Journal of Occupational and Environmental Hygiene最新文献

Farming is a noisy occupation, resulting in a high prevalence of hearing loss among agricultural workers. The aim of this study was to improve the accuracy of an automatic algorithm designed to cluster individual sound events into tasks. This work is part of the HearSafe Study, which aimed to increase agricultural workers' use of hearing protection devices by providing personalized information on hazardous noise to workers. Participants in the study interacted with the HearSafe System: a small sound level meter, a website, and an algorithm to associate noise with tasks. They wore the sound level meter that recorded loud (≥ 80 dBA) sound "events," their location, and audio clips. They interacted with the website to view where and when participants were exposed to hazardous noises during the day. To simplify interpretation, an algorithm clustered individual sound events into tasks based on their proximity in time and location. The system's effectiveness hinges on the accuracy of this clustering algorithm. In Phase I, the accuracy was determined using parameters for time between events (2, 5, and 10 min) and distances between tasks (5, 9, and 18 m). In Phase II, the algorithm was refined to account for pauses in work and riding on equipment. Researchers manually clustered events into tasks by listening to the audio clips. Algorithm accuracy was measured as the percentage of events matching the manual clustering. The automating accuracy was improved from 57% with the base algorithm to 87% with the most accurate algorithm (p = 0.02; 10 min between events, 9 m average distance between tasks, and added the condition to combining consecutive tasks that were within 9 m of each other). Increased accuracy in identifying noisy tasks will improve the efficacy of the HearSafe System to communicate when and where use of hearing protection devices are needed among agricultural workers.

This study assessed whether self-rated physical and mental work demands were associated with cognition among older working adults and whether their effects were dependent. The cross-sectional sample consisted of 6,377 working older adults using the Health and Retirement Study in 2004. Self-rated work demands were summarized from four questions about the frequency of mental or physical demands in the respondent's current job. Cognition was assessed using a subset of the Telephone Interview for Cognitive Status. Multivariable linear regression assessed the associations and additive interaction between physical and mental work demands and cognition, adjusted for age, sex, race, education, and practice effect. Independently, higher physical work demands were associated with poorer cognition (change per one unit increase: 0.50, 95% CI: 0.36, 0.65), and higher mental work demands were associated with better cognition (change per one unit increase: -0.31, 95% CI: -0.44, -0.19). The effect of one work demand measure became more negative as the level of the other increased (Beta for interaction = -0.23, 95% CI: -0.43, -0.03). A one-point increase in mental work demands was associated with 0.79 (95% CI: 0.51, 1.08) points higher cognition score when physical work demands were lowest, but was not associated with cognition when physical work demands were highest (0.11, 95% CI: -0.26, 0.48). The highest predicted cognition score was for the highest mental and lowest physical work demands. Results were robust to additional adjustment for health and behavior covariates. The associations of self-rated mental and physical work demands on cognition are dependent. Future studies should strongly consider examining interactions to capture the range of work demand effects.

Workers frequently struggle to acquire, maintain, and use personal protective equipment (PPE) during infectious disease outbreaks. Strategic PPE distribution, guidance, and interventions can help address these challenges, but the effectiveness of these measures depends on timely characterization of how these challenges manifest across the U.S. workforce-data which no U.S. public health surveillance system currently provides. This article describes a mechanism of generating such data by using a machine learning model to detect various PPE concerns in workplace safety complaints submitted to the U.S. Occupational Safety and Health Administration (OSHA). A publicly available dataset of 78,770 OSHA complaints received during the COVID-19 pandemic was used to assess the feasibility of this approach. Results demonstrate that these OSHA complaints contained a substantial variety and number of PPE concerns, and that a machine learning model trained on these data was capable of detecting three types of PPE concerns with at least 90% precision and 90% recall: unavailable or inaccessible PPE, lack of PPE use among workers, and inadequate enforcement of PPE use. Furthermore, analyses of ML-facilitated detections were shown to elucidate national and industry-specific trends in worker PPE concerns. Although further development is needed to accurately detect a broader set of PPE concerns, the results of this study suggest that machine learning can help efficiently repurpose OSHA complaints to generate insightful real-time data on worker PPE concerns during future outbreaks.

Silver-based biocides applied in fabric-based mouth- and nose-covering face masks require characterization due to the potential toxic effects of silver to which users may be exposed. In the absence of reliable silver release data in realistic usage conditions, current safety assessment of face masks relies on a safe-by-design principle. To contribute to the refinement of specifications of safe face masks, types of particulate silver biocides actively applied in face masks on the market were identified and characterized. Ultramicrotomy followed by scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (STEM-EDX) analysis showed that a wide variety of silver-based biocides were applied. This includes metallic silver nanoparticles (NPs), silver salts in NP form, silver ion exchangers, and notably, various silver nanocomposites with other particulate materials such as synthetic amorphous silica (SAS), TiO₂, and ZnO. These composites are added to face masks to combine different modes of biocidal action or to facilitate gradual silver release, thereby extending biocidal activity. In five out of seven silver-containing masks, silver-containing NPs were identified on the surface of fibers. Additionally, significant numbers of other NPs (SAS, TiO₂) were found coating the fiber surfaces. Sizes of silver-containing NPs ranged from 3 to 200 nm across all masks, with the large majority of particles below 50 nm. These findings imply that for safety assessment, no-adverse effect levels of all incorporated compounds should be taken into account and that the effects of co-exposure to multiple compounds should be considered. The completion of particle release studies, exposure assessments, and regulatory oversight of face masks is recommended.

The Cold War provided incentive for radiation geneticists from the United States (U.S.) to offer guidance on scientific/public health issues. A notable case involved the U.S. National Academy of Sciences (NAS) recommendations concerning radiation-related heredity/cancer risk assessment, which have guided regulatory agencies from the 1950s to the present. A neglected, generally unknown, yet important strategic direction, involves influence exerted over the development of secondary school biological education programs in the U.S. With U.S. federal government funding, the American Institute for Biological Sciences (AIBS) led the development of a major revision of secondary school biological sciences' curricula, called the Biological Science Curriculum Study (BSCS), with the first education product widely adopted in 1963. The BSCS textbook content was directed by Arnold Grobman and Bentley Glass, leaders of the academic genetics community, especially those who participated in the Manhattan Project and the NAS Genetics Panel and how they engaged the involvement of the Nobel Laureate, Hermann Muller, to transform the actions of the BSCS committee to create an educational framework in which evolution was the overriding and integrative theme. Muller would ensure that the BSCS curriculum was based on the Dobzhansky rubric that "Nothing in biology makes sense except in light of evolution." Muller also led these geneticists in a failed attempt to integrate "reform" eugenics principles and practices into the BSCS curriculum While Muller's influence on hereditary/cancer risk assessment has been extraordinary, his role in framing what biology students were taught, and how it would influence their concept of life, beliefs about humanity's place in the universe, and how humans could or should direct their evolution, has remained largely unknown.

While the hazards posed by lead in gunshot residues (GSRs) are recognized, little is known about the glove permeation of the organic components. The permeation behavior of the major organic GSRs methyl centralite and ethyl centralite through disposable nitrile glove material was investigated. The compounds were contained in three solvents: Hoppe's no. 9 gun cleaning solvent (GCS), n-decane, and a GCS surrogate, n-decane/ethanol 7:3 (w/w) mixture. The aim was to identify whether ethanol was the key driver of a previously reported carrier effect. A modified ASTM F739-20 method was used for permeation testing at 35.0 ± 0.5 °C with closed-loop n-decane collection solvent without recirculation. Gas chromatography-mass spectrometry analysis facilitated GSR quantification. Significant differences occurred in intrarun but not interrun glove physical characteristics and in analyte permeation for the GCS and its surrogate. The GCS caused a substantial increase in permeation rate before a lower steady state permeation rate (SSPR). In contrast, n-decane/ethanol produced its SSPRs as the maximum permeation rate, but with decreased permeation rates and total permeated analyte mass. n-Decane solvent caused none of the GSR to enter the steady state and exhibited much longer breakthrough times. This study underscores the importance of considering the complete chemical composition of mixtures in assessing their interactions with glove personal protective equipment (PPE) and highlights the need for comprehensive testing protocols in PPE selection. Limitations included the lack of previous research on organic GSR glove permeation and challenges in comparing study results with manufacturer-reported glove resistance data. Adjusted concentrations for analytes and stepwise reconstitution of GCS components are recommended for future investigations. The present research provided insight into the glove permeation behavior of complex chemical mixtures for better glove PPE selection and testing practices.

Noise-induced hearing loss and tinnitus are two of the most prevalent service-connected disabilities of United States military veterans. Educational materials meant for hearing conservation program-eligible Airmen were evaluated from active-duty, continental United States (CONUS) Air Force bases for compliance with US Air Force (USAF), Department of Defense (DoD), and Occupational Safety and Health Administration (OSHA) regulations. Understandability and actionability were assessed using the Patient Education Materials Assessment Tool for Audiovisual Materials (PEMAT-A/V), while readability was assessed with Flesch-Kincaid Grade Level (FKGL). Educational materials were received from 44 of 61 (72%) active-duty, CONUS bases, with 27 bases sending one item and 17 bases sending multiple items, for a total of 67 educational materials, which were evaluated by three evaluators. Educational materials were categorized into one of four types: (A) supervisor's guide to hearing conservation (n = 21); (B) new worker hearing conservation training (n = 20); (C) two-page hearing conservation program training pamphlet (n = 14); and (D) other (n = 12). Overall mean compliance was 84% (CI: 63,100) (USAF), 83% (CI: 62,100) (DoD), and 88% (CI: 67,100) (OSHA), respectively. Overall mean understandability was 75% (CI: 63,87) and actionability was 89% (67,100). There was good agreement between the three evaluators for each of the criteria (87-90%). Overall mean readability was grade level 10.68 ± 1.68 on the FKGL scale. For educational materials, 65 of the 67 (97%) were above the recommended 6th-grade reading level, and 62 of the 67 (93%) educational materials were above the average American 8th-grade reading level. This study established compliance, understandability, actionability, and readability scores for educational materials that military service members receive upon entry into the hearing conservation program, gathered from active-duty, CONUS Air Force bases. Using the determined scores, recommendations, such as providing active feedback and condensing information, were given to improve future hearing conservation educational materials.

As the range of allergens continues to expand and the food industry evolves, there is a growing need for more efficient, affordable, and comprehensive methods to monitor protein exposures. This study aimed to assess the concentrations of inhalable aerosols and soluble proteins (SP) in food manufacturing environments. Additionally, the study sought to optimize the extraction methods for determining SP across diverse food matrices. One hundred forty-six participants from 12 different dry food production facilities were included in the study. The mass of inhalable aerosols was determined using gravimetric analysis, and the concentration of SP was determined using a bicinchoninic acid (BCA) protein assay kit. A mixed-effects Tobit regression model was employed to assess the relationship between aerosol and SP concentrations across different production environments and work tasks. The optimized SP extraction method proved effective across a wide range of powder food matrices, although variability in relative extraction efficiency across matrices highlighted the importance of using multiple extraction rounds for accurate protein quantification. Significant differences in SP concentrations were found across production environments. Confectionery and chocolate production (p < 0.001) and snacks, nuts, and chips production (p = 0.007) were associated with significantly lower SP concentrations compared to bakery production. Tasks such as grinding and milling (p = 0.037) and weighing and mixing (p = 0.019) showed significantly higher SP concentrations. The positive association between inhalable aerosol and SP concentrations suggests that higher aerosol concentrations generally correspond to higher protein exposure, but the strength of this relationship varied across productions and tasks. This study demonstrates the feasibility and potential value of measuring SP concentrations as an addition to aerosol measurements in food manufacturing environments. Given the health risks associated with inhaled proteins, particularly in provoking allergic reactions and respiratory problems, measuring total SP concentrations may serve as a more reliable indicator of occupational exposures, especially during tasks and in production types where the relationship between inhalable aerosols and proteins is weak.

Parallel Particle Impactors (PPIs) for respirable aerosols were introduced by SKC Inc. approximately 10 years ago and have been applied in the field; however, their collection efficiency curves have not yet been published. PPI consists of four impactors with different 50% cutoff sizes (d₅₀) arranged in parallel, and their resulting performance is designed to follow the convention for respiratory aerosol sampling. This study investigated the collection efficiency curves and d₅₀ values of disposable and reusable PPI models designed to operate at flow rates of 2, 4, and 8 L/min. The samplers were challenged with polydisperse sodium chloride (NaCl) particles and select sizes of polystyrene latex (PSL) particles. Bias maps and Bias Performance Criterion (BPC) values were calculated for challenge aerosols with mass median aerodynamic diameters (MMADs) ranging from 1 to 25 µm and geometric standard deviations (GSDs) ranging from 1.75 to 3.5. Results showed that 2, 4, and 8 L/min disposable PPI models had d₅₀ values close to 4 µm, with minimal bias compared to an ideal respirable sampler, and an average BPC exceeding 95%. The reusable 2 L/min model also closely followed the respirable convention, with a d₅₀ of 4.07 µm and a BPC of 100%. However, the d₅₀ for the reusable 4 L/min and 8 L/min units was slightly higher, at 4.27 µm. A ∼7% increase in the sampling flow rate to 4.3 L/min resulted in the d₅₀ of ∼4 µm, with a BPC of 100%. Overall, the respirable PPI samplers, particularly their disposable models, show excellent adherence to the respirable aerosol sampling convention and contribute to the arsenal of tools for estimating exposures to respirable particles. The availability of PPI samplers operating at different flow rates offers flexibility in selecting a suitable sampler model based on available personal sampling pumps, anticipated concentrations of the respirable aerosol fraction, and desired sampling times.