Publications (2)5.23 Total impact
Article: Physicochemical characteristics and biological activities of seasonal atmospheric particulate matter sampling in two locations of Paris.[show abstract] [hide abstract]
ABSTRACT: Fine particulate matter present in urban areas seems to be incriminated in respiratory disorders. The aim of this study was to relate physicochemical characteristics of PM2.5 (particulate matter collected with a 50% efficiency for particles with an aerodynamic diameter of 2.5 microm) to their biological activities toward a bronchial epithelial cell line 16-HBE. Two seasonal sampling campaigns of particles were realized, respectively, in a kerbside and an urban background station in Paris. Sampled-PM2.5 mainly consist of particles with a size below 1 microm and are mainly composed of soot as assessed by analytical scanning electron microscopy. The different PM2.5 samples contrasted in their PAH content, which was the highest in the kerbside station in winter, as well as in their metal content. Kerbside station samples were characterized by the highest Fe and Cu content, which appears correlated to their hydroxyl radical generating properties measured by electron paramagnetic resonance. Particles were compared by their capacity to induce cytotoxicity, intracellular ROS production, and proinflammatory cytokine release (GM-CSF and TNF-alpha). At a concentration of 10 microg/cm2, all samples induced peroxide production and cytokine release to the similar extent in the absence of cytotoxicity. In conclusion, whereas the PM2.5 samples differ by their PAH and metal composition, they induce the same biological responses likely either due to components bioavailability and/ or interactions between PM components.Environmental Science and Technology 12/2004; 38(22):5985-92. · 5.23 Impact Factor
Article: Crossed optical and chemical evaluations of modern glass soiling in various European urban environments[show abstract] [hide abstract]
ABSTRACT: As part of the MULTI-ASSESS and VIDRIO EC projects, the soiling of modern glass is characterised in various European urban atmospheres. Our original methodology relies on crossed chemical measurements of the deposit (evaluation of the ion, elemental and organic carbon contents, and subsequent “mass closure”) and exhaustive measurements of glass optical properties (light reflectance, transmittance and absorption). Samples were exposed sheltered from rain in Athens, Krakow, London, Montelibretti (Italy), Prague and Troyes (France), during increasing exposure durations, up to more than two years. Although a slowing down of the deposition rate is observed for some species at some sites, no obvious saturation phenomenon seems to occur for the particle deposition. The chemical composition of the deposit is shown to reflect the atmospheric environment of the exposure site. Some post-deposit evolutions, such as the disappearance of ammonium and possibly of particulate organic matter, are found to occur. For thin deposits, the glass optical properties (e.g. light absorption and diffuse transmittance) are found to evolve quasi-linearly with species concentrations (EC and ions, respectively). However, for conditions creating heavier deposits such as long time exposures in rather polluted environments, a saturation phenomenon is observed. Using a simple model, light absorption, which is primarily due to EC particles, is shown to reach the saturation level (S) for A≈16% and the concentration for which the semi-saturation level is reached (C1/2) is found to be about 15 μgC of EC/cm2. For diffuse transmittance, due to scattering species, these parameters are found to be about 30% and 65 μg of ions/cm2, respectively. These values may be considered as representative of the soiling in Europe.Atmospheric Environment.