<p> Construction safety is an essential aspect of the construction industry and measuring safety performance has been of continuing concern. Most of the preceding studies concentrated on two widely used metrics in industry to evaluate and improve safety performance, EMR and incidence rates. However, it is recognized that these metrics have shortcomings, such as being reactive and not proactive, or representing a macroscopic approach and not microscopic approach, or disregarding the events that lead to accidents and only being result-oriented. Improving safety is one aspect of a research but using an appropriate safety measure is as important. Using these parameters comes with their limitations, and they need to be well understood while drawing conclusions so as not to mislead an owner while comparing companies' safety performance or making a decision to select a safe contractor, the same holds true for the contractor's own management while self-assessing its safety performance and deficiencies. </p><p> This study focused on a new safety performance metric by introducing a proactive safety performance measurement system through observed safety violations of OSHA standards. The new metric, site safety performance value (SSPV) was based on OSHA's Gravity Based Penalty (GBP) system and quantified general contractors' site safety performance to measure their ability to comply with OSHA safety rules and regulations. This metric is a leading indicator based on pre-accident driven data. It was also used to develop a new predictive model to evaluate general contractors' safety performance and examine the relationships between the project and company demographics and the proactive safety measure, SSPV, for advancement of construction safety performance. The statistical model constructed can predict future contractor safety performance, and it may contribute to the contractor selection process. The methodology additionally included an investigation of specific construction trades to find out which trades carry the highest risk in terms of safety and impact construction safety performance the most. </p><p> The findings of this study can be used by numerous groups including the general contractors, owners, safety professionals and researchers to identify where safety performance can be improved, and determine the significant parameters that could help identify the areas of concern by utilizing a new proactive safety performance evaluation system.</p>

<p> Low back pain (LBP) is the most prevalent work-related musculoskeletal disorder. Occupational risk factors have been studied for current ergonomic prevention strategies; however, other underlying mechanisms may exist since not all workers performing the same task develop the same severity. Previous research has identified personal and psychosocial risk factors that also contribute to LBP. Research quantifying the interactive effects of the various personal, psychosocial and occupational factors is limited, along with research on the effect of risk factor combinations on LBP severity. </p><p> The objectives of this study were to: 1) study the various factors that are known to be involved in low back pain and analyze interactions, and 2) develop a model to predict low back pain and validate it. In order to address these objectives, 2 studies were conducted. </p><p> The first study investigated the effects of various personal, genetic, occupational and psychosocial factors on two subjective LBP severity ratings: Oswestry Disability Index (ODI) and a Visual Analog Scale (VAS), and three physician-based ratings: MRI severity, canal stenosis and nerve impingement. Personal and psychosocial factors, in addition to occupational factors, were found to significantly affect the severity ratings. </p><p> The second study involved building predictive models of LBP severity for each risk factor category as well as a combined risk factor model. Results showed that the combined risk factor models considering interaction effects both within and across risk factor categories were significantly better in predicting severity ratings than the individual models. However, validation conducted using 5 random samples showed inconsistent accuracies. Results obtained may help to develop a more reliable way to predict and, hence, prevent chronic LBP.</p>

<p> Stress has long been conceptualized as consisting of two factors, eustress, or good stress, and distress, or bad stress (Selye, 1956). The occupational stress literature identifies <i>challenge</i> stressors as those associated with favorable outcomes, and <i>hindrance</i> stressors as those associated with negative outcomes (Cavanaugh, Boswell, Roehling, &amp; Boudreau, 2000). The current study had three objectives: 1) to investigate occupational level stressor appraisal by K-12 teachers, 2) to explore how the perception of the availability of resources influences individual level stressor appraisal, and 3) to test differential outcomes of challenge and hindrance stress. Results indicate that K-12 teachers appraise workload as a hindrance stressor more than as a challenge stressor, which is contrary to existing management literature categorizing workload a challenge stressor. Perceived resources also accounted for significant variance in individual appraisal of stressors as a hindrance. Results pinpoint precise personal and organizational resources that contribute to stressor appraisals as a hindrance. Finally, hindrance stress significantly detracted from engagement while challenge stress did not affect work engagement.</p>

Behavior as related to occupational danger was explored in this research by examining industrial workers' reactions to accidents they had on the job. An observational study was conducted using longitudinal data to investigate relationships between hypothesized antecedent conditions and the occurrence of accidents at a large petrochemical refining and manufacturing complex. Models were developed that indicated the extent to which job-related injuries affected the duration of subsequent accident-free periods prior to another accident. Results indicated that a worker's job category and cumulative accident history as well as characteristics associated with previous accidents reliably influenced accident propensity. The tendency to be involved in accidents was unrelated to seasonal or weekly influences. Results are discussed in terms of the relative magnitude of various system factors on accident liability. It is anticipated that the theoretical and analytical techniques employed will be useful in developing strategies for clarifying the mechanisms through which workers perceive, assess and respond to danger in the workplace and enhancing decisions with regard to the targeting of prevention efforts.

Background: Farming is an hazardous occupation. The underlying determinants of farm injury are not well understood among adolescent populations, particularly from a gender lens. Objectives: (1) To evaluate the association between gender and occupational health and safety practices reported for hazardous work among working adolescent farm children; and, (2) to evaluate the association between use of such practices and time to farm injury, and also whether such associations vary by gender. Methods: Survey data from an existing farm injury cohort were available for analysis. Occupational health and safety practices were: non-use of personal protective equipment, non-use of training and supervision for work with heavy equipment, non-use of training and supervision for work with large animals, and conduct of hazardous tasks. Logistic regression was used to examine associations between gender and use of safety practices, and Cox regression was used to examine relationships between occupational health and safety practices and time to first injury. Results: Girls reported increased odds for the non-use of personal protective equipment (adjusted OR 2.39 [95% CI: 1.16, 4.94]). There was no evidence of an association between gender and the conduct of hazardous tasks (adjusted OR 0.69 [95% CI: 0.28, 1.73]). Gender patterns surrounding non-use of training and supervision for work with equipment (adjusted OR 2.38 [95% CI: 0.53, 10.66]) and with animals (adjusted OR 1.52 [95% CI: 0.75, 3.06]) were not significant. Use of personal protective equipment (adjusted HR 1.25 [95% CI: 0.76, 2.06]) did not significantly reduce the risk of farm injury, neither did use of training and supervision during equipment work (HR 1.25 [95% CI: 0.69, 2.28]), nor during animal work (HR 1.06 [95% CI: 0.59, 1.92]), or the conduct of hazardous tasks (HR 1.04 [95% CI: 0.67, 1.63]). Further, there was no significant modification of these associations and injury by gender. Conclusions: Among adolescents, farm occupational health and safety practices appear to vary by gender. Girls on farms report fewer exposures to hazards, and receive less training and supervision and less use of personal protective equipment, consistent with assigned tasks. While gender appears to play a role in the assignment of farm tasks and occupational health and safety practices, these practices did not reduce the likelihood of subsequent injury. As well, the latter associations did not appear to vary by gender. A public health approach that recognizes gender as a determinant of hazardous farm exposures and associated occupational health and safety practices is needed. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2010-09-19 19:25:41.479

No description available.

A continuing challenge in occupational hygiene is that of estimating exposure to the multitude of airborne chemicals found in the workplace and surrounding community. Occupational exposure limits (OELs) have been established to prescribe the acceptable time weighted average for many different chemicals. Comparing the OELs to the measured workplace concentration allows occupational hygienists to assess the health risks and the need for control measures. Hence, methods to more effectively sample contaminants in the workplace are necessary to ensure that accurate exposure characterizations are completed. Evacuated canisters have been used for many years to collect ambient air samples for gases and vapors. Recently, increased interest has arisen in using evacuated canisters for personal breathing zone sampling as an alternative to sorbent samplers. A capillary flow control device was designed at McGill University mid 1990s. The flow control device was designed to provide a very low flow rate to allow a passive sample to be collected over an extended period of time. This research focused on the development and evaluation of a methodology to use a small canister coupled with the capillary flow controllers to collect long term time weighted air samples for gases and vapors. / A series of flow rate experiments were done to test the capillary flow capabilities with a 300 mL canister for sampling times ranging from a few minutes to over 40 hours. Flow rates ranging from 0.05 to 1.0 mL/min were experimentally tested and empirical formulae were developed to predict flow rates for given capillary geometries. The low flow rates allow for the collection of a long term air sample in a small personal canister. / Studies to examine the collection of air contaminants were conducted in laboratory and in field tests. Air samples for six volatile organic compounds were collected from a small exposure chamber using the capillary-canisters, charcoal tubes and diffusive badges at varied concentrations. The results from the three sampling devices were compared to each other and to concentration values obtained by an on-line gas chromatography. The results indicate that the capillary-canister compares quite favorably to the sorbent methods and to the on line GC values for the six compounds evaluated. / Personal air monitoring was conducted in a large exposure chamber to assess the effectiveness of the capillary-canister method to evaluate breathing zone samples. In addition, field testing was performed at a manufacturing facility to assess the long term monitoring capabilities of the capillary-canister. Precision and accuracy were found to parallel that of sorbent sampling methods. / The capillary-canister device displayed many positive attributes for occupational and community air sampling. Extended sampling times, greater capabilities to sample a broad range of chemicals simultaneously, ease of use, ease of analysis and the low relative cost of the flow controller should allow for improvements in exposure assessment.

The work describes the results obtained following the development and testing of a new device used to measure ventilation efficiency for indoor air quality (IAQ) in office buildings. The method uses concentration data obtained by the repeated injection of CO$ sb2$, used as a tracer gas simulating human respiration. The device measures the efficiency of the ventilation in reducing and evacuating pollutants. Ventilation efficiency was measured in a test chamber and was demonstrated in an office building. The method was tested to determine if it responded well to the effect of air flows, air velocities, air temperatures, number of diffusers and room temperatures. Results compared well with the theoretical predictions obtained from a two-chamber compartment model and could be predicted using simple regression models (r = 0.85). The work concludes that the new method can be used to measure ventilation efficiency and a chart is proposed for using the method with respect to recommended outdoor air flow rates in an office.

The purpose of this research is to examine the effectiveness of the Bill C-45 amendments to the Criminal Code in addressing workplace fatality incidents. This research involved both qualitative and quantitative research and utilized two research methods. The first method involved a secondary analysis of thirty-eight Incident Investigation Reports completed by WorkSafeBC. These were supplemented with additional case information about these incidents provided via the Freedom of Information offices in British Columbia. The second method utilized nine semi-structured interviews with respondents in the field of occupational health and safety and corporate criminality who were familiar with the Bill C-45 amendments. The study found that employers could be found liable in half of the cases examined; that there appeared to be unique characteristics of British Columbia that effect the use of criminal charges; that the criminal law is not very effective in cases of criminal negligence for workplace fatality; and that improvements could be made to the criminal law.

Sampling methods used for the assessment of exposure to volatile organic chemicals (VOCs) in the workplace or for environmental studies are now limited to an upper integrative sampling time of 24 hours or less. Generally, these methods lack versatility and are difficult to use. A passive sampler that can extend sampling periods was developed as part of this research. This novel sampler relies on capillary tubes to restrict and control ambient air entry into an evacuated sample container. / A mathematical model was derived by modifications to the Hagen-Poiseuille and ideal gas laws. This model defines the relationship between container volume and capillary geometry (length/internal diameter) required to provide selected sampling times. Based on theoretical considerations, simulations were performed to study the effects of dimensional parameters. From these results, capillaries having 0.05 and 0.10 mm internal diameters were selected according to their ability to reduce sampling flow rates and to increase sampling times. Different capillary lengths were tested on various sampler prototypes. It was found that a constant sampling flow rate was delivered when a maximum discharge rate was established under the influence of a pressure gradient between a vacuum and ambient pressure. Experimental flow rates from 0.018 to 2.6 ml/min were obtained and compared with model predictions. From this comparison, empirical relationships between capillary geometry and maximum discharge rate given by the pressure gradient were defined. Essentially, based on these empirical relationships, capillary sampling flow controller specifications can be calculated to offer extended integrated sampling periods. On this basis, sampler prototypes were configured for stationary sampling and personal sampling. / Studies, based on theory, have indicated that factors such as temperature, humidity and longitudinal molecular diffusion are not likely to influence the passive sampling process. Subsequent experiments confirmed that temperature changes should not significantly affect flow rates delivered by controllers, and that molecular diffusion does not have any impact on the representativeness of long-term samples. Recovery tests provided acceptable results demonstrating that selected capillaries do not contribute to adsorption that could seriously affect the validity of this sampling approach. / Field demonstration studies were performed with both stationary and personal sampler prototypes in the indoor and outdoor environments. The performance of the sampler compared favorably, and in some instances, exceeded that of accepted methodology. These novel samplers were more reliable, had greater versatility and principally, allowed sampling periods extending from hours to a month. These inherent qualities will assist industrial hygienists and environmentalists in the study of emission sources, pollutant concentrations, dispersion, migration and control measures. This novel sampler is presently the only device available for the effective study of episodic events of VOC emission. / Selected capillary geometries acting as a restriction to the entry of ambient air into evacuated sample container can provide a simple, versatile and reliable alternative for the collection of VOCs. This approach can contribute to a better understanding of VOC effects on human health and the environment.