Respirators are used to minimize the exposure to air contaminants. A good fit is essential for the effective functioning of a respirator. The Occupational Safety and Health Administration (OSHA) requires an annual respirator fit testing. Respirator fit can be assessed either qualitatively or quantitatively. Two studies were conducted to assess the fit testing program with specific objectives to: (1) assess leak rates in full and half mask respirators; (2) assess the effectiveness of "feedback"1 on the quality of fit; (3) evaluate the effect of daily beard growth on respirator leak rates. In the first study, it was found that the half mask respirator has a significantly lower leak rate than the full face respirator. A significant reduction in leak rate in both respirator types with "feedback" was also observed. The finding that half mask respirators have lower leak rates directly contradicts American National Standard Institute's (ANSI) guidelines of higher Assigned Protection Factor (APF) for full mask respirator. Further studies are necessary to determine these findings and to amend respirator recommendations in the future. As expected in the second study, beard growth was associated with respirator leak rate. The effect of daily growth on leak rate over a period of twelve days could be defined by a second order regression equation. An attempt was made to describe some characteristics of beard that affect the leak rate. After 12 days of beard growth, it was found that the aspect ratio (length/diameter) of hair was inversely correlated with leak rate (r = 0.64). 1Feedback: A numerical value measuring the minimum leak rate that can be gotten from a respirator fitting with a normal donning.

<p> The Occupational Health and Safety Administration (OSHA) estimates that half a million surgical staff are exposed to laser smoke or plume each year. It has been suggested that the type and intensity of exposure is dependent in part on the way a laser is used during surgery. The purpose of this study was to estimate emission rates of the gas phase constituents of laser generated air contaminants using a validated emission chamber methodology while differentiating the effects of the laser operational parameters power, pulse-repetition frequency, and beam diameter, and ultimately to model a set of plausible occupational exposures. </p><p> An emission chamber was designed, fabricated, and validated to quantify the emission rates of gases and particles associated with laser generated air contaminants (LGACs) during a simulated surgical procedure. The emission chamber was built of inert materials, including a glass hood section connected to a duct section for collection and allowing for lasing of tissue. The performance, plume capture, and air flow of the emission chamber system were validated. This validated emission chamber and methodology enabled accurate estimation of emission rates with low experimental variability that can be used in mathematical modeling of exposure. </p><p> Two medical lasers (Holmium Yttrium Aluminum Garnet [Ho:YAG] and carbon dioxide [CO₂]) were set at varying operational parameters in a simulated laser surgery on porcine skin to generate a plume in an emission chamber. Porcine skin was pyrolyzed with a medical laser set to a range of surgically plausible operational parameters. Consistency in the rate and depth of incision was established by a system to control the speed of laser movement and aim angle of the laser tip, and was validated by measurement of tissue loss. The plume was sampled for seven gas phase contaminants of combustion products (volatile organic compounds [VOC], formaldehyde, hydrogen cyanide [HCN], carbon dioxide (CO₂), carbon monoxide [CO]). The effect of each operational parameter was determined using a fractional factorial design coupled with a sequential screening process that evaluated the parameters for their influence on emission rates. </p><p> Measured concentrations of the gas phase contaminants were below the limit of detection (LOD). Confined to the experimental conditions of this investigation, results indicated that beam diameter was significantly influential to emission rates when using the Ho:YAG laser but not with the CO₂ laser. Power and pulse repetition frequency were not influential to emission rates of these gas phase contaminants. </p><p> Emission rates of LGAC from the experimentally determined concentrations were used to estimate a range of physically plausible occupational exposures to surgical staff. A two-zone semi-empirical model was implemented with input variables varied over a range based on the general requirements of a laser surgical suite in compliance with regulatory agencies. Twenty-minute time weighted averages were developed for the near- and far-field zones within the surgical suite as estimates of the occupational exposure to LGAC. These values were compared to relevant occupational exposure limits; estimated exposures were at least three times in magnitude less than the exposure limits and thus do not appear to present an occupational hazard.</p>

No description available.

The hands-free technique is the indirect transfer of surgical instruments between surgeon(s) and other scrubbed personnel as well as circulating personnel, during which only one person touches the same sharp item at the same time. Items are usually placed in a designated neutral zone, which can be a section of the surgical field or a container, from where they can be retrieved. / Use of the hands-free technique for passing sharp instruments during surgery has been recommended as a work practice by many professional organizations in order to reduce accidents, but its effectiveness has not been adequately studied. This study was designed to determine whether use of the hands-free technique resulted in a decrease in injuries, contaminations and glove tears. / A prospective approach was used. All surgeries performed from the end of October, 1995 to mid-April 1996 at The Providence Medical Center in Seattle, Washington were eligible for inclusion in the study. / In 3,765 of 5,388 (70%) eligible surgeries performed during that five and one/half month period, circulating nurses filled out forms in the operating rooms right after a surgical case, assessing the proportion of passes done where no more than one person touched a sharp instrument at the same time. / In addition to use of the hands-free technique during surgery, type of surgery, length of surgery, bloodloss during surgery, noise levels, emergency status, number of personnel present and time of day, were also recorded. / Results. The hands-free technique was used, as defined, in about 42% of the surgeries. In another 50% of the surgeries it was used half the time or almost never. It was not used at all in 8% of surgeries. An overall injury, contamination and glove tear rate of 3.9% was measured during the study period. / Conclusion. Use of the hands-free technique at The Providence Medical Center during the study period was associated with a reduction in injuries, contaminations and glove tears, in surgeries with more than 100cc blood loss but a similar reduction was not observed when blood loss was less than 100 cc. (Abstract shortened by UMI.)

The objective of this thesis was to characterize the distribution, variability and determinants of exposures to extremely low frequency (ELF) electric and magnetic fields in environments where no information was previously available, and to advance the methodology of exposure estimation. The thesis is divided into three related papers. / The first paper reports a study of personal ELF field exposure measurements of 465 randomly selected workers in an electrical utility. By job category, arithmetic mean magnetic field exposures ranged from 0.09 to 2.36 $ mu$T (electric fields: 2.5 to 400 V/m). ELF magnetic field exposures were highest for substation workers, hydroelectric generating station operators and cable splicers; electric fields were highest for forestry workers, equipment electricians and distribution linemen. Most alternative indices of exposure were highly correlated with the arithmetic or the geometric means (r $ ge$ 0.8). Job category explained half of the total variance in logarithms of weekly magnetic and electric field means. / The second paper reports a method developed to estimate past ELF field exposures of the electric utility workers. The present intensities and durations of exposures for tasks were measured, then separately extrapolated to the past based on information from interviews with long-service personnel at the utility. From reconstructed time weighted average (TWA) exposures, magnetic fields were estimated to have increased most over time for substation and distribution-line jobs; the increase for electric fields was less than for magnetic. The method is applicable to other exposures where monitoring records allow calculation of the intensity and duration of exposures for tasks and estimates of past intensities and durations of exposures for these tasks can be obtained. / In the third paper, the methodology developed in the occupational setting was applied to a study of personal exposures to ELF fields among 365 randomly selected Canadian children. Overall, the arithmetic mean total magnetic field was 0.121 $ mu$T (electric field: 14.4 V/m), with magnetic fields highest in Quebec and lowest in Alberta. Magnetic fields were highest at home during the day. Measurements were at their lowest at night but provided the highest correlation with total magnetic field exposure (r =.91). This study found that children's magnetic fields exposures varied substantially between certain provinces (province accounting for 14.7% of the variation) most likely because of differences in the proportion of residences in multiple dwellings, heated electrically or cooled by air conditioning. These attributes were identified as potentially useful predictors of magnetic fields.

The role of occupational exposures in the genesis of airways disease may be underestimated in workforce studies because of the "healthy" worker effect, due either to those with more resistant airways entering a workplace or those with work related airways disease changing or quitting their job. Both effects are minimised in population-based studies which have the disadvantage that occupational exposures are of necessity self-reported. The overall goal of this research was to develop and validate an instrument to measure occupational exposures in epidemiologic research in general population studies of airways disease. / The study hypothesis was that self-reported exposure information pertinent to airway disease was as accurate a reflexion of exposure as information derived from industrial hygiene expertise. To examine the study hypothesis, use was made of occupational questionnaires completed by 338 adults participating in a Montreal community based study. A list of 927 reported jobs was submitted for coding of exposures to 2 industrial hygienists working independently to code exposures. / Intra-subject reproducibility of questionnaire information, assessed using a test-retest approach in 33 subjects showed good overall concordance for most components of the work history. Inter-rater reliability (between hygienists) was also good for some categories of exposures. / Validity analysis of self-reported exposure, using as a reference criterion the exposure coding by either hygienist lead to poor values for sensitivity and phi-coefficients but not for specificity. Slight improvement in sensitivities and phi-coefficients was found for latest job. / While smoking, a family history and atopy were determinants of asthma in multivariate models, significant exposure response relationships were obtained only with self reported exposure, not with exposures coded by either hygienist. Nevertheless the coefficients and confidence intervals for self-reported exposures were, for most part, in the same direction and range as those for exposure coded by the 2 hygienists. / These results are consistent with the study hypothesis that self reported exposures perform comparably, possibly even better than exposures based on industrial hygiene expertise in characterising exposure response relationships for airway disease in community based studies.

<p> Workers' compensation programs have emerged as among the largest and most important social programs in the United States. Workers' compensation claims in the state of Michigan account for an expenditure of approximately 1.3 billion dollars annually (Michigan Workers' Compensation Agency, 2011. 2011 <i>Annual Report</i>). Back injuries are the most prevalent work-related injury in the United States. Since 2002, such injuries in the baby-boomer generation have increased at a rate of 50% (Toossi, 2005. <i> Labor force projections to 2014: Retiring boomers</i>). The purpose of this study is to describe the personal lived experiences of older (over 55 years old) injured employees as a result of injuring their lower backs at work. The study only examined occupational lower back injuries suffered while assembling automotive parts in the state of Michigan. The study incorporates a qualitative design, specifically an interpretative phenomenological analysis, to focus on the lived experiences of the participants, and underpins the theory of planned behavior to assist with forecasting and understanding the particular behaviors within this population. A four-step data analysis method was used to illustrate and understand the meaning and essence of the lived experience of the injured, older automobile assembler worker.</p>

<p> <i>Background.</i> Nursing assistants, working in long&ndash;term care facilities, have consistently been among the top occupational groups experiencing work-related musculoskeletal injuries. These injuries have been attributed the physical demands of lifting and moving the individuals in their care. Great strides in research have identified successful risk reduction strategies such as the implementation safe patient handling and mobility programs. The benefits of these programs have been advocated over the last two decades, but the rate of injuries among nursing assistants continues to be more than double the national average for all other industries. The purpose of this study was to investigate the influence of safe patient handling and mobility policies and procedures, facility resources, and work practices on the trends in injury rates and the associated costs in long-term care facilities.</p><p> <i>Methods.</i> Thirty-eight facilities contributed information to the study. Data were gathered on safe patient handling policies, facility resources, work practices, work-related injuries and workers&rsquo; compensation costs for 2002 &ndash; 2011.</p><p> <i>Results.</i> Eighty-four percent of the facilities had patient handling policies or were preparing to implement in the upcoming year. All of the facilities had mechanical lifting devices, employee training and procedures for embedding safe patient handling into daily work practices. Nineteen facilities contributed one to ten years of data, showing injury rates decreased 63% from 2002 &ndash; 2011. Eleven facilities provided worker&rsquo;s compensation information showing medical and indemnity costs decreased 54% from 2006 &ndash; 2011. The presence of a policy, was not found to independently influence these factors. The number of days away from work due to work-related injuries was significantly lower in facilities with patient handling policies. <i> Conclusion.</i> The presence of the policy was not found to independently influence injury rates or costs, but the prevalence of safe patient handling policies, mechanical lifting devices and safe work practices suggested that a safety culture may finally be present in long-term care. Despite the impressive reductions in injuries and costs, the continued higher than average rate of injuries among this occupational group may indicate that other factors now play a greater role in work-related injuries.</p>

<p> Objectives: The purpose of this secondary data analysis was to examine "stage of change" as a predictor of attrition among participants in a worksite wellness program. A Conceptual Model of Attrition was developed to examine health screening, health risk appraisal (HRA), and demographic predictors of attrition as well. Methods: Data for this study were drawn from a worksite wellness program which was sponsored by an integrated rural healthcare system. The sample consisted of 1058 individuals for whom valid demographic, health screening, and HRA data were available. Of the total sample, 414 did not participate in a subsequent year (39.1% attrition). This research was conducted as a predictive correlational study using binary logistic regression analysis. Results: Significant associations between stage of change and attrition were found for the physical activity, nutrition, weight, stress, and overall healthy lifestyle health behavior areas. The stage of change with the highest odds of attrition was the preparation stage across these health behavior areas. In the Conceptual Model of Attrition, significant associations with attrition were found for emotional symptoms, emotional health limitations, health view, and overall healthy lifestyle stage of change. Conclusions: This research has shown that the stage of change construct is useful for predicting attrition. Identification of participants' stage of change offers a leverage point for engagement in worksite wellness programs and for prevention of program attrition. For employers, retention of these employees in their worksite wellness program could yield a greater return on investment resulting in lower health care costs, fewer missed work days, and higher productivity on the job.</p>

In spite of the vast technological progress and improvement in the standard of management systems within hazardous industries around the world, occupational health and safety incidents and fatalities continue to devastate thousands of lives each year. Throughout the last decade, significant improvement has been achieved in the reduction of health and safety incident rates across the South African petrochemical environment. However, a persistent roller-coaster fatality rate still prevails. Recent studies have shown that in order to conquer the relentless battle in realizing sustainable world-class health and safety performance, an organisation has to move beyond the traditional compliance orientated safety focus towards an interdependent safety culture in which safety is ubiquitous and embedded in the hearts of all employees. The root causes of more and more occupational health and safety incidents are no longer as a result of mechanical or systems failure, but instead originate from the attitude, values and beliefs of management and employees with regard to the significance of safety, also known as the safety culture. This has ignited a rising interest in the concept of safety culture among organisations because of the positive impact on occupational health and safety in reducing the potential for fatalities, injuries and workplace incidents. Hence the primary objective of this study is to determine the maturity of the current safety culture in the South African petrochemical environment by identifying particular culture shortfalls which could lead to hesitant progress towards the desired interdependent state. In order to reach this objective, three secondary objectives have also been set. Firstly, an understanding of the concept of organisational culture and safety culture is crucial. In simple terms, organisational culture can be described as the shared values, assumptions and beliefs in an organisation that ultimately direct employee behaviour. Organisational culture is characterised by three layers known as artefacts, espoused values and basic assumptions. These layers represent the manifestation of the organisational culture and vary in terms of outward visibility and resistance to change. Understanding and analysing these layers provide the reasons why employees behave in certain ways. Safety culture is a subset of organisational culture; in other words, it is the manifestation of the organisation?s attitude, values and commitment in regard to the importance of health and safety. Companies which have developed effective safety cultures have demonstrated unequivocal results in closing the elusive health and safety performance gap. Secondly, the fundamental components conducive of an effective safety culture were explored. These components include management and employee commitment to health and safety, accountability and involvement, communication and trust, risk awareness and compliance, competency and learning and finally recognition. Most of the components can be assigned to the artefact level or a combination of the level of artefacts and espoused values with only a small number more appropriately associated with the level of basic assumptions. The effectiveness within each of these areas ultimately dictates the nature of the safety culture and the success in preventing health and safety incidents. The focus of the last secondary objective was to determine the development stages leading to an effective safety culture known as an interdependent safety culture. Each of these stages represents the degree of maturity of the attitudes and commitment of management and employees in relation to the ongoing health and safety improvement in the organisation. The DuPont model suggests that in a reactive safety culture, safety is merely a natural instinct with no real perceived value for the individual or organisation. Moving towards a dependent safety culture, employees start to value safety but only so they do not get caught. The next stage called an independent safety culture is characterised by self preservation. In this stage, the mindset of employees changed towards an attitude of ?I do things safe so I do not get hurt?. In the final stage known as interdependent safety culture, employees embrace safety as a personal virtue not only for their own safety but also in contribution to the safety of their peers. In such a culture it is employees? desire to do things safely so that no-one gets hurt. An empirical study was conducted through a quantitative research approach in the form of a safety climate questionnaire. The target population consisted of first-line managers and non-managerial personnel within the production; maintenance; laboratory; technical, and the safety, health and environment departments in a petrochemical organisation. In light of the results emanating from the empirical study it can be concluded that an overall positive perception was observed towards the selected safety culture components indicative through the mean response scores above the neutral scale of 3. Older and more experienced employees demonstrated a more positive response to the safety compared to younger employees. However, several distinctive safety culture shortcomings were also identified. In the current safety culture, health and safety is sometimes overlooked due to productivity or cost implications. Employees tend to withhold safety related information to themselves as a culture of guilt prevails and mere compliance to safety standards is considered adequate. Solutions to health and safety problems are most of a short-term nature and do not address the root cause. It therefore provides evidence that the organisation under evaluation has not yet reached the desired safety culture maturity stage of interdependence. Although the study population is limited to a single organisation, the shortfalls identified could relate to the larger petrochemical environment and thus could explain the recent fluctuating health and safety performance. This assumption, however, can only be validated through further research within a much greater sample size inclusive of more than one organisation in the petrochemical environment. It is thus clear that the existing safety culture within the petrochemical organisation could lead to potential health and safety incidents if the shortcomings are not appropriately addressed. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2011.