Éditeur(s) : HAL CCSD Springer
Résumé : International audience
One of the most important topics that occupy public health problems is the air quality. That is the reason why mechanical ventilation and air handling units (AHU) were imposed by the different governments in the collective or individual buildings. Many buildings create an artificial climate using heating, ventilation and airconditioning (HVAC) systems. Among the existing aerosols in the indoor air, we can distinguish the bioaerosol with biological nature such as bacteria, viruses, fungi. Respiratory viral infections are a major public health issue because they are usually highly infective. We spend about 90% of our time in closed environments such as homes, workplaces or transport. Some studies have shown that AHU contribute to the spread and transport of viral particles within buildings. The aim of this work is to study the characterization of viral bioaerosols in indoor environments and to understand the fate of mengovirus eukaryote RNA virus on glass fiber filter F7 used in AHU. In this study, a setup close to reality of AHU system was used. The mengovirus aerosolized was characterized and measured with the Electrical Low Pressure Impact (ELPI) and the Scanner Mobility Particle Size (SMPS) and detected with RT-qPCR. The results about quantification and the level of infectivity of mengovirus on the filter and in the biosampler showed that mengovirus can pass through the filter and remain infectious upstream and downstream the system. Regarding the virus effectiveness on the filter under a constant air flow, and mengovirus was remained infectious during 10 hours after aerosolization.
ISSN: 1867-0334

hal-01636427
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01636427
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01636427/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01636427/file/Fate%20of%20mengovirus%20on%20fiberglass%20filter_accepted.pdf
DOI : 10.1007/s12560-017-9310-8

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
Portable microbial samplers are useful for detecting microorganisms in the air. However, limited data are available on their performance when sampling airborne biological agents in a routine practice. We compared bacterial and fungal concentrations obtained in field conditions using three impactor samplers with different designs (AES Chemunex Sampl'Air, bioMérieux Air Ideal, and Sartorius AirPort MD8/BACTair). The linearity of mold collection was tested in the range of 100 L to 1000 L, and all the devices had a correlation coefficient higher than 0.95. For optimal comparison of the samplers, we performed experiments in different hospital rooms with varying levels of air biocontamination. Each sampling procedure was repeated to assess reproducibility. No significant difference between the samplers was observed for the mold concentrations on Sabouraud agar, whereas Sampl'Air collected significantly more bacteria on tryptic soy agar than Air Ideal or BACTair at one of the sites. Impactor location in the room was nevertheless associated with the variability observed with the three samplers at the highest microbial concentration levels. On the basis of their performance, autonomy and simplicity of use, these three impactors are suitable for routine indoor evaluation of microbial air contamination.
ISSN: 1545-9624

hal-00874614
https://hal.archives-ouvertes.fr/hal-00874614
DOI : 10.1080/15459624.2013.800955
PUBMED : 23799861

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
Respiratory illnesses have been linked to children's exposures to water-damaged homes. Therefore, understanding the microbiome in water-damaged homes is critical to preventing these illnesses. Few studies have quantified bacterial contamination, especially specific species, in water-damaged homes. We collected air and dust samples in twenty-one low-mold homes and twenty-one high-mold homes. The concentrations of three bacteria/genera, Stenotrophomonas maltophilia, Streptomyces sp., and Mycobacterium sp., were measured in air and dust samples using quantitative PCR (QPCR). The concentrations of the bacteria measured in the air samples were not associated with any specific home characteristic based on multiple regression models. However, higher concentrations of S. maltophilia in the dust samples were associated with water damage, that is, with higher floor surface moisture and higher concentrations of moisture-related mold species. The concentrations of Streptomyces and Mycobacterium sp. had similar patterns and may be partially determined by human and animal occupants and outdoor sources of these bacteria.
Indoor Air

hal-00877905
https://hal.archives-ouvertes.fr/hal-00877905
DOI : 10.1111/ina.12035
PUBMED : 23397905

Éditeur(s) : HAL CCSD WB Saunders
Résumé : International audience
BACKGROUND: Environmental surveillance is important in high-risk areas of hospitals to prevent fungal infections in immunosuppressed patients. Conventional culture methods for enumerating environmental fungi are time-consuming. AIM: In this field study, a solid-phase cytometry technique (SPC) and a more conventional culture-based method to quantify fungal contamination of hospital air and surface samples were compared. METHODS: For the air sampling, a liquid cyclone air sampler was used with a flow rate of 300 L/min for 10 min in each of four hospital locations. Surface swabbing was done in two locations, with two different swab types. Samples from all areas were processed by SPC and by culture on malt extract agar. FINDINGS: The mean airborne concentrations of viable fungi determined by SPC were about 1.5-fold higher than the mean concentrations obtained with the culture-based method. These differences for air samples were significant in three hospital environments. No significant difference was observed for surface samples between the two swab types and between the two analytical methods. One of the prominent advantages of SPC was its rapidity in comparison with the culture-based method (5 h versus 5 days). CONCLUSION: In this study, we showed that SPC allows for rapid monitoring of viable fungi in hospital environments. SPC can thus be used to provide an early warning and a rapid implementation of corrective measures. Viable fungi detection may be an important tool to assess infectious risk in wards with immunosuppressed patients.
ISSN: 0195-6701

hal-00874713
https://hal.archives-ouvertes.fr/hal-00874713
DOI : 10.1016/j.jhin.2012.10.004
PUBMED : 23313088

Résumé : This synthesis report assesses the current state of the marine hydrobiological knowledge acquired in the surroundings of the Flamanville electronuclear site (north-west of Cotentin), in the framework of the various project and monitoring programs in the pelagic, benthic and halieutic domains carried out on this site since 1976. Each domain is divided, as much as necessary, into different study areas such as hydrobiology, phytoplankton, microbiology, crustacean larvae or macrophyte algae. For each area, a series of parameters, considered as representative of the evolution of this area, is studied. In this way, for the hydrological area, the sea water temperature and salinity, the mineral nutriment concentrations, the holagen compounds and the boron are monitored. The evolution of each of these parameters enabled us to draw the following conclusions. The vegetal and animal species' physiology is conditioned by climate changes. The study of the pluviometry and air temperature parameters shows that the 1986/2005 period is slightly less humid and warmer than the 1949/2005 period. This reflects also on the sea water temperature whose average values increase on a regular basis.
Ce rapport de synthèse fait le point sur l'état des connaissances hydrobiologiques marines acquises aux abords du site électronucléaire de Flamanville (nord-ouest Cotentin), dans le cadre des différents programmes de projet et de surveillance des domaines pélagique, benthique et halieutique, menés sur ce site depuis 1976. Chaque domaine est divisé, autant que nécessaire, en compartiments d'étude, tels que l'hydrologie, le phytoplancton, la microbiologie, les larves de crustacés ou les algues macrophytes. Pour chaque compartiment, une série de paramètres, jugés représentatifs de l'évolution de ce compartiment, est étudié. Ainsi, pour le compartiment hydrologique, sont suivis la température et la salinité de l'eau de mer, les concentrations en nutriments minéraux, les composés halogénés et le bore. Les évolutions de ces différents paramètres ont permis d'élaborer les conclusions suivantes. La physiologie des espèces animales et végétales est conditionnée par les changements climatiques. L'examen des paramètres pluviométrie et température de l'air montre que la période 1986/2005 est sensiblement plus humide et plus chaude que la période 1949/2005. Cela se répercute également sur la température de l'eau de mer dont les valeurs moyennes croissent régulièrement.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2006/rapport-6405.pdf
http://archimer.ifremer.fr/doc/00000/6405/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND: We aimed to assess, for the first time, the nature of the indoor air contamination of hospitals. METHODS AND FINDINGS: More than 40 volatile organic compounds (VOCs) including aliphatic, aromatic and halogenated hydrocarbons, aldehydes, alcohols, ketones, ethers and terpenes were measured in a teaching hospital in France, from sampling in six sampling sites--reception hall, patient room, nursing care, post-anesthesia care unit, parasitology-mycology laboratory and flexible endoscope disinfection unit--in the morning and in the afternoon, during three consecutive days. Our results showed that the main compounds found in indoor air were alcohols (arithmetic means ± SD: 928±958 µg/m³ and 47.9±52.2 µg/m³ for ethanol and isopropanol, respectively), ethers (75.6±157 µg/m³ for ether) and ketones (22.6±20.6 µg/m³ for acetone). Concentrations levels of aromatic and halogenated hydrocarbons, ketones, aldehydes and limonene were widely variable between sampling sites, due to building age and type of products used according to health activities conducted in each site. A high temporal variability was observed in concentrations of alcohols, probably due to the intensive use of alcohol-based hand rubs in all sites. Qualitative analysis of air samples led to the identification of other compounds, including siloxanes (hexamethyldisiloxane, octamethyltrisiloxane, decamethylcyclopentasiloxane), anesthetic gases (sevoflurane, desflurane), aliphatic hydrocarbons (butane), esters (ethylacetate), terpenes (camphor, α-bisabolol), aldehydes (benzaldehyde) and organic acids (benzoic acid) depending on sites. CONCLUSION: For all compounds, concentrations measured were lower than concentrations known to be harmful in humans. However, results showed that indoor air of sampling locations contains a complex mixture of VOCs. Further multicenter studies are required to compare these results. A full understanding of the exposure of healthcare workers and patients to complex mixtures of chemical compounds can then be related to potential health outcomes.
ISSN: 1932-6203

hal-00874694
https://hal.archives-ouvertes.fr/hal-00874694
https://hal.archives-ouvertes.fr/hal-00874694/document
https://hal.archives-ouvertes.fr/hal-00874694/file/VOC_Contamination-accepted.pdf
DOI : 10.1371/journal.pone.0055535

Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: Dairy working increases the prevalence of lower airway respiratory diseases, especially COPD and asthma. Epidemiological studies have reported that chronic inhalation of organic dusts released during specific daily tasks could represent a major risk factor for development of these pathologies in dairy workers. Knowledge on size, nature and biological activity of such organic dusts remain however limited. OBJECTIVE: To compare size distribution, microbial composition and cellular effects of dusts liberated by the spreading of straw bedding in five French dairy farms located in Brittany. RESULTS: Mechanized distribution of straw bedding generated a cloud of inhalable dusts in the five dairy farms' barns. Thoracic particles having a 3-7.5µm size constituted 58.9-68.3% of these dusts. Analyses of thoracic dusts by next generation sequencing showed that the microbial dust composition differed between the five French farms, although Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria represent more than 97.5% of the bacterial phyla detected in each sample. Several bacteria genera comprising of human pathogenic species, such as Pseudomonas, Staphylococcus, Thermoactinomyces or Saccharopolyspora were identified. Cladosporium and Alternaria fungal genera, which are potent environmental determinants of respiratory symptoms, were detected in dusts collected in the five farms and their levels reached 15.5-51.1% and 9-24.7% of assignable fungal sequences in each sample, respectively. Finally, all dust samples significantly and strongly increased the expression of the pro-inflammatory TNF-α, IL-1β, IL-6 and IL-8 cytokines at both mRNA and protein levels in human monocyte-derived macrophages. Their effects were dose-dependent and detectable from 1µg/ml. The intensity of the macrophage responses however differed according to the samples. CONCLUSIONS: Our results strengthen the hypothesis that organic dusts released during the distribution of straw bedding are mainly constituted of thoracic particles which are small enough to deposit on lower bronchial epithelium of dairy farmers and induce inflammation.
Environmental Research

hal-01579610
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579610
DOI : 10.1016/j.envres.2017.07.025
PUBMED : 28735230

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

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