<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>

No description available.

<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>

The purpose of this project was to evaluate noise exposures of helicopter pilots, nurses and paramedics at a hospital by collecting area and personal samples, determining noise levels inside the helmet, and evaluating the current selection of personal protective equipment (PPE). Measurements gathered during personal sampling were statistically analyzed and calculated using OSHA 1910.95 App A to determine dose, reference duration and the Time-Weighted Average (TWA). Using a mannequin head, with the noise dosimeters in the ears, tests were performed on the headset inside the helmets to determine the sound pressure levels generated from the radio communications at different volume levels. According to our results, the crew is not exposed to hearing levels above the OSHA permissible exposure limit (PEL), because their flight times are usually only 20-30 minutes and the dose not above 22% of the OSHA limit. If the total flight times were 6.5 hours or more, the crew could be above the OSHA PEL. Testing the helmet speakers resulted in a recommendation that the setting not be set above the 6 o'clock position so that the crew would not be exposed to sound pressure levels about 80 dBA

<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>