| 1. |
- Abrahamsson, Camilla, et al.
(författare)
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Aerosolized particulate matter from fragmentation of carbon nanotube-enhanced concrete
- 2023
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Ingår i: Abstracts from the 2022 Airmon-10 conference and the 2023 Inhaled Particles and NanOEH conference. - 2398-7316 .- 2398-7308. ; 67:Supplement_1, s. i94-i95
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Konferensbidrag (refereegranskat)abstract
- Construction and demolition workers are exposed to high levels of particulate matter (PM) from building materials throughout their working life. Although nano-enabled building materials (NEBMs) may improve the performance and functionality of buildings, concerns are being raised regarding health risks from occupational exposure to PM from NEBMs. In this work, an experimental set-up for integrated resuspension and characterization of PM from NEBMs was developed and tested using three types of concrete (low density, normal, high strength), each enhanced with Carbon Nanotubes (CNTs) at different concentrations (0, low, high). The performance of portable devices used in occupational exposure assessments (DustTrak and NanoTracer) was compared with stationary instruments and gravimetric filter techniques. 40-70% of the mass and 90-98% of the number of particles were within the respirable fraction, with primary modes at 150 nm and 2-3 µm. Addition of CNTs significantly decreased mean particle number concentrations (PNCs) across the entire characterized size range (7 nm - 20 µm) for low density concrete, whereas the opposite was the case for normal strength and high strength concrete. It was hypothesised that the concrete matrix primarily governs the PM formation, which is in turn modulated by CNT-matrix interactions either suppressing or supporting fragmentation during crushing. SEM imaging could display partially submerged CNTs protruding from concrete fragments. Fundamental interactions at the interface of the nanomaterial and the surrounding matrix needs to be investigated to determine how the PM generated from NEBMs differ from their non-nano counterparts and how to prevent future exposure during demolition.
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| 2. |
- Arvidsson, Inger, et al.
(författare)
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Action Levels for the Prevention of Work-Related Musculoskeletal Disorders in the Neck and Upper Extremities : A Proposal
- 2021
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press (OUP). - 2398-7308 .- 2398-7316. ; 65:7, s. 741-747
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Tidskriftsartikel (refereegranskat)abstract
- There are several well-known risk factors for work-related musculoskeletal disorders (MSDs). Despite this knowledge, too many people still work in harmful conditions. The absence of occupational exposure limits (OELs) for physical workload impedes both supervision and preventive work. To prevent myalgia, tendon disorders, and nerve entrapments in the upper musculoskeletal system, we propose action levels concerning work postures, movement velocities and muscular loads recorded by wearable equipment. As an example, we propose that wrist velocity should not exceed 20°/s as a median over a working day. This has the potential to reduce the prevalence of carpal tunnel syndrome (CTS) in highly exposed male occupational groups by 93%. By reducing upper arm velocity in highly exposed female groups to the suggested action level 60°/s, the prevalence of pronounced neck/shoulder myalgia with clinical findings (tension neck syndrome) could be reduced by 22%. Furthermore, we propose several other action levels for the physical workload. Our ambition is to start a discussion concerning limits for physical workload, with the long-term goal that OELs shall be introduced in legislation. Obviously, the specific values of the proposed action levels can, and should, be discussed. We hope that quantitative measurements, combined with action levels, will become an integral part of systematic occupational health efforts, enabling reduction and prevention of work-related MSDs.
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| 3. |
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| 4. |
- Bergsten, Eva L., et al.
(författare)
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Daily shoulder pain among flight baggage handlers and its association with work tasks and upper arm postures on the same day
- 2017
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press (OUP). - 2398-7308 .- 2398-7316. ; 61:9, s. 1145-1153
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study of flight baggage handlers aimed at examining the extent to which shoulder pain developed during single work shifts, and whether a possible development was associated with biomechanical exposures and psychosocial factors during the same shift.Methods: Data were collected during, in total, 82 work shifts in 44 workers. Right and left shoulder pain intensity was rated just before and just after the shift (VAS scale 0-100 mm). Objective data on time in extreme and time in neutral upper arm postures were obtained for the full shift using accelerometers, and the baggage handlers registered the number of aircrafts handled in a diary. During half of the shift, workers were recorded on video for subsequent task analysis of baggage handling. Influence at work and support from colleagues were measured by use of Copenhagen Psychosocial Questionnaire (COPSOQ). Associations between exposures and the increase in pain intensity during the shift (daily pain) were analysed for the right and left shoulder separately using Generalized Estimating Equations (GEE).Results: Daily pain was observed in approximately one third of all shifts. It was significantly associated with the number of aircrafts handled for both the right and left shoulder. In multivariate models including both biomechanical exposures and the psychosocial factors influence at work and support from colleagues, aircrafts handled was still significantly associated with daily pain in both shoulders, and so was influence and support, however in opposite directions.Conclusions: Daily pain was, in general, associated with biomechanical exposures during the same shift and with general influence and support in the job. In an effort to reduce pain among flight baggage handlers, it may therefore be justified to consider a reduction of biomechanical exposures during handling of aircrafts, combined with due attention to psychosocial factors at work.
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| 5. |
- Conway, Paul Maurice, et al.
(författare)
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Optimal Cut-Off Points for the Short-Negative Act Questionnaire and Their Association with Depressive Symptoms and Diagnosis of Depression
- 2018
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press (OUP). - 2398-7308 .- 2398-7316. ; 62:3, s. 281-294
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The behavioural experience method has been extensively used in the literature for the measurement of potential bullying behaviours at work. However, this approach presents limitations when used to classify respondents as targets or non-targets of workplace bullying. Therefore, the present study aimed to: (i) identify optimal cut-off points, reflecting a possible subjectively experienced exposure to occasional and frequent workplace bullying, for the 9-item Short Negative Act Questionnaire (S-NAQ), and (ii) examine the criterion validity of these cut-off points in relation to depressive symptoms and diagnosis of depression.Methods: The study was based on a sample of 4882 participants from the Danish MODENA cohort study (year 2011), which included both the S-NAQ (score range 9-45) and a one-item measure applying the self-labelling method with a definition to assess occasional and frequent workplace bullying. We employed receiver operating characteristic (ROC) curve analyses to derive the cut-off points for the S-NAQ. Based on these cut-off points, we created a new S-NAQ variable with three levels of exposure (i.e. 'not exposed', 'first threshold', and 'second threshold') and tested its criterion validity in relation to depressive symptoms (N = 4071) and diagnosis of depression (N = 4844).Results: The S-NAQ cut-off points obtained were ≥12 and ≥16 when using occasional and frequent bullying as reference standards, respectively. Both cut-off points showed high classification accuracy (area under the curve = 0.89 and 0.93) as well as good sensitivity (84.8% and 88.0%) and specificity (77.4% and 94.7%). In the adjusted linear regression analyses, both the first (B = 0.78, 95% confidence interval [CI] = 0.66-0.90) and the second threshold of exposure (B = 1.65, 95% CI = 1.44-1.86) were significantly associated with depressive symptoms. In the adjusted logistic regression analyses, both the first (odds ratio [OR] = 3.55, 95% CI = 1.98-6.38) and the second threshold of exposure (OR = 5.90, 95% CI = 2.93-11.88) were significantly associated with diagnosis of depression.Conclusions: The two cut-off points for the S-NAQ identified in this study showed a significant association with both depressive symptoms and diagnosis of depression. However, future prospective studies are needed to establish the predictive validity of the proposed cut-off points.
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| 6. |
- Dahlman-Hoglund, A., et al.
(författare)
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Endotoxin in Aerosol Particles from Metalworking Fluids Measured with a Sioutas Cascade Impactor
- 2022
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press (OUP). - 2398-7308 .- 2398-7316. ; 66:2, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim of this study was to characterize personal occupational exposure to endotoxin in size-separated airborne particles of MWF aerosol, using a Sioutas cascade impactor (SCI). Methods Exposure to inhalable fractions of MWF aerosol and endotoxin was measured by personal sampling of 52 individuals over an 8-h work shift using a PAS-6 sampler in parallel with a SCI (<0.25, 0.25-0.5, 0.5-1.0, 1.0-2.5, and 2.5-10 mu m). Aerosol mass concentration was measured for each worker with a real-time instrument (DataRAM) during a full shift. Samples of MWF were collected from the machines and central tanks during the work shift. Results A total of 117 measurements of inhalable MWF aerosols were made among 52 workers. The geometric mean of inhalable MWF aerosol was 0.16 mg m(-3) air. The geometric mean of endotoxin concentration on the inhalable sampler was 0.15 EU m(-3). Airborne endotoxin was found on all size fractions from the impactor, with the major part seen in the fraction (2.5-10 mu m). There was a correlation between the inhalable fraction of endotoxin measured by the PAS-6 sampler and on the SCI sampler (2.5-10 mu m), estimated to be 0.51 for all samples (P < 0.0001). The concentration of endotoxin varied between the MWFs, as did the proportion of Gram-negative bacteria among the culturable bacteria (>80% in one MWF and <1.5% in the other three). Conclusions The personal exposure to inhalable fractions of endotoxin contained in the MWF aerosol were low, where most of the endotoxin were found in fraction (2.5-10 mu m), measured by SCI. There are differences between factories and MWF systems regarding the distribution of endotoxin and so results from one context should not be generalized to other plants and systems. Compressed air was used for less than 10 min shift(-1). The mixed-effect model showed that working with open machines and grinding as cutting task were important determinants of exposure to inhalable aerosol. It is important to keep occupational exposure to aerosols low with the help of good ventilation systems, enclosed machines, and organization of work.
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| 7. |
- de Sousa, NR, et al.
(författare)
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Operative and Technical Modifications to the Coriolis® µ Air Sampler That Improve Sample Recovery and Biosafety During Microbiological Air Sampling
- 2020
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Ingår i: Annals of work exposures and health. - : Oxford University Press (OUP). - 2398-7316 .- 2398-7308. ; 64:8, s. 852-865
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Tidskriftsartikel (refereegranskat)abstract
- Detecting infectious aerosols is central for gauging and countering airborne threats. In this regard, the Coriolis® µ cyclonic air sampler is a practical, commercial collector that can be used with various analysis methods to monitor pathogens in air. However, information on how to operate this unit under optimal sampling and biosafety conditions is limited. We investigated Coriolis performance in aerosol dispersal experiments with polystyrene microspheres and Bacillus globigii spores. We report inconsistent sample recovery from the collector cone due to loss of material when sampling continuously for more than 30 min. Introducing a new collector cone every 10 min improved this shortcoming. Moreover, we found that several surfaces on the device become contaminated during sampling. Adapting a high efficiency particulate air-filter system to the Coriolis prevented contamination without altering collection efficiency or tactical deployment. A Coriolis modified with these operative and technical improvements was used to collect aerosols carrying microspheres released inside a Biosafety Level-3 laboratory during simulations of microbiological spills and aerosol dispersals. In summary, we provide operative and technical solutions to the Coriolis that optimize microbiological air sampling and improve biosafety.
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| 8. |
- Eriksson, Kåre, et al.
(författare)
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Temporal trend in wood dust exposure during the production of wood pellets
- 2017
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press. - 2398-7308 .- 2398-7316. ; 61:4, s. 429-439
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Wood dust data collected in the production of wood pellets during 2001 to 2013 were evaluated to study a temporal trend in inhalation exposure. Methods: A linear mixed effects model of natural ln-transformed data was used to express the relative annual difference in inhalation wood dust exposure. Results: There was an annual decrease of -20.5% of the geometric mean wood dust exposure during 2001 until 2013. The results were based on 617 inhalable dust samples collected at 14 different production units. The exposure to wood dust at the industrial premises investigated has decreased from a relatively high level of 6.4 mg m-3 in 2001 to 1.0 mg-3 in 2013. The Swedish Occupational Exposure Limit (SOEL) of 2 mg m-3 may still be exceeded. Conclusion: Analysis of the temporal trend in soft wood production units revealed declines in exposure of 20.5% per annum. It is important that precautions are taken to protect workers from a hazardous exposure to wood dust at the premises as the SOEL of 2 mg m-3 at some occasions is still exceeded. Additional measurements of wood dust exposure should be carried out on a regular basis in wood pellet production units in Sweden as well in other countries.
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| 9. |
- Forsell, Karl, et al.
(författare)
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Benzene Exposure and Biomarkers in Alveolar Air and Urine Among Deck Crews on Tankers Transporting Gasoline
- 2019
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Ingår i: Annals of work exposures and health. - : Oxford University Press. - 2398-7316 .- 2398-7308. ; 63:8, s. 890-897
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Increased rates of leukaemia have been found among tanker crews. Occupational exposures to the leukomogen benzene during loading, unloading, and tank cleaning are possible causes. Studies on older types of tankers carrying gasoline with most handling being done manually have revealed important exposures to benzene. Our study explores benzene exposures on tankers with both automatic and manual systems. Correlations between benzene exposure and benzene in alveolar air (AlvBe), benzene in urine (UBe), and trans,trans-muconic acid (ttMA) in urine were investigated.METHODS: Forty-three male seafarers (22 deck crewmembers and 21 not on deck) on five Swedish different product and chemical tankers transporting 95- or 98-octane gasoline were investigated between 1995 and 1998. The tankers used closed systems for the loading and unloading of gasoline but stripping and tank cleaning were done manually. Benzene in respiratory air was measured using personal passive dosimeters during a 4-h work shift. Samples for biomarker analyses were collected pre- and post-shift. Smoking did occur and crewmembers did not use any respiratory protection during work.RESULTS: The average 4-h benzene exposure level for exposed was 0.45 mg m-3 and for non-exposed 0.02 mg m-3. Benzene exposure varied with type of work (range 0.02-143 mg m-3). AlvBe, UBe, and ttMA were significantly higher in post-shift samples among exposed and correlated with exposure level (r = 0.89, 0.74, and 0.57, respectively). Smoking did not change the level of significance among exposed.DISCUSSION: Benzene in alveolar air, unmetabolized benzene, and ttMA in urine are potential biomarkers for occupational benzene exposure. Biomarkers were detectable in non-exposed, suggesting benzene exposure even for other work categories on board tankers. Work on tankers carrying gasoline with more or less closed handling of the cargo may still lead to significant benzene exposure for deck crewmembers, and even exceed the Swedish Occupational Exposure Limit (OEL; 8-h time-weighted average [TWA]) of 1.5 mg m-3.
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| 10. |
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