No description available.

The objectives of this study were: (1) to compare lung fibre concentration and dimensions found in two groups of former Quebec chrysotile miners (Asbestos and Thetford-Mines) and, (2) to investigate the relationship between lung-retained mineral fibre concentration and dimension (length, diameter, and aspect ratio) to severity of interstitial lung fibrosis (asbestosis) within these groups. / Lung fibre content was determined for 86 former employees of chrysotile mines and mills in two Quebec mining regions: Thetford-Mines and Asbestos (Jeffrey Mine). Six lung samples were selected for each subject from predetermined intrapulmonary sites. / In summary, the concentrations of tremolite for short (<5 mum) intermediate-length (5--10 mum) and long (>10mum) fibres were 4, 2, and 2 fold higher respectively among workers of Thetford-Mines than those from Asbestos. These differences were statistically significant between the two groups (p < 0.05 for all tremolite size categories). No consistent and biologically important difference was found among fibre dimensions in any of the size categories (p > 0.1 for all fibre types and size categories). These observations suggested that the much higher exposure in Thetford-Mines to asbestos fibres, tremolite fibres being more apparent, is the most plausible factor which may explain the higher incidence of lung diseases among the former miners and millers of Thetford-Mines. / Concentration of short (<5 mum) tremolite fibres was the best predictor of asbestosis severity in both mining groups (r = 0.44, p < 0.01 and r = 0.39 p < 0.01 for Thetford-Mines and Asbestos, respectively). Chrysotile fibre concentration showed a lower correlation with asbestosis severity among subjects from Thetford-Mines (r = 0.28, p < 0.1 and r = 0.39, p < 0.01 and for fibres <5 mum and fibres 5--10 mum respectively). Long (>10 mum) amosite fibre concentrations showed a linear relationship with asbestosis severity in the group of miners and millers from Asbestos (r = 0.5, p < 0.01). Shorter commercial amphibole concentrations did not show this relationship and these fibres were largely absent from the lungs of miners from Thetford-Mines. Concentration of asbestos bodies from lung digests was significantly associated with fibrosis for subjects from Thetford-Mines only (r = 0.3, p = 0.05). (Abstract shortened by UMI.)

The management of post-stroke recovery has changed considerably in recent decades, with approximately 80% of individuals returning home and rehabilitating in the community made possible because of the support of family members to provide care to meet their daily needs. Stroke caregivers are required to quickly learn rehabilitation and medical management techniques, while adjusting to changes in their relationships with the person who experienced the stroke. Unsurprisingly, stroke caregivers report high levels of stress and burden related to the deterioration of their own health status, social relationships, quality of life, and poor rehabilitation outcomes for the stroke survivor. Emotional vitality is an emerging concept characterized by a sense of positive energy and effective emotional regulation in order to remain interested, engaged and productive in life. While emotional vitality may serve as a critical buffer against caregiver strain, very little is known about what enables some caregivers to thrive and be emotionally vital in this role, and others to burnout. This thesis was designed to contribute to the understanding of the caregiving experience by taking a longitudinal view of emotional vitality.The first three studies contributed to the development of a conceptual and measurement framework for caregiver emotional vitality that included five domains: i) physical health and well-being; ii) support and recognition from others; iii) engagement in meaningful activity; iv) mood regulation; and v) a sense of control/mastery of new skills. The fourth study contributed evidence towards the measurement properties of a set of 19 items that reflect the emotional vitality construct as it pertains to caregivers of stroke survivors.A final study was aimed at providing preliminary evidence for how this measure of emotional vitality behaved longitudinally. Specifically, the objectives were to (i) estimate the extent to which caregiver emotional vitality changes in the first caregiving year; and (ii) estimate the extent to which caregiver characteristics and the functional profile of the care recipient impacts a caregiver's emotional vitality in the first year. From a sample of 409 caregivers (mean age 59 years, SD 15), five trajectories of emotional vitality were identified. Most caregivers (4 trajectories representing 78% of participants) displayed low levels of emotional vitality that remained persistently low over time. The concordance between caregiver baseline levels of mastery and emotional vitality was fair (kappa=0.45). In summary, emotional vitality in caregivers was on average very low in the first caregiving year. Mastery may be a component cause of emotional vitality, lending support to the importance of the need for health professionals to incorporate assessment of caregiver emotional vitality and mastery throughout the caregiving experience. / Depuis les dernières décennies, la gestion de la guérison suite à un accident vasculaire cérébral (AVC) a considérablement évolué. Approximativement, 80% des gens retournent à la maison et font leur réhabilitation dans la communauté. Ceci est rendu possible grâce au soutient des membres de la famille qui leur procurent des soins pour rencontrer leurs besoins quotidiens. Les aidants naturels des personnes ayant eu un AVC doivent apprendre rapidement des techniques de réadaptation et de gestion des médicaments, tout en s'adaptant à des changements dans leur relation avec la personne ayant eu un AVC. Il n'est donc pas surprenant de voir chez ces aidants naturels un niveau de stress plus élevé. De plus, le fardeau lié à la détérioration de leur propre état de santé, de leurs relations sociales et de leur qualité de vie résulte souvent en de mauvais résultats de réhabilitation chez les survivants d'un AVC.La vitalité émotionnelle est un concept émergent caractérisé par un sentiment d'énergie positive et une régulation des émotions efficace afin de rester intéressé, engagé et productif dans la vie. Alors que la vitalité émotionnelle peut servir de tampon contre la pression ressentie chez les aidants naturels, on en connait très peut sur ce qui permet à certains aidants naturels de réussir et être émotionnellement vital dans ce rôle et d'autres seront complètement épuisés. Le but de cette thèse est de contribuer à la compréhension de l'expérience des aidants naturels en prenant une vue longitudinale de la vitalité émotionnelle. Les trois premières études ont contribué à l'élaboration d'un cadre conceptuel et de mesure pour la vitalité émotionnelle chez les aidants naturels. Ce cadre inclus cinq domaines : i) la santé et le bien-être physique ; ii) l'appui et la reconnaissance d'autrui ; iii) l'engagement dans des activités significatives ; iv) la régulation de l'humeur ; et v) le sentiment de contrôle/maîtrise de nouvelles compétences. La quatrième étude a contribué aux évidences des propriétés de mesure d'un ensemble de 19 items illustrant le concept de la vitalité émotionnelle en ce qui a trait aux aidants naturels des survivants d'un AVC.Une dernière étude a utilisé cette mesure afin (i) d'estimer la mesure dans laquelle la vitalité émotionnelle chez les aidants naturels change dans la première année de soins; et (ii) d'estimer la mesure à laquelle les caractéristiques des aidants naturels ainsi que le profil fonctionnel du bénéficiaire des soins influencent la vitalité émotionnelle des aidants naturels dans la première année. À partir d'un échantillon de 409 aidants naturels (moyenne d'âge de 59 ans, SD=15), cinq trajectoires de vitalité émotionnelle ont été identifiées. La majorité des aidants naturels (quatre trajectoires représentant 78% des participants) a démontré un faible niveau de vitalité émotionnelle qui est demeuré bas au fil du temps. La concordance de départ entre le niveau de maîtrise et de vitalité émotionnelle chez les aidants naturels était bonne (kappa=0.45).En résumé, la vitalité émotionnelle chez les aidants naturels était en moyenne très faible dans la première année de soins. La maîtrise peut être une partie constituante de la vitalité émotionnelle. Ceci démontre l'importance et la nécessité que les professionnels de la santé intègrent dans leur évaluation la vitalité émotionnelle et la maîtrise des aidants naturels, et ce, tout au long de l'expérience de soins.

Two subject groups, seven PPS (4 males, 3 females) and 15 normal controls (9 females, 6 males) were matched on the basis of age, height and weight and participated in this study. Three repeated measurements were conducted to evaluate the reliability of isokinetic measurement of strength (at 4 velocities) and fatigability (25 reciprocal contractions at 3.14 rads.s$ sp{-1}$). Data from two subsequent test days were used to evaluate the fatigue responses of the PPS subjects while ON or OFF pyridostigmine. Significant strength differences were seen between the two groups, however there was no observed difference in the rate of development of fatigue. Reliability of strength was demonstrated for the knee extensors and flexors of the PPS subjects after three consecutive test days. Fatigability of the knee extensors in PPS subjects could be tested reliably after three test days but more time would be required for reliable performance of the knee flexors. Reliability of strength and fatigability was seen for both the knee extensor and flexors of the normal controls after only two consecutive test days. A beneficial effect of the drug on fatigability was not seen in the three female PPS subjects, but was demonstrated in one male subject. The drug appeared to have a beneficial effect on strength in the remaining three male subjects.

A significant gap exists between evidence-based practice (EBP) and actual occupational therapy (OT) practice in the management of a disabling post-stroke impairment - unilateral spatial neglect (USN). With improved patient outcomes linked to the use of best practices, it is crucial to modify OTs' actual practices in stroke care. To date, no research study has used knowledge translation (KT) to increase knowledge of EBP specific to OTs managing post-stroke USN. The first manuscript of this thesis explores how the "Knowledge to Action Process" model developed by Graham and colleagues, can be used as a step by step guide in creating an effective KT intervention for OTs working in acute stroke care. It describes how previous research has already addressed the "Knowledge Creation" domain of the model through the creation of synthesized materials and knowledge tools. It then goes on to describe how the first two steps of the "Action Cycle" domain have also been addressed; the main problem between EBP and actual practice has been identified and the evidence on best practice USN management has been adapted for acute care. The subsequent two steps that have not yet been addressed include assessing barriers to knowledge use and implementing an intervention. The Knowledge to Action Process model stresses that in order for a KT intervention to be effective in changing clinician practices, the facilitators and barriers faced by clinicians treating a specific clientele, in a specific type of setting, need to be identified.A few studies have assessed the barriers and facilitators to using EBP in rehabilitation; however none are specific to occupational therapists treating post-stroke USN. Thus, the objectives of the second manuscript were twofold: Phase 1) to identify the barriers and facilitators that affect EBP use by acute care OTs treating individuals with post-stroke USN; and Phase 2) to create, to pilot test, to evaluate the feasibility and to conduct preliminary analyses of effectiveness of a multi-modal KT intervention geared towards increasing EBP knowledge acquisition and self-efficacy for USN assessment and treatment. A sub-objective was to conduct preliminary analyses of the association between potential explanatory variables and change in knowledge acquisition and EBP self-efficacy.In the first phase, two focus groups (n=9) were held where acute care OTs treating patients with stroke discussed the barriers and facilitators to EBP use faced in practice. Key barriers included lack of time and basic EBP skills, and lack of personal motivation to change current practices and habits. Key identified facilitators included a multidisciplinary stroke team, recent graduation, and having access to learning material and several educational days annually. In the second phase, a multi-modal USN KT intervention was pilot tested on 20 OTs from Quebec and Ontario. Clinicians took part in an 8 week intervention beginning with a 7 hour in-person USN KT training session. This was followed by an 8 week reinforcement period where they continued their learning online. A pre, pre, post assessment of the main outcome - knowledge of best practices in USN management, was measured online via the Knowledge Questionnaire. The secondary outcome EBP self-efficacy, was assessed using the EBP Self-Efficacy Scale immediately prior to and following the in-person training session. All OTs improved in knowledge of EBP USN management and as a group, a statistically significant improvement was achieved. Similarly, significant improvement was found in clinicians' level of EBP self-efficacy. These results demonstrate that a multi-modal KT intervention based on the Knowledge to Action Process model and identified barriers and facilitators is feasible and effective based on preliminary analysis. However, further investigation of this KT intervention through a randomized control trial is necessary to validate the results on effectiveness obtained in this study. / Il existe un grand écart entre les données probantes et la pratique actuelle des ergothérapeutes traitant les patients qui ont subi un accident vasculaire cérébral (AVC) et qui sont atteints de la négligence spatiale unilatérale (NSU). Il est très important de modifier les pratiques actuelles de ces cliniciens vu l'amélioration remarquable des symptômes de NSU reliés à l'utilisation des données probantes. À date, il n'existe aucune étude de recherche utilisant l'application des connaissances (ADC) comme moyen d'augmenter les connaissances des données probantes spécifiquement pour ergothérapeutes traitant la NSU. Le premier manuscrit de cette thèse décrit comment un modèle d'ADC le « Knowledge to Action Process » conçu par Graham et collègues, peut guider le développement d'une ADC efficace ces ergothérapeutes. Il décrit la façon dont les études de recherches précédentes ont déjà adressés le domaine de la création des connaissances. Le manuscrit poursuit en décrivant comment les deux premières étapes du domaine du cycle d'actions ont aussi été adressées. Les deux étapes suivantes qui évaluent les obstacles à l'usage des données probantes et qui mettent en œuvre une intervention d'ADC n'ont pas été adressé à date. Le modèle souligne que l'intervention d'ADC ne pourra être efficace que si les obstacles et facilitateurs vécus par les cliniciens travaillant dans ce domaine sont identifiées. Il existe aucune étude à date qui identifie les obstacles et facilitateurs à l'utilisation des données probantes pour ergothérapeutes travaillant avec les patients avec AVC et la NSU. Les objectifs du deuxième manuscrit sont : Phase 1) d'identifier les obstacles et facilitateurs qui contribuent au manque d'utilisation des données probantes par les ergothérapeutes travaillant en soins aigues avec les patients atteints de la NSU suite à un AVC, et Phase 2) de créer, d'évaluer la plausibilité et d'exécuter des analyses préliminaires d'efficacité d'une intervention d'ADC ayant comme but d'augmenter les connaissances des données probantes et aussi d'auto-efficacité dans l'évaluation et le traitement de l'NSU parmi le même groupe de cliniciens.Dans la première phase, deux groupes de discussions (n=9) avec ergothérapeutes des soins aigues travaillant avec les individus atteints de NSU suite à un AVC ont eu lieu. Les obstacles les plus importants étaient le manque: de temps, d'habileté dans le domaine des données probantes, et de motivation personnelle à changer leur pratique actuelle. Les facilitateurs dominants étaient ayant: une équipe de AVC composée de différentes disciplines, terminée les études récemment et accès aux matériaux d'apprentissages et journées de formation annuellement. Dans la deuxième phase, une intervention d'ADC a été mise à l'essai sur 20 ergothérapeutes provenant des provinces de Québec et de l'Ontario. L'intervention a commencé avec une formation de sept heures suivie par huit semaines de renforcement où les cliniciens ont continué leur apprentissage sur l'internet. Deux évaluations préliminaires et une ultérieure des résultats principaux – les connaissances des données probantes pour la gestion de l'NSU ont été mesurées à travers le « Knowledge Questionnaire » répondu sur l'internet. Le deuxième résultat - d'auto-efficacité pour utiliser les données probantes a été évalué en utilisant le « EBP Self-Efficacy Scale». Les résultats ont démontré que tous les ergothérapeutes ont amélioré leurs connaissances de la gestion de la NSU et en tant que groupe, une amélioration significative a été atteinte. De même, une amélioration significative a été remarquée au niveau d'auto-efficacité pour l'utilisation des données probantes. Ces résultats démontrent qu'une intervention d'ADC basée sur le « Knowledge to Action Process » est réalisable et basée sur l'analyse préliminaire est aussi efficace. Cependant, un essai de contrôle randomisé est requis pour valider les résultats obtenus ici sur l'efficacité de l'intervention d'ADC.

Cerebral Palsy (CP) is the most common cause of physical disabilities in children. It is a broad term that describes a set of conditions that is associated with major physical impairments and other developmental deficits and arises in the early stages of brain development. Children and youth with CP often experience limitations in everyday activities in different life situations.Participation in leisure activities is an important aspect of health, as described by the International Classification of Functioning, Disability and Health (ICF). Engagement in leisure activities is essential for the development of a series of crucial competencies for a healthy development. Recently, studies have found factors related to participation in children with physical disabilities. However, information is lacking with regards to participation of adolescents, particularly what types of leisure activities are preferred by this population and predictors of participation in different type of leisure activities. Understanding of factors associated with participation in leisure activities may contribute to the development of rehabilitation and community programs and policies.The primary objective of this study is to quantify the level (intensity and diversity) of participation in leisure activities of adolescents (12-19 years of age) with cerebral palsy (CP), and to estimate the potential influence of both intrinsic child characteristics and extrinsic environmental factors as determinants of leisure participation. The secondary objective of this study is to determine factors associated with preferences for specific leisure activities in this population of interest. A cross sectional design was used. A total of 185 adolescents (12-20 years old) completed the study. Participation was measured with the Children's Assessment of Participation and Enjoyment (CAPE) and preferences for activities was measured with the Preferences for Activities of Children (PAC). Results demonstrate that adolescents with CP participated in a variety of out-of-school leisure activities. Adolescents participated more in informal activities than formal activities. Adolescents engaged in a variety of recreational and social activities, but not in many self-improvement activities. Participation in skill-based activities was the least frequent type of activity done, but diversity and frequency of participation in physical activities was also limited.In terms of preferences for activities, social and physical activities were most preferred, and self-improvement activities were least preferred. Family factors, personal factors and functional abilities influenced leisure preferences. High preference for certain activities was not always associated with actual involvement in these activities. Models of determinants of intensity of participation in five leisure activity domains demonstrated that leisure is a multifaceted construct that appears to be associated with a variety of factors related to the adolescents' functional characteristics and attitudes, the family environment and socioeconomic status and other contextual factors such as school type. Aspects of the adolescent's mastery motivation and behavior were also associated with participation in different activity domains. The adolescent's perception of self in relation to competence in different life skills and physical appearance was also associated with participation in certain types of leisure activities. Rehabilitation interventions should consider adolescents' preferences and family dynamics to minimize barriers to leisure participation, such as low motivation or environmental obstacles, so as to promote engagement in leisure activities. Expanding the scope of rehabilitation interventions to support the creation of programs in the community and advocate for policies that may facilitate participation in a variety of activities is needed, to promote a healthy development and well-being for this at-risk population. / La paralysie cérébrale (PC) est un ensemble de conditions associées à des déficiences majeures et à des déficits au niveau du développement qui se forment lors des premiers stades de développement du cerveau et est la cause de handicap physique la plus importante chez les enfants. Souvent, les individus atteinent de la PC peuvent être limité dans ses activités de tous les jours. La participation à des activités de loisir est un aspect important de la santé, selon la Classification Internationale du Fonctionnement, du Handicap et de la Santé (CIF). Participer à des activités de loisir est essentiel pour le développement d'une série de compétences. Récemment, des études ont démontré des facteurs liés à la participation chez des enfants souffrant de handicaps physiques. Par contre, la documentation concernant la participation d'adolescents, particulièrement les types d'activités de loisirs préférés par cette population et les prédicteurs de la participation dans différents types d'activités de loisir, est incomplète. L'objectif principal de cette étude est de quantifier le niveau, l'intensité et la diversité de la participation des adolescents (de 12 à 19 ans) souffrant de paralysie cérébrale (PC) à des activités de loisir et d'estimer l'influence potentielle des caractéristiques intrinsèques de l'enfant et les facteurs environnementaux extrinsèques en tant que déterminants de la participation à l'activité de loisir. Le second objectif de cette étude est de déterminer les facteurs associés aux préférences pour des activités de loisirs spécifiques chez cette population. Notre étude, de type transversale, a été complétée par 185 adolescents entre 12 et 20 ans. La participation a été mesurée avec le "Children's Assessment of Participation and Enjoyment" (CAPE), et les préférences pour les activités ont été mesurées avec le "Preferences for Activities of Children" (PAC). Les résultats démontrent que les adolescents souffrant de PC participent à une variété d'activités récréatives et sociales, mais à très peu d'activités de croissance personnelle. La participation à des activités basées sur les compétences était le type d'activité le moins populaire, mais la diversité et la fréquence de la participation à des activités physiques était également limitée. En ce qui a trait à la préférence pour certaines activités, les activités sociales et physiques étaient les plus populaires, et les activités de croissance personnelle étaient les moins populaires. Des facteurs familiaux et personnels ainsi que les habiletés fonctionnelles influençaient les préférences. Une préférence élevée pour certaines activités n'était pas toujours associée à la participation à ces activités. Des modèles déterminant l'intensité de la participation à cinq domaines d'activités ont démontré que le concept de loisir comporte de nombreuses facettes qui sont associées à une variété de facteurs reliés à l'environnement familial, au statut socio-économique et à divers facteurs contextuels comme le type d'école fréquenté. La motivation et le comportement étaient aussi associés à la participation dans différents domaines d'activité. La perception de soi de l'adolescent en relation avec la maîtrise des différentes compétences de base et l'apparence physique étaient également associées à la participation à certains types d'activités de loisir.Les interventions visant la réhabilitation devraient considérer les préférences des adolescents et les dynamiques familiales afin de minimiser les obstacles à la participation à des activités de loisir. Il est nécessaire de développer la portée des interventions de réhabilitation afin de supporter la création de programmes dans la communauté et de plaider en faveur de politiques qui faciliteront la participation à une variété d'activités. Ceci permettrait de promouvoir le développement sain ainsi que le bien-être de cette population à risque.

It is accepted that material handling is an activity presenting a high risk for injury, particularly to the back. In this study, an observation strategy has been developed and validated in order to evaluate the presence of these risky conditions while performing a handling task. Moreover, certain future utilisation conditions were specified. / Fifty-one observation variables were identified and an observation structure was elaborated from three data sources. These sources were: a literature review on observation grids, interviews with expert handlers and video sequences of a laboratory manual handling study where 10 inexperience subjects performed a total of 1500 container transfers. Observational data entry was recorded from a sample of these 174 sequences for which biomechanic measures were also done. / The results show that observations can be reliable and valid and that the diversity of observation objects can be important and extend beyond postural variables. The observations performed on an uninterrupted video sequence are the ones that present the most difficulties. The observers' experience does not seem to be an important factor in obtaining reliable results. On the other hand, the observation criteria, the training and the breakdown of variable classes are factors susceptible to influence reliability. / Many observation variables for balance had a significative impact on the biomechanical measure of balance, particularly when the object is taken and put down. This is the case with the number of foot supports, the weight distribution at the base of support and the position of the object, especially it's lateral deportation with respect to the body. The backward movement of the pelvis, which enables to compensate for the added external weight to the body, was significantly associated to balance. In general grouped variables, have more impact on the measure of balance than variables taken individually. Grouped variables are also less prone to variations when handling contexts are changed. For asymmetry, shoulder orientation with respect to the pelvis, back flexion, parallelism of the shoulders to the ground, and the position of the hands on the object handled all had a significative impact on the effort asymmetries when the object was taken from the plate-form. For the control and fluidity, a difficulty in finding a corresponding biomechanical measure or reliability problems did not enable us to verify whether our observations could have permitted to evaluate the risky conditions. (Abstract shortened by UMI.)

This study addressed the question of silica exposure, silicosis, and lung cancer in respect of lung particle burden. Sixty seven paraffin-embedded lung tissue samples of silicotic gold miners (39 non-lung cancer (NLC-SI) and 28 lung cancer (LC-SI)), were analyzed by transmission electron microscopy and energy dispersive X-ray spectroscopy for angular particles and fibres/cleavage fragments. Crystalline silica was characterized by X-ray powder diffraction on silver membrane filter. / Results indicated that both silicotic groups had non-significantly different concentrations and sizes of all particle types except quartz. Indeed, the NLC-SI group had a higher concentration of quartz than the LC-SI (3.77 $ mu$g/mg dry lung tissue compared to 2.47 $ mu$g/mg, p = 0.006, Mann-Whitney test). After adjusting for the differences in age at death, silicosis severity, and other dust exposure variables, but not for unknown smoking habit, the NLC-SI group still had a higher, through statistically non-significant, quartz concentration than did the LC-SI group (3.34 and 2.35 $ mu$g/mg respectively, p = 0.106, ANCOVA). This pattern was in good agreement with a pattern of a higher silicosis severity score in the NLC-SI group. The calendar year of first exposure was a prime determinant of lung burden of total particles, silica, and clay, with the coefficients of determination $ rm (R sp2)$ of 11-15%. A significant correlation between the concentrations of silica particles and quartz was observed, although quartz was the only significant predictor of the silicosis severity in the gold miners $ rm (p < 0.001, R sp2 = 20.5 %).$ A significant correlation between quartz concentration and the year interval since last exposure to death (r = + 0.25, $ rm p < 0.05)$ suggested a possibility of impaired lung clearance of quartz. Years of dust exposure did not show a significant linear relationship with any types of lung particles. The very low asbestos concentrations detected in only a small number of cases ruled out the suspicion of asbestos as a confounder of lung cancer in the miners. In conclusion, this study of lung concentration of quartz and other minerals did not support the association of silica, silicosis, and lung cancer.

A comparison was made between NIOSH-type, prepacked nutshell charcoal tubes and layers of commercial charcoal cloth in a stainless steel cassette designed for the active sampling/adsorption of different concentrations of a mixture of volatile organic chemicals (VOCs) (benzene, trichloroethylene, toluene, tetrachloroethylene, chlorobenzene and o-xylene). Physicochemical parameters of the charcoal cloth including breakthrough times and volumes and adsorption capacities were determined for toluene and the VOC mixture. The quantitative removal of VOCs from the charcoal cloth by solvent desorption, by supercritical fluid extraction (SFE), and by thermal desorption was studied prior to analysis by gas liquid chromatography with photoionization detection. Optimal conditions were explored both in laboratory and industrial environments. / Charcoal cloth was comparable to the NIOSH tube, adsorbed VOCs being quantitatively removed at any time up to 32 days after sampling. Although solvent (pentane, hexane) desorption yielded accurate, reproducible results with a high percent recovery of the VOCs, a major disadvantage was the irreparable damage done to the cloth, preventing its repeated use. Desorption by SFE proved unreliable for these low molecular weight VOCs, both the collecting solvents and the VOCs being lost during extraction. Thermal desorption proved to be efficient, sensitive and reliable, repeated heating having no effect on the adsorptive properties of the cloth. Charcoal cloth would appear to be a useful adsorbing medium for air sampling of both industrial and office building/home environments for either single chemicals or mixtures.

No description available.