Annals Of Work Exposures and Health最新文献

When comparing the particle emissivity for different materials and/or mechanical activities, a serious methodological issue emerges due to the dynamic nature of solid aerosols. Particle size distribution and concentration depend on initial particle emission that constantly evolves due to aerodynamic collisions. In this context, we propose a methodological approach and an experimental setup that enables to assess the release of fine/ultra-fine particles maintaining a steady-state inhalable mass concentration, here chosen at the Swiss occupational exposure level value for biopersistent granular particles (OEL: 10 mg/m3) in a controlled ventilation chamber. As a case study, this methodological protocol was tested in the occupational exposure scenario in which a series of insulating materials based on silica aerogel and conventional mortar and concrete were subjected to handling or sawing. Once the OEL was reached, the particle size distribution and morphology of the aerosols were characterized using direct reading instruments (scanning mobility sizer, aerosol photometer) and electron microscopy (SEM and TEM) analyses. As a main result, the presence of silica aerogel in the mortar did not modify the emission profile for submicronic particles during sawing in comparison to the bulk mortar. Emission factors for ultra-fine particles were found to be 88 × 106 and 81 × 106 particles/µg of inhalable dust for the aerogel mortar and bulk mortar, respectively. For concrete sawing, the number concentration of submicronic particles at the OEL is one order of magnitude greater. The aerogel-glass-wool handling generated similar particle number concentration at the OEL with ultra-fine particle emission factors of 647 × 106 particles/µg of inhalable dust, in comparison to 758 × 106 particles/µg of inhalable dust during dry concrete sawing. In conclusion, the methodology introduced in this work provides standardized particle emission factors for comparing materials and activities, while establishing a link between particle number emissions and occupational exposure limits.

Carbon fiber-reinforced plastics (CFRP) are leading functional materials with superior strength and low mass density compared to metal. Our previous factory site analyses found that CFRP processing generates fibrous debris and fine micro/nano-sized particles of various shapes. The present interventional study was conducted at a factory located in Japan and evaluated debris consisting of various-sized particles generated during the industrial processing of CFRP, such as cutting, grinding, and turning of CFRP pipes, using real-time particle monitoring devices of the following: PM4 Digital Dust Monitor (DDM), handled Optical Particle Counter (OPC), Condensation Particle Counter (CPC), and Scanning Mobility Particle Sizer (SMPS). In addition, personal exposure of workers was evaluated using a novel wearable PM2.5-compatible device (P-sensor). First, we confirmed the presence of micro/nano particles in the dust generated during industrial processing of CFRP. Finer CFRP-generated particles were detected by the nanoparticle-compatible devices; CPC and SMPS, but not by OPC or DDM. The dynamic detection pattern of the P-sensor resembled that recorded by the nanoparticle-compatible devices. The novel wearable P-sensor can be used to measure finer particles generated by CFRP processing in occupational settings. Second, the exposure assessment was conducted twice and the levels of the micro/nano particles in the second survey were significantly (less than half) lower than that in the first survey. By avoiding immediate power-off of the exhaust system after operations, the scattering of particles was effectively reduced. Our results indicate that effective use of local exhaust ventilation system improves the workplace environment for particle exposure.

Objective: The objectives of this study were to evaluate daily hand-arm vibration (HAV) exposure among groundskeepers, characterize power tools used, and estimate lifetime cumulative HAV exposure dose.

Methods: Seventeen groundskeepers and ten office workers employed at two US southeasterrn institutions were recruited as a target exposure group and a reference group, respectively. A 6-d exposure assessment of HAV was scheduled, and vibration dosimeters were used to obtain daily vibration exposure value, A(8). Information on power tools used and corresponding operation duration was recorded to assign the real-time vibration data collected from the dosimeters for tool characterization in terms of vibration total value (ahv) and frequency. Lifetime cumulative exposure dose, ahv-lifetime, was determined using ahv for all tools used and lifetime exposure duration obtained through a questionnaire.

Results: The individual groundskeepers' average A(8) ranged from 0.8 to 2.6 and from 1.0 to 2.6 m/s2 for the right hand and left hands, respectively. Among 11 power tools used by the groundskeepers, grass trimmers contributed the most to the vibration exposure. The average ahv of the individual tools ranged from 8.0 (chainsaws) to 1.9 m/s2 (seating mowers and handheld blowers) for the right hand and from 6.4 (push mowers) to 1.4 m/s2 (backpack blowers) for the left hand. The highest acceleration peak of grass trimmers, edgers, backpack blowers, pole saws, riding blowers, and hedgers was observed between 100 and 200 Hz while riding mowers, seating mowers, push mowers, and chainsaws showed the highest acceleration peak at lower frequencies (≤63.5 Hz). The groundskeepers' average ahv-lifetime was 76,520.6 and 61,955.5 h m/s2 for the right and left hands, respectively. The average ahv-lifetime of office workers was 2,306.2 and 2,205.8 h m/s2 for the right and left hands, respectively, which was attributed to personal hobby activities.

Conclusion: Three groundskeepers' average A(8) reached 2.5 m/s2, the Action Limit recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). The highest contribution to the vibration exposure was observed during grass trimmer operations with a major acceleration peak at 100 Hz. The groundskeepers' ahv-lifetime was 33 and 28 times higher for the right and left hands, respectively, than the office workers.

Efficient sampling materials are essential for assessing nicotine levels in vape shops and other settings where nicotine exposures may exist. Two different treatments of Whatman glass fiber type A (GF/A) filters (sodium bisulfate treated and citric acid treated) were evaluated for nicotine capture, desorption efficiency, and holding capacity using Gas Chromatography-Mass Spectrometry (GC-MS). The Filters were treated with 0.8 mL of 0.1 M sodium bisulfate or citric acid solution and oven-dried (80 °C) for 30 min. Nicotine was desorbed off the filters using a modified analytical method. The average nicotine desorption efficiency for sodium bisulfate-treated GF/A filters (98.4%) was significantly higher than that of citric acid-treated GF/A filters (60.9%) over a range of 1-100 µg nicotine. Sodium bisulfate-treated and citric acid-treated GF/A filters experienced a 10% nicotine breakthrough after being dosed with about 550 and 2,750 µg of nicotine, respectively compared to 75 µg for untreated GF/A filters. Citric acid-treated GF/A filters had a much greater nicotine-holding capacity, but nicotine desorption from citric acid-treated GF/A filters was below the recommended criteria. Therefore, we recommend that sodium bisulfate-treated GF/A filters are employed for sample of nicotine with the GC-MS method.

Increased focus on renovating and maintaining the existing building stock is an integral part of the circular economy, however this might pose challenges to workers health. The aim of this study was to assess the renovation workers' exposure to inhalable dust, thoracic dust, respirable dust, and respirable crystalline silica (RCS). Personal aerosol samples were collected as full shift samples from 92 workers to a total of 407 samples. Fourteen locations around Oslo, Norway was visited for multiple days with repeated measurements of the same individual. Particulate matter from 3 aerosol fractions, respirable, thoracic, and inhalable, were analyzed gravimetrically, and the respirable fraction was analyzed for RCS by NIOSH 7500 method for X-ray diffraction (XRD) with low temperature plasma ashing sample preparation. The total measured concentrations of respirable dust (n = 192) had a geometric mean (GM) of 0.88 mg/m3, RCS concentrations (n = 182) had a GM of 0.040 mg/m3, thoracic dust (n = 131) had GM 2.4 mg/m3, and inhalable dust (n = 84) had a GM of 8.5 mg/m3. The maximum measured concentrations were 29 mg/m3, 3.2 mg/m3, 65 mg/m3, and 163 mg/m3, respectively. Workdays involving tasks such as mechanical demolition and clearing out demolished materials led to the highest exposure levels of both dust and RCS. However, other workers at the renovation sites were indirectly exposed to a considerable amount of RCS. This study revealed substantial exposure to both RCS and dust during renovation, and protective measures are warranted to reduce exposure levels in the industry.

Introduction: Eldercare organizations face high sickness absence rates and staff turnover and rely heavily on temporary workers to fill staffing gaps. Temporary workers may experience differences in job demands and resources compared with permanent workers, but this has been largely understudied.

Objective: To compare perceived job demands and resources between permanent and temporary Swedish eldercare workers.

Methods: Permanent and temporary eldercare workers in a Swedish municipality were invited to answer a digital survey on work environment conditions. Differences between permanent and temporary workers in job demands and resources were analyzed using multivariate analysis of variance adjusted for age, sex, place of birth, and percent of full-time work and univariate analyses were conducted to consider differences in specific factors.

Results: A total of 1076 permanent and 675 temporary workers received the survey, and the final study sample included 451 permanent and 151 temporary workers. Multivariate analyses revealed that temporary workers reported statistically significant lower job demands compared to permanent workers, but no statistically significant differences in resources were found between the groups. Univariate analyses showed that temporary workers reported lower quantitative demands, perceived exertion, and time spent bending forward, than permanent workers. These data suggest comparable support across groups, but a higher workload among permanent workers.

Conclusion: Our findings indicate that temporary workers experienced lower job demands than permanent workers, but that no notable difference was found in resources. Interventions aimed at distributing job demands more evenly among eldercare workers with different employment forms may be necessary.

Objectives: This study measured cooking fumes to which workers in school cafeterias may be exposed.

Methods: The measurement items were respirable dust, formaldehyde, and carbon monoxide. A total of 111 samples were obtained from 55 schools. Data on variables such as school size and daily cooking oil usage were collected. Correlation and association analysis were performed.

Results: The median of concentrations of respirable dust was 38.37 µg/m3 (min-max: 20.73-49.71 µg/m3). The concentrations of formaldehyde and carbon monoxide also showed levels that did not exceed 20% for occupational exposure limits. The increase in school size was significantly correlated with the increase in daily cooking oil usage and had a significant correlation with respirable dust concentration (Spearman's correlation coefficient, 0.36; P <0.05). The linear regression test results adjusting for other variables were also similar.

Conclusions: Cooking food by frying at high heat using cooking oil can increase the exposure of kitchen workers to respirable dust.

Aim: The aim was to evaluate the role of insufficient use of personal protective equipment (PPE) in SARS-CoV-2 transmission risk for healthcare workers (HCW) during the COVID-19 pandemic.

Methods: Prospective study within the COBRA cohort, including 15,127 HCW. Daily assessment of insufficient use of PPE, defined as self-reported PPE failure or noncompliance, in relation to SARS-CoV-2 infection ascertained by polymerase chain reaction (PCR) test. Statistical analysis involved calculating incidence rate ratios with 95% confidence intervals (CI).

Results: The included HCW contributed to 780,515 risk days including 67,723 d (8.7%) with insufficient PPE use and 133 events (positive PCR test). Self-reported insufficient use of PPE was slightly associated with infection with COVID-19 in HCW, but the data were statistically consistent with parameter values ranging from a protective effect to a to a doubling in risk (IRR 1.3, 95% CI 0.8; 2.3). Sensitivity analyses restricted to high-risk departments and to a period with a sufficient supply of PPE and a fully developed testing system, respectively, confirmed these findings.

Conclusion: Insufficient use of PPE among HCW during the pandemic in Denmark was uncommon but associated with a slightly increased risk of COVID-19 among HCW. However, the findings are uncertain due to the limited number of cases and the potential for misclassification bias stemming from the self-reported nature of the exposure.