Background: Nuclear and conventional weapons industry workers are at risk for exposures to beryllium, asbestos, high explosives and barium, all of which are implicated in the pathogenesis of pneumoconiosis. Beryllium has also been shown to cause sensitization (BeS) carrying a risk of progression to Chronic Beryllium Lung Disease (CBD). Data are lacking on the epidemiology of beryllium related health effects in conventional munitions workers and limited studies have been published on the prevalence of BeS in workers with minimal exposure. Data on the prevalence of pneumoconiosis in nuclear weapons workers is also lacking. The main objectives of this study were to determine prevalence and risk factors for beryllium sensitization in former nuclear and conventional munitions workers and rates of and risk factors for pneumoconiosis in former nuclear weapons workers, both cohorts from the Iowa Army Ammunition Plant (IAAAP) in Burlington, IA. Methods: Former nuclear weapons workers were offered chest x-ray (CXR) and blood screening for sensitization with beryllium lymphocyte proliferation test (BeLPT) as part of the Department of Energy (DoE) Former Worker Medical Screening Program. Conventional munitions workers were offered BeLPT and clinical follow-up if sensitized, as part of a Department of Defense (DOD) funded study. Chest x-rays were reviewed by three readers according to the International Labour Organization's Classification system for Radiographs for Pneumoconioses (ILO system). Exposures under study were characterized qualitatively by the industrial hygiene team and based on former worker interviews and historical industrial hygiene records. Results: The prevalence of beryllium sensitization in nuclear and conventional munitions workers was found to be slightly higher than in other workforces and weapons worker populations at low risk for exposure. The prevalence of parenchymal disease was higher in these nuclear weapons workers than in other DoE studies, while the prevalence of coincident parenchymal and pleural and isolated pleural disease was lower than in other nuclear weapons populations. Workers who occasionally dressed the copper-beryllium alloy tools were found to have an increased risk of beryllium sensitization, compared to those in administrative or other jobs with insignificant potential for exposure on site. Exposure to beryllium, asbestos, high explosives or barium was not associated with lung disease in this population. Conclusions: The findings from this study have potential policy implications for DOE and DOD to extend or implement beryllium surveillance and lung disease screening for their workforces and better control use of the copper-beryllium alloy tools in their production processes.

Agriculture workers can be exposed to hazardous concentrations of airborne contaminants such as, particulate matter (PM), carbon dioxide (CO2), and volatile organic compounds (VOCs). Exposure to these contaminants has been associated with a high prevalence of acute and chronic respiratory symptoms: coughing, wheezing, shortness of breath, and phlegm, as well as a reduction in lung function. Commercial low-cost indoor air quality (IAQ) monitors have the ability to detect many of the contaminants commonly found in agriculture. Limited research has been conducted on the performance of low-cost monitors in different occupational settings. Therefore, the purpose of this study was to evaluate whether the Foobot (Airboxlab, San Francisco, CA, USA), a low-cost (IAQ) monitor, is sufficiently robust to operate in agricultural environments and provide useful and accurate information to farmers. Foobots were deployed at two sites, a tractor repair shop (“Shop”) for 43 days and a finishing room in a swine production building (“Barn”) for 40 days, where they monitored PM2.5, CO2, and VOCs. Reference direct-reading monitors to compare Foobot readings were collocated with the Foobots. Paired sample results were compared over 19 days at the shop and 21 days at the barn. At neither of the two sites did the Foobots meet the National Institute for Occupational Safety and Health (NIOSH) acceptable bias criterion of ± 10% when compared to the reference monitors. Linear regression results indicate that a strong linear relationship does not exist (R2< 0.66) between the Foobots and reference monitors. A significant difference (P< 0.031) was found between contaminant concentrations reported by each Foobot but the difference was not found to be substantial. The Foobot CO2 and VOC concentrations were highly correlated (R2=0.99). However, a strong linear relationship between the Foobot CO2 concentrations and the reference CO2 concentrations was not found at the shop (R2 = 0.02) or barn (R2 = 0.61). After 40 days in the barn, the Foobots were reporting that damage had occurred to the sensors and were no longer functioning. In addition, the PM sensors in the three Foobots in the barn were contaminated after the study. Therefore, it was concluded that the Foobots were unable to supply farmers with accurate information and were not durable enough for agricultural environments. Future research will investigate the use of other low-cost monitors in agriculture.

Despite the enactment of hearing protection laws and recommended standards over the last four decades, the prevalence of hearing loss among workers has remained unchanged. Limiting the amount of time spend in high noise areas, as well as wearing hearing protection devices, can reduce the effects of noise on hearing loss. Though research has examined the consistency of use of hearing protection devices (HPD) among workers, the importance of fit, and a real-world comparison to the marketed attenuation needed further examination. The goal of this project is to evaluate the effectiveness of HPDs used by agricultural and industrial workers enrolled in a hearing conservation program by comparing personal attenuation rating (PAR) to the manufacturer’s reported noise reduction rating (NRR). The two study groups were selected since workplaces are required to train workers enrolled in an OSHA Hearing Conservation Program on proper insertion techniques, but farmers do not typically receive any training on using hearing protection unless they are employed elsewhere. The effectiveness of the inserted HPDs were quantified via the 3M E-A-RfitTM Dual Ear Validation System, and the results were compared to the NRR provided by the manufacturer. The fit of hearing protection was evaluated for 60 farmers (247 plug pairs) and 76 workers (275 plug pairs), using four models of earplugs (two formable and two non-formable). The results show that although formable ear plugs have higher reported NRRs, a higher percentage of participants achieved PARs greater than or equal to the A-weighted adjusted NRR-7 for the non-formable plugs.

In order to evaluate a biologically relevant measure of exposure, inhalable samplers are designed to match the aspiration efficiency of the human head. Human inhalability is evaluated in wind tunnel studies using mannequins as human surrogates or using numerical and computational methods. There has been differences between human aspiration efficiency estimates using wind tunnel studies and computational fluid dynamics (CFD) modeling, particularly for larger particle sizes (>68 µm). The objective of this dissertation was to evaluate biases in low velocity inhalability studies in an effort to explain the discrepancies in results between experimental and computational inhalability studies. This research addressed the phenomena of secondary aspiration on human facial skin, evaluated the appropriateness of mannequin surfaces as surrogates for humans, and evaluated the performance of the thin-walled reference sampler in low velocities to quantify potential biases in low velocity inhalability studies. The first study determined a realistic coefficient of restitution (CoR) for human facial skin over a range of ages under nine environmental conditions. This study found human facial skin is non-uniform across the face and identified significant interaction between age and sampling location, indicating that how CoR varies with age is dependent on the location sampled. The second study applied the average CoR values for forehead, cheeks and nose in CFD simulations to evaluate the effect of secondary aspiration on human aspiration efficiency estimates and determine how refined the CoR value needed to be to accurately model human aspiration efficiency. This study identified significant increases in aspiration when allowing for particle bounce, but no significant differences between uniform CoRs of 0.5, 0.8 and 1.0, indicating differences between different mannequin surfaces and particle interactions would have minimal effect on aspiration efficiency estimates. The third study evaluated the performance of a horizontally-aligned reference sampler in low wind speeds (0.1 to 0.4 m s-1). While significant differences from unity were identified, differences ranged from -1 to 6% and would have a negligible effect on sampler efficiency estimates. The use of a horizontally-aligned isokinetic reference sampler was found to be appropriate in freestream velocities ranging from 0.1 to 0.4 m s-1.

This research focuses on injuries from all mechanisms, with particular focus on road traffic injuries in urban Gambia. Data from trauma registries established in two major trauma hospitals were used to address three aims: 1) examine the general characteristics of injured individuals and their injuries, and identify factors associated with discharge status from the hospital emergency room; 2) identify differences in road-user, collision, vehicle, and driver factors, among individuals hospitalized with a road traffic injury; and 3) examine personal, crash, and injury factors associated with transfer status among road traffic injured (RTI) patients, and identify limitations of the current trauma systems that might be improved for more efficient use of resources. Data used for this dissertation were from trauma registries established in two major trauma hospitals in The Gambia: Edward Francis Small Teaching Hospital (EFSTH) and Serrekunda General Hospital (SGH). At intake, the treating physicians and nurses completed an accident and emergency ward survey form for injuries from all mechanisms. For admitted road traffic injured patients (admission more than 24 hours), the road traffic injured admission form is completed. Data about risk factors contributing to crashes and injuries were collected from the patients. At hospital discharge, treating physicians used a 19-item questionnaire to collect data on the discharge status and disability at discharge of road traffic injured patients. Using the trauma registry data from March 1, 2014 to March 31, 2016, we found the leading mechanism of injury was road traffic. For place of occurrence, injuries mostly occur at home and on the road. Assault was higher among young females (19 to 44 years) than males. Males have increased odds for admission and disability due to road traffic injuries. We also found that among admitted road traffic injured patients, injuries to pedestrians, bicyclists, and motorcyclists were higher than other road users. Crashes involved risk factors at person, crash, and environment levels. Head/skull injuries were common, and concussions/brain injuries were higher among pedestrians, bicyclists, and motorcyclists than vehicle occupants. Finally, our results also suggest that vehicle occupants, and professionals/skilled personnel had increased odds of being transferred than directly admitted RTI patients. Fractures/dislocations, and concussions/brain injuries were frequent among transfers. Intravenous fluid was the most frequent treatment administered to patients transferred to the definitive-care hospitals. This project shows that injuries, especially road traffic, create a large burden of injury in The Gambia and the many contributing factors. It also provides evidence that there are many opportunities to intervene at personal, crash, and environment levels. Additionally, creating trauma registries across the country as well as trauma response system will have a greater impact to reduce burden of road traffic crashes in The Gambia.

Inhalation of organic dust, including endotoxin, has been associated with inflammatory response of the pulmonary system. Limited studies have evaluated the work shift effects of endotoxin on respiratory outcomes for workers in the dairy industry, such as spirometry changes. Measurement techniques for exhaled nitric oxide (eNO) have been standardized by the American Thoracic Society (ATS) and used as a biomarker to identify diseases marked with lung inflammation. Dairy parlor workers are known to work long hours in one location with little job variability. The objectives of this study were to quantify exposure concentrations of inhalable dust and endotoxin among dairy parlor workers, evaluate acute cross-shift changes in respiratory status using spirometry, and assess the effectiveness of exhaled nitric oxide for detecting cross-shift bronchial inflammation changes. The cross-sectional study recruited 62 dairy parlor workers from 10 large herd dairy farms across Iowa, Minnesota, Wisconsin, and South Dakota. Data collected before and after the work shifts included spirometry tests, eNO measurements, and pulmonary symptom questionnaires. Personal breathing zone exposure to inhalable dust was assessed during the shift using Button Aerosol Samplers. Gravimetric analysis was used to determine airborne concentrations of inhalable dust and endotoxin concentration was determined using the recombinant factor C assay. Inhalable dust concentrations ranged from 0.09 - 4.95 mg/m3 with a geometric mean of 0.58 mg/m3. Inhalable endotoxin concentrations ranged from 4-1968 EU/m3 with a geometric mean of 117 EU/m3. The study participants pre-shift forced expiratory volume in the first second (FEV1) as a percentage of predicted was an average of 93.4%. Study group cross-shift FEV1 decreased by -1.16%. Six participants with moderate post-shift concentrations of eNO had an average FEV1 cross-shift change of -3.19%. Dairy parlor workers are exposed to concentrations of organic dusts that may adversely impact health. Future studies should test interventions in milking parlors to reduce dust exposure among dairy workers.

The U.S. military currently uses a flag system based on wet-bulb globe temperature (WBGT) and metabolic rate to recommend heat stress exposure limits. This paper addresses the ability of the flag system to recommend safe heat exposures in a non-military population. Two progressive heat stress studies provided data on 528 observations of safe or unsafe exposures of 4 hours over a range of WBGT conditions and metabolic rates using 29 participants wearing woven cotton clothing. For the two studies, range of WBGT conditions was 25 to 42C, and the range of metabolic rates was 100 to 650 watts. These exposures were compared with the flag system’s recommendations of safe exposure to determine the sensitivity and specificity of the flag system. A separate study provided 62 observations with participants undergoing a time-limited protocol at constant WBGT conditions. Observed durations of safe exposure time were compared to the flag system’s recommended safe limits to determine sensitivity and specificity. Based on the progressive protocol, sensitivity and specificity of the flag system for five ranges of WBGT and three categories of metabolic rate were 0.98 and 0.25, respectively. For the time-limited protocol, which applied only to the highest range of WBGT and light and moderate metabolic rate, both sensitivity and specificity were zero. This study suggests that the flag system has high sensitivity but low specificity for long duration exposures, along with low sensitivity and specificity for time-limited exposures. However, the WBGT exposures in the time-limited trials were substantially higher than the threshold for the highest WBGT range in the flag system, which may account for the system’s unexpected performance in the time-limited protocol.

This research explores whether a firm's psychosocial stressors contribute to strains or outcomes important to the organization. The psychosocial stressors chosen for study include: role conflict and ambiguity, workload (qualitative and quantitative), participative decision making, autonomy, and security. Independent variables were the emotional strains of job satisfaction and job commitment. The independent variables for behavioral strains included injury, lost days, workers' compensation claims, and absenteeism. Three moderators: age, gender, and social support were evaluated for interaction effects. The study sampled 77 occupationally injured and 81 non-injured employees from one medium sized Army community hospital. This study uses multivariate hierarchical multiple set regression as its principal analytical method. The hierarchial procedure orders the sets into an a priori hierarchy and enters each set sequentially from the hierarchy, evaluating the increase in $\rm R\sp2.$ The results suggest that psychosocial stressors are significant variables to consider when investigating workers' emotional and behavioral strains. For example, age, participation, and satisfaction were found statistically significant in differentiating between the occupationally injured and the non-injured samples. The study also found that ambiguity, participation, and autonomy influenced emotional strains. Additionally, age and social support appear to moderate the relationship between some psychosocial factors and emotional and behavioral strains. Age moderated the relationship with only emotional strains, while social support moderated both emotional and behavioral strains. Further, social support was found to have a main effect on the emotional strains of satisfaction and commitment, but not on any behavioral ones. Age was found to have a direct effect on the behavioral strains of workers' compensation claims. Finally, although not statistically significant when entered as a set and evaluated using the statistical analysis techniques in this study, a relationship between age and workers' compensation claims and qualitative workload and absenteeism were suggested. The economic and human costs associated with occupational injury are staggering. These findings suggest that attention to psychosocial factors within control of the employer, can promote good management outcomes, improve employee quality of worklife, and contain costs.

Thesis (MPH.) -- University of Limpopo, 2021 / Background Health care facilities are characterised by a high level of exposure to hazardous agents, which significantly endanger the health and life of workers. Occupational hazards, exposure to blood and body fluids accidents and safety precautions constitute an important public health issue. Occupational health is the identification and control of risks arising from physical, chemical, and other workplace hazards in order to establish and maintain a safe and healthy working environment. The high occurrence and burden of occupational hazards in hospitals include sharps/needlestick injuries, contact with blood and body fluids, blood-borne infections, and accidents. Health workers at Letaba Hospital are facing occupational health and safety risk at their workplace. Objectives The objectives of the study were to identify the type of work and related hazards that health workers are exposed to at Letaba Hospital and to find out if health workers at Letaba Hospital are aware of the occupational hazards at the workplace. Methods A quantitative descriptive cross-sectional method was used. The population comprised 649 nurses, doctors, cleaners, kitchen workers, laboratory technicians and laboratory technologists employed at Letaba Hospital. Stratified random sampling was used to select 374 health workers who participated in the study. A self-administered questionnaire was used for data collection. Descriptive and inferential statistics were used for data analysis. Results The study showed that health works, particularly nurses and doctors and nurses are exposed to needle pricks and kitchen workers are exposed to sharps. Cleaners and porters are exposed to slippery floors as well as uneven floors. Laboratory technicians, laboratory technologists and porters are exposed to specimen containers. Health vi workers lack knowledge on the toxic gases available at the hospital. The study also revealed that health workers are aware of the risk of using uneven floors and the risk of using stairs/steps at their workplace. Conclusion The study concluded that health workers at Letaba Hospital experienced physical, biological, chemical as well as psychosocial hazards at their workplace. Keywords Occupational hazards, health workers and occupational health.

Firefighter Emergency Medical Service (EMS) responder personnel are at a high risk for occupational exposures to bloodborne and airborne infectious pathogens due to their unpredictable work duties in the pre-hospital environment. Not much is known about the compliance with Universal Precautions (UP) among firefighter EMS responders' personnel with regards to occupational exposures to infectious diseases. The purpose of this cross-sectional research study was to determine the relationship between compliance with UP, knowledge of UP, attitudes towards UP, occupational practices, and occupational exposures to bloodborne and airborne pathogens to prevent transmission of infectious disease among firefighter EMS responder personnel in the pre-hospital environment. A convenience sample (n = 246, 99% response) was gathered from the 6 career fire service departments in Miami-Dade County Florida. The participants completed a 40-question, self-administered survey questionnaire. Research questions and related hypotheses were evaluated with Pearson's product moment correlation, t test, analysis of variance, and linear regression models. In this study, the correlation between knowledge and compliance with UP was statistically significant (p = 0.005). This suggest that the compliance with UP among firefighter EMS responder participants increased with increase in knowledge. However, firefighter EMS personnel are not consistently complying with UP to prevent exposures to infectious diseases in the pre-hospital work environment. This research contributed to positive social change by increasing innovative knowledge that will allow the firefighter EMS responders to improve occupational practices and compliance with universal precautions.