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  • 1.
    Andersson, Lena
    et al.
    Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Burdorf, Alex
    Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
    Bryngelsson, Ing-Liss
    Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
    Westberg, Håkan
    Örebro University, School of Science and Technology. Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
    Estimating trends in quartz exposure in Swedish iron foundries: predicting past and present exposures2012In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 56, no 3, p. 362-372Article in journal (Refereed)
    Abstract [en]

    Background: Swedish foundries have a long tradition of legally required surveys in the work place that, from the late 1960s onwards, included measurements of quartz. The availability of exposure data spanning almost 40 years presents a unique opportunity to study trends over that time and to evaluate the validity of exposure models based on data from shorter time spans. The aims of this study were (i) to investigate long term trends in quartz exposure over time, (ii) using routinely collected quartz exposure measurements to develop a mathematical model that could predict both historical and current exposure patterns, and (iii) to validate this exposure model with up-to-date measurements from a targeted survey of the industry.

    Methods: Eleven foundries, representative of the Swedish iron foundry industry, were divided into three groups based on the size of the companies, i.e. the number of employees. A database containing 2333 quartz exposure measurements for 11 different job descriptionswas used to create three models that covered time periods which reflected different work conditions and production processes: a historical model (1968– 1989), a development model (1990–2004), and a validation model (2005–2006). A linear mixed model for repeated measurements was used to investigate trends over time. In all mixed models, time period, company size, and job title were included as fixed (categorical) determinants of exposure. The within- and between-worker variances were considered to be random effects. A linear regression analysis was erformed to investigate agreement between the models. The average exposure was estimated for each combination of job title and company size.

    Results: A large reduction in exposure (51%) was seen between 1968 and 1974 and between 1975 and 1979 (28%). In later periods, quartz exposure was reduced by 8% per 5 years at best. In the first period, employees at smaller companies experienced ~50%higher exposure levels than those at large companies, but these differences became much smaller in later years. The furnace and ladle repair job were associated with the highest exposure, with 3.9–8.0 times the average exposure compared to the lowest exposed group. Without adjusting for this autonomous trend over time, predicting early historical exposures using our development model resulted in a statistically significant regression coefficient of 2.42 (R2 5 0.81), indicating an underestimation of historical exposure levels. Similar patterns were seen for other historical time periods. Comparing our development model with our validation model resulted in a statistically significant regression coefficient of 0.31, indicating an overestimation of current exposure levels.

    Conclusion: To investigate long-term trends in quartz exposure over time, overall linear trends can be determined by using mixed model analysis. To create individual exposure measures to predict historical exposures, it is necessary to consider factors such as the time period, type of job, type of company, and company size. The mixed model analysis showed systematic changes in concentration levels, implying that extrapolation of exposure estimates outside the range of years covered by measurements may result in underestimation or overestimation of exposure.

  • 2.
    Antonsson, Ann-Beth
    et al.
    KTH, School of Technology and Health (STH), Ergonomics (Closed 20130701).
    Christensson, Bengt
    KTH. IVL Svenska Miljöinstitutet.
    Berge, Johan
    Rättsmedicinalverket.
    Sjögren, Bengt
    Karolinska Institutet.
    Fatal Carbon Monoxide Intoxication After AcetyleneGas Welding of Pipes2013In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 57, no 5, p. 662-666Article in journal (Refereed)
    Abstract [en]

    Acetylene gas welding of district heating pipes can result in exposure to high concentrations of carbon monoxide. A fatal case due to intoxication is described. Measurements of carbon monoxide revealed high levels when gas welding a pipe with closed ends. This fatality and these measurements highlight a new hazard, which must be promptly prevented.

  • 3.
    Barbieri, Dechristian
    et al.
    Department of Physical Therapy, Federal University of São Carlos,.
    Brusaca, Luiz Augusto
    Department of Physical Therapy, Federal University of São Carlos,.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Oliveira, Ana Beatriz
    Department of Physical Therapy, Federal University of São Carlos,.
    Effects of the time proportions of sitting and standing on pleasantness, acceptability, fatigue and pain when using a sit-stand table – a controlled experiment on overweight and normal-weight subjects2020In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162Article in journal (Refereed)
  • 4.
    Bergsten, Eva L.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kwak, Lydia
    Unit of Intervention and Implementation Research for worker health, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Vingård, Eva
    Occupational and Environmental Medicine, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
    Daily shoulder pain among flight baggage handlers and its association with work tasks and upper arm postures on the same day2017In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 61, no 9, p. 1145-1153Article in journal (Refereed)
    Abstract [en]

    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.

  • 5.
    Bergsten, Eva L.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine. Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, SE-801 76 Gävle, Sweden.
    Mathiassen, Svend Erik
    Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gävle, SE-801 76 Gävle, Sweden.
    Kwak, Lydia
    Unit of Intervention and Implementation Research for worker health, Institute of Environmental Medicine, Karolinska Institutet, SE- 171 77 Stockholm, Sweden.
    Vingård, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Daily shoulder pain among flight baggage handlers and its association with work tasks and upper arm postures on the same day2017In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 61, no 9, p. 1145-1153Article in journal (Refereed)
    Abstract [en]

    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.

  • 6. Blanco, Luis E.
    et al.
    Aragon, Aurora
    Lundberg, Ingvar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Wesseling, Catharina
    Nise, Gun
    The determinants of dermal exposure ranking method (DERM): A pesticide exposure assessment approach for developing countries2008In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 52, no 6, p. 535-544Article in journal (Refereed)
    Abstract [en]

    A new method for assessment of dermal exposure to pesticides in subsistence farmers by use of determinants of dermal exposure is described. The method, called the determinants of dermal exposure ranking method (DERM), is a combination of checklists and expert rating assessment. Thus, determinants are listed in a form, which is used to check their presence and to assess them using a simple algorithm based on two factors, the type of transport process (T value) and the area of body surface exposed (A value). In addition, the type of clothing worn during applications is included as a protection factor. We applied the DERM to real pesticide applications, characterizing dermal exposure and comparing DERM estimates with earlier developed semiquantitative visual scores based on fluorescent tracer, the total visual score (TVS) and contaminated body area (CBA). DERM showed a very good level of agreement with both the TVS (r = 0.69, P = 0.000) and the CBA (r = 0.67, P = 0.000). DERM allowed identification of the determinants that had the highest effect on exposure and the farmers with the highest exposure. In conclusion, DERM provided information on the determinants responsible for dermal exposure in a group of subsistence farmers. This can be useful to design monitoring and preventive programs, define priorities for intervention and prioritize and select most adequate measurement strategies. DERM promises to be a low-cost easy-to-use method to assess dermal exposure to pesticides in developing country conditions.

  • 7. Blanco, Luis E.
    et al.
    Aragón, Aurora
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lundberg, Ingvar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Wesseling, Catharina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Nise, Gun
    The Accuracy of DERM may be a Self-fulfilling DREAM Reply2008In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 52, no 8, p. 784-785Article in journal (Refereed)
  • 8.
    Burström, Lage
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Lundström, Ronnie
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Hagberg, Mats
    Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Vibrotactile perception and effects of short-term exposure to hand-arm vibration2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 53, no 5, p. 539-547Article in journal (Refereed)
    Abstract [en]

    This study clarifies whether the established frequency weighting procedure for evaluating exposure to hand-transmitted vibration can effectively evaluate the temporary changes in vibrotactile perception thresholds due to pre-exposure to vibration. In addition, this study investigates the relationship between changes of the vibrotactile perception thresholds and the normalized energy-equivalent frequency-weighted acceleration. The fingers of 10 healthy subjects, five male and five female, were exposed to vibration under 16 conditions with a combination of different frequencies, intensities, and exposure times. The vibration frequencies were 31.5 and 125 Hz and exposure lasted between 2 and 16 min. According to International Organization for Standardization (ISO) 5349-1, the energy-equivalent frequency-weighted acceleration for the experimental time of 16 min is 2.5 or 5.0 m s(-2) root-mean-square, corresponding to a 8-h equivalent acceleration, A(8), of approximately 0.5 and 0.9 m s(-2), respectively. A measure of the vibrotactile perception thresholds was conducted before the different exposures to vibration. Immediately after the vibration exposure, the acute effect was measured continuously on the exposed index finger for the first 75 s, followed by 30 s of measures every minute for a maximum of 10 min. If the subject's thresholds had not recovered, the measures continued for a maximum of 30 min with measurements taken every 5 min. Pre-exposure to vibration significantly influenced vibrotactile thresholds. This study concludes that the influence on the thresholds depends on the frequency of the vibration stimuli. Increased equivalent frequency-weighted acceleration resulted in a significant change in threshold, but the thresholds were unaffected when changes in the vibration magnitude were expressed as the frequency-weighted acceleration or the unweighted acceleration. Moreover, the frequency of the pre-vibration exposure significantly influenced (up to 25 min after exposure) recovery time of the vibrotactile thresholds. This study shows that the frequency weighting procedure in ISO 5349-1 is unable to predict the produced acute changes in the vibrotactile perception. Moreover, the results imply that the calculation of the 'energy-equivalent' frequency-weighted acceleration does not reflect the acute changes of the vibration perception thresholds due to pre-exposure to vibration. Furthermore, when testing for the vibrotactile thresholds, exposure to vibration on the day of a test might influence the results. Until further knowledge is obtained, the previous practice of 3 h avoidance of vibration exposure before assessment is recommended.

  • 9. Bye, E.
    et al.
    Foreland, S.
    Lundgren, Lennart
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kruse, K.
    Ronning, R.
    Quantitative Determination of Airborne Respirable Non-Fibrous alpha-Silicon Carbide by X-ray Powder Diffractometry2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 53, no 4, p. 403-408Article in journal (Refereed)
    Abstract [en]

    Objectives: The purpose of the present investigation was to establish a method for the determination of airborne respirable non-fibrous silicon carbide (SiC). The main application is within the industrial production of SiC. Methods: Due to the complex airborne aerosol mixture of crystalline compounds in the SiC industry, X-ray powder diffractometry was selected as the most appropriate method. Without any international standard material for the respirable fraction of non-fibrous SiC, pure and suitable products from three SiC plants in Norway were selected. These products have a median particle diameter in the range 4.4-5.1 mu m. The method is based on thin sample technique, with the dust deposited on a polycarbonate filter. Absorption correction is done by standard procedures with the use of a silver filter, situated below the polycarbonate filter. Results: The diffraction line used for quantitative determination was selected carefully. This was done to avoid interferences from quartz, cristobalite, and graphite, which all are airborne components present in the atmosphere during the industrial process. The instrumental limit of detection for the method is 12 mu g. Conclusions: This method has been used to determine airborne non-fibrous SiC in a comprehensive ongoing project in the Norwegian SiC industry for further epidemiological studies. The method is fully applicable for compliance work.

  • 10. Bye, E.
    et al.
    Føreland, S.
    Lundgren, L.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Kruse, K.
    Rønning, R.
    Quantitative determination  of airborne fibrous silicon carbide by X-ray powder diffractometry2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162Article in journal (Refereed)
  • 11.
    Bylund, Sonya H
    et al.
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Burström, Lage
    Knutsson, Anders
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine, Occupational Medicine.
    A descriptive study of women injured by hand-arm vibration2002In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 46, no 3, p. 299-307Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to describe the symptoms and the prognosis of vibration injuries in women. The investigation was based on a study of 374 women who had reported an injury due to hand-arm vibration to the Social Insurance Office or had received financial compensation from the Swedish Labor Market Insurance scheme during 1988-1997. Information on, for example, self-rated health symptoms and vibration exposure was collected by means of a questionnaire. On average, the first symptoms started after 7 yr of exposure and the first visit to a doctor took place after 11 yr. Neurological symptoms developed after a shorter period of exposure compared to vascular symptoms, 6.8 and 9.2 yr, respectively. The prevalence of numbness at the time of reporting the injury was 91% and the prevalence of white fingers was reported by 54%. The occupational group with the highest prevalence of vibration injuries was dental technicians. Two thirds of the women had stopped using vibrating machines in their work. Among the women who suffered from white fingers when they reported the injury, 50% declared impairment or no improvement of the symptoms. One woman in five was retired and the same number of women had retrained due to the occupational injury.

  • 12.
    Coenen, Pieter
    et al.
    Curtin University, Perth, Australia; VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Kingma, Idsart
    VU University Amsterdam, the Netherlands; Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands.
    Boot, Cécile
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; EMGO Institute, VU University Medical Center, Amsterdam, the Netherlands.
    Bongers, Paulien
    Body@Work, Research Center on Physical Activity, Work and Health, the Netherlands; TNO Healthy Living, Hoofddorp, the Netherlands.
    van Dieën, Jaap
    VU University Amsterdam, the Netherlands; King Abdulaziz University,Jeddah, Saudi Arabia.
    Bias and power in group-based epidemiologic studies of low-back pain exposure and outcome: effects of study size and exposure measurement efforts2015In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 59, no 4, p. 439-454Article in journal (Refereed)
    Abstract [en]

    Objectives: Exposure-outcome studies, for instance on work-related low-back pain (LBP), often classify workers into groups for which exposures are estimated from measurements on a sample of workers within or outside the specific study. The present study investigated the influence on bias and power in exposure-outcome associations of the sizes of the total study population and the sample used to estimate exposures.

    Methods: At baseline, lifting, trunk flexion, and trunk rotation were observed for 371 of 1131 workers allocated to 19 a-priori defined occupational groups. LBP (dichotomous) was reported by all workers during three years of follow-up. All three exposures were associated with LBP in this parent study (p<0.01).

    All 21 combinations of n=10,20,30 workers per group with an outcome, and k=1,2,3,5,10,15,20 workers actually being observed were investigated using bootstrapping, repeating each combination 10,000 times. Odds ratios (OR) with p-values were determined for each of these virtual studies. Average OR and statistical power (p<0.05 and p<0.01) was determined from the bootstrap distributions at each (n,k) combination.

    Results: For lifting and flexed trunk, studies including n≥20 workers, with k≥5 observed, led to an almost unbiased OR and a power >0.80 (p-level 0.05). A similar performance required n≥30 workers for rotated trunk. Small numbers of observed workers (k) resulted in biased OR, while power was, in general, more sensitive to the total number of workers (n).

    Conclusions: In epidemiologic studies using a group-based exposure assessment strategy, statistical performance may be sufficient if outcome is obtained from a reasonably large number of workers, even if exposure is estimated from only few workers per group.

  • 13.
    Edman, Katja
    et al.
    Örebro University, Department of Natural Sciences.
    Löfstedt, Håkan
    Berg, Peter
    Eriksson, Kåre
    Axelsson, Sara
    Bryngelsson, Ing-Liss
    Fedeli, Cecilia
    Exposure assessment to alpha- and beta-pinene, delta(3)-carene and wood dust in industrial production of wood pellets2003In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 47, no 3, p. 219-226Article in journal (Refereed)
    Abstract [en]

    The main aim of the study was to measure the exposure to monoterpenes (alpha- and beta-pinene and Delta(3)-carene) and wood dust during industrial production of wood pellets and briquettes. Additional aims were to compare the results from wood dust sampled on a filter with real time measurements using a direct reading instrument and to identify peak exposures to dust. Twenty-four men working at six companies involved in industrial production of wood pellets and briquettes participated in the study. Monoterpenes were measured by diffusive sampling and wood dust was measured as total dust. A data logger (DataRAM) was used for continuous monitoring of dust concentration for 18 of the participants. The sampling time was approximately 8 h. The personal exposure to monoterpenes ranged from 0.64 to 28 mg/m(3) and a statistically significant (Kruskal-Wallis test, P = 0.0002) difference in levels of monoterpenes for workers at different companies was seen. In the companies the personal exposure to wood dust varied between 0.16 and 19 mg/m(3) and for 10 participants the levels exceeded the present Swedish occupational exposure limit (OEL) of 2 mg/m(3). The levels of wood dust during the morning shift were significantly (Mann-Whitney test, P = 0.04) higher compared with the afternoon shift. Continuous registration of dust concentration showed peak values for several working operations, especially cleaning of truck engines with compressed air. For 24 workers in six companies involved in industrial production of wood pellets the personal exposure to monoterpenes was low and to wood dust high compared with the present Swedish OEL and previous studies in Swedish wood industries. Since the DataRAM can identify critical working tasks with high wood dust exposure a reduction in exposure levels could probably be achieved by changes in working routines and by the use of protective equipment

  • 14.
    Elfman, Lena
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Hogstedt, Carl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Engvall, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lampa, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Occupational and Environmental Medicine.
    Lindh, Christian H
    Department of Occupational and Environmental Medicine, Lund University Hospital.
    Acute health effects on planters of conifer seedlings treated with insecticides2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 53, no 4, p. 383-390Article in journal (Refereed)
    Abstract [en]

    No clear, acute adverse health effects could be found in planters after exposure to conifer seedlings treated with imidacloprid (Merit Forest) or cypermethrin (Forester), as compared with planting untreated seedlings. The metabolite, 3-PBA, was found in low levels in urine and was increased after exposure to cypermethrin. However, no clear relationships could be found between exposure and reported symptoms or between elevated 3-PBA levels and reported symptoms.

  • 15.
    Elihn, Karine
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Berg, Peter
    Ultrafine particle characteristics in seven industrial plants.2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 53, no 5, p. 475-484Article in journal (Refereed)
    Abstract [en]

    Ultrafine particles are considered as a possible cause of some of the adverse health effects caused by airborne particles. In this study, the particle characteristics were measured in seven Swedish industrial plants, with a special focus on the ultrafine particle fraction. Number concentration, size distribution, surface area concentration, and mass concentration were measured at 10 different job activities, including fettling, laser cutting, welding, smelting, core making, moulding, concreting, grinding, sieving powders, and washing machine goods. A thorough particle characterization is necessary in workplaces since it is not clear yet which choice of ultrafine particle metric is the best to measure in relation to health effects. Job activities were given a different order of rank depending on what particle metric was measured. An especially high number concentration (130 x 10(3) cm(-3)) and percentage of ultrafine particles (96%) were found at fettling of aluminium, whereas the highest surface area concentration (up to 3800 mum(2) cm(-3)) as well as high PM10 (up to 1 mg m(-3)) and PM1 (up to 0.8 mg m(-3)) were found at welding and laser cutting of steel. The smallest geometric mean diameter (22 nm) was found at core making (geometric standard deviation: 1.9).

  • 16.
    Eriksson, Kåre
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Liljelind, Ingrid
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Fahlén, Jessica
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Lampa, Erik
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Should styrene be sampled on the left or right shoulder?: An important question in employee self-assessment.2005In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 49, no 6, p. 529-533Article in journal (Refereed)
    Abstract [en]

    A self-operated personal sampling technique called 'self assessment of exposure' (SAE) has been suggested as an easy method for collecting inhalation exposure data, as the workers themselves are performing the sampling. Employers and employees have raised the question of whether a different estimate of the air concentration is likely to be obtained depending on whether the sampler is fastened at the left or the right shoulder. In order to answer this question, the exposure to styrene vapour in two different small enterprises within the reinforced plastics industry was measured. Seven workers participated and the air sampling was performed by diffusive sampling. We observed no statistically significant difference in the determined air concentration of styrene between the left and right shoulder (P = 0.878). The results strongly indicate that the fastening of a sampler on the left or right shoulder does not produce a difference in the estimation of the inhalation exposure. SAE can thus be used to collect reliable exposure data of styrene vapour. The reliability of SAE will most certainly inspire occupational hygienists, physicians and other experts to involve the workers in repeated exposure measurements. Taking the exposure variability into account, repeated measurements are crucial when evaluating acute and chronic health effects following inhalation exposure to gases and vapours from chemical hazards.

  • 17.
    Eriksson, Kåre
    et al.
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine, Occupational and Enviromental Medicine.
    Wiklund, Leif
    Dermal exposure to styrene in the fibreglass reinforced plastics industry.2004In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 48, no 3, p. 203-8Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: The aim of this study was to assess the potential dermal exposure to styrene in the fibreglass reinforced plastics industry. METHODS: Assessment was performed during spraying and rolling using a patch sampling technique. The patch was made of charcoal sandwiched between two layers of cotton fabric. Samplers were fastened at 12 different spots on a sampling overall, each spot representing a body area. One patch was fastened at the front of a cap. A patch fastened to a string worn around the neck assessed the exposure at chest level inside the clothing. Patches were fastened to cotton gloves at sites representing the dorsal side and the palm of the hand to evaluate exposure on these areas. Following sampling the patches were solvent desorbed and styrene was analysed by gas chromatography flame ionization detection. RESULTS: The potential body exposure for the participating individuals was between 544 and 17 100 mg/h with a geometric mean (GM) of 3780 mg/h. The legs, arms and outer chest in general had the highest exposures. The left and right hands had mean (GM) exposures of 344 and 433 mg/h, respectively. Styrene was determined for the patch at the inside of the clothing, indicating contamination of the dermal layer. CONCLUSIONS: The charcoal patch can be used to evaluate potential exposure to styrene. The results indicate that the dermal layer of the worker is exposed to styrene. Precautions should be performed to reduce dermal exposure.

  • 18.
    Eriksson, Kåre
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Wiklund, Leif
    Larsson, Cecilia
    National Institute for Working Life, Umeå.
    Levin, Jan-Olof
    National Institute for Working Life, Umeå.
    Dermal exposure to terpenic resin acids in Swedish carpentry workshops and sawmills2004In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 48, no 3, p. 267-275Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: The aim of this study was to evaluate dermal exposure to the resin acids abietic acid, dehydroabietic acid and 7-oxodehydroabietic acid during collecting in sawmills and during sawing in carpentry workshops, respectively. METHODS: Sampling was performed by fastening patches at 12 different areas on a sampling overall, one patch on the front of a cap, one patch on the chest inside the clothing and one patch on the inner lower right leg. Exposure of the hands was assessed by fastening patches on cotton gloves representing the dorsal sides and the palms of the left and right hands. Sampling was performed on 30 different occasions in the sawmills and in the carpentry workshops with mean sampling times of 120 and 59 min, respectively. The acids were solvent desorbed from the patches. Identification and quantification of the resin acids was performed by gas chromatography-mass spectrometry. RESULTS: The geometric means (GMs) of the potential body exposures to abietic acid, dehydroabietic acid and 7-oxodehydroabietic acid during sawing and collecting of wood from pine and spruce were 3346 and 17 247 micro g/h, respectively. The GM of the potential exposure on the hands was 3020 micro g/h in the carpentry workshops and 4365 micro g/h in the sawmills. Resin acids were detected on the inner chest and inner lower front right leg, respectively. CONCLUSIONS: There is a potential dermal exposure to terpenic resin acids in carpentry workshops as well as in sawmills. The hands have the highest exposure during sawing as well as during collecting. There is a spatial distribution of contaminants, with the outer chest, arms and legs showing the highest exposures. Resin acids also contaminated the inner chest and inner lower leg. It is necessary to take action to reduce dermal exposure to these allergenic substances.

  • 19.
    Freitag, Sonja
    et al.
    Institution for Statutory Accident Insurance and Prevention.
    Ellegast, Rolf
    Dulon, Madeleine
    Nienhaus, Albert
    Quantitative Measurement of Stressful Trunk Postures in Nursing Professions2007In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 51, no 4, p. 385-395Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION:

    The evaluation of stress to the spinal column in the provision of care has mostly concentrated on the handling of loads. However, awkward body postures alone, without load transfer, can also be stressful for the spinal column. Therefore in this study all the body postures and movements of nurses were quantitatively measured within a working shift.

    METHODS:

    The body postures were recorded with the CUELA measurement system (computer-assisted recording and long-term analysis of musculoskeletal loads), coupled to the individual, and this detected all movements of the trunk and the legs. These measurements were supported by video recordings, so that exact allocation of the measured data to the tasks performed was possible. In all, 24 shift measurements were carried out in 8 wards. Extent, frequency and duration of trunk postures were measured in three planes and assessed on the basis of several standards (DIN EN 1005-1, DIN EN 1005-4, ISO 11226).

    RESULTS:

    A mean of 1131 (+/-377) trunk inclinations of >20 degrees were performed in each shift. This corresponds to a frequency of 3.5 min(-1). A total of 237 of these inclinations lasted for >4 s. A total of 72 (+/-35) min was spent bending forward with an inclination of >20 degrees . However, the mean time spent in transferring patients (counting only the lifting process) and heavy materials was only 2 min per shift. Postures with trunk inclination of >60 degrees were adopted for a mean of 175 (+/-133) times. The main tasks responsible for this were 'bed making' (21%), 'basic care' (16%) and 'clearing up/cleaning' (16%).

    CONCLUSIONS:

    It could be shown that many stressful trunk postures are assumed in nursing work during a shift. Future preventive measures should therefore consider not only load handling but also tasks with awkward postures.

  • 20.
    Freitag, Sonja
    et al.
    Institution for Statutory Accident Insurance and Prevention in Health, Welfare Services.
    Fincke-Junod, Isabell
    Seddouki, Rachida
    Dulon, Madeleine
    Hermanns, Ingo
    Kersten, Jan Felix
    Larsson, Tore J.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Nienhaus, Albert
    Frequent Bending-An Underestimated Burden in Nursing Professions2012In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 56, no 6, p. 697-707Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to quantify the total duration per shift in which nurses work in a forward bending position over 20 degrees. Furthermore, the influence of several factors on the occurrence of sagittal trunk inclinations in nurses was investigated. Trunk postures were recorded for nine nursing home nurses from four German nursing homes and 18 hospital nurses from seven hospitals using the CUELA measurement system. A total of 79 shifts, 27 in nursing homes and 52 in hospitals, were analysed. All measurements were supported by video recordings. Specially developed software (WIDAAN 2.75) was used to synchronize the measurement data and video footage. The total duration of inclinations per shift was significantly affected by the working area (nursing home or hospital) with an increase of 25.3 min in nursing homes (95% confidence interval 2.4-48.2; P = 0.032). Another factor was the extent of personal basic care tasks performed by the nurses (P < 0.001). Nursing home nurses worked about twice as long per shift in a forward bending position compared with hospital nurses (112 versus 63 min; P < 0.001) and they assumed almost one-third more inclinations per shift (1541 versus 1170; P = 0.005). Nursing staff perform a large number of inclinations. The amount of time spent by nurses working in a forward bending position was highly dependent on the working area and the extent to which patients were in need of help. It is very likely that future preventive measures, focussing on reducing the huge amount of inclination, would reduce the physical stress in everyday nursing work substantially.

  • 21.
    Freitag, Sonja
    et al.
    BGW–Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services.
    Seddouki, Rachida
    UKE–University Medical Centre Hamburg-Eppendorf.
    Dulon, Madeleine
    BGW–Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services.
    Kersten, Jan Felix
    UKE–University Medical Centre Hamburg-Eppendorf.
    Larsson, Tore J.
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Nienhaus, Albert
    UKE–University Medical Centre Hamburg-Eppendorf.
    The effect of working position on trunk posture and exertion for routine nursing tasks: An Experimental Study2014In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 58, no 3, p. 317-325Article in journal (Refereed)
    Abstract [en]

    Objectives:To examine the influence of the two following factors on the proportion of time that nurses spend in a forward-bending trunk posture: (i) the bed height during basic care activities at the bedside and (ii) the work method during basic care activities in the bathroom. A further aim was to examine the connection between the proportion of time spent in a forward-bending posture and the perceived exertion.Methods:Twelve nurses in a geriatric nursing home each performed a standardized care routine at the bedside and in the bathroom. The CUELA (German abbreviation for 'computer-Assisted recording and long-Term analysis of musculoskeletal loads') measuring system was used to record all trunk inclinations. Each participant conducted three tests with the bed at different heights (knee height, thigh height, and hip height) and in the bathroom, three tests were performed with different work methods (standing, kneeling, and sitting). After each test, participants rated their perceived exertion on the 15-point Borg scale (6 = no exertion at all and 20 = exhaustion).Results:If the bed was raised from knee to thigh level, the proportion of time spent in an upright position increased by 8.2% points. However, the effect was not significant (P = 0.193). Only when the bed was raised to hip height, there was a significant increase of 19.8% points (reference: thigh level; P = 0.003) and 28.0% points (reference: knee height; P < 0.001). Bathroom tests: compared with the standing work method, the kneeling and sitting work methods led to a significant increase in the proportion of time spent in an upright posture, by 19.4% points (P = 0.003) and 25.7% points (P < 0.001), respectively. The greater the proportion of time spent in an upright position, the lower the Borg rating (P < 0.001) awarded.Conclusions:The higher the proportion of time that nursing personnel work in an upright position, the less strenuous they perceive the work to be. Raising the bed to hip height and using a stool in the bathroom significantly increase the proportion of time that nursing personnel work in an upright position. Nursing staff can spend a considerably greater proportion of their time in an ergonomic posture if stools and height-Adjustable beds are provided in healthcare institutions.

  • 22.
    Geng, Qiuqing
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Holmer, I.
    Hartog, D.E.A.
    Havenith, G.
    Jay, O.
    Malchaire, J.
    Piette, A.
    Rintamaki, H.
    Rissanen, S.
    Temperature limit values for touching cold surfaces with the fingertip2006In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 50, no 8, p. 851-862Article in journal (Refereed)
    Abstract [en]

    Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfaces. Methods: Data were collected in four laboratories with a total of 20 males and 20 females performing a grand total of 1655 exposures. Each touched polished blocks of aluminium, stainless steel, nylon-6 and wood using the distal phalanx of the index finger with a contact force of 1.0, 2.9 and 9.8 N, at surface temperatures from +2 to -40°C for a maximum duration of 120 s. Conditions were selected in order to elicit varying rates of skin cooling upon contact. Contact temperature (TC) of the fingertip was measured over time using a T-type thermocouple. Results: A database obtained from the experiments was collated and analysed to characterize fingertip contact cooling across a range of materials and surface temperatures. The database was subsequently used to develop a predictive model to describe the contact duration required for skin contact temperature to reach the physiological criteria of onset of pain (15°C), onset of numbness (7°C) and onset of frostbite risk (0°C). Conclusions: The data reflect the strong link between the risk of skin damage and the thermal properties of the material touched. For aluminium and steel, skin temperatures of 0°C occurs within 2-6 s at surface temperatures of -15°C. For non-metallic surfaces, onset of numbness occurs within 15-65 s of contact at -35°C and onset of cold pain occurs within 5 s of contact at -20°C. The predictive model subsequently developed was a non-linear exponential expression also reflecting the effects of material thermal properties and initial temperature. This model provides information for the protection of workers against the risk of cold injury by establishing the temperature limits of cold touchable surfaces for a broad range of materials, and it is now proposed as guidance values in a new international standard. © The Author 2006. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  • 23.
    Gupta, Nidhi
    et al.
    National Research Centre for the Working Environment, Copenhagen .
    Lund Rasmussen, Charlotte
    National Research Centre for the Working Environment, Copenhagen .
    Holtermann, Andreas
    National Research Centre for the Working Environment, Copenhagen .
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Time-based data in occupational studies - the whys, the hows and some remaining challenges in Compositional Data Analysis (CoDA)2019In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162Article in journal (Refereed)
  • 24.
    Gustavsson, Marcus
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Meiby, Elinor
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Gylestam, Daniel
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Dahlin, Jakob
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Spanne, Mårten
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Karlsson, Daniel
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Dalene, Marianne
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Skarping, Gunnar
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Tveterås, Björn Oscar
    Pedersen, Age Engen
    Adsorption Efficiency of Respirator Filter Cartridges for Isocyanates2010In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, no 4, p. 377-390Article in journal (Refereed)
    Abstract [en]

    In some industries, the temperature and the humidity will vary greatly between different work places, such as outdoor work in arctic or tropical climates. There is therefore a need to test respirator filters at conditions that simulate conditions that are relevant for the industries that they are used in. Filter cartridges were exposed to controlled atmospheres of varying isocyanate concentration, air humidity, and temperature in an exposure chamber. For isocyanic acid (ICA) and methyl isocyanate (MIC), the exposure concentrations were between 100 and 200 p.p.b., monitored using a proton transfer reaction mass spectrometer. ICA and MIC were generated by continuous thermal degradation of urea and dimethylurea. The breakthrough was studied by collecting air samples at the outlet of the filter cartridges using impinger flasks or dry samplers with di-n-butylamine as derivatization reagent for isocyanates followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. For hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI), the exposure concentrations were between 4 and 20 p.p.b. and were generated by wet membrane permeation. To reveal the profile of adsorption in different layers of the respirator filters, representative samples from each of the layers were hydrolyzed. The hydrolysis products hexamethylene diamine and isophorone diamine were determined after derivatization with pentafluoropropionic anhydride (PFPA) followed by LC-MS/MS analysis. The two filter types studied efficiently absorbed both ICA and MIC. There was no trend of impaired performance throughout 48-h exposure tests. Even when the filters were exposed to high concentrations (similar to 200 p.p.b.) of ICA and MIC for 96 h, the isocyanates were efficiently absorbed with only a limited breakthrough. The majority of the HDI and IPDI (> 90%) were absorbed in the top layers of the absorbant, but HDI and IPDI penetrated farther down into the respirator filters during 120 h of exposure as compared to 16 h exposure.

  • 25.
    Gylestam, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Gustavsson, Marcus
    Karlsson, Daniel
    Stockholm University, Faculty of Science, Department of Analytical Chemistry. Institutet för Kemisk Analys Norden AB, Sweden.
    Dalene, Marianne
    Stockholm University, Faculty of Science, Department of Analytical Chemistry. Institutet för Kemisk Analys Norden AB, Sweden.
    Skarping, Gunnar
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Sampling of Respirable Isocyanate Particles2014In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 58, no 3, p. 340-354Article in journal (Refereed)
    Abstract [en]

    An advanced design of a denuder impactor (DI) sampler has been developed for characterization of possible airborne isocyanate exposure in different particle size fractions. The sampler is equipped with 12 different parallel denuder tubes, 4 impaction stages with the cut-off values (d50) of: 9.5, 4, 2.5 and 1 µm, and an end filter that collects particles < 1 µm. All collecting parts were impregnated with di-n-butylamine DBA as the reagent in a mixture with acetic acid. The performance of the DI sampler was studied on a standard atmosphere containing gas and particulate isocyanates. The isocyanate atmosphere was generated by liquid permeation of 2,4-, 2,6-Toluene Diisocyanate (TDI), 1,6-Hexamethylene Diisocyanate (HDI) and Isophorone Diisocyanate (IPDI). 4,4’-Methylene Diphenyl Diisocyanate (MDI) particles were generated by heating of technical MDI and condensing the mixture of gas and particle-borne MDI in an atmosphere containing mixed salt particles. The study was performed in a 0.85 m3 environmental chamber with stainless steel walls. With the advancement of the DI sampler it is now possible to collect isocyanate particle samples for up to 320min. The performance of the DI sampler is essentially unaffected by the humidity. The DI sampler and the ASSET™ EZ4-NCO sampler (Sigma-Aldrich/Supelco, Bellefonte, PA, USA) gave similar results. Sample losses within the DI sampler are low. In the environmental chamber it was observed that the particle distribution may be affected by the humidity and ageing. A scanning mobility particle sizer (SMPS) was used to separate a flow of selected fractions containing MDI particles from mixed MDI and salt particles. The particle-size distribution had a maximum at about 300nm, but later in the environmental chamber 1 µm dominated. The distribution was very different as compared to with only NaCl or MDI present. The biological relevance for studying isocyanate nano particles is significant as these have the possibility to reach the lower airways where allergic reactions may occur. SMPS and isocyanate air sampling can be used for the investigation of isocyanate nano particles.

  • 26.
    Gylestam, Daniel
    et al.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Riddar, Jakob B.
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Karlsson, Daniel
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Dahlin, Jakob
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Dalene, Marianne
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Skarping, Gunnar
    Stockholm University, Faculty of Science, Department of Analytical Chemistry.
    Dry Sampling of Gas-Phase Isocyanates and Isocyanate Aerosols from Thermal Degradation of Polyurethane2014In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 58, no 1, p. 28-49Article in journal (Refereed)
    Abstract [en]

    The performance of a dry sampler, with an impregnated denuder in series with a glass fibre filter, using di-n-butylamine (DBA) for airborne isocyanates (200ml min−1) is investigated and compared with an impinger flask with a glass fibre filter in series (1 l min−1). An exposure chamber containing 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and 2,4- and 2,6-toluene diisocyanate (TDI) in the concentration range of 5–205 μg m−3 [0.7–33 p.p.b.; relative humidity (RH) 50%], generated by gas- and liquid-phase permeation, was used for the investigation. The precision for the dry sampling for five series with eight samplers were in the range of 2.0–6.1% with an average of 3.8%. During 120-min sampling (n = 4), no breakthrough was observed when analysing samplers in series. Sixty-four exposed samplers were analysed after storage for 0, 7, 14, and 21 days. No breakdown of isocyanate derivatives was observed. Twenty-eight samplers in groups of eight were collecting isocyanates during 0.5–32h. Virtually linear relationships were obtained with regard to sampling time and collected isocyanates with correlation coefficients in the range of 0.998–0.999 with the intercept close to the origin. Pre- or post-exposure to ambient air did not affect the result. Dry sampling (n = 48) with impinger-filter sampling (n = 48) of thermal decomposition product of polyurethane polymers, at RH 20, 40, 60, and 90%, was compared for 11 isocyanate compounds. The ratio between the different isocyanates collected with dry samplers and impinger-filter samplers was in the range of 0.80–1.14 for RH = 20%, 0.8–1.25 for RH = 40%, 0.76–1.4 for RH = 60%, and 0.72–3.7 for RH = 90%. Taking into account experimental errors, it seems clear that isocyanic acid DBA derivatives are found at higher levels in the dry samples compared with impinger-filter samplers at elevated humidity. The dry sampling using DBA as the reagent enables easy and robust sampling without the need of field extraction.

  • 27.
    Hagström, Katja
    et al.
    Örebro University, Department of Natural Sciences.
    Lundholm, Cecilia
    Eriksson, Kåre
    Liljelind, Ingrid
    Variability and determinants of wood dust and resin acid exposure during wood pellet production: measurement strategies and bias in assessing exposure-response relationships2008In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 52, no 8, p. 685-694Article in journal (Refereed)
    Abstract [en]

    Production of wood pellets is a relatively new and expanding industry in which the exposure profiles differ from those in other wood-processing industries like carpentries and sawmills where there are lower levels of wood dust. Sixty-eight personal exposure measurements of wood dust (inhalable and total dust) and resin acids were collected for 44 participants at four production plants located in Sweden. Results were used to estimate within- and between-worker variability and to identify uniformly exposed groups and determinants of exposure. In addition, overexposure, whether the risk of the long-term mean exposure of a randomly selected worker exceeding the occupational exposure limit is acceptably low, was calculated as well as the underestimation of the exposure–response relationship (attenuation). Greater variability in exposure between work shifts than between workers was observed with the within-worker variation accounting for 57–99% of the total variance in the individual-based model. Several uniformly exposed groups were detected but were mostly associated with a between-worker variation of zero which is an underestimation of the between-worker variation but an indication of uniformly exposed groups. Cleaning was identified as a work task that increases exposure slightly; so reducing workers’ exposure during this operation is advisable. The levels of wood dust were high and were found to pose unacceptable risks of overexposure at all plants for inhalable dust and at three out of four plants for total dust. These findings show that exposure to dust needs to be reduced in this industry. For resin acids, the exposure was classed as acceptable at all plants. According to an individual-based model constructed from the data, the level of attenuation was high, and thus there would be substantial bias in derived dose–response relationships.

  • 28.
    Hedlund, Ulf
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Jonsson, Håkan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Eriksson, Kåre
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Järvholm, Bengt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Exposure-response of silicosis mortality in Swedish iron ore miners.2008In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 52, no 1, p. 3-7Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To assess the exposure-response relationship between exposure to quartz and fatal silicosis. METHODS: The mortality from silicosis in 7729 miners was analyzed and compared to their estimated exposure to respirable quartz. The miners had been working as a miner for at least 1 year between 1923 and 1996. Their mortality between 1952 and 2001 was studied by using information from the national cause of death register. Both underlying and contributing causes of death were considered in the analysis. The exposure to quartz was estimated from job titles and using 3239 measurements of personal exposure to respirable quartz from 1965 to 1999. The mortality rates were adjusted to attained age and years of birth using a Poisson regression. RESULTS: The median cumulative exposure among the 7729 miners was 0.9 mg x years m(-3). There were 58 deaths from silicosis. Their median cumulative exposure was 4.8 mg x years m(-3). The crude mortality rate was 53 cases per 100,000 person-years with an exposure-response relationship. CONCLUSION: There seems to be an increased risk of fatal silicosis at exposure levels around 3 mg x years m(-3) for respirable quartz.

  • 29.
    Heiden, Marina
    et al.
    Univ Gavle, Ctr Musculoskeletal Res, Dept Occupat & Publ Hlth Sci, S-80176 Gavle, Sweden..
    Mathiassen, Svend Erik
    Univ Gavle, Ctr Musculoskeletal Res, Dept Occupat & Publ Hlth Sci, S-80176 Gavle, Sweden..
    Garza, Jennifer
    Univ Gavle, Ctr Musculoskeletal Res, Dept Occupat & Publ Hlth Sci, S-80176 Gavle, Sweden.;UConn Hlth, Div Occupat & Environm Med, Farmington, CT 06030 USA..
    Liv, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centre for Research and Development, Gävleborg. Univ Gavle, Ctr Musculoskeletal Res, Dept Occupat & Publ Hlth Sci, S-80176 Gavle, Sweden..
    Wahlström, Jens
    Umea Univ, Dept Publ Hlth & Clin Med, Occupat & Environm Med, S-90187 Umea, Sweden..
    A Comparison of Two Strategies for Building an Exposure Prediction Model2016In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 60, no 1, p. 74-89Article in journal (Refereed)
    Abstract [en]

    Cost-efficient assessments of job exposures in large populations may be obtained from models in which 'true' exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising 'true' exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.

  • 30. Heiden, Marina
    et al.
    Mathiassen, Svend Erik
    Garza, Jennifer
    Liv, Per
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    A Comparison of Two Strategies for Building an Exposure Prediction Model.2016In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 60, no 1, p. 74-89Article in journal (Refereed)
    Abstract [en]

    Cost-efficient assessments of job exposures in large populations may be obtained from models in which 'true' exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising 'true' exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.

  • 31.
    Heiden, Marina
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Garza, Jennifer
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Division of Occupational and Environmental Medicine, UConn Health, Farmington, CT, United States .
    Liv, Per
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Centre for Research and Development, Uppsala University/County Council of Gävleborg.
    Wahlström, Jens
    Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, Umeå, Sweden.
    A comparison of two strategies for building an exposure prediction model2016In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 60, no 1, p. 74-89Article in journal (Refereed)
    Abstract [en]

    Cost-efficient assessments of job exposures in large populations may be obtained from models in which “true” exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising “true” exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users.

  • 32.
    Klasson, Maria
    et al.
    Örebro University, School of Health Sciences. Department of Occupational and Environmental Medicine, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Bryngelsson, Ing-Liss
    Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
    Pettersson, Carin
    Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
    Husby, Bente
    Department of Occupational and Environmental Medicine, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Arvidsson, Helena
    Department of Occupational and Environmental Medicine, Örebro University Hospital, Örebro, Sweden.
    Westberg, Håkan
    Örebro University, School of Science and Technology. Department of Occupational and Environmental Medicine, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Occupational Exposure to Cobalt and Tungsten in the Swedish Hard Metal Industry: Air Concentrations of Particle Mass, Number, and Surface Area2016In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 60, no 6, p. 684-699Article in journal (Refereed)
    Abstract [en]

    Exposure to cobalt in the hard metal industry entails severe adverse health effects, including lung cancer and hard metal fibrosis. The main aim of this study was to determine exposure air concentration levels of cobalt and tungsten for risk assessment and dose-response analysis in our medical investigations in a Swedish hard metal plant. We also present mass-based, particle surface area, and particle number air concentrations from stationary sampling and investigate the possibility of using these data as proxies for exposure measures in our study. Personal exposure full-shift measurements were performed for inhalable and total dust, cobalt, and tungsten, including personal real-time continuous monitoring of dust. Stationary measurements of inhalable and total dust, PM2.5, and PM10 was also performed and cobalt and tungsten levels were determined, as were air concentration of particle number and particle surface area of fine particles. The personal exposure levels of inhalable dust were consistently low (AM 0.15mg m(-3), range <0.023-3.0mg m(-3)) and below the present Swedish occupational exposure limit (OEL) of 10mg m(-3) The cobalt levels were low as well (AM 0.0030mg m(-3), range 0.000028-0.056mg m(-3)) and only 6% of the samples exceeded the Swedish OEL of 0.02mg m(-3) For continuous personal monitoring of dust exposure, the peaks ranged from 0.001 to 83mg m(-3) by work task. Stationary measurements showed lower average levels both for inhalable and total dust and cobalt. The particle number concentration of fine particles (AM 3000 p·cm(-3)) showed the highest levels at the departments of powder production, pressing and storage, and for the particle surface area concentrations (AM 7.6 µm(2)·cm(-3)) similar results were found. Correlating cobalt mass-based exposure measurements to cobalt stationary mass-based, particle area, and particle number concentrations by rank and department showed significant correlations for all measures except for particle number. Linear regression analysis of the same data showed statistically significant regression coefficients only for the mass-based aerosol measures. Similar results were seen for rank correlation in the stationary rig, and linear regression analysis implied significant correlation for mass-based and particle surface area measures. The mass-based air concentration levels of cobalt and tungsten in the hard metal plant in our study were low compared to Swedish OELs. Particle number and particle surface area concentrations were in the same order of magnitude as for other industrial settings. Regression analysis implied the use of stationary determined mass-based and particle surface area aerosol concentration as proxies for various exposure measures in our study.

  • 33.
    Lampa, Erik G.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Leif
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Liljelind, Ingrid E.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Bergdahl, Ingvar A.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Optimizing occupational exposure measurement strategies when estimating the log-scale arithmetic mean value: An example from the reinforced plastics industry2006In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 50, no 4, p. 371-377Article in journal (Refereed)
    Abstract [en]

    When assessing occupational exposures, repeated measurements are in most cases required. Repeated measurements are more resource intensive than a single measurement, so careful planning of the measurement strategy is necessary to assure that resources are spent wisely. The optimal strategy depends on the objectives of the measurements. Here, two different models of random effects analysis of variance (ANOVA) are proposed for the optimization of measurement strategies by the minimization of the variance of the estimated log-transformed arithmetic mean value of a worker group, i.e. the strategies are optimized for precise estimation of that value. The first model is a one-way random effects ANOVA model. For that model it is shown that the best precision in the estimated mean value is always obtained by including as many workers as possible in the sample while restricting the number of replicates to two or at most three regardless of the size of the variance components. The second model introduces the ‘shared temporal variation’ which accounts for those random temporal fluctuations of the exposure that the workers have in common. It is shown for that model that the optimal sample allocation depends on the relative sizes of the between-worker component and the shared temporal component, so that if the between-worker component is larger than the shared temporal component more workers should be included in the sample and vice versa. The results are illustrated graphically with an example from the reinforced plastics industry. If there exists a shared temporal variation at a workplace, that variability needs to be accounted for in the sampling design and the more complex model is recommended.

  • 34.
    Landberg, Hanna E.
    et al.
    Inst Lab Med, Dept Occupat & Environm Med, Univ Hosp, Lund, Sweden.
    Berg, Peter
    Dept Occupat & Environm Med, Region Örebro County, Örebro, Sweden.
    Andersson, Lennart
    Dept Occupat & Environm Med, Region Örebro County, Örebro, Sweden.
    Bergendorf, Ulf
    Inst Lab Med, Dept Occupat & Environm Med, Univ Hosp, Lund, Sweden.
    Karlsson, Jan-Eric
    Inst Lab Med, Dept Occupat & Environm Med, Univ Hosp, Lund, Sweden.
    Westberg, Håkan
    Örebro University Hospital. Dept Occupat & Environm Med, Örebro University Hospital, Örebro, Sweden.
    Tinnerberg, Håkan
    Inst Lab Med, Dept Occupat & Environm Med, Univ Hosp, Lund, Sweden.
    Comparison and Evaluation of Multiple Users' Usage of the Exposure and Risk Tool: Stoffenmanager 5.12015In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 59, no 7, p. 821-835Article in journal (Refereed)
    Abstract [en]

    Stoffenmanager is an exposure and risk assessment tool that has a control banding part, with risk bands as outcome and a quantitative exposure assessment part, with the 90th percentile of the predicted exposure as a default outcome. The main aim of the study was to investigate whether multiple users of Stoffenmanager came to the same result when modelling the same scenarios. Other aims were to investigate the differences between outcomes of the control banding part with the measured risk quota and to evaluate the conservatism of the tool by testing whether the 90th percentiles are above the measured median exposures. We investigated airborne exposures at companies in four different types of industry: wood, printing, metal foundry, and spray painting. Three scenarios were modelled and measured, when possible, at each company. When modelled, 13 users visited each company on the same occasion creating individual assessments. Consensus assessments were also modelled for each scenario by six occupational hygienists. The multiple users' outcomes were often spread over two risk bands in the control banding part, and the differences in the quantitative exposure outcomes for the highest and lowest assessments per scenario varied between a factor 2 and 100. Four parameters were difficult for the users to assess and had a large impact on the outcome: type of task, breathing zone, personal protection, and control measures. Only two scenarios had a higher measured risk quota than predicted by the control banding part, also two scenarios had slightly higher measured median exposure value than modelled consensus in the quantitative exposure assessment part. Hence, the variability between users was large but the model performed well.

  • 35.
    Lidén, Göran
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    The European Commission Tries to Define Nanomaterials2011In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 55, no 1, p. 1-5Article in journal (Refereed)
    Abstract [en]

    In 2010, the European Commission held a short consultation on a proposed definition for nanomaterials, to be used in European Union legislation and programmes. This was in response to a European Parliament resolution, and the definition followed a proposal by one of the Commission's scientific committees. The definition has three parts: on size distribution, size of internal structural elements, and surface area; a material caught by any of these parts meets the definition. There are a number of problems. The definition seems to be written with engineered nanomaterials in mind but as written applies to non-supplied materials, such as smokes. The structural element component seems to capture items such as sunscreen and tennis rackets, which include nanomaterials. Use of the definition will require some international standards, which have yet to be written and which will involve some difficult decisions. It is understandable why there are both size and surface area requirements, but they are not wholly consistent. The Commission plans a further consultation in 2012, but it might be better to delay this until after the standardisation work.

  • 36.
    Lidén, Göran
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Surakka, Jouni
    A headset-mounted mini sampler for measuring exposure to welding aerosol in the breathing zone.2009In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 53, no 2, p. 99-116Article in journal (Refereed)
    Abstract [en]

    There is a need for a small personal aerosol sampler for measuring occupational exposure to airborne particles in the breathing zone. Existing aerosol samplers are too large to be mounted inside modern welder's protective equipment without disturbing the worker. A headset-mounted mini sampler has been developed to fill this gap with focus on manganese exposure. This mini sampler is easy to use and can be mounted inside modern, slimline welder's face shield. The mini sampler is based on a commercially available 13-mm filter holder that has been modified to incorporate an inlet nozzle made of aluminium. The nominal flow rate of the mini sampler is 0.75 l min(-1). The mini sampler is to be worn mounted on a headset, modified from professional microphone headsets. Several aspects related to using the mini sampler have been tested by personal and static sampling at five workplaces and in the laboratory. Four headset models were tested for their suitability as a sampler holder, of which three models were accepted by the welders. The sampling bias of the mini sampler versus the IOM sampler and the open-face 25-mm filter holder, respectively, depends on the size distribution of the sampled aerosol. At the lowest encountered mass concentration ratio of the open-face 25-mm filter holder to the IOM sampler (0.65), the sampling bias of the mini sampler versus the IOM sampler is approximately -26% and versus the open-face 25-mm filter holder is approximately +12%. For manganese, the negative root mean square (RMS) sampling bias of the mini sampler versus the IOM sampler is -0.046 and versus the open-face 25-mm filter holder is non-significant. Both these biases are statistically non-significant. The mini sampler can therefore be employed for determining welders' occupational exposure to manganese. The pressure drop across the filter can become excessive due to the small filtration area. Compared to the Casella Apex pump, the SKC AirChek2000 pump was generally found to be able to keep its flow rate constant within +/-5% at higher concentrations and for longer sampling times. Our results indicate that the inhalable fraction of the welding aerosol mass at the visited plants only consisted of 25-55% welding fume particles (agglomerates of coagulated particles generated by nucleation/condensation). The rest of the mass is made up of particles from spattering and grinding. More than 65% of manganese is generally found in the fume particles. The weighing precision of 13-mm filters is 2.2 microg. The RMS sample loss due to transport when loaded samples are shipped by mail in padded envelopes is 6 microg. Both figures are very low in comparison to the mass expected to be collected by personal sampling, generally exceeding 200 microg. The headset-mounted mini sampler is user-friendly, easy to adjust individually, does not disturb the welder during sampling and allows sampling inside personal protective equipment. The headset mounting arrangement improves personal sampling as it maintains the sampler close to the nose/mouth during the whole sampling period. This study shows that the developed headset-mounted mini sampler is suitable for assessing exposure to manganese in welding aerosol.

  • 37.
    Lidén, Göran
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Waher, Jüri
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Experimental investigation of the concept of a 'breathing zone' using a mannequin exposed to a point source of inertial/sedimenting particles emitted with momentum2010In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, no 1, p. 100-116Article in journal (Refereed)
    Abstract [en]

    An inhaling mannequin, CALTOOL, was used in a specially ventilated room to compare the concentrations inhaled with those sampled by samplers mounted across the breathing zone. The CALTOOL is made from metal sheets and consists of a cylindrical torso (42 x 24 x 54 cm) with a circular cylinder as head. A circular nozzle simulates the mouth. This nozzle is part of a cassette that holds a filter. The inhalation rate is not periodic but kept constant at nominally 20 l min(-1). The CALTOOL was placed in a horizontal air stream ( approximately 10 cm s(-1)) either facing or back to the wind. In front of the lower chest of the CALTOOL, a particle source was mounted which emitted particles with a momentum directed upwards at an angle of 45 degrees towards the CALTOOL. Five monodisperse aluminium oxide powders were used as test aerosols. The mass median aerodynamic diameters of the test aerosols ranged approximately 10 to 95 mum. Six conically shaped aerosol samplers were mounted horizontally and over the breathing zone of the CALTOOL, one on each shoulder, three across the upper torso, and one at the lower torso centre. Four to six runs per test aerosol and CALTOOL orientation in the airflow were conducted. The samples were analysed gravimetrically. The concentration ratio aerosol sampler to the CALTOOL cassette was determined for the investigated mounting positions. The results showed that when the CALTOOL was exposed to particles emitted with momentum from a point source in front of the lower chest, the variation in concentration over the breathing zone was large. The ratio of the concentration sampled by an aerosol sampler mounted somewhere within the breathing zone to the CALTOOL cassette concentration, would, for specific particle sizes, easily differ by a factor of 3, but may extend up to 10-100, depending on the particular conditions. The basic concept of a breathing zone consisting of a hemisphere of radius 25-30 cm is therefore not well suited for workers handling a point source emitting large particles. For such sampling situations, it is suggested that the radius of the breathing zone is reduced to 10 cm, which may be achieved by a head-mounted sampler.

  • 38.
    Liljelind, I.
    et al.
    Dept Publ Hlth & Clin Med, Umeå Univ, Umeå, Sweden.
    Norberg, C.
    Örebro University Hopital, Örebro, Sweden; Department of Natural Sciences, Örebro University, Örebro, Sweden.
    Egelrud, L.
    IVL Swedish Environm Res Inst Ltd, Stockholm, Sweden.
    Westberg, Håkan
    Örebro University, School of Science and Technology. Örebro University Hospital, Örebro, Sweden.
    Eriksson, K.
    Dept Occupat & Environm Med, Umeå Univ Hosp, Umeå, Sweden.
    Nylander-French, L. A.
    Dept Environm Sci & Engn, Gillings Sch Global Publ Hlth, Univ N Carolina, Chapel Hill NC, USA.
    Dermal and Inhalation Exposure to Methylene Bisphenyl Isocyanate (MDI) in Iron Foundry Workers2010In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, no 1, p. 31-40Article in journal (Refereed)
    Abstract [en]

    Diisocyanates are a group of chemically reactive agents, which are used in the production of coatings, adhesives, polyurethane foams, and parts for the automotive industry and as curing agents for cores in the foundry industry. Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) is associated with respiratory sensitization and occupational asthma. However, limited research has been performed on the quantitative evaluation of dermal and inhalation exposure to MDI in occupationally exposed workers. The objective of this research was to quantify dermal and inhalation exposure levels in iron foundry workers. Workers involved in mechanized moulding and mechanized production of cores were monitored: 12 core makers, 2 core-sand preparers, and 5 core installers. Personal breathing-zone levels of MDI were measured using impregnated filter sampling. Dermal exposure to MDI was measured using a tape-strip technique. Three or five consecutive tape-strip samples were collected from five exposed skin areas (right and left forefingers, left and right wrists, and forehead). The average personal air concentration was 0.55 mu g m(-3), 50-fold lower than the Swedish occupational exposure limit of 30 mu g m(-3). The core makers had an average exposure of 0.77 mu g m(-3), which was not significantly different from core installers' and core-sand preparers' average exposure of 0.16 mu g m(-3) (P = 0.059). Three core makers had a 10-fold higher inhalation exposure than the other core makers. The core makers' mean dermal exposure at different skin sites varied from 0.13 to 0.34 mu g while the two other groups' exposure ranged from 0.006 to 0.062 mu g. No significant difference was observed in the MDI levels between the skin sites in a pairwise comparison, except for left forefinger compared to left and right wrist (P < 0.05). In addition, quantifiable but decreasing levels of MDI were observed in the consecutive tape strip per site indicating MDI penetration into the skin. This study indicates that exposure to MDI can be quantified on workers' skin even if air levels are close to unquantifiable. Thus, the potential for uncured MDI to deposit on and penetrate into the skin is demonstrated. Therefore, dermal exposure along with inhalation exposure to MDI should be measured in the occupational settings where MDI is present in order to shed light on their roles in the development of occupational isocyanate asthma.

  • 39.
    Liljelind, Ingrid E
    et al.
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine, Occupational and Enviromental Medicine.
    Michel, Ingegerd
    Damm, Maria
    Eriksson, Kåre A
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine, Occupational and Enviromental Medicine.
    Development, evaluation and data acquired with a tape-stripping technique for measuring dermal exposure to budesonide at a pharmaceutical manufacturing site.2007In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 51, no 4, p. 407-13Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: Although corticosteroids have been used for over 50 years as anti-inflammatory and anti-proliferative agents, few studies have examined their exposure levels and health effects on workers employed in the corticosteroid manufacturing industry. The aims of the study reported here were to develop a tape-stripping technique for monitoring budesonide (a corticosteroid used in inhalators for treating respiratory diseases) and to apply the method in a pilot study to estimate the potential dermal exposure to budesonide among workers at a pharmaceutical formulation site. METHODS: The tape-stripping method was evaluated by applying 0.5 and 2.07 microg of budesonide dissolved in ethanol on tape strips. The same amounts were also applied on a cleaned glass plate and human skin of volunteers, which were then stripped by series of tapes immediately, and 30 min later, the amounts collected by the tapes were measured. Finally, the technique was used to study the exposure of budesonide among eight employees at a pharmaceutical industry site. Three exposure sites were tested: the tip of the forefinger, palm of the hand and ventral part of the lower arm. Five consecutive tape strips per sampling site were used in both the recovery studies and the field study. RESULTS: The mean overall recoveries from spiked tapes and the glass plate were 96 and 81%, respectively, while for human skin the corresponding figure was 38%, (for applications of 2.07 microg; no detectable amounts were recovered from human skin after 0.5 microg applications). The recovered amount was found on two consecutive tapes after 0 min, but only on the first tape strip after 30 min. The inter-individual variability was 4-fold. In the field, quantifiable amounts were found for four of eight employees and a concentration gradient was detected along the two or three consecutive tape strips. The tip of the forefinger and the palm of the hand were the most highly exposed sites to budesonide. CONCLUSIONS: A tape-stripping method can be used to determine potential dermal exposure to budesonide. The results also indicate that budesonide is taken up by the skin of operators who are exposed to the substance at their workplace.

  • 40.
    Liljelind, Ingrid
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Norberg, C
    Egelrud, L
    Westberg, H
    Eriksson, Kåre
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nylander-French, L A
    Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) in iron foundry workers.2010In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, no 1, p. 31-40Article in journal (Refereed)
    Abstract [en]

    Diisocyanates are a group of chemically reactive agents, which are used in the production of coatings, adhesives, polyurethane foams, and parts for the automotive industry and as curing agents for cores in the foundry industry. Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) is associated with respiratory sensitization and occupational asthma. However, limited research has been performed on the quantitative evaluation of dermal and inhalation exposure to MDI in occupationally exposed workers. The objective of this research was to quantify dermal and inhalation exposure levels in iron foundry workers. Workers involved in mechanized moulding and mechanized production of cores were monitored: 12 core makers, 2 core-sand preparers, and 5 core installers. Personal breathing-zone levels of MDI were measured using impregnated filter sampling. Dermal exposure to MDI was measured using a tape-strip technique. Three or five consecutive tape-strip samples were collected from five exposed skin areas (right and left forefingers, left and right wrists, and forehead). The average personal air concentration was 0.55 microg m(-3), 50-fold lower than the Swedish occupational exposure limit of 30 microg m(-3). The core makers had an average exposure of 0.77 microg m(-3), which was not significantly different from core installers' and core-sand preparers' average exposure of 0.16 microg m(-3) (P = 0.059). Three core makers had a 10-fold higher inhalation exposure than the other core makers. The core makers' mean dermal exposure at different skin sites varied from 0.13 to 0.34 microg while the two other groups' exposure ranged from 0.006 to 0.062 microg. No significant difference was observed in the MDI levels between the skin sites in a pairwise comparison, except for left forefinger compared to left and right wrist (P < 0.05). In addition, quantifiable but decreasing levels of MDI were observed in the consecutive tape strip per site indicating MDI penetration into the skin. This study indicates that exposure to MDI can be quantified on workers' skin even if air levels are close to unquantifiable. Thus, the potential for uncured MDI to deposit on and penetrate into the skin is demonstrated. Therefore, dermal exposure along with inhalation exposure to MDI should be measured in the occupational settings where MDI is present in order to shed light on their roles in the development of occupational isocyanate asthma.

  • 41.
    Liljelind, Ingrid
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Pettersson, Hans
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Leif
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Toomingas, Allan
    Karolinska Institutet, Institute of Environmental Medicine, Unit of Occupational Medicine SE-171 76 Stockholm, Sweden.
    Lundström, Ronnie
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Determinants Explaining the Variability of Hand-Transmitted Vibration Emissions From Two Different Work Tasks: Grinding and Cutting Using Angle Grinders2013In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 57, no 8, p. 1065-1077Article in journal (Refereed)
    Abstract [en]

    Background: There are numerous factors including physical, biomechanical, and individual that influence exposure to hand-transmitted vibration (HTV) and cause variability in the exposure measurements. Knowledge of exposure variability and determinants of exposure could be used to improve working conditions. We performed a quasi-experimental study, where operators performed routine work tasks in order to obtain estimates of the variance components and to evaluate the effect of determinants, such as machine–wheel combinations and individual operator characteristics.

    Methods: Two pre-defined simulated work tasks were performed by 11 operators: removal of a weld puddle of mild steel and cutting of a square steel pipe. In both tasks, four angle grinders were used, two running on compressed air and two electrically driven. Two brands of both grinding and cutting wheels were used. Each operator performed both tasks twice in a random order with each grinder and wheel and the time to complete each task was recorded. Vibration emission values were collected and the wheel wear was measured as loss of weight. Operators’ characteristics collected were as follows: age, body height and weight, length and volume of their hands, maximum hand grip force, and length of work experience with grinding machines (years). The tasks were also performed by one operator who used four machines of the same brand. Mixed and random effects models were used in the statistical evaluation.

    Results: The statistical evaluation was performed for grinding and cutting separately and we used a measure referring to the sum of the 1-s r.m.s. average frequency-weighted acceleration over time for completing the work task (a sa). Within each work task, there was a significant effect as a result of the determinants ‘the machine used’, ‘wheel wear’, and ‘time taken to complete the task’. For cutting, ‘the brand of wheel’ used also had a significant effect. More than 90% of the inherent variability in the data was explained by the determinants. The two electrically powered machines had a mean a sa that was 2.6 times higher than the two air-driven machines. For cutting, the effect of the brand of wheel on a sa was ~0.1 times. The a sa increased both with increasing wheel wear and with time taken to complete the work task. However, there were also a number of interaction effects which, to a minor extent, modified the a sa. Only a minor part (1%) of the total variability was attributed to the operator: for cutting, the volume of the hands, maximum grip force, and body weight were significant, while for grinding, it was the maximum grip force. There was no clear difference in a sa between the four copies of the same brand of each machine.

    Conclusions: By including determinants that were attributed to the brand of both machine and wheel used as well as the time taken to complete the work task, we were able to explain >90% of the variability. The dominating determinant was the brand of the machine. Little variability was found between operators, indicating that the overall effect as due to the operator was small.

  • 42.
    Liljelind, Ingrid
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Leif
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    Toomingas, Allan
    Institute of Environmental Medicine, Karolinska Institutet, Stockholm.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Variability in Hand-Arm Vibration During Grinding Operations2011In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 55, no 3, p. 296-304Article in journal (Refereed)
    Abstract [en]

    Background: Measurements of exposure to vibrations from hand-held tools are often conducted on a single occasion. However, repeated measurements may be crucial for estimating the actual dose with good precision. In addition, knowledge of determinants of exposure could be used to improve working conditions. The aim of this study was to assess hand–arm vibration (HAV) exposure during different grinding operations, in order to obtain estimates of the variance components and to evaluate the effect of work postures.

    Methods: Ten experienced operators used two compressed air-driven angle grinders of the same make in a simulated work task at a workplace. One part of the study consisted of using a grinder while assuming two different working postures: at a standard work bench (low) and on a wall with arms elevated and the work area adjusted to each operator’s height (high). The workers repeated the task three times. In another part of the study, investigating the wheel wear, for each grinder, the operators used two new grinding wheels and with each wheel the operator performed two consecutive 1-min grinding tasks. Both grinding tasks were conducted on weld puddles of mild steel on a piece of mild steel. Measurements were taken according to ISO-standard 5349 [the equivalent hand–arm-weighted acceleration (m s−2) averaged over 1 min]. Mixed- and random-effects models were used to investigate the influence of the fixed variables and to estimate variance components.

    Results: The equivalent hand–arm-weighted acceleration assessed when the task was performed on the bench and at the wall was 3.2 and 3.3 m s−2, respectively. In the mixed-effects model, work posture was not a significant variable. The variables ‘operator’ and ‘grinder’ together explained only 12% of the exposure variability and ‘grinding wheel’ explained 47%; the residual variability of 41% remained unexplained. When the effect of grinding wheel wear was investigated in the random-effects model, 37% of the variability was associated with the wheel while minimal variability was associated with the operator or the grinder and 37% was unexplained. The interaction effect of grinder and operator explained 18% of the variability. In the wheel wear test, the equivalent hand–arm-weighted accelerations for Grinder 1 during the first and second grinding minutes were 3.4 and 2.9 m s−2, respectively, and for Grinder 2, they were 3.1 and 2.9 m s−2, respectively. For Grinder 1, the equivalent hand–arm-weighted acceleration during the first grinding minute was significantly higher (P = 0.04) than during the second minute.

    Conclusions: Work posture during grinding operations does not appear to affect the level of HAV. Grinding wheels explained much of the variability in this study, but almost 40% of the variance remained unexplained. The considerable variability in the equivalent hand–arm-weighted acceleration has an impact on the risk assessment at both the group and the individual level.

  • 43. Lillienberg, Linnea
    et al.
    Andersson, Eva
    Janson, Christer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Respiratory Medicine and Allergology.
    Dahlman-Hoglund, Anna
    Forsberg, Bertil
    Holm, Mathias
    Gislason, Thorarinn
    Jõgi, Rain
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Omenaas, Ernst
    Schlunssen, Vivi
    Sigsgaard, Torben
    Svanes, Cecilie
    Toren, Kjell
    Occupational Exposure and New-onset Asthma in a Population-based Study in Northern Europe (RHINE)2013In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 57, no 4, p. 482-492Article in journal (Refereed)
    Abstract [en]

    In a large population-based study among adults in northern Europe the relation between occupational exposure and new-onset asthma was studied. The study comprised 13 284 subjects born between 1945 and 1973, who answered a questionnaire 19891992 and again 19992001. Asthma was defined as Asthma diagnosed by a physician with reported year of diagnose. Hazard ratios (HR), for new-onset adult asthma during 19802000, were calculated using a modified job-exposure matrix as well as high-risk occupations in Cox regression models. The analyses were made separately for men and women and were also stratified for atopy. During the observation period there were 429 subjects with new-onset asthma with an asthma incidence of 1.3 cases per 1000 person-years for men and 2.4 for women. A significant increase in new-onset asthma was seen for men exposed to plant-associated antigens (HR 3.6; 95% CI [confidence interval] 1.49.0), epoxy (HR 2.4; 95% CI 1.34.5), diisocyanates (HR 2.1; 95% CI 1.23.7) and accidental peak exposures to irritants (HR 2.4; 95% CI 1.34.7). Both men and women exposed to cleaning agents had an increased asthma risk. When stratifying for atopy an increased asthma risk were seen in non-atopic men exposed to acrylates (HR 3.3; 95% CI 1.47.5), epoxy compounds (HR 3.6; 95% CI 1.67.9), diisocyanates and accidental peak exposures to irritants (HR 3.0; 95% CI 1.27.2). Population attributable risk for occupational asthma was 14% for men and 7% for women. This population-based study showed that men exposed to epoxy, diisocyanates and acrylates had an increased risk of new-onset asthma. Non-atopics seemed to be at higher risk than atopics, except for exposure to high molecular weight agents. Increased asthma risks among cleaners, spray painters, plumbers, and hairdressers were confirmed.

  • 44. Lillienberg, Linnea
    et al.
    Andersson, Eva M.
    Järvholm, Bengt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Toren, Kjell
    Respiratory Symptoms and Exposure-Response Relations in Workers exposed to Metalworking Fluid Aerosols2010In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 54, no 4, p. 403-411Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to identify specific health risks and exposure-response relationships associated with exposure to metalworking fluid (MWF) aerosols. In a cross-sectional study of machine workers exposed to MWF aerosols in five companies in Sweden, a self-administered questionnaire about health symptoms, work tasks, and exposure situations was sent out to 2294 employees, 1632 exposed and 662 referents. Referents were office workers and metal workers not working with MWFs. In four of the companies, there were recent measurements of personal exposure to MWF aerosols. Log-binomial regression models were used to estimate prevalence ratios with 95% confidence intervals for different health outcomes in relation to different variables of exposure. The response rate after two reminders was 67% resulting in 1048 (923 male, 125 female) workers exposed to MWF aerosols and 451 (374 male, 77 female) referents. The study indicates that metal workers in Sweden currently exposed to a mean value of MWF aerosols of 0.4 mg m(-3) have a significantly higher prevalence of wheeze, chronic bronchitis, chronic rhinitis, and eye irritation compared to the referents. At a mean exposure of 0.4 mg m(-3), a level below the Swedish 8-h exposure limit value of 1 mg m(-3), machine operators showed increased prevalence of symptoms in eyes and airways. Thus, the current exposure limit value does not seem to protect the workers from such symptoms.

  • 45. Lillienberg, Linnéa
    et al.
    Andersson, Eva
    Janson, Christer
    Dahlman-Höglund, Anna
    Forsberg, Bertil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Holm, Mathias
    Gislason, Thorarinn
    Jögi, Rain
    Omenaas, Ernst
    Schlünssen, Vivi
    Sigsgaard, Torben
    Svanes, Cecilie
    Torén, Kjell
    Occupational exposure and new-onset asthma in a population-based study in Northern Europe (RHINE)2013In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 57, no 4, p. 482-492Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: In a large population-based study among adults in northern Europe the relation between occupational exposure and new-onset asthma was studied.

    METHODS: The study comprised 13 284 subjects born between 1945 and 1973, who answered a questionnaire 1989-1992 and again 1999-2001. Asthma was defined as 'Asthma diagnosed by a physician' with reported year of diagnose. Hazard ratios (HR), for new-onset adult asthma during 1980-2000, were calculated using a modified job-exposure matrix as well as high-risk occupations in Cox regression models. The analyses were made separately for men and women and were also stratified for atopy.

    RESULTS: During the observation period there were 429 subjects with new-onset asthma with an asthma incidence of 1.3 cases per 1000 person-years for men and 2.4 for women. A significant increase in new-onset asthma was seen for men exposed to plant-associated antigens (HR = 3.6; 95% CI [confidence interval] = 1.4-9.0), epoxy (HR = 2.4; 95% CI = 1.3-4.5), diisocyanates (HR = 2.1; 95% CI = 1.2-3.7) and accidental peak exposures to irritants (HR = 2.4; 95% CI = 1.3-4.7). Both men and women exposed to cleaning agents had an increased asthma risk. When stratifying for atopy an increased asthma risk were seen in non-atopic men exposed to acrylates (HR = 3.3; 95% CI = 1.4-7.5), epoxy compounds (HR = 3.6; 95% CI = 1.6-7.9), diisocyanates and accidental peak exposures to irritants (HR = 3.0; 95% CI = 1.2-7.2). Population attributable risk for occupational asthma was 14% for men and 7% for women.

    CONCLUSIONS: This population-based study showed that men exposed to epoxy, diisocyanates and acrylates had an increased risk of new-onset asthma. Non-atopics seemed to be at higher risk than atopics, except for exposure to high molecular weight agents. Increased asthma risks among cleaners, spray painters, plumbers, and hairdressers were confirmed.

  • 46.
    Lindahl, Roger
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Claeson, Anna-Sara
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Akhtar Khan, Muhammad
    Department of Chemistry, University of Eastern Finland, Yliopistokatu 7, FI-80220 Joensuu, Finland.
    Levin, Jan-Olof
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Development of a method for the determination of naphthalene and phenanthrene in workplace air using diffusive sampling and thermal desorption GC-MS analysis2011In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 55, no 6, p. 681-687Article in journal (Refereed)
    Abstract [en]

    Diffusive sampling methods have been validated for the determination of naphthalene and phenanthrene in workplace air. The diffusive sampler tested was the Perkin Elmer ATD tube, and the analysis was performed with thermal desorption, gas chromatography, and mass spectrometric detection. The sampling methods were validated in controlled test atmospheres, mainly according to the protocol proposed in the European standard EN 838. For the determination of naphthalene, the diffusive sampling rate was 0.41 ml min21 with a coefficient of variation (CV) of 19%. The mean sampling rate for phenanthrene was 0.49 ml min21 with a CV of 21%. Field tests confirmed the naphthalene results but could not be used to confirm the phenanthrene results. The method is not recommended for phenanthrene sampling unless the method has been tested in the specific environment and the results confirm the laboratory tests.

  • 47.
    Liv, Per
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Svendsen, Susanne Wulff
    Danish Ramazzini Center, Department of Occupational Medicine, Herning Hospital, Denmark.
    Theoretical and empirical efficiency of sampling strategies for estimating upper arm elevation2011In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 55, p. 436-449Article in journal (Refereed)
    Abstract [en]

    Objectives

    To investigate the statistical efficiency of strategies for sampling upper arm elevation data, which differed with respect to sample sizes and sample allocations within and across measurement days. The study was also designed to compare standard theoretical predictions of sampling efficiency, which rely on several assumptions about the data structure, with “true” efficiency as determined by bootstrap simulations.

    Methods

    Sixty-five sampling strategies were investigated using a data set containing minute-by-minute values of average right upper arm elevation, percentage of time with the arm elevated less than 15°, and percentage of time with an arm elevated more than 90° in a population of 23 house painters, 23 car mechanics and 26 machinists, all followed for four full working days. Total sample times per subject between 30 and 240 minutes were subdivided into continuous time blocks between 1 and 240 minutes long, allocated to one or four days per subject. Within day(s), blocks were distributed using either a random or fixed-interval principle. Sampling efficiency was expressed in terms of the variance of estimated mean exposure values of 20 subjects, and assessed using standard theoretical models assuming independence between variables and homoscedasticity. Theoretical performance was compared to empirical efficiencies obtained by a nonparametric bootstrapping procedure.

    Results

    We found the assumptions of independence and homoscedasticity in the theoretical model to be violated, most notably expressed through an autocorrelation between measurement units within working days. The empirical variance of the mean exposure estimates decreased, i.e. sampling efficiency increased, for sampling strategies where measurements were distributed widely across time. Thus, the most efficient allocation strategy was to organize a sample into one-minute blocks collected at fixed time intervals across four days. Theoretical estimates of efficiency generally agreed with empirical variances if the sample was allocated into small blocks, while for larger block sizes the empirical, “true” variance was considerably larger than predicted by theory. Theory overestimated efficiency in particular for strategies with short total sample times per subject.

    Conclusions This study demonstrates that when exposure data are autocorrelated within days – which we argue is the major reason why theory overestimates sampling performance – sampling efficiency can be improved by distributing the sample widely across the day or across days, preferably using a fixed-interval strategy. While this guidance is particularly valid when small proportions of working days are assessed, we generally recommend collecting more data than suggested by theory if a certain precision of the resulting exposure estimate is needed. More data per se give a better precision, and sampling larger proportion(s) of the working day(s) also alleviate the negative effects of possible autocorrelation in data

  • 48.
    Liv, Per
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Mathiassen, Svend Erik
    Högskolan i Gävle, Centrum för belastningsskadeforskning.
    Svendsen, Susanne Wulff
    Danish Ramazzini Center, Department of Occupational Medicine, Herning Hospital, Denmark.
    Theoretical and empirical efficiency of sampling strategies for estimating upper arm elevation2011In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 55, no 4, p. 436-449Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To investigate the statistical efficiency of strategies for sampling upper arm elevation data, which differed with respect to sample sizes and sample allocations within and across measurement days. The study was also designed to compare standard theoretical predictions of sampling efficiency, which rely on several assumptions about the data structure, with 'true' efficiency as determined by bootstrap simulations.

    METHODS: Sixty-five sampling strategies were investigated using a data set containing minute-by-minute values of average right upper arm elevation, percentage of time with an arm elevated <15°, and percentage of time with an arm elevated >90° in a population of 23 house painters, 23 car mechanics, and 26 machinists, all followed for four full working days. Total sample times per subject between 30 and 240 min were subdivided into continuous time blocks between 1 and 240 min long, allocated to 1 or 4 days per subject. Within day(s), blocks were distributed using either a random or a fixed-interval principle. Sampling efficiency was expressed in terms of the variance of estimated mean exposure values of 20 subjects and assessed using standard theoretical models assuming independence between variables and homoscedasticity. Theoretical performance was compared to empirical efficiencies obtained by a nonparametric bootstrapping procedure.

    RESULTS: We found the assumptions of independence and homoscedasticity in the theoretical model to be violated, most notably expressed through an autocorrelation between measurement units within working days. The empirical variance of the mean exposure estimates decreased, i.e. sampling efficiency increased, for sampling strategies where measurements were distributed widely across time. Thus, the most efficient allocation strategy was to organize a sample into 1-min block collected at fixed time intervals across 4 days. Theoretical estimates of efficiency generally agreed with empirical variances if the sample was allocated into small blocks, while for larger block sizes, the empirical 'true' variance was considerably larger than predicted by theory. Theory overestimated efficiency in particular for strategies with short total sample times per subject.

    CONCLUSIONS: This study demonstrates that when exposure data are autocorrelated within days-which we argue is the major reason why theory overestimates sampling performance-sampling efficiency can be improved by distributing the sample widely across the day or across days, preferably using a fixed-interval strategy. While this guidance is particularly valid when small proportions of working days are assessed, we generally recommend collecting more data than suggested by theory if a certain precision of the resulting exposure estimate is needed. More data per se give a better precision and sampling larger proportion(s) of the working day(s) also alleviate the negative effects of possible autocorrelation in data.

  • 49.
    Luger, Tessy
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. TNO Leiden, Leiden, The Netherlands; Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands; Institute of Occupational and Social Medicine and Health Services Research, Faculty of Medicine, University Hospital, Eberhard Karls University Tübingen, Tübingen, Germany.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Srinivasan, Divya
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Industrial and Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, USA.
    Bosch, Tim
    TNO Leiden, Leiden, The Netherlands; Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.
    Influence of work pace on upper extremity kinematics and muscle activity in a short-cycle repetitive pick-and-place task2017In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 61, no 3, p. 356-368Article in journal (Refereed)
    Abstract [en]

    Aim: This study investigated the extent to which controlled changes in work pace in a cyclic pick-and-place task influence upper extremity kinematics and muscle activity, and whether an effect depends on working height. Methods: Thirteen participants performed the task four minutes at each of five work paces ranging from 8 to 12 cycles·min-1 in each of two experimental conditions where the hand was moved horizontally with an average upper arm elevation of 30° and 50°, respectively. For each work cycle, we calculated the average and standard deviation of the upper arm elevation angle and the activity of the trapezius and deltoid muscles, as well as the angular peak velocity. We summarized these seven variables by calculating averages across cycles and cycle-to-cycle variabilities. Results: At 30° arm elevation, pace significantly influenced within-cycle angle variation, cycle-to-cycle variability of the average angle, angular peak velocity, and cycle-to-cycle variability of peak velocity. However, only angular peak velocity increased monotonically across all paces from 8 to 12 cycles·min-1). Average activity in the trapezius and the deltoid were the only muscle activity variables to increase consistently with pace. These effects of work pace did not change with working height. Conclusion: The present study did not find any consistent work pace effect on upper extremity kinematics and muscle activity, in spite of a comprehensive empirical basis compared to previous literature. While our results suggest that work pace may not be of critical concern in an occupational health context, we encourage further studies verifying or disproving this notion.

  • 50.
    Mathiassen, Svend Erik
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Jackson, Jennie
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research.
    Punnett, Laura
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational health science. University of Gävle, Centre for Musculoskeletal Research. Department of Work Environment, University of Massachusetts Lowell, USA.
    Statistical performance of observational work sampling for assessment of categorical exposure variables: A simulation approach illustrated using PATH data2014In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 58, no 3, p. 294-316Article in journal (Refereed)
    Abstract [en]

    Objectives. Observational work sampling is often used in occupational studies to assess categorical biomechanical exposures and occurrence of specific work tasks. The statistical performance of data obtained by work sampling is, however, not well understood, impeding informed measurement strategy design. The purpose of this study was to develop a procedure for assessing the statistical properties of work sampling strategies evaluating categorical exposure variables, and to illustrate the usefulness of this procedure to examine bias and precision of exposure estimates from samples of different sizes.

    Methods. From a parent data set of observations on 10 construction workers performing a single operation, the probabilities were determined for each worker of performing four component tasks and working in four mutually exclusive trunk posture categories (neutral, mild flexion, severe flexion, twisted). Using these probabilities, 5000 simulated data sets were created via probability-based re-sampling for each of six sampling strategies, ranging from 300 to 4500 observations. For each strategy, mean exposure and exposure variability metrics were calculated at both the operation- and task-levels and, for each of these, bias and precision were assessed across the 5000 simulations.

    Results. Estimates of exposure variability were substantially more uncertain at all sample sizes than estimates of mean exposures and task proportions. Estimates at small sample sizes were also biased. With only 600 samples, proportions of the different tasks and of working with a neutral trunk posture (the most common) were within 10% of the true target value in at least 80% of all the simulated data sets; rarer exposures required at least 1500 samples. For most task-level mean exposure variables and for all operation- and task-level estimates of exposure variability, performance was low, even with 4500 samples. In general, the precision of mean exposure estimates did not depend on the exposure variability between workers.

    Conclusions. The suggested probability-based simulation approach proved to be versatile and generally suitable for assessing bias and precision of data collection strategies using work sampling to estimate categorical data. The approach can be used in both real and hypothetical scenarios, in ergonomics as well as in other areas of occupational epidemiology and intervention research. The reported statistical properties associated with sample size are likely widely relevant to studies using work sampling to assess categorical variables.

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