Documents dust measurement 12 results

"Jusqu'à la moitié des années 1990, l'amiante de type chrysotile a été intentionnellement ajouté dans certains revêtements routiers afin d'assurer une meilleure durabilité de la couche de finition, les chaussées pouvant être sujettes à une usure prématurée selon le taux de fréquentation et de sollicitation des véhicules (Cf. Encadré 1). Or, les travaux de réfection ou de réaménagement des chaussées peuvent déstructurer la matrice du revêtement, émettre des fibres d'amiante et, par conséquent, avoir un effet sur la santé des travailleurs si les mesures de prévention ne sont pas adoptées par les professionnels. Afin de préconiser des mesures de prévention adaptées aux niveaux d'empoussièrement en fibres d'amiante réglementaires observés lors de ces travaux et de permettre aux professionnels de vérifier le respect de la nouvelle VLEP fixée à 10 f/l en moyenne sur 8?h (VLEP-8h) en vigueur depuis le 2 juillet 2015, un recueil des données d'empoussièrement des processus a été effectué auprès des professionnels, de donneurs d'ordre publics et du réseau prévention des Carsat. Cette étude de cas présente des recommandations de prévention établies à partir de l'analyse de 302 mesurages issus de 53 chantiers."

"Pour être accrédité par le Cofrac et intervenir dans le champ réglementaire français, les organismes procédant à des mesures d'empoussièrement en fibres d'amiante au poste de travail ont l'obligation de participer chaque année à l'essai inter-laboratoires de comptage de fibres d'amiante par Meta organisé par l'INRS. Cet article dresse un état des lieux des pratiques des laboratoires y participant à la suite du bilan de ces 10 dernières années et, plus particulièrement, sur les résultats rendus en 2014. Pour certains laboratoires accrédités, les anomalies constatées sont alarmantes et interrogent le respect du référentiel d'accréditation. Le comptage rigoureux du nombre de fibres d'amiante représentant un enjeu majeur pour la santé publique et la santé au travail, des pratiques anormales et inacceptables relevées ici doivent être rapidement améliorées."

"Objectives: To compare respiratory symptoms and upper airway inflammation in domestic waste collectors and controls, and to find the association between measures of upper airway inflammation on the one hand and exposure concentrations of organic dust or respiratory symptoms on the other hand.

Methods: In a cross sectional study among 47 waste collectors and 15 controls, questionnaire data on respiratory symptoms were collected. Nasal lavage (NAL), to assess upper airway inflammation, was performed before and after a work shift at the beginning and at the end of the working week. In NAL fluid, cells were counted and differentiated and concentrations of interleukin 6 (IL6), IL8, tumour necrosis factor-? (TNF?), and IL1ß were measured. In collectors, inhalable dust samples were collected in which bacterial endotoxin and mould ß(1?3)-glucan were assessed.

Results: Prevalence of respiratory symptoms was higher in waste collectors than in controls. Geometric mean exposure concentrations were 0.58 mg/m3 for dust, 39 EU/m3 for endotoxin, and 1.3
g/m3 for ß(1?3)-glucan. At the end of the week collectors had higher concentrations of total cells and IL8 in NAL before and after a shift than controls (cells, before 1.9-fold p<0.10, after 3.3-fold p<0.01; IL8, before and after 1.8-fold p<0.05), and after/before work shift ratios of total cells were also higher (2.3-fold p=0.06) in collectors than in controls. Cells in NAL fluid consisted predominantly of neutrophils and epithelial cells, whereas eosinophils and mononuclear cells were rarely found. Exposure to dust and endotoxin was associated with concentrations of IL8 after the shift (p<0.05). Increased concentrations of IL8 (p<0.05) and total cells (p<0.10) after the shift were associated with respiratory symptoms. Concentrations of IL6, TNF?, and IL1ß were not associated with waste collecting, symptoms, or exposure.

Conclusions: Waste collectors show signs of increased upper airway inflammation and respiratory symptoms compared with controls. Exposure to organic dust probably underlies the inflammation mediated by neutrophils that result in respiratory symptoms."

Background To determine dimensions of airborne fibers in the U.S. refractory ceramic fiber (RCF) manufacturing industry, fibers collected through personal air sampling for employees at RCF manufacturing and processing operations have been measured. Methods Data were derived from transmission electron microscopy analyses of 118 air samples collected over a 20-year period. Results Characteristics of sized fibers include: diameter measurements of <60; 0.19 to 1.0 m, of which 75% are less than 0.6 m; and length ranging from < 0.6 to > 20 m, with 68% of fibers between 2.4 and 20 m. Conclusions Exposures in RCF manufacturing include airborne fibers with dimensions (diameter < 0.1-0.4 m, length < 10 m) historically associated with biological effects in pleural tissues. Air sampling data and a review of studies relating fiber size to pleural effects in animals and humans support the belief that information on fiber dimensions is essential for studies with synthetic vitreous fibers.

"La méthode présentée permet d'établir, au moyen d'un modèle dit de "score", la contribution relative de paramètres d'influence à une grandeur finale et la hiérarchisation de cette grandeur en fonction du choix de différentes combinaisons des paramètres en cause.Cette méthode a été appliquée à l'évaluation des performances des cabines ventilées dans le secteur de la taille de pierre. Elle a permis de classer les cabines par rapport à un indice estimé de performance prenant en compte d'une part, la concentration de poussière émise (fraction alvéolaire) au cours de différents travaux de taille et d'autre part, la valeur limite d'exposition.Le classement, issu de cette méthode d'estimation basée sur des valeurs réelles, met en évidence la supériorité des cabines à flux vertical dans la majorité des situations. Viennent ensuite les cabines à flux "oblique" dont les performances sont plus proches du flux vertical que du flux horizontal. Les cabines à flux horizontal se situent en dernière position et se trouvent, pour la plupart des situations de travail, exclues du domaine d'utilisation considéré."(Résumé des auteurs)

"Evaluates the carcinogenic risk to humans posed by occupational exposures to wood dust and formaldehyde. A number of occupational situations that involve exposure to wood dust also entail exposure to formaldehyde, as in plywood and particle board manufacture, during furniture and cabinet-making, and during parquet floor sanding and varnishing. The carcinogenic risks of wood dust are evaluated in the first monograph. The highest occupational exposures were noted to occur in wood furniture and cabinet manufacture, especially during machine sanding and similar operations, in the finishing departments of plywood and particle-board mills, and in the workroom air of sawmills and planer mills near chippers, saws, and planers. Citing findings from several recent well-designed case-control studies, the monograph concludes that occupational exposure to wood dust is causally related to adenocarcinoma of the nasal cavities and paranasal sinuses. The evaluation further concluded that the excess risk of cancer is attributable to wood dust per se, rather than to other exposures in the workplace. Wood dust was classified as carcinogenic to humans. Cancer risk associated with occupational exposure to formaldehyde is assessed in the second monograph. The assessment draws on findings from several cohort and case-control investigations of the relationship between exposure to formaldehyde and cancer of the oral cavity, pharynx, and respiratory tract. Citing inconsistencies in the reported results, the monograph concludes that these epidemiological studies can do no more than suggest a causal role of occupational exposure to formaldehyde in carcinoma of the nasal cavities and paranasal sinuses. The review found no evidence of excess risk for oropharyngeal, laryngeal or lung cancer among exposed workers. Several studies in which formaldehyde was administered to rats by inhalation showed evidence of carcinogenicity. Similar studies in hamsters showed no evidence of carcinogenicity, and studies in mice either showed no effect or were inadequate for evaluation. In rats administered formaldehyde in drinking-water, increased incidences were seen of forestomach papillomas in one study and of leukaemias and gastrointestinal tract tumours in another; two other studies gave negative results. Formaldehyde was classified as probably carcinogenic to humans."

"Working and living inside buildings expose people to all kinds of biological contaminants. This is a report on health hazards posed by the presence in indoor air of biological contaminants including suspended viable particles, suspended allergens, animal dander, fragments of dust mites and other biologically derived suspended material. Emphasis is placed on construction materials and building elements such as cooling towers, humidifiers, ventilation systems and design features leading to high indoor humidity, that can introduce or spread airborne biological contaminants. The first chapter catalogues some 16 infectious diseases, allergic reactions and other health risks linked to the presence of biological contaminants in indoor air. The second chapter presents hazard assessment and offers advice on strategies available for the investigation of individuals or populations suffering from suspected indoor air-related infectious diseases including Legionnaires disease, allergic reactions or toxic reactions following the inhalation of mycotoxins. Other chapters review methods for environmental sampling and analysis, discuss the main sources of microbiological contaminants in buildings and identify factors in the indoor environment that can enhance the risk of contamination. The final chapter discusses strategies for control, concluding that most biological aerosols in buildings are caused by persistent moisture and inadequate ventilation, and that proper building design and maintenance are needed to reduce acute infections and allergic episodes caused by contaminated indoor air."