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Le Touquet – Paris-Plage, France

Garcia J.,CEA Saclay Nuclear Research Center | Nguyen T.-D.,CEA Saclay Nuclear Research Center | Tran-Thi T.-H.,CEA Saclay Nuclear Research Center | Laurent A.-M.,Laboratoire Dhygiene Of La Ville Of Paris
Proceedings - 1st International Conference on Sensor Device Technologies and Applications, SENSORDEVICES 2010 | Year: 2010

The control of air quality is of great importance, in particular for the protection of the workers who can be exposed to toxic gas. The present work reports the development of new chemical sensors for the detection of halogenated gases. These sensors are based on the use of nanoporous matrices doped with cationic surfactants and acting as sponges to trap the targeted pollutants. These chemical sensors can be used for the detection of chlorine Cl2 or nitrogen trichloride NCl3 at ppb level. © 2010 IEEE. Source

Nguyen T.-H.,CEA Saclay Nuclear Research Center | Rivron C.,CEA Saclay Nuclear Research Center | Tran-Thi T.-H.,CEA Saclay Nuclear Research Center | Chevallier E.,CEA Saclay Nuclear Research Center | And 2 more authors.
2013 Transducers and Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS 2013 | Year: 2013

The control of air quality is of great importance, in particular for the protection of individuals and workers who can be exposed to harmful gases. We here describe innovative chemical and colorimetric sensors for the detection of nitrogen trichloride, NCl3 a pollutant present in indoor swimming pools. These sensors are nanoporous matrices doped with specific probe-molecules, which can efficiently react with NCl3. They act as sponges to trap the targeted pollutant and turn from transparent to pink-violet. These sensors can detect NCl3 at ppb level within 15 minutes in humid atmosphere and ambient temperature of indoor swimming pools. © 2013 IEEE. Source

Enkiri F.,Laboratoire Dhygiene Of La Ville Of Paris | De Baynast H.,University Blaise Pascal | Squinazi F.,Laboratoire Dhygiene Of La Ville Of Paris
Journal Europeen d'Hydrologie | Year: 2011

The main objective of this study was to evaluate the influence of "repeated treatments", performed on three materials, on the potential of these materials to promote microbial growth. These three materials; copper, CPVC and a variety of PEX, are widely used in water distribution systems inside buildings. These materials were tested as new and in a degraded condition; achieved by treating the material 120 times with a succession of cleaning and disinfection procedures typical of those applied to distribution systems inside buildings (in terms of products, durations and concentrations) and representative of the service life of a system that suffers from contamination problems. The test method is the project European standard CEN TC164/WG3/AHG3 (Biomass Production Potential - BPP - Enhancement of Microbial Growth) and is based on the determination of the concentration of active biomass in the water phase and on the material, by assaying the microbial adenosine triphosphate (ATP), under so-called "semi-dynamic" conditions. The three materials studied differed significantly from each other in terms of their ability to promote microbial growth. Consequently, the promotion of microbial growth was found to be dependent on the type of material. The highest level of growth was observed for PEX (1520 pg ATP/cm2) with much lower levels for CPVC and copper (35 pg ATP/cm2 and 11 pg ATP/cm2 respectively). These tests also revealed the absence of any impact of the repeated treatments, performed on these three materials, on their ability to form biofilms (similar ATP content per cm2 for new and "treated" material), even though the treatments were observed to have slightly attacked the surfaces of the CPVC, PEX and copper materials. These repeated treatments probably do not modify the properties of the materials with regards to the ability of the micro-organisms to attach and proliferate. This study considered to a very limited extent the structural changes induced by the ageing of the materials under actual conditions of use: surface condition, scaling phenomena and corrosion. Tests under dynamic conditions, in pilot systems, which represent more closely the actual conditions in which the materials are used, could be conducted and the results compared with those obtained with the BPP test, for an optimal understanding of the risks of uncontrolled development of biofilms, relating to the properties of the materials. © ASEES, 2012. Source

Ranciere F.,University of Paris Descartes | Dassonville C.,University of Paris Descartes | Roda C.,University of Paris Descartes | Laurent A.-M.,Laboratoire Dhygiene Of La Ville Of Paris | And 2 more authors.
Science of the Total Environment | Year: 2011

Indoor aldehydes may result from ozone-initiated chemistry, mainly documented by experimental studies. As part of an environmental investigation included in the PARIS birth cohort, the aim of this study was to examine ozone contribution to airborne aldehyde formation in Paris homes. Formaldehyde, acetaldehyde and hexaldehyde levels, as well as styrene, nitrogen dioxide and nicotine concentrations, comfort parameters and carbon dioxide levels, were measured twice during the first year of life of the babies. Ambient ozone concentrations were collected from the closest background station of the regional air monitoring network. Traffic-related nitrogen oxide concentrations in front of the dwellings were estimated by an air pollution dispersion model. Home characteristics and families' way of life were described by questionnaires. Stepwise multiple linear regression models were used to link aldehyde levels with ambient ozone concentrations and a few aldehyde precursors involved in oxidation reactions, adjusting for other indoor aldehyde sources, comfort parameters and traffic-related nitrogen oxides. A 4 and 11% increase in formaldehyde and hexaldehyde levels was pointed out when 8-hour ozone concentrations increased by 20μg/m3. The influence of potential precursors such as indoor styrene level and frequent use of air fresheners, containing unsaturated volatile organic compounds as terpenes, was also found. Thus, our results suggest that ambient ozone can significantly impact indoor air quality, especially with regard to formaldehyde and hexaldehyde levels. © 2011 Elsevier B.V. Source

Grange D.,Observatoire regional de sante dIle de France | Chatignoux E.,Observatoire regional de sante dIle de France | Sommen C.,Observatoire regional de sante dIle de France | Dusseaux M.,Laboratoire Dhygiene Of La Ville Of Paris | And 5 more authors.
12th International Conference on Indoor Air Quality and Climate 2011 | Year: 2011

This study aims to compare different methods to assess household mold exposure in an epidemiological study. A total of 150 dwellings were selected in Ile-de-France region and investigated by trained investigators between 2007 and 2009. Air samples were collected in order to estimate mycotoxins and ergosterol levels and to detect an active contamination (active fungal growth) from an index based on microbial volatile organic compounds. If visible fungi were detected, surface samples were collected to identify fungal species and genera. Mold stains were detected in 17% of dwellings and 90% of the surface samples had a potentially allergenic genus. Among dwellings where air samples were collected, an active contamination was detected in 80% of cases and an indoor source of ergosterol in 22%. In conclusion, mold contamination cases are numerous and complex and this study pointed out the difficulty of elaborating simple exposure indices. Source

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