University of Kentucky
Collaborators: Dr. Steven Browning, Dr. Wayne Sanderson, Dr. Terry Bunn
Excessive noise exposure, a critical workplace hazard affecting more than 22 million workers (Tak et al., 2009), is a largely preventable hazard that can lead to Occupational Hearing Loss (OHL) (NIOSH, 2024). Despite the safety and regulatory protection measures that have been implemented to protect workers from OHL, the all-industry prevalence of OHL has yet to decline (Masterson et al. 2015). A cross-sectional analysis was conducted on OHL workers’ compensation First Report of Injury (FROI) data between 2005-2019 from Kentucky to uncover demographic, situational, and temporal trends of OHL FROI in Kentucky and further discern characteristics of OHL burden (n=1125). As Kentucky has high Manufacturing and Mining employment, both industries that consistently have high OHL incidence, this study attempts to ascertain worker groups that are more vulnerable to OHL (Bureau of Labor Statistics, 2023a; Masterson et al., 2015; Masterson et al., 2023). The average age in OHL FROIs was found to be 52.75 years ± 9.47, and 90.40% were male. 966 employees (85.87%) lost time due to OHL, and more employees that reported traumatic hearing loss lost time (p<0.0001). In line with previous literature, the rates of OHL FROI were highest in the Mining, Quarrying, and Oil and Gas Extraction (122.6 per 100,000 workers, 95% CI: 109.8, 136.5) and the Transportation and Warehousing (13.1 per 100,000 workers, 95% CI: 11.34, 15.06) industry. Construction and Extraction Occupations had the most OHL FROI (n=328). Between the 2005-2019 period, a reporting peak was identified in 2014 with 143 FROI. Workers’ compensation has been found to be a gross underrepresentation of OHL incidence (Masterson et al. 2023), meaning that better hearing safety practices need to be implemented to prevent further OHL.
University of Cincinnati
Collaborators: Kermit Davis
Work-related musculoskeletal disorders (WMSDs) continue to plague the manufacturing sector of industry1. To resolve this challenge, firms have pursued solutions, such as job rotation with about 40% adopting it as a permanent measure (Jorgensen et al., 2005)4. The effectiveness of the rotation scheme is dependent upon the amount of biomechanical stress alleviated across various body regions. One immediate indicator of effectiveness would be body discomfort across the shift as the worker rotates from job to job.
Work-related discomfort is a serious concern in physically demanding jobs, resulting in decreased productivity and potentially a leading indicator of more serious WMSDs2. Job rotation is a basic ergonomic intervention that attempts to reduce the stress on the worker by changing jobs throughout the day3. However, to date, it is unclear whether job rotation is effective in reducing the risk and discomfort of the worker. The objective of the study was to evaluate whether job rotation schemes can effectively control or even reduce discomfort throughout a work shift.
The research team evaluated 24 manufacturing workers during an 8-hour shift as they rotated among 4 different jobs (e.g., every 2 hours). Each worker had their own job rotation scheme. An ergonomic assessment of each job was completed that included the LIFFT, DUET, and the Shoulder Tool assessments. Further, a body discomfort survey was completed at baseline and at the end of each job (prior to rotation) that assessed the discomfort of neck, left/right shoulder, left/right elbow, left/right wrist, low back, upper back, right/left hip, right/left knee, and right/left ankle. Discomfort levels were recorded on a 0 (none) to 10 (unbearable) Likert scale. A one-way ANOVA was utilized to test the effect of job rotation on each of the body discomfort areas.
Baseline discomfort was the highest in many of the body parts, indicating workers had a pre-condition of starting the shift with some discomfort. On average, the workers discomfort was in the mild range (around 2) across all body parts for all four jobs within the rotation schemes. While there was not a completely linear increasing trend for discomfort in most body parts, several body parts did have increases for later jobs (e.g. low back, upper back, hips, elbows, and wrists. As such, this may reflect that some jobs had varying levels of stress for specific body regions, resulting in the non-linear relationship. Although not the focus of the current results, the research team is investigating the risk for lower back, hand/wrist, and shoulders using fatigue failure assessment tools to determine whether the ergonomic risk may be driving the discomfort directly.
Based on the results of this preliminary assessment, job rotation appears to be marginally effective in controlling the discomfort across the body for the worker throughout the day. For some workers, discomfort was not an issue, but many had discomfort throughout the day and even started with elevated discomfort. Further research analysis is being done to investigate the role of ergonomic stress in the development of body discomfort.
University of Cincinnati
Collaborators: Amour Dondi, MS, Yevgen Nazarenko PhD, Kemit Davis, PhD
Background: Tobacco smoke poses a significant health risk, contributing to heart and lung diseases. In the United States, secondhand smoke leads to about 35,000 deaths each year. Home healthcare workers are particularly at risk due to the lack of smoking restrictions in private residences. While high-efficiency air purifiers might help reduce this exposure, their effectiveness remains uncertain.
Methods: This study used an environmentally controlled chamber to simulate workplace conditions and assess the effectiveness of air purifiers in removing smoke aerosols. Mannequins were used to represent the patient and caregiver. Smoke-aerosols were generated by a lit cigarette at three positions: left, right, and center relative to the patient. Three conditions were tested: no air purifier, TruSens Z-3500 air purifier, and TruSens Z-7000 air purifier. Two real-time measuring instruments were used to measure smoke particles: P-Trak and the Optical Particle Counter. Measurements were taken for 10 mins during smoke generation and a further 10 mins after the smoke has been extinguished. Smoke aerosol particle concentration was analysed for each scenario, and the performance of the air purifiers was evaluated.
Results: The highest mean particle concentration was observed under “no purifier” condition and the least observed with TruSens Z-7000. Mean particle concentration was highest when the position was “center”. Complete smoke clearance could not be achieved within 10 minutes of extinguishing the smoke. The decay rate was highest with the Z-7000 purifier and lowest under the “no purifier” condition. Smoke particles showed a relatively homogenous distribution. Decay did not commence until approximately 2-3 mins after the removal of the smoke source.
Conclusion: In most cases, air purifiers can reduce overall exposure by 1% to 50%, assuming one cigarette is smoked per hour. Typically, filters improve air quality in the room during the emission period and for the following hour. However, in a well-ventilated room, air purifiers might inadvertently increase exposure to caregivers while the source is present. In this study, the cigarette burned more slowly than it would during actual smoking because we did not replicate the inhaling and exhaling process, so the data may not accurately reflect real cigarette emissions.
Keywords – secondhand smoke, air purifiers, Nanoscan, P-Trak, Optical Particle Counter.
Michigan State University
Collaborators: Dawn P. Misra
Background: Preterm birth (PTB) contributes significantly to infant mortality and morbidity among Black infants. Prenatal workplace exposures and experiences have rarely been studied among Black women. Our aim was to examine the role of work conditions (work hours, job loss) on the odds of PTB among Black women.
Methods: We used data from the Life Course Influences of Fetal Environments (LIFE) retrospective cohort study of Black women in Metropolitan Detroit, Michigan. We restricted our study to the 695 employed during pregnancy. We used multivariable logistic regression analyses to determine the role of work conditions on the risk of PTB and to adjust for the potential covariates. On a multiplicative scale, we explored effect measure modification for each potential effect modifier (psychosocial factors and experiences of racism) by adding an interaction term to the regression models. Results are presented as odds ratios (OR) and 95% Confidence Intervals (95% CI).
Results: 104(15.0%) of the participants had a preterm birth. In adjusted models, working more than 40 hours per week was positively associated with PTB risk (aOR = 1.34; 95% CI: 0.86, 2.25). Women who faced job loss were at a lower risk for PTB (aOR = 0.78; 95% CI: 0.42, 1.45). However, these associations were not statistically significant. Social support modified the prolonged work hours(more than 40 hours/week)-PTB association (prolonged hours*social support p = 0.06), such that working for prolonged hours was associated with increased odds of PTB (aOR = 1.89; 95% CI: 1.05, 3.41) among women with low social support.
Conclusion: Our results suggest that working for prolonged hours and job loss may increase PTB rates in Black women. Evidence of interactions between prolonged work hours and social support suggests that impacts are intertwined. Findings highlight the need to develop social and economic policies focused on accommodation reforms that will improve the livelihood of Black pregnant women in the workforce.
PTB: Preterm birth; OR: Odds ratio; aOR: Adjusted odds ratio.
University of Michigan
Collaborators: Dr. Xiangyu Peng, Prof. Leia Stirling
Robotic exoskeletons are being developed and tested for reducing musculoskeletal injury in the workplace. Exoskeletons can be passive (i.e. with no powered components) or active (i.e. with powered components). While active exoskeletons have the ability to dynamically support the user, there are challenges in usability when the control schemes assume an ideal user. The elbow exoskeleton we are using relies on muscle activation to trigger the controller and assumes a person will relax their muscle when they do not want to flex or extend. However, this relaxation can be difficult for new users, particularly at positions where relaxation would be impossible without exoskeleton support, causing inconsistencies between the intended movement predicted by the control scheme and their real intended movement. To enhance the predictive element of these control schemes, this research uses the contact force between the user’s forearm and the exoskeleton to disambiguate movement intention from relaxation difficulty. We are developing a method to use the force data to disambiguate muscle activation data when we detect inconsistencies between the muscle data and the movement. For example, when there is high bicep activity but no movement, we use the force sensors to determine if the intent is to move up or to hold current position. With this updated control algorithm, we can evaluate how to enhance usability of the exoskeleton with users who may not match the behavior assumed by a solely muscle activation-based control scheme. This enables exoskeletons to be used more effectively in the workplace with less training, thus reducing worker musculoskeletal load and musculoskeletal injury, and supporting return-to-work.
University of Michigan
Collaborators: Leia Stirling
Upcoming Lunar and Martian exploration extravehicular activity (EVA) will require crew to perform field geology to accomplish overarching mission science goals. To support crew during science operations, technological work aids are currently in the process of being developed. However, deploying novel technologies inherently changes the characteristics of a work domain, which may introduce undesired work demands on operators, leading to an increased risk of occupational injury. In this study, terrestrial field geologists were interviewed to derive human-centered engineering design requirements that help guide ongoing system development efforts in order to mitigate the human spaceflight risks of adverse mission outcomes due to Earth independent human-systems operations and risk of injury and compromised performance during EVA operations. Semi-structured interviews were conducted with currently practicing field geology experts (n=8) who specialize in domains that align with NASA’s science goals in order to (1) characterize the constraints, goals, and current operations of Earth-based geological fieldwork, (2) characterize the mental models geologists use for operational decision making, and (3) collect feedback on use cases of work aids and function allocations between human and robotic agents. A qualitative analysis was conducted on interview transcripts to generate a codebook and synthesize themes to address each overarching study objective. Synthesized themes were used to support the creation of (1) an abstraction hierarchy for the terrestrial field geology work domain, (2) decision diagrams for critical field geology operational decisions and (3) user need statements generated from use case discussions. Key findings from this study revealed various decision-making influences on field geology operations and produced a set of preliminary human-centered engineering design requirements derived from geologist need statements. Design requirements can be adopted by analogous systems to those presented in the use cases to improve future human health and performance during planetary science operations.
University of Cincinnati
Exposure to spaceflight causes many physiological changes. These changes have the potential to expose astronauts to adverse effects from drugs as a result of altered distribution, metabolism and clearance. We are developing a physiologically-based pharmacokinetic model to evaluate the effects of microgravity on drug disposition for all medications on the exploration candidate formulary.
The University of Michigan School of Nursing
Faculty Mentor: Heather Banules MSN, RN, FNP
Residency Faculty: Laura Gultekin, PhD, FNP-BC
Background/Purpose:
Greater awareness over the importance of concussion assessment has grown in recent decades. Many pathophysiological pathways can be part of the symptomology of concussion making the assessment process challenging. The inclusion of various signs and symptoms in the diagnostic pathway has also remained disputed, and many providers remain unfamiliar with the most up-to-date recommendations. Despite improvements in concussion diagnosis among other populations, the working adult population remains understudied.
Design:
The main objective of this project is to form a policy recommendation about concussion assessment and diagnosis in OHS. This policy allows stakeholders to provide input about change options and to provide opinions about influential factors. Additionally, beliefs and practices of stakeholders are also considered as a supplement to the policy recommendation to lay the foundation for the successive stage of this project.
Methods:
Interviews and informal discussions among stakeholders were conducted to collect ideas and opinions. Clinicians and other relevant persons were also provided with change options. Themes have been distilled from their discussion and input.
Results:
The series of discussions and interviews yielded several important themes. These included: merits of developing a guideline tool, negative impact of prolonged time off work, crucial areas to include in concussion diagnosis, confusion among the types of clinical sites involved, and the existence of several relevant clinician clusters.
Conclusions/Implications:
Currently no common set of concussion guidelines exist in OHS. Based on stakeholder input, a moderate change is recommended to build an informal guideline tool for concussion diagnosis to be done in consultation with three identified clinician clusters. As this project is the first stage of several, basic ideas for guidelines are proposed and projections for the goals of future stages are offered. These will be shared with impacted parties including the successive DNP student that will continue the project lifespan.
University of Cincinnati
The rise of nano- and microplastics (NMP) in the environment is a growing concern, but little is known about occupational exposure to airborne NMP and how it differs from environmental exposure. Research has shown that airborne NMP concentrations near plastic manufacturing can be much higher than ambient levels, yet the health risks and specific exposure levels to workers remain underexplored. Common plastics, often containing harmful chemicals like BPA and phthalates, are linked to health issues, but there are no established occupational exposure limits for airborne NMP. Therefore, there is an urgent need for a protocol to capture, identify, and quantify airborne NMP to accurately estimate worker exposure.
Current methods, like Raman micro-spectroscopy, can detect and quantify airborne NMP larger than 1-2 microns, but the respirable fraction of airborne NMP (smaller particles) remains poorly understood. To address this, we will adapt a method from the National Institute for Occupational Safety and Health (NIOSH) for respirable crystalline silica analysis to quantify respirable airborne NMP, using 3D printing as a model process. The pilot study will focus on three common plastics (PLA, ABS, and PETG), testing if direct-on-filter (DoF) Raman analysis can distinguish and quantify exposure to each plastic. Success in this approach would help identify sources of respirable airborne NMP, aiding future studies of short-term and chronic occupational exposure.
University of Michigan - Ann Arbor
The purpose of this pilot study is to evaluate the usability and impact of a passive low-back exoskeleton during simulated Emergency Medical Services (EMS) tasks. Usability in this context refers to the effectiveness, efficiency, and satisfaction of using the exoskeleton while performing physically demanding EMS-related activities. The study aims to address the high prevalence of musculoskeletal injuries among EMS providers by assessing the feasibility of integrating exoskeleton devices into their workflows. A total of 30 participants will be recruited to perform five standardized EMS tasks: stair climbing with gear, CPR, manikin dragging, backboard lifting, and barbell stair climbing. Each participant will complete three rounds of tasks while wearing the exoskeleton, with breaks between rounds. Following the final task sequence, participants will complete validated surveys assessing usability, perceived exertion, and discomfort, including the Technology Acceptance Model (TAM), Rate of Perceived Exertion (RPE), Rate of Perceived Discomfort (RPD), and NASA TLX scales. Observational data and participant feedback will be recorded to evaluate the device’s performance in terms of comfort, task efficiency, and user satisfaction. The study aims to provide valuable insights into the feasibility and challenges of implementing exoskeletons in EMS settings. The findings will contribute to a broader understanding of how supportive technologies can enhance EMS occupational safety. Impact Statement By exploring innovative strategies to prevent injuries and improve the physical well-being of EMS providers, this study aims to contribute actionable solutions for enhancing EMS occupational safety.
University of Michigan
Collaborators: Seunghyeon Yang, University of Alabama at Birmingham; Justin Leach, University of Alabama at Birmingham; Jonghwa Oh, University of Alabama at Birmingham
Long-term, excessive exposure to hand-arm vibration (HAV) from hand-powered tools, such as grass trimmers, may induce adverse neurological, vascular, and muscular health effects, collectively known as hand-arm vibration syndrome (HAVS). Nevertheless, there is currently no standard to quantify the musculoskeletal health of HAVS. The study aims to assess the feasibility of using Myotonometry as a non-invasive quantitative health indicator for muscular disorders induced by HAV. The study measured PS of APB muscle by the myotonometer (MyotonPro, Myoton, Tallinn, Estonia) among 17 groundskeepers and 10 office workers. For each study participant, the PS measurement was scheduled prior to the start of a work shift on each of 3 monitoring days within a week. The three-day average PS of APB for each study participant was then calculated. To compare the three-day average PS of APB between groundskeepers and office workers for both hands, a two-sample t test with unequal variance was used. The three-day average PS of APB muscle for right and left hands was 509.7 N/m (range 402.2-752.9 N/m) and 501.7 N/m (range 380.4-660.7 N/m), respectively, among groundskeepers, while 422.0 N/m (range 365.0-517.2 N/m) and 430.3 N/m (range 359.2-591.9 N/m) for right and left hands, respectively, among office workers. Significant differences of 87.7 N/m (p-value=0.002) and 71.4 N/m (p-value=0.019) for right and left hands, respectively in PS between groundskeepers and office workers were observed, supporting using myotonometry as a promising health indicator for muscular disorders induced by HAV. More studies are needed to explore the potential association between HAV exposure and PS measurement using myotonometry among groundskeepers in the future.
University of Cincinnati
Collaborators: Yevgen Nazarenko
Indoor air quality (IAQ) is important for health, productivity, and comfort, yet maintaining adequate IAQ while optimizing energy efficiency remains a challenge. Energy Recovery Ventilators (ERVs) offer a solution by reducing energy consumption while improving ventilation. However, their impact on nanoparticle emissions and IAQ remains poorly understood. This study evaluates the influence of ERVs on nanoparticle generation, circulation, and potential cross-contamination. Five ERVs (ERV1–ERV5) were tested under controlled conditions inside a Thermo Scientific™ Class II Biological Safety Cabinet to eliminate background particle interference. Prior to testing, all units underwent a 24-hour pre-initialization phase at maximum power to remove manufacturing residues. Aerosol emissions were measured using a TSI Fast Mobility Particle Sizer (5.6–560 nm) and a TSI Optical Particle Sizer (300 nm–10 µm), capturing real-time data at low, medium, and high power levels. Results indicate that ERVs contribute to nanoparticle emissions, with variations in total aerosol particle concentration across power settings. Additionally, evidence of aerosol generation due to internal wear and potential cross-contamination between air streams was observed. These findings highlight the need for improved ERV design to minimize unintended particle emissions and enhance IAQ. The study provides insights for optimizing ERVs to balance energy efficiency with air quality improvements in indoor environments. Results from this study will also help manufacturers design a new generation of ERV systems that provide better indoor air quality.
University of Illinois at Chicago
Collaborators: Margaret Sietsema, PhD
Annual fit testing confirms a respirator provides adequate protection to a worker at the time of testing, but does not guarantee stable fit during point of use in the workplace. Current instruments, limited by their size, weight, rudimentary data logging, and reliance on external power, cannot assess fit during actual use. This study introduces the OmniCount by TSI, Incorporated, designed to provide real-time, in-situ respirator fit measurements. Our objectives were to evaluate the OmniCount’s ability to detect respirator leakage, identify which activities most accurately predict overall simulated workplace protection factor (SWPF) fit, and examine how the respirator fit changes over time. The SWPF study was conducted with 19 participants performing 15 tasks of varying intensities, repeated twice. Participants were divided into groups with and without intentional leaks. The leaks were created using a Y-valve that allowed 25% of ambient air particles into the mask. Using Welch’s t-test, significant differences in both activity-specific and overall SWPFs were observed between groups (p < 0.05). Spearman’s Rank Correlation identified five of the fifteen activities as strong predictors of fit: bending over, p = 0.01; facial expressions, p = 0.02; loading and unloading a cart, p = 0.04; army crawl, p = 0.01; and assessing a manikin, p = 0.04. The current study confirms the OmniCount’s ability to assess respirator fit changes in real time and under physical exertion, enabling its use in future workplace protection factor assessments.