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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

Air sanitation the nature and control of air contaminants, including dusts, fumes and smokes; mists and fogs; vapors, gases and odors; pollen, spores and bacteria : a preliminary report on a study of the scope of air sanitation and of contemporary problems in the control of air quality : submitted in partial fulfillment ... Master of Science in Public Health Engineering ... /

Witheridge, William N. January 1946 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1946.
12

(1-3)-B-D glucan exposure assessment in poultry farms in South Africa

Dayal, Payal 13 April 2015 (has links)
Introduction: Poultry workers have an increased risk of respiratory symptoms associated with various irritant and allergenic exposures causing airway inflammation. This study investigated the levels of (1-3)-β-D glucan exposure in several poultry farming processes. The objectives involved categorising the different tasks undertaken in the poultry industry. After which a method was established and validated to detect and quantify the levels of (1-3)-β-D glucan using the Glucatell assay. This assay was used to measure the amount of (1-3)-β-D glucan poultry farm workers were exposed to using personal sampling. Thereafter, general respiratory symptoms were described briefly via the administration of a respiratory questionnaire. Method: A total of 308 personal air samples were collected from several poultry farming processes (rearing, laying, hatchery, broilers, catching) of a large poultry farm in the North West Province. A walkthrough checklist was used to obtain information on various exposure determinants such as farm size, number of chickens, ventilation system, bedding material used and poultry feed used. The Glucatell assay (Associates of Cape Cod, East Falmouth, MA, USA) was used to quantify the concentration of (1-3)-β-D glucans in the air samples. Results: The geometric mean concentrations of (1-3)-β-D glucans ranged from 24.38 to 645.98 ng/m3 across the various poultry farming processes investigated. Workers in the broiler farms were exposed to two times higher levels of (1-3)-β-D glucans compared to those in the breeding farms. The sizes of the broiler farm houses as well as the age of the chickens were among the main determinants of exposure. The larger broiler farm houses (GM=5.2 ng/m3, GSD=3.74) had significantly (p<0.05) lower levels than the smaller broiler farm houses (GM=6.4 ng/m3, GSD=2.14) whilst houses with older chickens had higher (1-3)-β-D glucan levels (G=5.8 ng/m3,
13

Allergy to laboratory animals : risk factors for development of allergy and methods for measuring airborne rodent allergens /

Renström, Anne, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 7 uppsatser.
14

A case-crossover study of particulate matter air pollution and out-of-hospital primary cardiac arrest in King County, Washington /

Levy, Drew Griffin, January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 123-130).
15

Particularly harmful particles? : a study of airborne particles with a focus on genotoxicity and oxidative stress /

Karlsson, Hanna, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.
16

An investigation of the association between household biomass fuel smoke exposure, anaemia and stunting in children aged 12-59 months participating in the 2006-2007 Swaziland Demographic and Health Survey

Machisa, Mercilene Tanyaradzwa 25 January 2013 (has links)
Background Indoor air pollution due to use of biomass fuels (BMF) for household cooking and heating is a known risk factor of morbidity and mortality in children under the age of five years. A recent study in India suggested an association between biomass fuel smoke exposure anaemia and stunting among children under the age of five. The aim of this study was to investigate the association between BMF use, stunting and anaemia in children aged 12-59 months who participated in the 2006-2007 Swaziland Demographic and Health Survey (SDHS), whilst adjusting for potential confounders. Methods The study was cross-sectional and based on secondary data analysis of data collected through the household and women’s questionnaires in the 2006-2007 SDHS, which employed a multistage random sampling. Anthropometric measurements taken in the SDHS and the World Health Organization (WHO) 2006 Multi-Centre Child growth reference standards were used to ascertain children’s health status and the stunting outcome variable. A child, whose height-for-age ratio was below three standard deviations (SD) from the median of the WHO reference population in terms of height-for-age, was severely stunted or short for his/her age. A child, whose height-for-age ratio was between three and two SD below the median of the WHO reference population in terms of height-for-age, was mildly stunted. The exposure to BMF smoke variable was ascertained indirectly by type of fuel used for cooking. The exposure was a three category variable of cleaner fuel, outdoor BMF and indoor BMF use. All statistical analysis was done in STATA version 10. The relationship between BMF use and stunting or anaemia was determined using multinomial logistic regression analyses, whilst adjusting for potential confounding factors, identified in previous research. Results Of the 1612 children included in the study, 37% were anaemic. Nineteen percent were mildly and 18% were moderate to severely anaemic. Indoor BMF use, child age, low birth weight, mother’s age at birth, iron supplementation during pregnancy and mother’s anaemia status was significantly associated with child anaemia in univariate analysis. Outdoor BMF exposure, low birth weight, child age, mother’s anaemia status and wealth index was associated with child anaemia after adjusting for potential confounding. Overall 31% of children were stunted. Twenty percent were mildly stunted and 11% were moderate to severely stunted. Child sex, age, birth order, preceding birth interval, low birth weight, diarrhoea in preceding two weeks, anaemia status, iron supplementation during pregnancy, mother’s age at birth ,mother’s body mass index, mother’s education, wealth index, indoor BMF exposure and household crowding were each independently associated with stunting in univariate analysis. Only child sex, low birth weight and child age were significantly associated with stunting after adjusting for potential confounding. There was no evidence of an association between indoor BMF smoke exposure and child stunting after adjusting for all potential confounding factors. Conclusion This study did not find sufficient evidence to suggest that indoor BMF use is a statistically significant risk factor for anaemia or stunting in children aged 12-59 months participating in the 2006-2007 SDHS. There was however an evidence that, use of BMF outdoors significantly confers a protective effect against moderate to severe anaemia. Prospective research into these potential relationships are necessary, particularly the collection of primary data and accurate measurement of exposure to smoke emitted during BMF use for cooking and heating.
17

Assessment of indoor air quality in an office building in South Africa

Brits, Paul Jacobus 17 January 2012 (has links)
Introduction The problems associated with poor indoor air quality and the possible subsequent effects thereof on workers, as experienced by the Department of Health in the Regional office situated in the Karel Schoeman building (KSB) in Pretoria, were investigated and are discussed. The possible association between the physical indoor environmental conditions and the sick building syndrome (SBS) like symptoms as well as the seemingly low productivity and the above average rate of absenteeism are included in these discussions. To find a possible association between these poor physical environmental indoor conditions and the potential adverse affects on the health and motivation of workers, a cross sectional survey was conducted to assess the physical, biological and chemical quality of indoor air (Refer to as IAQ – Indoor Air Quality) as well as the chemical and biological quality of the drinking water. Objectives This research report documents a project to measure the environmental conditions which include CO(Carbon Monoxide), CO2(Carbon Dioxide), relative humidity( RH), temperature, air velocity, the microbial and chemical composition of the drinking water and culturable micro organisms in specific work environments within the KSB and to compare the outcome to standards for acceptable indoor working environments. The specific objectives of this study are:  To describe the environmental conditions CO, CO2, RH, temperature and air velocity exposures in specific work environments during the period 2003-2004;  To describe the microbial exposures to Legionellae (which is actually one of a group of similar diseases collectively known as Legionellosis.)  To compare measured environmental exposures to the Environmental Regulations for workplaces promulgated in terms of the Occupational Health and Safety Act 1993 (Act 85 of 1993) (OHSA), the National Institute for Occupational Safety and Health (NIOSH) standards and other national and internationally recognised standards and  To compare the microbial monitoring results including the evaluation results of the drinking water for culturable micro organisms and E.coli, to the NIOSH and other national and international recognized standards. Methods To control for confounding, samples of the drinking water as well as from a stagnant pool in the basement were taken and analysed for bacteriological and chemical compliance as well as identification of any microbes and chemicals that can contribute to SBS Environmental conditions which include CO, CO2, RH, temperature, air velocity, the microbial and chemical composition of the drinking water and culturable micro organisms including E.coli, in specific work environments were measured. Measurements were conducted in accordance with the procedures prescribed in the ASHRAE 41.6 of 1994, ACGIH (Handbook for industrial ventilation, EPA building Air quality guidelines, US Department of Labour –OHSA Technical manual),the respective manufacturers recommendations and the SABS Code 0400 of 1990 and sampling of the water in terms of the procedures prescribed by NIOH in the case of sampling for Legionellae and the Microbiological laboratory of the Rietvlei accredited water research laboratory with reference to sampling for identification of micro organisms including E.coli and the chemical composition. Appropriate recognized analytical methods were used to analyse and interpret the data generated from both the chemical and biological sampling results. Results Based on the outcome of the project results, it is clear that the air conditioning system does meet the mentioned minimum prescribed physical environmental national and international norms and standards for indoor air quality. The findings from the study indicate compliance of the physical environmental conditions to universally accepted standards and no association between those poor physical indoor environmental conditions and the sick building syndrome (SBS) like symptoms as well as the seemingly low productivity and the above average rate of absenteeism could therefore be made. The presence of coliform organisms above the norm in the air samples is however a concern. Discussion The OHSA requires employees to access the health and safety risks that hazards pose to their employees in their respective working environments and to take reasonably practicable steps towards eliminating or controlling these hazards. Like any other risks in a workplace environmental conditions need to be identified and controlled based on the principles of risk management. Conclusion The above high rate of absenteeism, as perceived by management, could not be associated with the environmental conditions covered in this project. It could however be ascribed, directly or indirectly to the following variables and assumptions which could be categorised under environmental conditions and the management thereof as well as the management of employees/workers located within the building. Environmental conditions such as substandard quality water supply, the management processes during the decommissioning of the old HVAC system and the commissioning of the replacement system, poor general housekeeping and unacceptable management principles of good quality clean working environments location of the building in the mid city centre of Pretoria and the possible contamination of indoor air by external sources bio quality could be variables contributing to the high rate of absenteeism. The seasonal occurrences of influenza and colds as well as home and external exposures could also possibly be considered as contributing factors in this regard. In addition poor general workers or people‟s management which could have resulted in low staff morale and personal motivation linked to poor supervision during a period of a very serious organizational restructuring which affected many workers could have also being considered as contributing factors to high absenteeism. Substandard ergonomics could have also played a role during this process.
18

Effects of Automoblie Tailpipe Emissions in the Hsuehshan Tunnel on the Air Quality of Neighboring Areas Using ADMS Model

Wang, Chen-wen 30 June 2009 (has links)
The Hsuehshan tunnel, whose length is about 12.9 kilometers, is the longest tunnel in Taiwan and Southeast Asia. Since the tunnel is used, it reduces the traveling time from Taipei to Ilan and brings the convenience of transportation; but the vehicles and pollution sources are added. Furthermore, the concentrations of pollutants are increased by accumulation in the long tunnel. This study estimates the effects of automobile tailpipe emissions in the Hsuehshan tunnel on the air quality of neighboring areas by using Atmospheric Dispersion Modelling System for Roads (ADMS-Roads). This work simulates carbon monoxide (CO), nitrous oxides (NOx) and sulfur dioxide (SO2) at two sites (Pin-Ling and Tou-Cheng management centers) in northern Taiwan in winter of 2008. The average concentrations of CO, NOx and SO2 at Pin-Ling (Tou-Cheng) management centers respectively are 0.49 (0.55) ppm, 10.60 (14.83) ppb and 4.80 (7.47) ppb on non-holiday and 0.66 (0.64) ppm, 16.88 (15.12) ppb and 4.70 (4.20) ppb on holiday. It shows that the concentrations of pollutants on holiday are higher than on non-holiday by increasing vehicles. Simulated results show that effects of traffic exhaust in the tunnel on the air quality of neighboring areas are less. Estimations using the ADMS-Roads suggest that the emissions are not the predominant contributors at two sites. The effect is the highest with northern (northeastern) winds at the southern (northern) area of the Hsuehshan tunnel. Comparisons between simulations and measurements at both sites are satisfactory. Simulated values are generally in agreement with measured values, with a correlation coefficient of R = 0.37 ¡V 0.81, the index of agreement (IOA) = 0.58 ¡V 0.77, and the normalized mean square error (NMSE) = 0.03 ¡V 0.25. The ADMS-Roads will be applied to assess the environmental impact while the tunnel will be allowed more types of vehicles to drive in the future.
19

Measurements of Volatile Organic Compounts in the Sewege System in a Southern Urban Area

Shen, Wei-sheng 30 June 2009 (has links)
This research investigate and analysis 77 kinds of volatile organic compounds (VOCs) in the sewage system of a southern urban area (A, B, C, D, E and F). The 77 kinds of VOCs will be divided into BTEX, chlorine-containing hydrocarbons and non-chlorine-containing hydrocarbons, and to estimate the emission of 27 kinds of hazardous air pollutants (HAPs). Cancer risk within 12 kinds of HAPs will also be part of the investigation by using Risk Assessment. In terms of consistency, except A1, D5 and E, VOCs are required mainly of non-chlorine-containing hydrocarbons at other areas, and main contribution species are ethylene, acetylene and ethane. There are 55.05 % of BTEX (1298.2 £gg/m3) and 35.51 % of non-chlorine-containing hydrocarbons (837.6 £gg/m3) in A1, but the main contribution are toluene, m-xylene and p-xylene. In D5, there is 76.39 % of BTEX (3744.7 £gg/m3) and the main contribution are m-xylene, p-xylene and toluene. In E, there is 80.02 % of chlorine-containing hydrocarbons (4807.1 £gg/m3) and the main contribution are chloromethane and toluene. Results show that the most emissions of total HAPs is D5 (12195.3 mg/hr), followed by B2 (4602.9 mg/hr), E (2659.4 mg/hr), A4 (2043.7 mg/hr) and A1 (1526.2 mg/hr). BTEX represent the largest proportion of the emissions of total HAPs in D5, A4 and A1. Chloroethene represents the largest proportion of the emissions of total HAPs in B2, followed by trichloroethene and tetrachloroethene. Chloromethane represents the largest proportion of the emissions of total HAPs in E. The most cumulative cancer risk in the sewage space is B2, followed by C2 and A3. The main contribution of the average cancer risk (not include B2) in a southern urban area are 1,1,2-trichloroethane, 1,2-dichloroethane and 1,4-dichlorobenzene.
20

Exposure to airborne asbestos in Jamaican hospitals

Scarlett, Henroy P. January 2007 (has links) (PDF)
Thesis (D.P.H.)--University of Alabama at Birmingham, 2007. / Title from PDF title page (viewed on Feb. 19, 2010). Includes bibliographical references (p. 145-153).

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