Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1626. Advisers: George L. Delclos; Beatrice J. Selwyn. Includes bibliographical references.

Heat stress conditions are prevalent in the working environment around the world. Often they are not readily engineered out. Administrative controls and, in extreme/toxic environments, personal protective gear are the means available to protect workers. For every combination of metabolic work rate, clothing ensemble and environmental WBGT, there is a time of exposure threshold, beyond which the worker can no longer compensate for the heat stress, and signs and symptoms of heat strain appear. Increasingly, worker environments require specialty clothing either for worker protection or to maintain a clean/sanitary environment. Prior to the publication of the USF safe exposure time equation, no simple method was available for determining safe worker exposure time based on a clothing adjustment factor. To demonstrate the validity of the USF SET equation, both direct and indirect data from different environments, metabolic rates, and clothing ensembles were collected to compare observed tolerance times to the predicted safe exposure time. Statistical analysis was performed using the Kolmogorov-Smirnov test. The USF SET equation predicted an acceptable safe exposure time, 19 % of the trials. Based upon this data, the USF safe exposure time heat stress equation over estimates safe exposure time for workers in hot environments, in various clothing ensembles at various metabolic work rates.

Excessive exposure to heat stress can cause a host of heat-related illnesses. For laborers, job specific work demands and protective garments greatly increase the risk of succumbing to the effects of heat stress. Microclimate cooling has been used to control heat stress exposure where administrative or engineering controls are not adequate. This study tested the performance of four personal cooling vests for use with insulated protective clothing (gas extraction coveralls) in warm-humid (35 ° C, 50% relative humidity) and hot-dry (40°C, 30% relative humidity) conditions. On 10 separate occasions, 5 male volunteers walked on a treadmill to elicit a target metabolic rate of 300 watts, for 120 minutes, while wearing a (a) water cooled vest, (b) air cooled vest, (c) frozen polymer vest (FP) (d) liquid CO2 cooling (LCO2) vest, or (e) no cooling (NC). A three-way mixed effects ANOVA was used to assess the results and a Tukey's Honestly Significant Difference multiple comparison test was used to identify where significant differences occurred ( < 0.05). The air, water, and FP systems produced significantly lower heat storage rates compared to NC. To the extent that the gas extraction coverall is worn in an environment between 30°C and 45°C and the rate of work is moderate, the FP, air and water vest were shown to manage heat storage well, reducing storage rate by about 48%, 56% and 65% respectively.

Needlestick injuries (NSIs) are a recognized risk for occupationally-related transmission of bloodborne pathogens (BBP). The occurrence of NSIs and BBP exposures among firefighters (FFs) and emergency medical services (EMS) personnel has been documented. The purposes of this study were: 1) to define the problem of NSI among FFs and EMS personnel in a suburban fire department (FD) and identify practices and factors that influence sharps use and safety; 2) design and implement and intervention to promote safer sharps device usage; and 3) to measure the effectiveness of the intervention among FFs and EMS personnel. A multi-phase, mixed methods approach was used that included a diagnosis phase that utilized a mixed methods exploratory design, an intervention period, and a quantitative evaluation phase that used a before and after evaluation design. In the diagnosis phase, data regarding sharps device practices were obtained through a count of discarded sharps devices. Qualitative data regarding sharps practices and factors which influenced those practice were obtained via focus groups. The PRECEDE/PROCEED model (PPM) was used as the theoretical framework for assessment, planning, implementation, and evaluation of an intervention to increase the occurrence of safer sharps device behaviors and decrease the frequency of riskier sharps device behaviors. The evaluation phase included a post-intervention sharps count and a post-intervention survey to assess changes in sharps practices and the impact of the intervention. During the baseline sharps count, 2743 sharps devices were counted and classified according to pre-established categories of safer or risky behaviors for NSI. Altered safety devices on IV stylets were the highest count for unsafe behaviors (n=105), followed by recapped traditional needles (n= 53). A statistically significant increase in risky behaviors was observed in discarded sharps from engines, as opposed to ambulances, among all sharps devices combined (p=0.000) and IV stylets (p=0.000). When comparing advanced life support (ALS) medications to all other medications, a statistically significant increase in unsafe behaviors occurred among all sharps devices combined (p=0.000) and prefilled syringes (p=0.000). Input from eight focus groups of firefighters allowed for identification of multiple themes which guided the development of an intervention. The intervention included distribution of a hands-on training kit and booklet, expansion of an existing required BBP training, and posters to increase awareness regarding NSI prevention. In the evaluation phase, a total of 2178 sharps devices were counted and classified in a post-intervention sharps count. Altered safety devices on IV stylets were the highest count of unsafe behaviors (n=50). Recapped traditional needles were the second highest count of unsafe behaviors (n=27), but experienced an 18.7% drop in frequency when compared to baseline. When comparing riskier behaviors to the pre-intervention baseline sharps count, statistically significant decreases in risky behaviors were observed in all sharps devices combined ( 2=25.71, p=0.000), IV stylets (2=16.87, p=0.000), and traditional needles (=5.07, p=0.024). A post-intervention survey, consisting of 15 Likert scale questions, was returned by 165 out of 383 active field personnel (41.3%). Results indicated high frequencies of strongly agree and somewhat agree responses regarding risk perception; the importance of using safer needle devices; the impact of the intervention on safer needle practices and sharps safety awareness. Critical predisposing, reinforcing, enabling, and environmental factors which influenced sharps device practices were identified. This study identified factors and practices which influenced unsafe sharps device behaviors. Due to the statistically significant decreases in risky behavior in the post-intervention sharps count and the positive responses in the post-intervention survey, it can be concluded that the intervention did positively impact sharps device behavior and reduced the risk of NSI. The implications of the study are numerous and include a need to explore these practices and factors at other fire departments and EMS agencies, address gaps in regulations; promote research targeting FFs and EMS personnel in regard to NSI, and promote a nationwide effort to prevent NSI among emergency responders.

Introduction: Asbestos has been employed in a myriad of industrial applications for more than a century. Of the 181 Mt of asbestos produced worldwide, over 31 Mt was consumed in the U.S. The production and consumption of this mineral eventually was found to cause asbestosis, lung cancer and mesothelioma. While the brunt of the human exposure to asbestos occurred in insulation work, many more workers in other jobs were expose to asbestos fibers. Very little is known about the potential exposure to asbestos in research labs. Goal: In order to investigate potential research lab work exposures, we simulated lab work with various asbestos-containing items commonly found in research laboratories: 6 wire gauze pads, 3 gloves, 3 beaker tongs, and 3 Transite boards. All samples were analyzed by Phase Contrast Microscopy and, when appropriate, by Transmission Electron Microscopy and Polarized Light Microscopy. Results: All tested items were confirmed by bulk sampling to have asbestos fibers in their composition. Exposures from the 7 wire gauze pads were significantly lower than the PEL and the excursion limit, the highest exposure concentration measuring 0.029 f/cc. For the 3 beaker tongs with asbestos sleeves, exposure was below the PEL for 2 of the 3, with one resulting in an exposure of 0.160 f/cc (8-h TWA = 0.01 f/cc). For the Transite boards had the highest exposures of all tested items, with a maximum concentration of 0.320 f/cc (8-h TWA = 0.02 f/cc). Conclusion: Asbestos exposure in our simulated research lab work was significantly lower than any of the historical exposures associated with asbestos-related disease including cancer.

published_or_final_version / Urban Planning and Design / Master / Master of Housing Management

No abstract available. / Thesis (M.Med.)-University of Natal, Durban, 1981.

No abstract available. / Thesis (MMed)-University of KwaZulu-Natal, Durban, 2006.

In the early decades of British industrialization, the ill-health of textile factory workers attracted considerable public interest and provoked discussion and debate among a growing number of medical men, operatives, manufacturers, and social and political commentators. Guided by previous studies of the “framing” of disease, this dissertation examines how such ill-health was conceived, designated and responded to in the period from 1784 to 1833. The dissertation reveals that workers themselves held a relatively constant view of their condition. In the early part of the nineteenth century, they drew attention to a variety of ailments and throughout the period they saw a clear link between their maladies and the conditions of their labour. By contrast, medical understanding shifted significantly, and as it traced a course more or less at odds with that of popular comprehension, the nature and causes of worker suffering were substantially redefined. In the 1780s and 1790s, doctors identified the illness of factory labourers as “low, nervous fever,” an acute contagious disorder generated by the crowding and confinement of human bodies. A generation later, in the period from 1815 to 1819, the ill-health of mill workers was conceptualized, by a portion of the medical community, as “debility,” a poorly-understood state of constitutional feebleness attributed to aspects of machine work. In the early 1830s, medical authorities regarded factory workers’ sickness primarily as “digestive disease” and located its source in habits and diet. The reconceptualization of worker ill-health yielded an ultimately optimistic assessment of the consequences of industrial growth, failing to offer strong support to demands for legislative restriction of factory operation. It also served to sanction changing social relations through providing evidence of the physical and moral distinctness of the manufacturing population. As medical theory altered, so, too, did practices of relief and assistance. While mill owners, and doctors, became increasingly unwilling to assume responsibility for the well-being of the industrial workforce, operatives engaged ever more extensively in practices of self-help. The expansion of the textile industry, however, ensured the continuation of their affliction and incapacity.

Aim The aim of this study was to determine the contribution of occupational exposures to the burden of Chronic Obstructive Pulmonary Disease (COPD) among a sample of hospital based patients. Methods Cases (n=110) with specialist physician diagnosed COPD from the three public sector specialist respiratory clinics in KZN and controls (n=102) from other nonrespiratory chronic ailment specialist clinics at the same institutions were selected. An interviewer administered questionnaire and exposure history was obtained for each participant. In addition, a valid lung function test was obtained for each case. Data was analysed using STATA version 10. Multivariate regression models were developed to examine the relationship between COPD and occupational exposures while adjusting for age, sex, smoking and previous history of tuberculosis. The relationship of FEV1 and occupational exposures, adjusted for age, height, previous history of tuberculosis and smoking history, was investigated among cases. Results Cases and controls were similar with respect to age and sex distribution. Cigarette smoking differed significantly between cases and controls with a larger proportion of cases having ceased to smoke compared to controls (72% vs 46%, p<0.01). A higher proportion of controls reported employment in administrative, managerial and quality control positions (21.3% vs 12.0%, 7.7% vs 2.6% and 5.4% vs 0.3% respectively). Employment in the construction and shoe manufacturing industries was reported more frequently by cases (10.3% vs 3.2% and 10.0% vs 4.9% respectively). Cases were more likely than controls to have been exposed to dust (72% vs 28%, p<0.001) or to chemicals, gas or fumes (74% vs 25.5%, p<0.001) and reported exposure durations 3-4 fold higher than that of controls (p<0.001). Dust and chemical, gas or fume exposure was associated with an increased odds of developing COPD. Exposure to dusts (OR 7.9, 95% CI 3.9-15.7, p<0.001), chemicals, gas or fumes (OR 6.4, 95% CI 3.2-12.8, p<0.001) were significantly associated with odds of developing COPD. In addition, previous history of tuberculosis, as well as smoking were associated with an increased odds of COPD (OR 5.7, 95% CI 1.2-27.4 p<0.001 and OR 6.4, 95% CI 2.3-17.7, p<0.001). Discussion and Conclusion This is one of the first hospital based case-control studies looking at occupational contribution to COPD undertaken in South Africa. In this sample of participants, strong associations were observed between self-reported occupational exposures to dust, and chemicals, gas or fumes, and physician’s diagnosis of COPD. The study also demonstrated a strong association between smoking and previous history of tuberculosis, and risk of COPD. The findings suggest that persons with known occupational exposures to respiratory irritants should be monitored to detect the onset of respiratory ill-health and that preventive strategies should reduce exposure to these agents in the workplace. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2009.