Long-term aging of fiber-cement corrugated sheets - The effect of carbonation, leaching and acid rain

This paper studies the performance of fiber-cement corrugated sheets exposed to long-term weathering, exploring the effect of different environments on fiber-cement degradation. Fiber-cement corrugated sheets that had been exposed to weathering, and in place for more than 30-years, were collected from two different Brazilian cities (Sao Paulo and Criciuma). Mechanical properties (MOR, MOE and fracture toughness) were tested on samples removed from the corrugated sheets. Microstructure was evaluated by X-ray diffraction, SEM with EDS analysis, MIP and TG. The results show that the 37-year-old asbestos-cement corrugated sheets from Sao Paulo presented similar characteristics to those of the non-aged asbestos-cement readily available on the market place. Conversely, deterioration of the asbestos-cement from the industrial area of Criciuma is related to acidic attack, along with carbonation and leaching as a consequence of continued exposition to acid rain during several decades. This process resulted in higher porosity and lower mechanical strength, revealing that leaching mechanisms can have important effect on the performance of thin fiber-cement sheets. (c) 2007 Elsevier Ltd. All rights reserved.

Lung Diffusing Capacity Relates Better to Short-Term Progression on HRCT Abnormalities Than Spirometry in Mild Asbestosis

Background Pulmonary function tests (PFT), particularly spirometry and lung diffusing capacity for carbon monoxide (DL(CO)), have been considered useful methods for the detection of the progression of interstitial asbestos abnormalities as indicated by high-resolution computed tomography (HRCT). However, it is currently unknown which of these two tests correlates best with anatomical changes over time. Methods In this study, we contrasted longitudinal changes (3-9 years follow-up) in PFTs at rest and during exercise with interstitial abnormalities evaluated by HRCT in 63 ex-workers with mild-to-moderate asbestosis. Results At baseline, patients presented with low-grade asbestosis (Huuskonen classes I-II), and most PFT results were within the limits of normality. In the follow-up, most subjects had normal spirometry, static lung volumes and arterial blood gases. In contrast, frequency of DL(CO) abnormalities almost doubled (P < 0.05). Twenty-three (36.5%) subjects increased the interstitial marks on HRCT. These had significantly larger declines in DL(CO) compared to patients who remained stable (0.88 vs. 0.31 ml/min/mm Hg/year and 3.5 vs. 1.2%/year, respectively; P < 0.05). In contrast, no between-group differences were found for the other functional tests, including spirometry (P > 0.05). Conclusions These data demonstrate that the functional consequences of progression of HRCT abnormalities in mild-to-moderate asbestosis are better reflected by decrements in DL(CO) than by spirometric changes. These results might have important practical implications for medico-legal evaluation of this patient population. Am. J. Ind. Med. 54:185-193, 2011. (c) 2010 Wiley-Liss, Inc.

Efeitos respirat��rios da exposi����o ao talco industrial em ex-trabalhadores de minera����o

OBJETIVO: Avaliar efeitos respirat��rios tardios da inala����o ocupacional de talco contaminado por asbesto. M��TODOS: An��lise de s��rie de casos de 29 ex-trabalhadores de minera����o de talco contaminado com asbestos provenientes de Caranda��, MG, atendidos no Centro de Refer��ncia Estadual de Sa��de do Trabalhador de Minas Gerais em 2004-2005. Os ex-trabalhadores foram submetidos a anamnese cl��nico-ocupacional, radiografia de t��rax e espirometria. Foi criado um escore de exposi����o que, multiplicado pela dura����o, originou um ��ndice de exposi����o cumulativa ao talco. Para verificar a associa����o do ��ndice de exposi����o cumulativa com a presen��a de altera����es radiol��gicas, sugestivas de pneumoconiose e/ou altera����es pleurais, foi ajustado um modelo de regress��o log��stica exata. RESULTADOS: Todos os ex-trabalhadores eram homens, com m��dia de idade de 48,2 anos. Nas radiografias de t��rax foram encontradas altera����es pleurais em tr��s deles, opacidades parenquimatosas compat��veis com pneumoconiose em um e suspeita em seis. Altera����es espirom��tricas ocorreram em tr��s. A regress��o log��stica apontou odds ratio de 1,059 (IC 95%: 1,012;1,125) para o ��ndice acumulado, ou seja, cada unidade no ��ndice resulta em um aumento de 5,9% na chance de apresentar altera����o radiol��gica compat��vel ou suspeita de pneumoconiose. Em rela����o �� mediana do tempo estimado de lat��ncia entre o in��cio da exposi����o at�� o diagn��stico das placas pleurais, ocorreu diferen��a significativa (p = 0,013) entre os casos (27,0 anos) e n��o casos (14,3 anos). CONCLUS��ES: Os achados apontam a necessidade de controle cl��nico nos trabalhadores que foram expostos a asbesto, particularmente devido aos efeitos tardios da exposi����o a esse mineral.

Remo����o de fibrocimento: amianto

Disserta����o para obten����o do grau de Mestre em Engenharia Civil Ramo Edifica����es

Mineralogia da frac����o argilosa da Forma����o de Vale ��lvaro (Bragan��a, NE Portugal)

The studied materials were sampled from several conglomerate and carbonate sandstone units, overlapped for 23 meters. This formation represents a debris flow dominated alluvial fan alternating with quiet sedimentary conditions. These deposits of probably Paleogene age were placed upon mafic and ultramafic rocks that are the exclusive source of sediments. Optical and SEM identification, microanalysis and XRD studies (with decomposition procedures) of clay fractions obtained after high-speed centrifugation were performed in order to characterise the clay minerals content. The results of the analytical program allowed the establishment of the following remarks: a) Fe-rich montmorillonite dominance over paligorskite, chlorite, chlorite-smectite mixed-layers, serpentine and talc; b) smectites in the 12.4 - 15 A range, expanding to about 17 A after EG treatment; c) serpentine and talc as secondary minerals in the interior of altered clasts; d) chlorite and clorite smectite mixed-layer compositions in the borders of the clasts and in the cement. The composition of sediments results from coarse clasts eroded from mafic and ultramafic rocks and clayey material. Clasts show evidences of post-depositional weathering (coatings of chlorite and smectite). Clayey material has the contributions of i) inherired chlorite, smectite and chlorite-smectite mixed-layers; ii ) authigenic crystallisation of Fe-montmorillonite (due to availability of Fe in the crystallising solutions following previous weathering events); iii) authigenic paligorskite associated to a carbonate cement.

Persistence of Vectobac WDG and Metoprag S-2G against Aedes aegypti larvae using a semi-field bioassay in Rio de Janeiro, Brazil

Persistence of Bacillus thuringiensis var. israelensis (Vectobac WDG) and methoprene (Metoprag S-2G) was evaluated against Aedes aegypti late third instar larvae of the Rockefeller strain in a semi-field bioassay. Tests were performed in Rio de Janeiro, using containers made of plastic, iron, concrete and asbestos, placed in a shaded area. The formulations used were 0.2 g of Vectobac-WDG and 1g of Metoprag S-2G per 100 liters of water in house storage containers. Vectobac WDG was tested twice, in March and in April/May, 2002. In March (temperature ranging from 21.5 to 39.3 ��C), 70-100% mortality was observed by the 7th day and declined abruptly thereafter. No significant differences were observed among the container types. In April/May (18.6 to 34.8 ��C) mortality was higher than 70% to 30-36 days in all cases, except in the iron container (40% mortality on the 12th day). Metoprag S-2G was evaluated in April/May, 2002, and induced mortality higher than 70% up to 15 days in the plastic and iron containers and only seven days in the concrete container. In the asbestos container, maximal mortality was achieved on day one post-treatment (66%). Our results point to a low persistence of both formulations in the weather conditions of Rio de Janeiro.

FIRST REPORT ON Cryptococcus neoformans IN PIGEON EXCRETA FROM PUBLIC AND RESIDENTIAL LOCATIONS IN THE METROPOLITAN AREA OF CUIAB��, STATE OF MATO GROSSO, BRAZIL

SUMMARYCryptococcosis is a severe systemic mycosis caused by two species of Cryptococcus that affect humans and animals: C. neoformans and C. gattii. Cosmopolitan and emergent, the mycosis results from the interaction between a susceptible host and the environment. The occurrence of C. neoformanswas evaluated in 122 samples of dried pigeon excreta collected in 49 locations in the City of Cuiab��, State of Mato Grosso, Brazil, including public squares (n = 5), churches (n = 4), educational institutions (n = 3), health units (n = 8), open areas covered with asbestos (n = 4), residences (n = 23), factory (n = 1) and a prison (n = 1). Samples collected from July to December of 2010 were seeded on Niger seed agar (NSA). Dark brown colonies were identified by urease test, carbon source assimilation tests and canavanine-glycine-bromothymol blue medium. Polymerase chain reaction primer pairs specific for C. neoformans were also used for identification. Cryptococcus neoformans associated to pigeon excreta was isolated from eight (6.6%) samples corresponding to six (12.2%) locations.Cryptococcus neoformans was isolated from urban areas, predominantly in residences, constituting a risk of acquiring the disease by immunocompromised and immunocompetent individuals.

Reacciones catal��ticas para Qu��mica Fina

El proyecto est�� dirigido a proporcionar m��todos catal��ticos para la preparaci��n de productos de Qu��mica Fina, ya sea como producto final o intermediarios, principalmente dentro del campo de la fabricaci��n de esencias, saborizantes y productos farmacol��gicos. Todo este proyecto tiene por finalidad la obtenci��n de datos que permitan en otro desarrollo, el escalado a mayor producci��n no solamente de proceso (productos) sino en el caso de obtenerse un catalizador s��lido, deber�� proveerse la t��cnica de preparaci��n del mismo, para cumplir con requerimientos habituales de las industrias, especialmente Pymes. (...) Otro tipo de proceso est�� representado por la s��ntesis v��a cat��lisis heterog��nea de ��steres del tipo del acetato de amilo y similares de uso, seg��n su calidad como saborizante y en la industria de la perfumer��a. En este caso la cat��lisis involucrada es de tipo ��cido. El objetivo general de este proyecto consiste en el desarrollo y s��ntesis de catalizadores heterog��neos para ser utilizado en reacciones seleccionadas de qu��mica fina, estudio de dichas reacciones y escalado de las mismas. Este objetivo general puede ser desglosado en cuatro partes u objetivos espec��ficos: a) Optimizaci��n del sistema de reacci��n para s��ntesis de catalizadores b��sicos como: * Arcillas ani��nicas; * ��xidos met��licos simples y mixtos; * Metales alcalinos y soportados; * Asbestos, carbones y resinas ani��nicas. b) Caracterizaci��n de los catalizadores utilizando FTIR, ��rea superficial, Volumen de poros, Distribuci��n y Capacidad de adsorci��n de mol��culas sonda. c) Empleo de los catalizadores desarrollados y caracterizados en procesos de Qu��mica Fina.

Forecasting nano law: defining nano

Law and science have partnered together in the recent past to solve major public health issues, ranging from asbestos to averting the threat of a nuclear holocaust. This paper travels to a legal and health policy frontier where no one has gone before, examining the role of precautionary principles under international law as a matter of codified international jurisprudence by examining draft terminology from prominent sources including the Royal Commission on Environmental Pollution (UK), the Swiss Confederation, the USA (NIOSH) and the OECD. The research questions addressed are how can the benefits of nanotechnology be realized, while minimizing the risk of harm? What law, if any, applies to protect consumers (who comprise the general public, nanotechnology workers and their corporate social partners) and other stakeholders within civil society from liability? What law, if any, applies to prevent harm?

Exposition �� l'amiante: des normes plus politiques que scientifiques

Complexe et variable selon les pays, la notion d'"exposition acceptable" �� un polluant repose tant sur des donn��es scientifiques, souvent lacunaires, que sur des crit��res sociaux, culturels, moraux et ��conomiques, analyse le sp��cialiste Miichel Guillemin. En jeu: la sant�� des travailleurs et des populations. [Editeur]

Focal dependent pleural thickening at MDCT: pleural lesion or functional abnormality?

PURPOSE: To describe the characteristics of reversible focal pleural thickenings (PTs) mimicking real plaques, that firstly suggest asbestos exposure or pleural metastasis; to propose an imaging strategy and propose an explanation for their mechanism of formation. PATIENTS AND METHODS: Retrospective review of data from 19 patients with PTs fitting the description of pleural plaques at chest computed tomography (CT) and presenting modifications (clearance or appearance) of at least one PT at an additional chest examination in prone position. RESULTS: A total of 152 PTs were recorded on the first chest CT examinations with a range of two to 19 pleural opacities per patient. All PTs had a posterior distribution in the lower lobes. On the additional acquisitions, 144 PTs disappeared. Seventeen patients presented complete regression of PTs and two patients presented persistence of eight PTs. CONCLUSION: Additional low dose acquisition in prone position should be performed in all patients presenting with focal PT in a dependent and basal location. This may allow to exclude a pleural plaque in case of asbestos exposure but also a pleural metastasis in oncologic patients. These reversible dependent PTs could be related to physiological focal accumulation of lymphatic fluid in subpleural area.

Iowa Brownfield Reuse Guide, September 15, 2008

Brownfield sites come in all shapes and sizes, from vacated industrial sites to a single building plagued with asbestos materials. Brownfield sites are found in both urban and rural settings and present challenges that make the cleanup and redevelopment of these sites unique as compared with other real estate projects.

Evaluation des risques relatifs au talc seul et au talc contamin�� par des fibres abestiformes et non abestiformes

[Table des mati��res] 1 Contexte de la saisine. - 2 D��finitions et terminologie. - 3 Min��ralogie et g��ologie du talc. - 4 Production et utilisation du talc. - 5 Echantillonnage et analyse des fibres. - 6 Exposition professionnelle �� la poussi��re de talc. - 7 R��glementation. - 8 Effets sur la sant�� - donn��es cliniques - autres effets que le cancer. - 9 Etudes ��pid��miologiques. - 10 Donn��es toxicologiques. - 11 Conclusions. - 12 Recommandations. - 13 Bibliographie. - Annexe 1: Liste des organismes sollicit��s dans le cadre de l'expertise. - Annexe 2: Compte rendu des auditions. - Annexe 3 : Analyse critique des ��tudes ��pid��miologiques men��es en industrie extractive. - Annexe 4 : Importations fran��aises du talc de 2007 �� 2009