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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The association between rhinitis and asthma of occupational origin /

Castaño, Roberto. January 2007 (has links)
The present thesis explores the relationship between occupational rhinitis and occupational asthma under the postulates of the "united airways disease" concept that refers to the multiple links observed between rhinitis and asthma. Accordingly, the main objective of this thesis is to demonstrate the concomitant expression of significant changes in nasal patency and bronchial calibre following exposure to occupational agents during specific inhalation challenges, complementing the assessment with the investigation of changes in markers of airways inflammation in nasal lavage. To achieve the objectives, we set up a protocol to diagnose occupational rhinitis and conducted a study from January 2005 to January 2007 at Hopital du Sacre-Coeur de Montreal in subjects undergoing investigation for occupational asthma. The reliability of the main research tools---acoustic rhinometry and nasal lavage---used to investigate occupational rhinitis was tested by analyzing the reproducibility of the methods. Both methods proved sufficiently reproducible to be included in our investigative protocol. The results presented in this thesis demonstrate a joint reaction of the nose and the lungs in a group of study subjects after performing specific inhalation challenge. This supports the concept of a "united airways disease" and its applicability to rhinitis and asthma of occupational origin. However, the results also show that although occupational rhinitis frequently coexists with occupational asthma it can also be present without occupational asthma. The assessment of upper airways inflammation in a subgroup of study subjects by the nasal lavage method allows us to observe significant changes in eosinophils counts after the challenge that correlates with the decrease in nasal patency observed in the same subjects.
12

Fluorinated hydrocarbons used as refrigerants : toxicokinetics and effects in humans /

Gunnare, Sara, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
13

Validation of two qualitative ocupational exposure assessment models for particulates and vapors

Elliott, Leshan J. January 2008 (has links) (PDF)
Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 11, 2009). Includes bibliographical references (p. 93-97).
14

Dissociation of hexavalent chromium from sanded paint particles into a simulated lung fluid /

Lange, Steven Harold January 2006 (has links) (PDF)
Thesis (M.S.P.H.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)
15

Determinacao de residuos de hexaclorociclohexano 'HCH' no soro sanguineo de trabalhadores expostos no arquivo historico de Joinville na decada de 80

LOIOLA, ELAINE C.D. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:29Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:58Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
16

"Poeira de soja inalada e seu impacto epidemiológico no desencadeamento de alergia respiratória" / Dust of inhaled soy and its epidemic impact in the respiratory allergy

Rodolpho José de Carvalho Pinto 20 June 2006 (has links)
Introdução: surtos de asma, por poeira da soja, têm sido relatados, havendo casos fatais. Objetivo: correlacionar exposição, sensibilização e alergia respiratória a esta, no Brasil. Métodos: 590 voluntários (testes de punctura e dosagem de IgE específica). Resultados: operários da indústria apresentaram 15% de. sensibilização à soja. Caminhoneiros 22%. Moradores no entorno da indústria 22% enquanto aqueles que residem distantes 6%. .Na região agrícola distante das plantações 13% e em meio à soja 28% com 5% de sensibilizados somente à soja. O percentual de IgE positivas para soja foi 16%. Houve marcante sensibilização aos fungos. Conclusão: A prevalência de sensibilização à soja demonstra o impacto desse tipo de poluição. A sensibilização aos fungos que colonizam a soja estocada não deve ser subestimada / Background: Asthma outbreaks, by soybean dust inhalation, have been reported fatal cases.. Objective: To correlate exposure and sensitization to soybean dust in Brazil.. Methods: 590 volunteers exposed to soy dust. Prick skin tests were performed and specific IgE were measured in sera.. Results: the workers from the oil refinery had sensitization to soy (15%). Truck drivers 22%. Industry neighborhood 22%. and people who live far from this place presented only 6%. People from agricultural area far from the soy plantations 13% and in the middle of the soy 28%.with 5% sensitized only by soybean . Positive IgE was 16 %. Conclusion: a high prevalence of sensitivity to soybean hull demonstrates the impact of this kind of pollution. The sensitization to the fungi which colonize soybean storage can not be underestimated
17

Determinação de resíduos de hexaclorociclohexano \"HCH\" no soro sanguíneo de trabalhadores expostos no Arquivo Histórico de Joinville na década de 80 / Determination of hexachlorcyciohexane residues on blood plasma of exposed employees of the Historical Archieve of Joinville on 80\'s decade

Elaine Cristina Damasceno Loiola 13 December 2007 (has links)
O Hexaclorociclohexano (HCH) é um inseticida do grupo dos organoclorados, composto por uma mistura de isômeros formados durante a síntese química, através de sucessivas adições de cloro ao benzeno. Estes isômeros podem contaminar não só o meio ambiente como também a população que tenha contato direto ou indireto com os resíduos. Nas décadas de 70 e 80, foi utilizado um produto comercial composto pelo ativo HCH comercializado como \"Hexabel®\" no controle de insetos xilófagos no Acervo Histórico de Joinville em Santa Catarina. A aplicação do inseticida foi realizada pelos próprios funcionários do Arquivo Histórico, e houve intensa manipulação dos documentos tratados durante uma mudança do prédio o presente trabalho teve como objetivo validar uma metodologia de determinação de resíduos do HCH e seus isômeros em soro sangüíneo, e analisar o grau de exposição dos funcionários e ex-funcionários do Arquivo Histórico de Joinville ao produto. Foram realizados exames sorológicos em todos os funcionários e ex - funcionários do local e também na população que sabidamente nunca tiveram contato com o ativo, denominada população controle. As análises foram realizadas após a validação do método multiresíduos que obtém todos os ativos em uma única extração e tem detecção por Cromatografia a gás com detector de captura (GC-ECD) de elétrons. Os resultados comprovaram comprovaram a eficiência do método, através de dados em conformidade com os critérios do ensaio. Os resultados obtidos no estudo da população mostraram que a quantidade de HCH no soro sangüíneo de funcionários, ex-funcionários e da população controle estão abaixo do limite de quantificação de 0,04μg dL-1 para Alfa HCH e Gama HCH \"Lindana\" e 0,08μg dL-1 para Beta e Delta HCH. / Hexachlorcyciohexane (HCH) is an organochloride insecticide formed by a mixture of chemical isomers produced during its chemical synthesis, obtained after successive inserts of chlorine atoms on benzene molecule. These isomers may contaminate both the environment and the people who had direct or indirect contact with the HCH residues. On 70\'s and 80\'s, its was used a commercial product which contained HCH on its formula and was commercialized as Hexabel®. The product was used to control the xylophage insect population on the Historical Archieve of Joinville, at Santa Catarina, Brazil. The own employees did the insecticide application and there was an intensive manipulation of the treated material during a building change. The objective of this work was to validate a methodology to quantify the HCH residues and its isomers on blood plasma and analyze the employee\'s exposure extent to the chemical. It was done serological investigation on employees, former-employees and on non-exposed people, which was classified as the control population. The analyses were done after the methodology validation. The method was capable to obtain all isomers on a unique extraction and the detection and quantification were done by gas chromatography with electron-capture detector (GC-ECD). The results obtained showed that the proposed method is accurate, and that the amount of HCH residues on blood plasma of all individuals analyzed was lower than the quantification limits established to the method, which were 0,04 μg dL-1 for the alpha- and gamma- HCH (lindana) and 0,08 μg dL-1 for the beta- and delta- HCH.
18

Harmful Algal Bloom Toxin Aerosol Exposure and Airway Inflammation

Breidenbach, Joshua David 15 June 2023 (has links)
No description available.
19

The association between rhinitis and asthma of occupational origin /

Castaño, Roberto. January 2007 (has links)
No description available.
20

Assessing Human Exposure to Emissions from Ultrasonic Humidifiers

Yao, Wenchuo 14 September 2021 (has links)
Portable ultrasonic humidifiers add moisture into room air, but they simultaneously add exposure risks of aerosolized metals from drinking water used as fill water. The inhalation exposure from emitted metals can be overlooked, and thus, co-exposure of inhalation and ingestion and co-exposure to multiple inorganic metals is investigated. The objectives of this work are: 1) predict airborne metal concentrations and particle sizes in four realistic room scenarios (33 m3 small or 72 m3 large, with varying ventilation rates from 0.2/hr -1.5/hr), and the investigated metals are arsenic, cadmium, chromium, copper, lead, and manganese; 2) characterize exposure doses and consequent risks for adults and 0.25, 1, 2.5, and 6 yr old children, when using identical drinking water ingested and as fill water, including inhalation of fine, respirable particles generated at the frequency of 8 hrs/day (equals 121.67 days/yr) and daily ingestion, under four realistic room scenarios. The risk assessment includes non-cancer [calculation of average daily dose (ADD) and hazard quotient (HQ)] and cancer risk evaluation; 3) quantify deposition fraction and deposited doses of multiple metals in human adult's and children's respiratory tract, using multi-path particle dosimetry (MPPD) model. Results show airborne-particle-bound metal concentrations increase proportionally with water metals, and a poorly ventilated room causes greater exposure. Ingestion ADDs are 2 magnitudes higher than inhalation ADD, at identical water metal concentrations and daily exposure frequency. However, in the worse-case scenario of 33 m3 small room with low air exchange rate, the consequent inhalation HQs are all greater than 1 for children and adults, except for lead, indicating significant non-cancer risks when exposed to humidifier particles under the worse-case scenario. The cancer risks for arsenic, cadmium, chromium, and lead metals reveal are greater than acceptable one case in a million population (1E-6) produced from inhalation of the humidifier emitted metal-containing particles only. The MPPD model results indicate inhaled metal-containing airborne particles deposit primarily in head and pulmonary regions, and a greater dose (unit in µg/kg body weight/day) deposits in children than adults. Inhalation of ultrasonic humidifier aerosolized metals results in additional, and potentially greater risks (indicated by HQinhalation >1, and greater deposited dose) than ingestion at the same aqueous metal concentration, especially for children. Room conditions (i.e. volume and ventilation) influence risks. Both inhalation and ingestion exposures require consideration for eliminating multiple metal exposures and health-based environmental policy making. Consumers should be aware that they may be degrading their indoor air quality by using ultrasonic humidifiers even when filling with acceptable water quality for drinking. / Doctor of Philosophy / The purpose of this work is to investigate the exposure from use of ultrasonic humidifiers filled with drinking water containing inorganic metals. Typical exposure pathway of drinking water metals is ingestion. However, inhalation of aerosolized metals can cause undesirable health effects towards metal exposure, when fill water of ultrasonic humidifiers is the same drinking water, and the inhalation of aerosolized metals exposure pathway can be overlooked. Emitted airborne particles are composed of soluble metals in drinking water, and are respirable with diameters between 100-200 nm. PM2.5 (particulate matter with aerodynamic under 2.5 µm) concentrations increase from approximately 2 µg/m3 to hundreds of µg/m3 in a common-sized room, exceeding the USEPA's regulatory level of 15 µg/m3 for ambient air PM2.5. The resulting air metal concentrations increase with increasing metals in the fill water, and/or lower ventilation rates in a household room. In addition, children receive greater average daily exposure doses than adults (i.e. average daily dose and deposited dose, in unit of µg/kg body weight/day), when assuming daily inhalation exposure of 8 hr/day and daily ingestion exposure. The ingestion doses from various metals are greater than inhalation doses, however, the inhalation risks may be greater for certain metals than ingestion. Even when using acceptable drinking water quality that meets regulations for metals, the indoor air quality is still degraded and can pose adverse health effects. In conclusion, the dissertation work presents a framework to estimate risks developed from multi-media and single or multi-metals exposure. The addition from inhalation of aerosolized metals in drinking water should be considered in an overall risk assessment, especially for the susceptible population of young children. Consumers should be aware that they may be degrading their indoor air quality by using ultrasonic humidifiers even when filling with acceptable water quality for drinking.

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