There has been recent interest in the possible carcinogenic potential of vegetable fibers (plant fibers) containing amorphous silica. These fibers referred to as Biogenic Amorphous Silica Fibers (BAS) are the normal constituents of number of plant species such as sugar cane, wheat, barley, oats, rice etc. Exposure to fibers within the respirable range has been documented during sugar cane and rice farming and processing operations. Some studies have suggested that such exposure could increase the risk for lung cancer while others have suggested the contrary. In countries like India, sugar cane farming is the major occupation in a number of provinces. A large workforce is involved in its farming and processing. In order to investigate the risk for lung cancer among one such population in Western Maharashtra, we carried out a hospital-based case-control study in the region. As part of this study we measured the exposures to BAS fibers during the harvesting of the sugar cane and the processing of the cane in the mills. / Cases of lung cancer were ascertained from 6 cancer treatment centers and matched to controls who had other types of cancers on age, sex, area of residence and timing of diagnosis. After controlling for potential confounding variables such as smoking, asbestos exposure, family history of lung cancer, income, education and farming of other crops, the risk for lung cancer was elevated in workers involved in the farming of the sugar cane, Odds ratio (OR) 1.92; 95% Confidence Interval (CI) 1.08--3.40. Specifically, the risks were elevated for those involved in the preparation of the farm (OR: 1.81; 95% CI: 0.99--3.27) and in the burning of the farms after harvesting (OR: 1.82; 95% CI: 0.99--3.34). Risks were moderately elevated for those involved in the harvesting of the crop (OR: 1.41; 95% CI: 0.70--2.90) and in the processing of the crop in the sugar mills (OR: 1.70; 95% CI: 0.20--12.60). Smoking modified the relationship between sugar cane farming and lung cancer. Sugar cane farmers who smoked had a 6-fold higher risk compared to those who never farmed and did not smoke. / Environmental measures both during harvesting and processing of the crop in the mills showed exposure to vegetable fibers. Some of these fibers contained silica and resembled BAS fibers in morphology. However a majority of the fibers lacked mineral content and were unlikely to be those of BAS. / The epidemiological study showed increased risk for lung cancer among sugar cane farmers but the limited exposure data did not show high concentration of BAS fibers. The role of polynuclear aromatic hydrocarbons and crystalline silica in particular needs to explored in future studies.

<p> In the spring of 2012, based on recommendations from the International Commission on Radiological Protection (ICRP), the Nuclear Regulatory Commission (NRC) proposed three amendments to reduce current radiation exposure limits for radiation workers. The NRC proposals have caused some concern within the radiopharmaceutical industry. The regulatory changes may affect the ability of radiopharmacy workers to remain on the job, thereby inflicting additional costs to radiopharmacies if they are required to replace workers who have reached their yearly exposure limits. </p><p> This research sought to determine whether or not the new regulatory proposals will in fact have a financial impact on the radiopharmaceutical industry. This research was a retrospective case study that analyzed four radiopharmaceutical production facilities and their employee radiation exposure reports. Results of the study suggest that the NRC's proposed amendments to reduce radiation levels will not have a great adverse effect, either financially or from an employee exposure standpoint, on the current radiopharmacy system. The research demonstrated that existing as low as reasonably achievable (ALARA) standards have resulted in radiopharmacy workers receiving exposures well below the current limits, and within the NRC proposed limits. Of 77 employees studied over a 10 year period, only seven employees (9 %) would have been removed from the production process for overexposure to any one of the NRC's proposed limits. However, this research reviewed small a subset of four radiopharmacies and did not examine other industries and professions utilizing ionizing radiation.</p>

<p>U.S. Army Regulations require soldiers to be fit, as excessive weight negatively impacts their readiness, health, and morale. A quantitative study examined if personal, behavioral, and/or environmental factors predict a soldier&rsquo;s self-efficacy and body mass index. Data were obtained from 117 soldiers on 6 scales: the Armed Services Vocational Aptitude Battery, the Army Physical Fitness Test, the General Self-Efficacy Scale, the Stress Management Questionnaire, the Lifestyle Assessment Inventory, and the Multifactor Leadership Questionnaire. Multiple regression analysis was used to determine if personal (intellectual capabilities and physical fitness), behavioral (lifestyle and stress management), and/or environmental (supervisor leadership) factors predict self-efficacy and body mass index in a convenience sample of battalion personnel. The analysis showed that lifestyle and stress management behavioral factors predict self-efficacy, whereas physical fitness predicts body mass index. In addition, there were significant correlations between self-efficacy, personal factors, and behavioral factors; between personal factors, behavioral factors, and body mass index; and between behavioral and environmental factors. Positive social change implications include the U.S. Army using these findings to promote healthy lifestyles, reduce stress, and increase physical fitness among soldiers to achieve higher self-efficacy and a lower body mass index. These findings also suggest that the military services would see better physical readiness by considering personal, behavioral, and environmental factors to meet standards. </p>

<p> Heat stress due to ambient outdoor temperatures is a workplace hazard that has not been well studied or characterized. The incidence of occupational heat-related illness is unknown. Heat-related morbidity and mortality have been well-studied at the population level, however it cannot be determined if these findings extend systematically to workers exposed to high heat conditions. Remarkably, there is no U.S. federal standard to protect workers from the peril of elevated environmental temperatures and few states have protective regulations. This dissertation research will add to the limited knowledge base of occupational heat-related illnesses, by characterizing worker fatalities due to environmental heat stress. Three independent, but related, research strategies were designed, executed, and completed to evaluate the current research, as well as knowledge gaps, and to thoroughly describe these fatalities based on available information. </p><p> This work was initiated with a thorough literature review to summarize research findings that characterize U.S. occupational heat-related morbidity and mortality and identify gaps in the existing research literature. This review of science, health, and medical databases found that few studies examine ambient heat stress or characterize the incidence of occupational heat-related illnesses and outcomes. Significantly more research examining the heterogeneity of worker and environmental risk factors to heat exposure is needed to identify unsafe working conditions and implement practical, evidence-based heat-stress policies and interventions. The subsequent study describes the epidemiological characteristics of heat-related deaths among workers in the U.S. from 2000 to 2010. Fatality data were obtained at the Bureau of Labor Statistics from the confidential on-site Census of Fatal Occupational Injuries database. Fatality rates and risk ratios with 95% confidence intervals were calculated by year, sex, age group, ethnicity, race, state, and industry. Between 2000 and 2010, 359 occupational heat-related deaths were identified in the U.S., for a yearly average fatality rate of 0.22 per 1 million workers. Highest rates were found among Hispanics, men, the agriculture and construction industries, the states of Mississippi and Arkansas, and very small establishments. This study provides the first comprehensive national profile of heat-related deaths in the U.S. workplace. Prevention efforts should be directed at small businesses, states, industries and individuals who may be at increased risk of heat stress. </p><p> Lastly, to further characterize these fatalities, research was performed to: 1) determine the ranges of heat index and temperature at which workers fatally succumb to environmental heat; 2) identify risk factors that may influence heat-related deaths; and 3) translate these findings to policy recommendations. The Census of Fatal Occupational Injuries and the National Climate Data Center were used to identify worker heat-related deaths in the U.S., 2000- 2010, and to assign a maximum daily temperature and heat index to each case. Demographic, meteorological, and geographical variables were analyzed to evaluate any differences in fatal heat exposure. The National Weather Service temperature alert tools, the Excessive Heat Event warning and the heat index category chart, were utilized to assess community threshold suitability for workers subjected to exertional heat stress. Of the 327 cases that qualified for the analysis, there were no differences found in mean temperatures and heat indexes between the sexes, races, age groups, ethnic groups, and industries. Southern workers died at significantly higher temperatures than workers in the North. This study supports the use of heat index and temperature as a guide when evaluating environmental conditions for workers. </p><p> Population-level heat index threshold alerts are unsuitable for preventing exertional heat stress and new warning systems should be developed. Since heat-related health hazards at work can be anticipated before they manifest, preventive measures can be implemented before illness occurs. With no federal regulatory standards to protect workers from environmental heat exposure, and with climate change as a driver for adaptation and prevention of heat disorders, it is increasing sensible and imperative for the Occupational Safety and Health Administration to take action. National leadership is needed to promulgate regulations, develop new heat alert tools using the heat index as a metric, and promote state-specific occupational heat stress prevention policies.</p>

There are limitations to conventional occupational health and safety research approaches and practices and numerous barriers to overcome in order to achieve progress. Occupational health and safety is impacted by the broader social-political environment. Corporatism affects the directions, ideas and practice of regulators, educators, the labour movement, scientists, medical professionals, and society as a whole, thus inhibiting workers' power to influence change. The thesis therefore explores both the wider influences and barriers to occupational health and safety advances, focusing particularly on the Canadian situation, through the general research questions: What has influenced occupational health and safety policies and practices, especially in Canada? What are some of the limitations of conventional occupational health and safety research and practices? To what extent can participatory action research and mapping address identified limitations? These questions are explored from the perspective of the population potentially at risk. New theories and approaches to occupational health and safety research are then applied in this thesis in order to explore a more specific multi-part research question: Can mapping within worker-based participatory action research be used to explore occupational health and safety conditions? In particular, can mapping contribute to occupational health and safety improvements at a local level and beyond; establish workers' previous exposures for compensation purposes; support efforts to bring about justice through compensation for workers affected by unsafe working conditions; and raise worker and public awareness of health and safety? These questions are explored through two different case studies, which examine, in depth, occupational health and safety action and possible remedies. Casino gaming workers in Windsor, Ontario, Canada undertook a collaborative study to investigate and improve current health and safety conditions. Former Holmes foundry and asbestos insulation workers in Sarnia, Ontario, Canada undertook a collaborative study to provide evidence of exposures and ensuing health problems to support claims for compensation. The outcomes of the case studies shed light on the bigger Canadian health and safety picture and demonstrate that mapping as a data collection method used within a participatory action research approach can accomplish a broad range of objectives. Mapping can raise workers' awareness, facilitate communication, build solidarity and cohesiveness, foster community support, mobilise workers to take action to reduce hazards or win compensation, in turn influencing employers, the compensation board and government agencies. The case studies accomplished the shared objective of raising worker and public awareness. The casino workers also gained occupational health and safety improvements and the Holmes workers were successful in gaining compensation.

The primary consequence of night shift work is a misalignment of the endogenous circadian pacemaker with the inverted sleep-wake cycle. This study evaluated the efficacy of a judicious schedule of light exposure on circadian adaptation to night work. Fifteen night shift workers (mean age +/-S.E.M.: 41.8 +/- 1.8 years) were studied for 3 weeks in their work environments under one of two experimental conditions. Treatment group participants underwent an intervention including bright light in the workplace, while control group participants were studied in their habitual light environments. The efficacy of the intervention was evaluated in the laboratory via constant routines. Following the intervention, treatment group subjects displayed a mean phase delay of (+/-S.E.M.) -9.32 +/- 1.06 hours and full entrainment to the night-oriented schedule while control group subjects displayed a phase delay -4.09 +/- 1.94 hours and a partial entrainment (F(1,30) = 11.33, p = 0.002). The results of this study suggest a means of alleviating the difficulties associated with night shift work with control of the overall pattern of light exposure.

A cohort study was conducted in Montreal (1988--1992) to test whether working in home care as a home maker entails a higher risk of developing low back pain than working in long term care hospitals as a nursing aide; and to investigate which risk factors may contribute to low back pain. Data from 978 self-administered questionnaires were analysed. Home makers suffered more than nursing aides from low back pain attributed to work. The adjusted odds ratios for home makers were: 1.63 (95% CI = 1.03--2.58) for a first episode of low back pain during 1998--1992, 2.43 (95% CI = 1.05--5.60) for disabling low back pain in 1992, 1.51 (95% CI = 1.13--2.02) for ever having low back pain as of 1992. The study subjects were divided into two cohorts, incident (newly hired persons during 1988--1992) and prevalent (at work in 1988 and in 1992). There was an excess risk of low back pain in the incident cohort; none in the prevalent cohort. The risk of low back pain was shown to decrease with increasing age, help to move patients, adequate equipment in the bedrooms, sufficient space in the bathrooms of patients. The risk increased with convalescent post-op patients, transfers of patients, seniority greater than 5 years, delivery of children, need of a patient-lift. Disabling low back pain could be reduced by introducing the following preventive measures: adequate bedroom equipment, help to move patients, training, sufficient space in the bathrooms, less transfers of patients.

Fatigue in the minerals industry of Western Australia is a greatly under-recognised issue that has serious potential consequences for shift workers at work and at home. A review of fatigue literature demonstrates the elusive nature of fatigue. It is something that most people have probably experienced at some time in their lives. It is a diffuse sensation that is accompanied by feelings of lethargy and a lack of interest in any activity. A general sensation of weariness is a major symptom of fatigue. Fatigue cannot be measured directly and subjective estimates have to be relied upon. Potentially life threatening consequences can result when shift workers perform under the influence of fatigue. Fatigue and sleepiness have the power to kill if not treated with the respect they deserve. A cross-sectional survey of five underground mines was conducted to obtain a better understanding of their fatigue risk management strategies and the views of managers and shift workers on their sleep and shift schedules. Four mines provided information on their fatigue risk management procedures. Ten underground mining crews comprising 147 shift workers provided their views by an anonymous survey questionnaire administered at each mine at the start of shift. Shift worker sleep at the five mines compared well with mines in Tasmania, New South Wales and Queensland. However, it was found that frequently waking earlier than intended was the most widely reported sleep concern for shift workers on day shift, night shift and days off. Falling asleep while on day shift and on night shift demonstrates that fatigue is an issue that can occur on day shift as well as night shift. Fatigue is not an issue that is confined to night shift. Mine fitness for work procedures focused primarily on: shift schedules, hours of work and drug and alcohol issues. The level of detail provided on fatigue risk management was considered to be less than adequate when compared with the three previous issues and fatigue risk management documentation sourced from the minerals industry and the transport industry. The survey data and fitness for work procedures provided by four mines suggests that considerably more work needs to be done to recognise and address sleep quantity and quality, as well as sleepiness and fatigue experienced by shift workers while on shift and at home on rest days. There is a serious need for the Western Australian minerals industry to recognise the vital importance of sleep to shift workers during their shift schedule and rest days. There needs to be a concerted and on-going campaign by the industry to raise and maintain the awareness of sleep as a key element in fitness for duty.

No description available.

This work undertook the examination of the perceived barriers that exist to the management of occupational noise exposure in the workplace. Exposure to excessive levels of noise results in cumulative damage to the hearing mechanism of the ear and a subsequent hearing loss. This hearing loss is permanent and does not recover over time. Initially the conventional method of addressing or controlling noise exposure was through Hearing Conservation Programs and more recently through Occupational Noise Management Programs that take more of a risk management approach. However, the numbers of new hearing loss claims submitted through the various ???workcover??? and ???worksafe??? authorities in Australia continue to remain very high. Hearing loss claims rank within the top two in number of new claims each year. The research conducted shows that there are four main barriers perceived by individuals that work against the institution of effective preventive action. These four main barriers in order of priority are hearing protectors, information, culture and management, and are themselves each composed of several lesser factors. Each of the barriers was examined more closely in an attempt to better understand how they operate and the potential to discover how they may be overcome. To briefly summarise the main barriers: 1) Hearing protectors are uncomfortable, impede communication and are unpleasant to wear; 2) Individuals would like more information on noise reduction and for this information to be supplied by management; 3) workplace and management culture needs to be supportive of occupational health and safety in general and with the implementation of supportive preventive measures in particular; and 3) management needs to be seen to place importance on occupational health and safety in the workplace in general and the reduction of excessive noise in particular. By being aware of the barriers and operation the design of future more effective intervention or better noise management programs should be possible.