Dissertations / Theses on the topic 'Wood dust'

ABSTRACT Occupational exposure to wood dust and biohazards associated with wood dust (endotoxins, (1->3)-b-D-glucans, Gram (-)ve bacteria and fungi), their correlation to respiratory function, and symptoms among woodworkers have been investigated in the present study. Wood dust, endotoxins, and allergenic fungi are the main hazards found in woodworking environments. Relatively very few studies have been done on wood dust exposure. The present study was designed to comprehensively investigate the health effects of wood dust exposure, and in particular provide new information regarding: Exposure to (1->3)-b-D-glucans in an occupational environment; Levels of exposure to wood dust and biohazards associated with wood dust in different woodworking environments; Correlations among personal exposures, especially correlations between (1->3)-b-D-glucans and fungi exposures, and endotoxins and Gram (-)ve bacteria exposures; Effects of personal exposure to biohazards on lung function; Effects of personal exposure to biohazards on work-related symptoms; and Determinants of inhalable exposures (provide which factors in the environment influence the personal inhalable exposures). Workers at four different woodworking processes; two logging sites, four sawmills, one major woodchipping operation and five joineries situated in the state of New South Wales in Australia were studied for personal exposure to inhalable dust (n=182) and respirable dust (n=81), fungi (n=120), Gram (-)ve bacteria (n=120), inhalable endotoxin (n=160), respirable endotoxin (n=79), inhalable (1->3)-b-D-glucan (n=105), and respirable (1->3)-b-D-glucan (n=62). The workers (n=168) were also tested for lung function. A questionnaire study (n=195) was carried out to determine the prevalence of work-related symptoms. The geometric mean inhalable exposure at logging sites was 0.56 mg/m3 (n=7), sawmills 1.59 mg/m3 (n=93), the woodchipping mill 1.86 mg/m3 (n=9) and joineries 3.68 mg/m3 (n=66). Overall, sixty two percent of the exposures exceeded the current standards. Among joineries, 95% of the hardwood exposures and 35% of the softwood exposures were above the relevant standards. Compared with green mills, the percentage of samples, which exceeded the hardwood standard was high for dry mills (70% in dry mills, 50% in green mills). The respirable dust exposures were high at the joineries compared with the other worksites. Exposure levels to fungi at logging sites and sawmills were in the range 103-104 cfu/m3, woodchipping 103-105 cfu/m3 and joineries 102-104 cfu/m3. The predominant fungi found at sawmills were Penicillium spp. High exposure levels of Aureobasidium pullulans were also found at two sawmills. At the woodchipping mill the predominant species were Aspergillus fumigatus, Penicillium spp., and Paecilomyces spp. The sawmills, which employed kiln drying processes, had lower exposure levels of fungi compared with the green mills. Those workplaces which had efficient dust control systems showed less exposure to fungi and bacteria. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and joineries exceeded the threshold limit value. The mean inhalable (1->3)-b-D-glucan level at the woodchipping mill was 2.32 ng/m3, at sawmills 1.37 ng/m3, at logging sites 2.02 ng/m3, and at joineries 0.43 ng/m3. For the respirable size fraction, mean endotoxin and mean (1->3)-b-D-glucan concentrations were much lower, being similar to observed dust concentrations. Significant correlations were found between mean inhalable endotoxin and Gram (-)ve bacteria levels (p<0.0001), and mean airborne inhalable (1->3)-b-D-glucan and fungi levels (p=0.0003). The correlations between mean respirable endotoxin levels vs Gram (-)ve bacteria exposure levels (p=0.005), and respirable (1->3)-b-D-glucan exposure levels vs total fungi levels (p=0.005) were also significant. Significant correlations were found between lung function and personal exposures. Multivariate analyses showed that the effect of all the personal exposures on cross-shift decrements in lung function was more prominent among sawmill and chip mill workers compared with joinery workers. Woodworkers had markedly high prevalence of cough, phlegm, chronic bronchitis, frequent headaches, throat and eye irritations, and nasal symptoms compared with controls. Among the woodworkers, smokers had a high prevalence of chronic bronchitis (20%) compared with non-smokers (10%). Some workers also reported a variety of allergy problems due to exposure to various types of wood dust. Both joinery workers and sawmill and chip mill workers revealed significant correlations between work-related symptoms and personal exposures. Chronic bronchitis was significantly correlated with personal exposure to wood dust, endotoxin, (1->3)-b-D-glucan, fungi, and Gram (-)ve bacteria among joinery workers. Whereas among sawmill workers chronic bronchitis was significantly correlated with personal exposure to endotoxin, (1->3)-b-D-glucan, and fungi. Woodworkers showed significant positive correlations between percentage cross-shift change (decrease) in lung function and respiratory symptoms. Significant inverse correlations were also found among percentage predicted lung function and respiratory symptoms. The elevated inhalable dust exposures observed in this study can be explained by a combination of factors, including: lack of awareness of potential health effects of wood dust exposure among both management and workers, aging equipment, inadequate and ineffective dust extraction systems or usually none especially for hand held tools, poor maintenance of the ventilation system in some, non-segregation of dusty processes, dry sweeping, and the use of compressed air jets. The determinant-of-exposure analysis confirmed the field observations. The significant determinants of personal inhalable dust exposures (n=163) were found to be: local exhaust ventilation, job title, use of hand-held tools, cleaning method used, use of compressed air, and green or dry wood processed. Type of wood processed was not found to be statistically significant. A majority of workers (~90%) did not wear appropriate respirators approved for wood dust, while the workers who did wear them, used them on average less than 50% of the time. Workers should be protected by controlling dust at its source. When exposure to wood dust cannot be avoided, engineering controls should be supplemented with the use of appropriate personal protective equipment.

The aims of the work this thesis is based upon were to develop convenient analytical procedures for determining resin acids in biological and environmental matrices, and apply them to enhance understanding of the occurrence, exposure to and uptake by exposed individuals of resin acids. Particular focus has been on the workplace environment of the Swedish wood pellets industry. Sample extraction procedures and high-performance liquid chromatography/electrospray ionisation-mass spectrometry (HPLC/ESI-MS) methodologies were developed for measuring resin acids in dust, skin and urine samples. Chromatographic separation of abietic (AA) and pimaric acid was achieved by using a polar-embedded C12 stationary phase. The HPLC/ESI-MS method avoids undesirable oxidation of AA, which was found to occur during the derivatisation step in the standard MDHS 83/2 gas chromatography/flame ionisation detection (GC/FID) methodology, leading to false observations of both AA and the oxidation product 7-oxodehydroabietic acid (7-OXO). Personal exposures to resin acids in the Swedish wood pellet production industry were found to be lower, on average, than the British Occupational Exposure Limit for rosin (50 µg/m3). The oxidised resin acid 7-OXO, was detected in both dust and skin samples indicating the presence of allergenic resin acids. A correlation between air and post-shift urinary concentrations of dehydroabietic acid (DHAA), and a trend towards an increase in urinary 7-OXO during work shifts, were also observed. Whether the increase in 7-OXO was due to direct uptake or metabolism of other resin acids cannot be concluded from the results. An efficient HPLC/UV methodology with diode-array detection was developed for screening commercial products for rosin that could be used in laboratories lacking mass spectrometers. Very high concentrations of free resin acids were detected in depilatory wax strips using the method.
At the time of doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.

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The present work aimed to highlight the study of polymeric composite development to be responsible with the environment and with the growth of the recycling of materials, from the use of high-density polyethylene (HDPE) with eucalyptus wood dust from the manufacturing furniture. The study started from a literature search where were analyzed the factors involving the subject in question, highlighting the concept of polymer, synthetic fibers, wood dust presence, and composites to identify and understand the problem in issue. Mechanical, morphological and rheological tests were done with composites with concentrations of 5, 10 and 20% of wood dust in relation to the polymer matrix in order to characterize and compare the obtained materials. It was noted that during the study samples with wood dust had higher mechanical performance compared to pure HDPE sample. Based on this context, this study was developed to analyze the possibilities ahead so the production of HDPE composite from different wood dust fractions.
O presente trabalho teve como objetivo destacar o estudo de desenvolvimento de compósito polimérico responsável com o meio ambiente e com o crescimento da reciclagem de materiais, a partir da utilização de polietileno de alta densidade (PEAD) com pó de madeira de eucalipto, proveniente da fabricação de móveis. O estudo iniciou a partir de uma pesquisa bibliográfica onde foram analisados os principais fatores que envolvem o tema em questão, destacando o conceito de polímero, das fibras sintéticas, a presença do pó de madeira, seus compósitos a fim de identificar e conhecer o problema em questão. O estudo desenvolveu-se a partir de ensaios mecânicos, morfológico e reológico, dos compósitos com as concentrações de 5, 10 e 20% de madeira em relação à matriz polimérica, a fim de caracterizar e comparar os materiais obtidos. Notou-se que durante os estudos as amostras com pó de madeira apresentaram maior desempenho mecânico comparado a amostra de PEAD puro. Baseado neste contexto, este estudo foi desenvolvido visando assim analisar as possibilidades frente a produção do compósito de PEAD a partir de diferentes concentrações de pó de madeira.

O processo de tratamento da madeira utiliza substâncias que geram compostos perigosos que podem contaminar os compartimentos ambientais. O presente estudo avaliou uma área sob influência da contaminação de solo proveniente das atividades de uma usina de tratamento de madeira desativada. A presença e o efeito de compostos mutagênicos em amostras ambientais foram utilizados como marcadores de exposição associada à avaliação de marcadores genéticos de efeito precoce em humanos, com foco em crianças como grupo sensível. Uma área 1750 m distante da usina, fora do quadrante dispersão preferencial atmosférica e em oposição à drenagem do local, foi utilizada como local de referência para a coleta de amostras e comparação. Extratos orgânicos de água de abastecimento, poeira de sótão e material particulado atmosférico fino (PM2,5) foram avaliados para mutagenicidade por meio do ensaio Salmonella/microssoma. Cobre (Cu), cromo (Cr), arsênio (As) e pentaclorofenol (PCP) foram quantificados em amostras de poeira do sótão. Os 16 Hidrocarbonetos Policíclicos Aromáticos (HPAs) prioritários foram avaliados nos extratos de PM2,5 e poeira do sótão. Crianças residentes no entorno da usina e na área de referência foram avaliadas quanto à presença de micronúcleos em amostras de sangue e mucosa oral, e danos primários no DNA, pelo ensaio cometa em linfócitos de sangue periférico. De acordo com a análise de metais, as residências perto da entrada da usina foram as mais afetadas. PCP foi identificado em amostras de poeira de sótão (0,49 mg/kg) e a concentração total de HPAs nesta matriz variou 0,40-13,31 mg/g, com maior dispersão. Todas as amostras de poeira do sótão em que a concentração total de HPAs estava acima de 2μg/g apresentaram resposta positiva para a atividade mutagênica. A contribuição dos HPAs para a mutagênese na poeira de sótão representou 10%, indicando que outros compostos podem contribuir para o efeito mutagênico. A atividade mutagênica e a concentração de HPAs nas amostras de PM2,5foram, de maneira geral, mais elevadas na área de risco, embora em alguns períodos de amostragem a área de referência atingiu valores semelhantes ou mesmo superiores. O efeito mutagênico e as concentrações de HPAs observados nas amostras de PM2,5 foram semelhantes aos valores encontrados em estudos que avaliaram áreas urbanas e com influência industrial. Extratos orgânicos de água de abastecimento não apresentaram mutagenicidade. As frequências de MN em linfócitos de sangue periférico e de células binucleadas na mucosa oral foram significativamente maiores no grupo de risco. Nos demais biomarcadores avaliados não foram observadas diferenças significativas entre os grupos. O conjunto de resultados indica a necessidade de novas avaliações utilizando grupo de referência menos suscetível às influências da área contaminada. O conjunto de dados coletados neste estudo indica a necessidade de uma avaliação mais cuidadosa dos biomarcadores individualmente e de um grupo de referência menos suscetível a influências da área contaminada. Apesar da ausência de diferenças significativas entre os grupos de risco e de referência em biomarcadores de danos no DNA avaliados em crianças, os resultados observados nas amostras de poeira de sótão e PM2,5 sugerem que a população esteve ou ainda está potencialmente exposta a substâncias capazes de causar efeitos adversos à saúde humana.
The mutagenic activity and the concentration of PAHs in PM2.5 samples were generally higher in the risk area, although in some periods the reference area has reached similar or even higher values. The mutagenic effect and the concentrations of PAHs recorded in the PM2.5 samples were similar to those found in studies that assessed areas of intense urban occupation and industrial influence. Organic extracts from supply water showed no mutagenicity. The MN frequencies in peripheral blood lymphocytes and binucleated cells of the oral mucosa were significantly higher in the risk group. No significant differences between children from the reference and risk area were observed in others genetic biomarkers assessed. The result set indicates the need for further evaluations using reference group less susceptible to the influences of the contaminated area. The set of data collected in this study indicates the need for a more cautious assessment of biomarkers individually, and a reference group less susceptible to influences from the contaminated area is necessary. Despite the absence of significant differences between the risk and reference groups in biomarkers of DNA damage assessed in children, the results in attic and PM2.5 samples suggest that the population was or is still potentially exposed to substances with strong negatives effects on human health.

Introduction et objectifs : Les travailleurs du bois sont exposés au risque de développer des adénocarcinomes dans une localisation spécifique : la fente olfactive. Les mécanismes de cancérogenèse de ces tumeurs rares sont mal connus et l’efficacité du dépistage actuel n’est pas démontrée. Les objectifs de ce travail étaient : 1/établir le lien entre le sous-type histologique d’adénocarcinome intestinal et l’exposition aux poussières de bois, 2/explorer les différentes raisons possibles à une telle localisation 3/confirmer ou infirmer les mécanismes supposés de la cancérogenèse (séquence métaplasie/cancer, rôle de CDX2, modifications génétiques et épigénétiques retrouvées pour d’autres modèles de cancérogenèse proches) et 4/développer une nouvelle approche non invasive pour le dépistage. Résultats : Nous avons d’abord étudié le lien spécifique entre le sous-type intestinal et l’exposition aux poussières de bois, puis nous avons montré sur modèle expérimental que le reste des fosses nasales est autant exposé aux poussières que la fente olfactive, même s’il reste possible que la clairance des poussières soit inférieure à ce niveau. L’hypothèse d’un mécanisme de reprogrammation oncogénique semble plus probable en raison de l’origine embryologique spécifique des tissus de la fente olfactive mais aussi des anomalies observées. Notre étude objective des variations d’expression de gènes qui pourraient participer à la dédifférenciation-redifférenciation de l’épithélium originel (CDX2, OCT3, FOXA1, FOXA2, SOX2, SOX9, SATB2, et certains gènes HOX). CACNA1C pourrait aussi jouer un rôle important dans la cancérogenèse. La séquence métaplasie/cancer pourrait s’intégrer dans cette reprogrammation : l’acquisition en situation ectopique de l’expression de CDX2 semble clef pour l’acquisition du phénotype intestinal. Cette acquisition n’est pas liée à la déméthylation de son promoteur. Grâce à une technique de brossage non invasive, bien acceptée et peu douloureuse, il a été possible d'identifier des modifications transcriptomiques et de méthylations cohérentes avec les profils phénotypiques et l'histoire naturelle des ITACs. Le prédicteur a permis d’identifier les individus porteurs d’un adénocarcinome avec une très bonne sensibilité et une très bonne spécificité. Conclusion : Nos résultats ouvrent la voie à une méthode de dépistage simple et non invasive pour les menuisiers et permettent un éclairage différent des mécanismes de cancérogenèse
Introduction and objectives : The relationship between wood dust exposure and nasal cancer is well estbalished, but the reasons why these tumours specifically arise from the olfactory cleft and the underlying mechanisms of carcinogenesis are poorly understood. Screening is currently based on the visualization of a tumour in nasofibroscopy and the effectiveness of this screening is not proven. The objectives of this work were: 1/ to establish the link between the intestinal subtype (intestinal type adenocarcinoma, ITAC) and wood dust exposure, 2/ to explore the different reasons for such a location (study of wood dust distribution and clearance in nasal cavity and of olfactory cleft embryological origin) 3/ to confirm or refute the supposed mechanisms of carcinogenesis (metaplasia / cancer sequence, role of CDX2, genetic and epigenetic modifications usually implicated in other similar carcinogenesis models) and 4/ to develop a new non-invasive approach for screening. Results: We first studied the specific link between ITACs and wood dust exposure. Then we demonstrated on an experimental model that the olfactory cleft does not seem to be more exposed to wood dust than the rest of the nasal cavity. Wood dust might stay longer in the olfactory cleft but based on our results we hypothesized that cancerogenesis might be rather due to oncogenic reprogramming, which is possible because of olfactory cleft embryological origin. The metaplasia/cancer sequence seems plausible. The ectopic acquisition of CDX2 expression seems to be a key point in the subsequent transformation to an intestinal phenotype tumor, but CDX2 activation is not related to its promoter demethylation. Our study highlighted gene expression variations that could be part of a dedifferentiation/redifferentiation process (CDX2, OCT3, FOXA1, FOXA2, SOX2, SOX9, SATB2, and some HOX genes). With an integrated approach, we also highlighted a potential implication of CACNA1C in carcinogenesis. Thanks to a non-invasive, well-accepted and painless brushing technique, it was possible to identify transcriptomic and methylation changes which were consistent with ITACs phenotypic profiles and natural history. The predictor identified patients with adenocarcinoma with a very good sensitivity and specificity. Conclusion: Our results pave the way for a simple, non-invasive screening method for woodworkers and for a better understanding of carcinogenesis mechanisms

The purpose of this study was to try to explain, using a rat model, the symptoms of bronchitis reported by some members of the workforce in wool textile mills in the north of England and in grain handlers. Inflammation was evident in rats following intratracheal instillation of dust collected from the air of wool mills and grain dusts. The inflammation could arise from at least four possible pathways and so we investigated each of these. 1) Direct toxicity towards airspace epithelial cells or alveolar macrophages. We demonstrated that there was no significant toxicity of wool or grain dust toward either cells of a human alveolar epithelial cell line (A549), or rat alveolar macrophages. 2) Activation of adhesion molecules on leukocytes. A constant finding in the lungs from wool and grain-treated animals was aggregates of mononuclear cells which were almost entirely macrophages. We hypothesised that prolonged up-regulation of adhesion molecules could account for aggregate formation, which may be mediated through the action of bacterial endotoxin present on the dusts, and which could enhance inflammation. We demonstrated that macrophage aggregation could be produced in vitro after stimulation, and that antagonists of adhesion molecule activation pathways abolished the formation of aggregates. 3) Secretion of pro-inflammatory cytokines by dust-exposed alveolar macrophages. Tumor Necrosis Factor (TNF) was secreted by alveolar macrophages after treatment with wool and grain dusts in vitro. Additionally, bacterial endotoxin which we detected on the dusts and which was present in leachates of dust, was shown to play an important role. Depletion of endotoxin in dust leachates resulted in substantially less TNF being released. 4) Immune responses to organic and antigens in the wool dust.

Cette thèse est dédiée à l'estimation de l'intensité d'une source de polluant de type particulaire par inversion de signaux de concentration mesurés avec un nombre fini de capteurs placés loin de la source. Cette méthode d'estimation inclut deux étapes distinctes. La première étape consiste à déterminer les paramètres du modèle d'inversion en utilisant une source d'aérosol connue et les mesures de concentration en particules correspondantes. Dans une seconde étape, une source d'aérosol inconnue est reconstruite à partir de l'inversion du modèle et des mesures de la concentration. Ce manuscrit traite dans un premier temps du cas stationnaire. L'approche théorique exposée permet de proposer un placement optimal des capteurs en plus de la méthode d'estimation de la source. Dans un second temps, on considère le cas où la source inconnue d'aérosol est instationnaire. La méthode d'estimation repose sur une approche convolutive du système, en introduisant la notion d'impédance source/capteur. Après une présentation de la technique d'inversion propre à la méthode d'estimation, elle est appliquée expérimentalement au cas des machines à bois éléctroportatives, dans le but de les discriminer en fonction de leur caractère émissif
This thesis is dedicated to the determination of unknown aerosol sources emission profiles from aerosol concentration measurements in the far-field. This procedure includes two distinct steps. The first step consists in determining the model linking the aerosol source and the concentration measurements using a known source of aerosols and the corresponding dust measurements. In a second step, the unknown source of aerosols is reconstructed by inverting the model for the measured aerosol concentrations. This manuscript deals in a first time with the stationary case. The exposed theoretical approach allows to suggest an optimal sensors placement in addition to the source estimation method. In a second time, we consider the case where the unknown aerosol source is unsteady. The estimation method is then based on a convolutive system approach, introducing the concept of source/sensor impedance. After a presentation of the numerical inversion technique, the method is applied experimentally to the real case of hand-held wood working machines so as to classify the machines with respect to their emission rate

Le mésothéliome pleural est considéré comme très spécifique d’une exposition à l’amiante. Cependant, certains aspects de l’étiologie de cette maladie n’ont pas encore été bien caractérisés. Les objectifs de cette étude sont : i) d’estimer la relation dose-effet entre exposition professionnelle aux fibres d’amiante et survenue de mésothéliome pleural selon différents indicateurs temporels d’exposition ; ii) d’étudier l’effet d’une exposition professionnelle aux laines minérales et aux poussières alvéolaires de silice cristalline libre sur le risque de survenue de mésothéliome pleural et iii) d’identifier les professions et secteurs d’activité à risque de survenue de mésothéliome pleural à partir de données recueillies sur une période de 20 ans. Les cas provenaient de ceux recrutés dans une précédente étude cas-témoins réalisée entre 1987 et 1993 et des cas enregistrés dans le programme national de surveillance du mésothéliome entre 1998 et 2006 (1 199 hommes). Les témoins ont été appariés en fréquence sur l’année de naissance et le sexe (2 378 hommes). L’exposition professionnelle à l’amiante, aux laines minérales et à la silice a été évaluée à partir de matrices emplois-exposition. Les relations dose-effet ont été estimées à l’aide du modèle logistique et leur forme a été obtenue grâce à l’utilisation de fonctions splines cubiques restreintes. Si la relation dose-effet à l’amiante est bien confirmée (particulièrement aux faibles doses), cette étude apporte de nouveaux résultats sur la relation temps-effet (rôle du temps écoulé depuis la dernière exposition ou effet de l’âge à la première exposition). Elle ouvre également de nouvelles perspectives sur le rôle des co-expositions (laines minérales) et permet d’identifier de nouvelles activités à risque, comme les mécaniciens automobiles
Asbestos exposure is recognized as the primary cause of pleural mesothelioma. However, some aspects of etiology of this disease have not been well characterized. The objective of this study was to elucidate dose-response relationships of temporal pattern of occupational asbestos exposure in males, using case-control data, to study effect of man made vitreous fibers and silica dust on the risk of pleural mesothelioma and finally, to describe occupations and industries at high risk for this cancer among men in France according a period of twenty years of observation. Cases came from a French case-control study conducted in 1987-1993 and from the French National Mesothelioma Surveillance Program in 1998-2006 (1,199 males). Population controls were frequency matched by sex and year of birth (2,378 males). Occupational asbestos exposure was evaluated with a job-exposure matrix. The dose-response relationships were estimated using logistic regression models and form of this relationship were estimated using restricted cubic spline functions. Dose-response relationship was confirmed (particularly for lowest doses). However, this study provides new results about time-effect relationships (role of time since last exposure or effect of age at first exposure). This study opens up new prospects on the role of co-exposure (mineral wool) and permit to identify new activities at risk for pleural mésothéliome as motor vehicle mechanics

碩士
臺北醫學大學
公共衛生學系
91
The aim of this study is to measure the distribution of wood dust and formaldehyde in a processing interior construction and to collect the health data of carpenters in interior construction. This is a cross-sectional study. Eight processing interior construction places were selected. Environmental samples included total wood dust, respirable dust and formaldehyde. 35 workers’ demographic and health data were collected by a constructive questionnaire and pulmonary functional test to evaluate the health situation of the workers. The results showed that the majority of workers are male with low education. They worked 40.2 hours per week. Most of 8-hour TWA total dust concentrations were lower than standard (10 mg/m3). However the highest level was up to 29 mg/m3, it varied with the work loading. The workers seldom use other personal protective devices except the wrong mouth muffles ues. Most of the workers smoke, environmental tobacco, dirty air, noise, and harmful chemical exposure were the most common complaints from our subjects. The top three of self-reported syndromes are eye irritation, cough and sputum. The results of lung functional test for workers showed that six workers suffered obstructive lung dysfunction and one suffered restrictive lung dysfunction. The multiple regression model showed that amount of cigarettes smoking, work years and mouth muffle use are negatively correlated with lung functional index (i.e. FEV1/FVC).

碩士
元智大學
生物科技與工程研究所
106
Prodigiosin is a red pigment that can be synthesized by microorganisms and belongs to secondary metabolites. It is known to be produced by microorganisms such as Serratia, Pseudomonas, Vibrio and Streptomyces. The literature pointed out that the addition of antibiotics in addition to the characteristics of antibiotics, but also inhibit the transfer of cancer cells and immunosuppressive function, for the emerging anti-cancer drugs. In view of the high manufacturing costs of prodigiosin, the first revision of the SG medium formulation was followed by the use of agricultural waste as an alternative carbon source to reduce the production costs of low prodigiosin and to introduce the concept of green technology into the pharmaceutical industry. In this study, first we explored Serratia marcescens SMΔR with glucose or soytone, but the yield of prodigiosin was very few, and glucose and soytone were added at the same time. The yield of prodigiosin was 79 mg/L. Then, Serratia marcescens SMΔR was cultured under the condition of glucose of 24 g/L, and it was found that the highest yield of 8 mg/L of soytone was 64 mg/L, and then the optimum C/N ratio, it was found that the maximum cell growth and maximum yield of prodigiosin were 83 mg/L at the C/N ratio of 6: 4 (glucose of 12 g/L), and then Serratia marcescens and hydrolysate liquid were tested. In order to be able to effectively obtain the glucose by wood dust. In this study, the wood dust was pretreated by steam explosion, then hydrolyzed by Ctec2, and finally Serratia marcescens was cultured with hydrolysate liquid to evaluate prodigiosin production. The results showed that the maximum glucose concentration of the hydrolysate was 26.06 g/L and the hydrolysis rate was 12.11% under the condition of 20% wood dust and with 10% enzyme. Further evaluation of prodigiosin production by Serratia marcescens in hydrolysate liquid showed a negative effect on the production of prodigiosin by S. marcescens, an inhibitor of excess hydrolysate after treatment and inhibition of cell growth. dilution of the hydrolysate liquid into different concentrations for prodigiosin production evaluation, the study found that the hydrolysate liquid diluted to 30% can get the highest yield of prodigiosin 27 mg/L. But the hydrolysate liquid need additional treatment.

碩士
國立成功大學
環境醫學研究所
88
Many adverse respiratory health outcomes occurred in wood workers are known to be associate with the exposure of wood dust. However, extent of the resultant health outcomes is varied with the type of wood using, exposure level and size-distribution of wood dust. In this study, workers employed by four hardwood furniture plants in Kaohsiung County were chosen as exposed group, and workers of three food processing and manufacturing plants were chosen as controls. Measurements were taken, including questionnaire’s survey and pulmonary function test, to compare differences in prevalence of respiratory symptoms and pulmonary function between the two groups. In addition, health related wood dust mass, number and surface concentrations were also measured using personal sampling technique, and to explore the relationship between change in pulmonary function of woodworkers and wood dust exposures. The results show that the exposed size distribution for each individual job title was found to be bimodal. MMAD of 9.82-17.98μm, NMAD of 1.25-5.44μm, and SMAD of 2.49-7.38μm for coarse mode, and MMAD of 0.64~1.44mm, NMAD of 0.07~0.35μm, and SMAD of 0.09~0.49mm for fine mode. Personal time-weighted-averaged inhalable wood dust exposure concentration was found as 3.29±1.74mg/m3, and with extrathoracic fraction of 41.3-63.1%. Above result suggests the difference among extrathoracic might over 20%. For number and surface area exposure concentration, fraction of alveolar exposure is found above 99.0% and 74.9-95.4%, respectively. The prevalence of cough (11.2%), phlegm (9.2%), shortness of breath (12.2%), rhinitis (16.3%) and eye irritation (14.3%) found in exposed group are higher than the controls. For baseline FVC, the exposed group is found worse than the controls, but for FEV/FVC and FEF50%, the controls are found worse than the exposed group. The exposed group is found with the decrease in pulmonary function for FVC, FEV1/FVC, FEF50%, FEF75% and FEF200-1200 after a work shift. Dose-response might worth further investigation in the future. It is concluded that hard wood dust exposure would causes workers'' adverse respiratory affections and pulmonary malfunction. For wood dust sampling, to measure the exposure level of each individual respiratory region will be more feasible to characterize workers’ exposures.

碩士
元智大學
生物科技與工程研究所
106
Prodigiosin (PG) is a red pigment which can be fermented by microorganisms. It is currently known to be synthesized by bacteria such as Serratia, plymuthica, Hahella chejuensis, Pseudomonas and Streptomyces. PG is a tripyrrole ring and belongs to bioactive secondary metabolites and accumulates in cell membranes and intracellular granules. The PG with antimicrobial, antifungal, anti-malarial, anti-protozoan, anti-cancer, immunosuppressive, antiproliferative charactecistics is regarded as a potential medicine. However due to high manufacturing costs of prodigiosin, this study tended sought to reduce the cost of prodigiosion by using agricultural waste as an alternative carbon source. In addition, an optimal fermentation strategy to increase overall production was also developed. First, wood dust was pre-treated by steam explosion. After steam explosion, the differences between dilute acid hydrolysis and enzymatic hydrolysis will be discussed. The enzyme hydrolysis rate is 3% higher than the dilute acid hydrolysis rate. Therefore, enzymatic hydrolysis is used as a follow-up experiment. and then enzymatic hydrolysis uses saccharified by Ctec2, a commercial enzyme for further use. Four methods were evaluated for enzymatic hydrolysis, including substrate ratios (wood dust / water, i.e. 10:90 to 25:75), pH values (3 to 7), enzyme concentrations (i. e 1.5% to 100%) and reaction temperatures (i.e. 30°C to 60°C). The findings showed that the highest glucose concentration was elevated from 33.14 g/L to 45.61 g/L when 60% Ctec2 and 25% wood dust were reacted at pH6, 40°C for enzymatic hydrolysis. As aforementioned, the wood dust hydrolyzate obtained from optimum hydrolysis was applied to produce PG by S. marcescens SM∆R. As literature, revealed excessive glucose would be harmful to bacterial growth due to high glucose concentration. Therefore, to avoid the phenomenon, the wood dust hydrolyzate was diluted in 5% ~100% as a carbon source for PG production. The experimental results showed that S. marcescens would inhibit PG production as well as cell growth when the excess wood dust hydrolysate (50% to 100%) was added into medium. As aforementioned results showed, the most suitable condition to produce prodigiosin (27.3 mg/L) by S. marcescens SM∆R was 10% of wood dusts hydrolysate. However, as the inhibitor contained in the hydrolysate suppresses the production of PG, this study used activated carbon to remove the inhibitors. The results showed that the most appropriate condition of prodigiosin production by S. marcescens SM∆R is around 10% for the wood dust hydrolysate and the PG production was 39.3 mg/L. Thus, diluted wood chips hydrolyzate was capable to produce PG. However, it still require to be treated properly prior to use as a nutrient source from available sustainable resources.