-00817898/document
http://www.hal.inserm.fr/inserm-00817898/file/Gangneux-Possible-Application-accepted.pdf
DOI : 10.1016/j.ijheh.2012.06.004

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Multiple chemicals are emitted in residential accommodation. Aggregate Daily Doses (ADD) (ng/kg-bw/d) were estimated for 32 semivolatile organic compounds (SVOCs) of different chemical families that are frequently detected in French dwellings in both air and settled dust. Daily doses were determined using steady-state models for the population, categorized into 11 age groups covering birth to age 30. Three routes of exposure were taken into account: dust ingestion, inhalation (gaseous and particulate phases) and dermal contact with the gaseous phase of air. Contamination levels were preferentially retrieved from large, nationwide representative datasets. A two-dimensional probabilistic approach was used to assess parametric uncertainty and identify the most influential factors. For children aged 2 to 3 years, ADD estimates spanned orders of magnitude, with median values ranging from 8.7 pg/kg-bw/d for 2,2′,3,4,4′-pentabromodiphenylether (BDE 85) to 1.3 μg/kg-bw/d for di-isobutyl phthalate (DiBP). Inhalation, ingestion and dermal pathway contributed at varying levels, and depending on compound, air was the dominant medium for 28 of the 32 compounds (either by inhalation or dermal contact). Indoor exposure estimate variance was mainly driven by indoor contamination variability, and secondarily by uncertainty in physical and chemical parameters. These findings lend support to the call for cumulative risk assessment of indoor SVOCs.
ISSN: 0160-4120

hal-01635777
https://hal.archives-ouvertes.fr/hal-01635777
https://hal.archives-ouvertes.fr/hal-01635777/document
https://hal.archives-ouvertes.fr/hal-01635777/file/Article_Expo_Pelletier_Manuscript%20Env%20Int%20rev2.pdf
DOI : 10.1016/j.envint.2017.08.024

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
Abstract Indoor fungal contamination has been associated with a wide range of adverse health effects, including infectious diseases, toxic effects and allergies. The diversity of fungi contributes to the complex role that they play in indoor environments and human diseases. Molds have a major impact on public health, and can cause different consequences in hospitals, homes and workplaces. This review presents the methods used to assess fungal contamination in these various environments, and discusses advantages and disadvantages for each method in consideration with different health risks. Air, dust and surface sampling strategies are compared, as well as the limits of various methods are used to detect and quantify fungal particles and fungal compounds. In addition to conventional microscopic and culture approaches, more recent chemical, immunoassay and polymerase chain reaction (PCR)-based methods are described. This article also identifies common needs for future multidisciplinary research and development projects in this field, with specific interests on viable fungi and fungal fragment detections. The determination of fungal load and the detection of species in environmental samples greatly depend on the strategy of sampling and analysis. Quantitative PCR was found useful to identify associations between specific fungi and common diseases. The next-generation sequencing methods may afford new perspectives in this area.
ISSN: 1040-841X

hal-00874670
https://hal.archives-ouvertes.fr/hal-00874670
DOI : 10.3109/1040841X.2013.777687
PUBMED : 23586944