The effects of anthropogenic aerosol, solid or liquid particles suspended in the air, are the biggest contributor to uncertainty in current climate perturbations. Heavy industry sites, such as coal power plants and steel manufacturers, large sources of greenhouse gases, also emit large amounts of aerosol in a small area. This makes them ideal places to study aerosol interactions with radiation and clouds. However, existing data sets of heavy industry locations are either not public, or suffer from reporting gaps. Here, we develop a supervised deep learning algorithm to detect unreported industry sites in high-resolution satellite data, using the existing data sets for training. For the pipeline to be viable at global scale, we employ a two-step approach. The first step uses 10 m resolution data, which is scanned for potential industry sites, before using 1.2 m resolution images to confirm or reject detections. On held-out test data, the models perform well, with the lower resolution one reaching up to 94% accuracy. Deployed to a large test region, the first stage model yields many false positive detections. The second stage, higher resolution model shows promising results at filtering these out, while keeping the true positives, improving the precision to 42% overall, so that human review becomes feasible. In the deployment area, we find five new heavy industry sites which were not in the training data. This demonstrates that the approach can be used to complement existing data sets of heavy industry sites.

We evaluated the distributions of dental splatters and the corresponding control measure effects with high-speed videography and laser diffraction. Most of the dental splatters were small droplets (<50 μm). High-volume evacuation combined with a suction air purifier could clear away most of the droplets and aerosols.

We propose the nasal administration of calcium-enriched physiological salts as a new hygienic intervention with possible therapeutic application as a response to the rapid and tenacious spread of COVID-19. We test the effectiveness of these salts against viral and bacterial pathogens in animals and humans. We find that aerosol administration of these salts to the airways diminishes the exhalation of the small particles that face masks fail to filter and, in the case of an influenza swine model, completely block airborne transmission of disease. In a study of 10 human volunteers (5 less than 65 years and 5 older than 65 years), we show that delivery of a nasal saline comprising calcium and sodium salts quickly (within 15 min) and durably (up to at least 6 h) diminishes exhaled particles from the human airways. Being predominantly smaller than 1 μm, these particles are below the size effectively filtered by conventional masks. The suppression of exhaled droplets by the nasal delivery of calcium-rich saline with aerosol droplet size of around 10 μm suggests the upper airways as a primary source of bioaerosol generation. The suppression effect is especially pronounced (99%) among those who exhale large numbers of particles. In our study, we found this high-particle exhalation group to correlate with advanced age. We argue for a new hygienic practice of nasal cleansing by a calcium-rich saline aerosol, to complement the washing of hands with ordinary soap, use of a face mask, and social distancing.

In this work, we present a model for an aerosol (air/particle mixture) in the respiratory system. It consists of the incompressible Navier-Stokes equations for the air and the Vlasov equation for the particles in a fixed or moving domain, coupled through a drag force. We propose a discretization of the model, investigate stability properties of the numerical code and sensitivity to parameter perturbation. We also focus on the influence of the aerosol on the airflow.

Earth has been habitable through most of its history, but the anthropogenically mediated greenhouse effect, if sufficiently strong, can threaten Earth's long-standing equability. This paper's main aim is to determine the strength of the anthropogenic greenhouse effect (the climate sensitivity) from observational data and basic physics alone, without recourse to the parameterisations of earth-system models and their inevitable uncertainties. A key finding is that the sensitivity can be constrained by harmonising historical records of land and ocean temperatures with observations of potential climate-change drivers in a non-steady state, energy-balance equation via a least-squares optimisation. The global temperature increase, for a CO2 doubling, is found to lie (95 % confidence limits) between 3.0oC and 6.3oC, with a best estimate of +4oC. Under a business-as-usual scenario, which assumes that there will be no significant change in people's attitudes and priorities, Earth's surface temperature is forecast to rise by 7.9oC over the land, and by 3.6oC over the oceans, by the year 2100. Global temperature rise has slowed in the last decade, leading some to question climate predictions of substantial 21st-Century warming. A formal runs test, however, shows that the recent slowdown is part of the normal behaviour of the climate system.

A Q fever outbreak occurred in the southeast of The Netherlands in spring and summer 2007. Risk factors for the acquisition of a recent Coxiella burnetii infection were studied. In total, 696 inhabitants in the cluster area were invited to complete a questionnaire and provide a blood sample for serological testing of IgG and IgM phases I and II antibodies against C. burnetii, in order to recruit seronegative controls for a case-control study. Questionnaires were also sent to 35 previously identified clinical cases. Limited environmental sampling focused on two goat farms in the area. Living in the east of the cluster area, in which a positive goat farm, cattle and small ruminants were situated, smoking and contact with agricultural products were associated with a recent infection. Information leaflets were distributed on a large scale to ruminant farms, including hygiene measures to reduce the risk of spread between animals and to humans.

The ELT project is currently under way in Europe and North America. Astronomical sites depend critically on sky transparency and on aerosol loadings. A quantitative survey of aerosol optical properties at candidate ELT sites is an essential part of the site selection process. There are basically two methods to characterize aerosol properties: ground based measurements and satellite measurements. In this paper we will establish a full climatology of two sites very close to each other, but at a difference of 2300m in altitude: Izaña and Santa Cruz located in the Canary Islands. Both have sun photometers from the AERONET network. We also use the aerosol index determined from TOMS satellite data to determine how aerosol optical properties vary with altitude. We establish a correlation between the TOMS index and the aerosol optical thickness in both sites. Aerosol optical properties show very good correlation between Izaña and Santa Cruz. As a result we establish a set of relationships helpful to characterize sites at elevated altitude from data of neighbouring sites at low altitude.


Ce travail entre dans le cadre du dossier “maîtrise du risque alpha sur des installations nucléaires” qui est issu du projet propreté radiologique d'EDF. Une validation du facteur réaliste de mise en suspension de contamination est nécessaire afin de s'assurer que les dispositions prises par EDF dans le cadre de la radioprotection des travailleurs lors des interventions sur des chantiers à risque alpha sont adaptées. Une expérimentation du facteur de mise en suspension sur l'arrêt de tranche 3 de la centrale nucléaire Cattenom, qui a subit une dissémination de matière fissile pendant l'arrêt de tranche en janvier 2001 a été réalisée. Le bilan des activités surfaciques et atmosphériques sur trois types de chantiers (pressuriseur, générateur de vapeur et piscine du bâtiment réacteur) est analysé. L'ensemble des valeurs obtenues permet de fixer et d'adopter en radioprotection opérationnelle la valeur la plus probable du facteur de mise en suspension des particules émettrices α F$_{\rm MES} = 1 \times 10^{-6}$ m-1.

Dans le cadre des études de toxicologie pulmonaire des oxydes mixtes (U,Pu)O2, nous avons étudié les propriétés physico-chimiques des poudres inhalables fabriquées selon le procédéindustriel COCA et MIMAS, prélevées au poste de rectification et renfermant respectivement 5.3 et 4.7 % de Pu. Ces poudres sont étudiées après inhalation chez le rat, dans les macrophagesalvéolaires extraits par lavage pulmonaire. L'analyse en spectrométrie X de dispersion d'énergie (EDS) couplée au microscope électronique a permis de mettre en évidence une fortehétérogénéité à l'échelle nanométrique de ces deux types de combustible. Les particules sont le plus souvent sous forme d'aggrégats. La plupart des particules unitaires (>60%) correspondent àde l'UO2 "pur" d'après le spectre EDS. Les autres sont soit du PuO2 "pur" soit (U, Pu)O2 avec des teneurs en Pu pouvant atteindre plus de 30 %. Les résultats semi-quantitatifs indiquent queles poudres MIMAS et COCA sont hétérogènes. L'étude autoradiographique confirme cette hétérogénéité et visualise la grande hétérogénéité de la répartition de dose au sein des tissuspulmonaires après inhalation.

La Commission Internationale de Protection Radiologique (CIPR), dans ses nouvelles recommandations, propose l'utilisation de paramètres déterminés expérimentalement pour effectuer uncalcul de dose efficace par unité d'incorporation (DPUI) spécifique pour chaque composé. Le but de cette étude est de définir une méthodologie (techniques d'analyse, test in vitro de dissolutionet test in vivo sur rats) permettant d'accéder à ces données et de présenter les méthodes de calcul utilisées, comme le logiciel GIGAFIT pour l'interprétation des données de transfert sanguin, etle logiciel LUDEP pour le calcul de dose. 
Ce travail a permis de déterminer pour un composé UO2 (uranium appauvri), utilisé dans la fabrication du combustible MOX, les principaux paramètres physico-chimiques et biologiques quientrent dans le calcul de dose : le Diamètre Aérodynamique Médian en Activité ou DAMA de 6,5 μm; la Surface Spécifique SS= 2,68 m2.g-1; et les fraction et taux de transfert sanguinrespectivement fr, entre 2,5% et 44,4%, Sr, entre 0,09 et 1,7 j-1 , et Ss, entre 6,4 10-4 et 1,5 10-3 j-1. Ces résultats intégrés dans LUDEP conduisent à une DPUI spécifique par inhalation pour ce composé UO2 égale à 2,84 10-6 Sv.Bq-1.