Annals Of Work Exposures and Health最新文献

Samples of the respirable fraction of airborne particles to which workers are exposed are an important component of many health protection programs, especially in those workplaces where there is a risk of health problems from exposure to respirable crystalline silica. The most common technique for size-selection of the respirable dust fraction is to use a miniature cyclone preselector, many of which are based on the "Higgens-Dewell" (HD) design. A variant of the HD cyclone, commonly referred to as the "aluminum (or aluminium) cyclone," was developed in Scandinavia. Early work showed that a flow rate of 2.2 l min-1 would be appropriate to meet the size-separation convention standardized under the International Organization for Standardization (ISO), while a later, non-peer-reviewed study suggested 2.5 l min-1 and this flow rate is currently recommended by the manufacturers. The International Sampler Comparison Group is working on revising the European Standard EN13205 on sampler performance testing for consideration as an ISO standard. In this work, 5 aluminum cyclone units were tested at 2.5 l min-1 and the cyclones were further tested at 2.3 and 2.2 l min-1 to determine the optimal flow rate. While the flow rate of 2.3 l min-1 had the lowest overall mean bias, a flow rate of 2.2 l min-1 gave bias <±10% over the whole area of size distributions of interest. This supports earlier findings and suggests that 2.2 l min-1 is the most accurate flow rate for sampling with the aluminum cyclone. However, 2.3 l min-1 also meets the specification of EN13205 in that the area of bias >±10% is minimal. The consequence of continuing to use the aluminum cyclone at 2.5 l min-1 is an underestimate of respirable particles when compared with the ISO convention.

Objectives: The Korean CARcinogen EXposure (K-CAREX) project previously assessed occupational exposure to 20 International Agency for Research on Cancer (IARC) Group 1 carcinogens in 2010. This study updated K-CAREX to reflect exposure data from 2020.

Methods: We selected 20 IARC Group 1 carcinogens for this update. Reference exposure prevalence estimates were calculated using 3 nationwide occupational databases: the Work Environment Measurement Database (WEMD), the Special Health Examination Database (SHED), and the Work Environment Condition Survey (WECS). Among 37 industrial hygienists from the previous study, 26 participated again, providing exposure estimates after reviewing reference estimates from the 3 data sources. The median of their estimates was used as the final exposure prevalence. The number of exposed workers was calculated by multiplying the final exposure prevalence by the 2020 national census data for each carcinogen and industry. Exposure intensity ratings were also estimated using the WEMD.

Results: Exposure prevalence and the number of exposed workers were estimated for 20 carcinogens across 232 industries. For example, in the "manufacture of basic chemicals" industry, benzene exposure prevalence was estimated at 9%, with 3,833 workers exposed and an exposure intensity rating of 2. The largest exposed population was to welding fumes (266,965 workers), followed by crystalline silica (246,807 workers), nickel (191,258 workers), and mineral oil mist (179,305 workers).

Conclusions: This updated data offers valuable insights into occupational carcinogen exposure, supporting cancer prevention efforts and future epidemiological studies.

Wildland and wildland-urban interface (W/WUI) fires are increasing in frequency and intensity, increasing concerns about firefighters' exposure to hazardous smoke and the need for respiratory protection. This qualitative study explored the perspectives of California fire service personnel on the use of respiratory protective devices (RPDs), particularly powered air-purifying respirators, and a potential Cal/OSHA regulation mandating their use in W/WUI firefighting. Participants were experienced in W/WUI firefighting and had some role in their fire department related to respiratory protection or other aspect of firefighter safety. While all participants recognized the health risks associated with smoke exposure, including cancer and acute respiratory symptoms, and that RPDs would reduce their exposures, participants had concerns that RPDs would negatively affect fatigue, comfort, communication, mobility, and situational awareness. Some concerns specifically relate to the design of the RPDs. Most participants supported using RPDs in specific scenarios such as mop-up and prescribed burns, but fewer supported RPD use during high-exertion tasks like cutting line. Participants preferred flexibility or guidance rather than prescriptive regulation and advocated for engagement of firefighters in the development of any potential regulation to ensure practicality and feasibility. Some participants acknowledged resistance to change in the industry as a barrier for RPD adoption, but felt that evidence of RPD effectiveness and usability, including opportunities for training with devices and changes to device design, could assist with adoption. A programmatic regulation, coupled with education and engagement, can facilitate the incorporation of RPDs in W/WUI firefighting.

Drilling is a common task throughout various industry sectors. When holes are drilled in silica-containing materials such as concrete, brick, and stone, respirable dust containing respirable crystalline silica (RCS) can be generated. Prolonged exposure to RCS can lead to silicosis, lung cancer, chronic obstructive pulmonary disease. Current good control practice includes the application of local exhaust ventilation (LEV) directly to the drills. This is via an external extraction system fitted to a shroud which extracts the dust generated during drilling. For several years, integrated LEV has been available for drills. Integrated LEV offers advantages over external LEV by providing increased portability, interlocked control, reduced trip hazards and reduced costs. However, little is known regarding the control effectiveness of integrated systems. The capture efficiency of 4 different integrated extractors and 1 external extraction system for controlling dust was measured using a real time respirable dust monitor. Furthermore, for 1 drill personal air sampling was conducted to assess the exposure potential to respirable dust from drilling repeatedly into concrete over a 1-h period using no LEV, integrated LEV, and external LEV options. The capture efficiency for respirable dust for 4 integrated drill LEV units ranged between 98.6% and 99.6%. This was comparable to the respirable dust capture efficiency provided by a self-sealing shroud fitted to an external extraction unit which provided efficiencies between 99.4% and 99.8%. The personal exposure testing showed respirable dust exposure was reduced by 87.6% for integrated LEV and 93.3% for external LEV fitted with a self-sealing shroud. The reason for the lower efficiency for the integrated LEV was attributed to dust generated as their dust bins were emptied more often throughout the tests. Given the size of the integrated LEV dust bins and the frequency at which they may require emptying, appropriate control measures to protect workers from dust exposure should be considered-eg emptying the units outdoors in conjunction with RPE.

Occupational exposure to airborne particles and bioaerosols in dental clinics is a potential hazard to dental health workers. Current studies on airborne particles and bioaerosols in dental clinics are limited and methodologically diverse, leaving gaps in the understanding of airborne particles in real-life dental settings. The aim of the study was to investigate the size, concentration, and composition of particles produced during dental procedures, and determine the exposure levels of dental personnel to respirable particles and bioaerosols in dental clinical environments with different characteristics. The study included two conventional dentist offices and one specialty clinic. The number concentration and size distribution of particles released during different dental procedures were monitored in real-time in dental procedure rooms. Personal samplers were used in parallel to collect the respirable and inhalable particle fractions. Total bacterial and total fungal DNA concentrations were quantified in the inhalable particle fraction by droplet digital polymerase chain reaction. Particle morphology and chemical composition were analyzed using scanning electron microscopy. The highest geometric mean value of the respirable particle mass concentration (0.06 mg/m3) was below the Norwegian occupational exposure limit for respirable dust of 5 mg/m3. Real-time sampling indicated that particle number concentrations were elevated during working hours in two clinics, with peak levels observed in one clinic coinciding with air polishing activities. The results also showed significant variations in bacterial and fungal DNA concentration levels (P < 0.0001). Many collected particles originated from powders used in dental treatments. Despite low respirable particle mass concentrations, increased levels of ultrafine particles during dental procedures highlight potential health risks to dental professionals. These findings also underscore the importance of advanced ventilation and safety measures to mitigate occupational exposure in dental environments.

Objectives: Studies addressing the epidemiology of silicosis in the artificial stone benchtop industry have shown that this industry includes a large number of migrant workers in Victoria, Australia. The objective of the current analyses was to compare characteristics of migrant workers in the industry with nonmigrant workers.

Methods: Data were derived from artificial stone benchtop workers who had health assessments through a regulator-funded screening program between 2019 and 2024. Migrant workers were defined as workers born outside Australia or had used an interpreter during the assessment. Participant characteristics, lung function, and silicosis prevalence were summarized by migrant status and compared between groups.

Results: There were 1,040 workers (n = 536 migrant workers). Migrant workers were older at assessment than nonmigrant workers (median age 39 versus 33 years, P < 0.001). About 1 quarter of migrant workers used an interpreter (23.8%) and 52% spoke English at home. Silicosis prevalence was higher in migrant compared with nonmigrant workers (23% versus 15%, risk-ratio 1.54, and 95% confidence interval 1.16 to 2.04) and migrant workers who used an interpreter had double the risk of silicosis than those who did not (46% versus 18%, risk-ratio 2.24, 95% confidence interval 1.61 to 3.10). Prelegislative changes, experience of carrying out dry processing was reportedly higher in nonmigrant than migrant workers. Fewer jobs among migrant workers than nonmigrant workers were reported using recommended respirators (44 versus 53%) or ventilation (24% versus 30%).

Conclusions: The risk of silicosis in the artificial stone benchtop industry differed by migration status and was higher among those with lower English language proficiency. As the use of appropriate respirators or ventilation was lower among migrant workers, this suggests the need for improved occupational health and safety practices among migrant workers, making sure the messages are communicated in a manner that is language and culturally appropriate.

Background: Antibiotics are handled in large amounts at hospitals at many different wards due to the wide range of bacterial infections that are treated. Unnecessary use and occupational exposure to antibiotics should be avoided due to the risk of bacterial resistance development and adverse health effects including skin and respiratory hypersensitivity reactions in persons handling these drugs.

Objectives: To develop a wipe test method for sampling and quantification of surface contaminations of antibiotics, to assess the current contamination levels in Swedish hospitals, and to propose hygienic guidance values for antibiotics based on these measurements.

Methods: A screening wipe test method and subsequent mass spectrometric analysis of 6 of the most frequently used antibiotics in healthcare was developed and applied in a screening campaign of 16 hospital wards. Wipe tests were sampled from surfaces such as workbenches, floors, storage shelves and handles in medicine rooms, patient rooms, rinsing rooms, utility rooms and corridors.

Results: Antibiotics were detected in most of the samples (cefotaxime 84% positive samples, piperacillin 81%, cloxacillin 65%, metronidazole 53%, ciprofloxacin 20%, and penicillin V 14%). Median values ranged from not detected up to 160 pg/cm2 for the 6 different compounds and the highest results from an individual wipe sample were 27 × 106 pg/cm2 (cefotaxime) and 3.0 × 106 pg/cm2 (piperacillin). For cloxacillin, piperacillin, and metronidazole, lower levels of contamination were observed in medicine rooms when closed systems were used compared with samples collected in rooms where preparations were made without closed systems. Comparison of contamination levels showed that there were significant differences between different surface categories. Out of the most frequently detected antibiotics, ie cloxacillin, piperacillin, and cefotaxime, highest median values were found for surface categories floor and storage whereas lower median values were found for workbenches.

Conclusion: A widespread environmental contamination of antibiotics was observed in hospital wards that potentially can contribute to the development of antibiotic-resistant bacteria as well as health impacts of exposed personnel. Probable sources include compounding, handling and administration of drug tablets, antibiotic contaminated waste as well as other sources such as excretions from patients and contaminated drug vials. Current surface cleaning routines do not sufficiently reduce spills and leakage regardless of source.

Objectives: Exposure determinant modeling can help industrial hygienists understand where, when, and how to control occupational exposures for their particular work environment. Yet, in practice, the ability to evaluate exposure determinants is degraded by selection bias (where only a subset of all exposed workers is sampled) and the statistical issue of "small n, large p" (few samples but many exposure determinants). This study explored the application of the causal inference framework and machine learning algorithms in exposure determinant modeling using a "small n, large p" example of potential determinants of heavy metal concentrations among informal electronic waste recycling workers.

Methods: As a case study, we used a multivariable logistic regression model to construct inverse probability weights to account for selection bias into a video substudy of 41 of 226 possible workers monitored for exposures to heavy metals. Forty-four determinants of biomarkers (eg tool use, job tasks, and personal protective equipment use) were quantified through video monitoring. Concentrations of heavy metals in blood (Pb and Mn) and urine (Ni and Cu) were sampled. We identified the best-performing biomarker determinant model by comparing the leave-one-out cross-validation root-mean-squared error (LOOCV-RMSE) of 5 models: 2 traditional models (multivariate linear regression and forward selection), and 3 machine learning algorithms (LASSO, boosted regression trees, and random forests). Using the best-performing model, we estimated reductions in heavy metal concentrations through hypothetical workplace controls to identify the most important determinant of biomarker concentrations.

Results: The random forest model had the lowest LOOCV-RMSE and was used as the final biomarker determinant model. Stopping workers from bending their backs while dismantling e-waste was the most important determinant of heavy metal concentrations. Using blood Pb as an example, this translated to an estimated reduction of 0.81 µg/dL (95% confidence interval: 0.66, 0.98) in comparison with maintaining the status quo. Using a traditional regression model (forward selection without inverse probability weights), back bending was not identified as an important determinant of blood Pb.

Discussion: Our causal inference approach with machine learning algorithms overcomes the common limitations of exposure determinant modeling and produces easy-to-interpret estimates of biomarker concentration reductions from hypothetical workplace controls. This can aid industrial hygienists in choosing the most effective hazard controls that can be contextualized to their particular work setting.

Objectives: To understand the total exposure of a human population to a chemical, it is necessary to aggregate exposures from different exposure routes (ingestion, inhalation, dermal uptake) and exposure sources (eg food, air, consumer products) from different environments (ie general, occupational, consumer use). Preventive actions or regulatory decisions require decisions to be taken on priority exposure routes and sources. This study explores the development of a quantitative decision tree to identify relevant exposure sources in the context of aggregate exposure. As a case study for spray applications, it focuses on joint exposure to a specific chemical in a consumer product through domestic use of hairspray, and exposure at the workplace involving surface spraying, such as spray application of paints.

Methods: Determinant of the exposure models ART (for workers) and ConsExpo (for the general population) were used to generate a wide range of realistic exposure scenarios. The dominance of one source over another was analyzed through pairwise random comparisons. Exposure estimates from one source containing a specific determinant are compared with those from the other source, scaled by a dominance ratio that defines how much higher one source's exposure must be to be considered dominant. For each comparison, the number of times one source exceeds the other by at least a dominance ratio is counted, resulting in the occurrence. The occurrence is compared with a predefined threshold (eg 80%). If the threshold is met or exceeded, the higher-contributing source is considered dominant and no exposure aggregation is needed; otherwise, aggregation of both sources is recommended.

Results: The findings indicated that the use of high- or medium-specification glove boxes, as forms of permanent encapsulation or encasing of the emission source, results in occupational exposure that is negligible compared with the exposure from consumer product use. When these glove boxes were used, hair spray exposure was the dominant source in 89% and 82% of cases, for high and medium specifications, respectively. A spraying activity with surface liquids performed outdoors (close to buildings) showed a significant trend toward occupational exposure dominance in 81% of cases. Using these three determinants, a three-layer quantitative decision tree was built to help users quickly decide whether aggregation was relevant before performing calculations. Aggregation was suggested in 91% of cases and avoided it in 9%.

Pressure to increase rates of recycling in Great Britain is expected to increase to meet circular economy and net zero drivers. There are concerns about worker exposure to persistent organic pollutants (POPs) during the processing and recycling of waste upholstered domestic seating (WUDS). The aim of this study was to understand worker exposures to POPs, specifically the flame retardants polybrominated diphenyl ethers (PBDEs), and other airborne substances hazardous to health, when WUDS go through the recycling process. Five WUDS processing sites were visited by a health and safety executive occupational hygienist, who collected worker and static air samples, bulk dust and bulk material samples, and assessed control measures in use. All exposures to inhalable dust and PBDEs were significantly below occupational exposure limits, while exposures to airborne bacteria and fungi were elevated at most sites. Exposures to endotoxins were above the recommended health-based nonbinding occupational exposure limits at 4 sites. Across all sites, recommended control measures were only partially met, indicating that exposures to airborne dust and biological agents could be reduced that these sites.