| 91. |
- Trask, Catherine, 1979-, et al.
(författare)
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Using observation and self-report to predict mean, 90th percentile, and cumulative low back muscle activity in heavy industry workers
- 2010
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 54:5, s. 595-606
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Tidskriftsartikel (refereegranskat)abstract
- Occupational injury research depends on the ability to accurately assess workplace exposures for large numbers of workers. This study used mixed modeling to identify observed and self-reported predictors of mean, 90th percentile, and cumulative low back muscle activity to help researchers efficiently assess physical exposures in epidemiological studies. Full-shift low back electromyography (EMG) was measured for 133 worker-days in heavy industry. Additionally, full-shift, 1-min interval work-sampling observations and post-shift interviews assessed exposure to work tasks, trunk postures, and manual materials handling. Data were also collected on demographic and job variables. Regression models using observed variables predicted 31-47% of the variability in the EMG activity measures, while self-reported variables predicted 21-36%. Observation-based models performed better than self-report-based models and may provide an alternative to direct measurement of back injury risk factors.
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| 92. |
- Wahlström, Jens, et al.
(författare)
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Full-Shift Trunk and Upper Arm Postures and Movements Among Aircraft Baggage Handlers
- 2016
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 60:8, s. 977-90
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The present study assessed full-shift trunk and upper arm postural exposure amplitudes, frequencies, and durations among Swedish airport baggage handlers and aimed to determine whether exposures differ between workers at the ramp (loading and unloading aircraft) and baggage sorting areas.METHODS: Trunk and upper arm postures were measured using inclinometers during three full work shifts on each of 27 male baggage handlers working at a large Swedish airport. Sixteen of the baggage handlers worked on the ramp and 11 in the sorting area. Variables summarizing postures and movements were calculated, and mean values and variance components between subjects and within subject (between days) were estimated using restricted maximum likelihood algorithms in a one-way random effect model.RESULTS: In total, data from 79 full shifts (651h) were collected with a mean recording time of 495min per shift (range 319-632). On average, baggage handlers worked with the right and left arm elevated >60° for 6.4% and 6.3% of the total workday, respectively. The 90th percentile trunk forward projection (FP) was 34.1°, and the 50th percentile trunk movement velocity was 8° s(-1). For most trunk (FP) and upper arm exposure variables, between-subject variability was considerable, suggesting that the flight baggage handlers were not a homogeneously exposed group. A notable between-days variability pointed to the contents of the job differing on different days. Peak exposures (>90°) were higher for ramp workers than for sorting area workers (trunk 0.6% ramp versus 0.3% sorting; right arm 1.3% ramp versus 0.7% sorting).CONCLUSIONS: Trunk and upper arm postures and movements among flight baggage handlers measured by inclinometry were similar to those found in other jobs comprising manual material handling, known to be associated with increased risks for musculoskeletal disorders. The results showed that full-shift trunk (FP) and, to some extent, peak arm exposures were higher for ramp workers compared with sorting workers.
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| 93. |
- Wahlström, Jens, et al.
(författare)
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Upper arm postures and movements in female hairdressers across four full working days
- 2010
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press. - 0003-4878 .- 1475-3162. ; 54:5, s. 584-594
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe upper arm postures and movements among female hairdressers, including the variability between hairdressers, between days within hairdresser, and between tasks, as a basis for understanding the characteristics of exposures in the job, considering possible sources of variation and recovery, and discussing appropriate exposure assessment strategies.Methods: Data on upper arm postures were collected using inclinometers during four working days the same week from 28 female hairdressers working in 13 salons. Twenty of the hairdressers noted customer on and off times in a diary, to allow separate analyses of customer tasks (CT) and auxiliary non-customer tasks (AT), including breaks. For a number of posture and movement variables, mean values and variance components between subjects (BS) and within subjects between days (BD) were estimated using restricted maximum likelihood algorithms in one-way random effect models.Results: For the 20 hairdressers with diaries, CT accounted for 279 min (58%) (SDBS = 39 min and SDBD = 85 min) of the working day and AT and breaks for 207 min (42%) (SDBS = 46 min and SDBD = 88 min). The hairdressers worked with the right arm elevated >60° for 6.8% of the whole job (SDBS = 2.8% and SDBD = 2.0%). On average, the hairdressers worked with the right arm elevated >60° for 9.0% of the time during CT, compared to 3.7% during AT, resulting in a contrast between tasks of 0.35.Conclusions: Hairdressers may be at risk for developing musculoskeletal disorders in the neck and shoulders due to a considerable occurrence of highly elevated arms, especially during CT. On the other hand, we do not find reasons to classify hairdressing as a job with too little variation. Posture variability between days within hairdressers was in the same order of magnitude as that between hairdressers, suggesting that ‘typical’ workdays do not exist. The exposure contrast between CT and AT for variables describing elevated arm postures indicates that for these variables a simple task-based approach for estimating job exposure could be successful.
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| 94. |
- Welling, Irma, et al.
(författare)
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Contaminant dispersion in the vicinity of a worker in a uniform velocity field
- 2000
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Ingår i: Annals of Occupational Hygiene. - 0003-4878 .- 1475-3162. ; 44:3, s. 219-225
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Tidskriftsartikel (refereegranskat)abstract
- The transportation of gaseous contaminant from a low and moderate low impulse (momentum<1 m s-1) source to the breathing zone was studied in a uniform air stream flow. Results of the effects of the direction and the velocity of principal air flow, convection due to a human body, arm movement of a human being and the type of source on the concentration profiles are presented. Three important results were obtained. Firstly, for a given low and moderate impulse low impulse contaminant source in the near field of a worker, his/her orientation relative to the principal air flow direction is the most important factor in reducing occupational exposure, with an air velocity of about 0.3 m s-1. Secondly, the effect of convection resulting from body heat on air flow was lower than expected. Thirdly, arm movements influence contaminant dispersion, and should be included when models assessing exposure are developed. The present data can also be used to validate existing computational fluid dynamic (CFD) models.
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| 95. |
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| 96. |
- Westerlund, Jessica, 1983-, et al.
(författare)
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Occupational Exposure to Trichloramine and Trihalomethanes in Swedish Indoor Swimming Pools : Evaluation of Personal and Stationary Monitoring
- 2015
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press. - 0003-4878 .- 1475-3162. ; 59:8, s. 1074-1084
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Chlorination is a method commonly used to keep indoor swimming pool water free from pathogens. However, chlorination of swimming pools produces several potentially hazardous by-products as the chlorine reacts with nitrogen containing organic matter. Up till now, exposure assessments in indoor swimming pools have relied on stationary measurements at the poolside, used as a proxy for personal exposure. However, measurements at fixed locations are known to differ from personal exposure.Methods: Eight public swimming pool facilities in four Swedish cities were included in this survey. Personal and stationary sampling was performed during day or evening shift. Samplers were placed at different fixed positions around the pool facilities, at similar to 1.5 m above the floor level and 0-1 m from the poolside. In total, 52 personal and 110 stationary samples of trichloramine and 51 personal and 109 stationary samples of trihalomethanes, were collected.Results: The average concentration of trichloramine for personal sampling was 71 mu g m(-3), ranging from 1 to 240 mu g m(-3) and for stationary samples 179 mu g m(-3), ranging from 1 to 640 mu g m(-3). The air concentrations of chloroform were well below the occupational exposure limit (OEL). For the linear regression analysis and prediction of personal exposure to trichloramine from stationary sampling, only data from personal that spent > 50% of their workday in the pool area were included. The linear regression analysis showed a correlation coefficient (r (2)) of 0.693 and a significant regression coefficient beta of 0.621; (95% CI = 0.329-0.912, P = 0.001).Conclusion: The trichloramine exposure levels determined in this study were well below the recommended air concentration level of 500 mu g m(-3); a WHO reference value based on stationary sampling. Our regression data suggest a relation between personal exposure and area sampling of 1:2, implying an OEL of 250 mu g m(-3) based on personal sampling.
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| 97. |
- Wingfors, Håkan, et al.
(författare)
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Identification of markers for PCB exposure in plasma from Swedish construction workers removing old elastic sealants
- 2006
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press. - 2398-7308 .- 2398-7316. ; 50:1, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the present study was to identify PCB-indicators of occupational exposure related to the removal of old elastic sealants. Blood samples were collected from workers involved in removing elastic sealants. Samples were also taken from age- and sex-matched controls. A majority of the exposed workers were re-sampled after 10 months. All samples were analysed for 19 PCBs. The levels in the exposed workers were twice as high as those in the controls, 575 and 267 ng g−1 lipid, respectively, but were essentially unchanged at the second sampling. The PCB patterns also differed. Levels of many less chlorinated PCBs were much higher in the exposed workers, compared to the controls, and principal component analysis (PCA) revealed that easily metabolized PCBs decreased in the exposed workers during the study. This finding indicates that elimination exceeded uptake during the study period, and that the safety information given to the workers had been effective. PCA was also used to identify exposure markers. The relatively persistent PCBs 56/60 and 66, the easily metabolized PCBs 44, 70 and 110 (with vicinal hydrogens in meta/para-positions) and the very persistent PCBs 153 and 180 were found to be good markers for occupational, recent occupational and background (dietary) exposure, respectively. A PCA model based on these markers was equally effective in differentiating between exposed individuals and controls, and between recent and less recent exposure, as a model based on all PCBs.
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