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| 2. |
- Andersson, Lena, et al.
(författare)
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Estimating trends in quartz exposure in Swedish iron foundries : predicting past and present exposures
- 2012
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Ingår i: Annals of Occupational Hygiene. - Oxford, United Kingdom : Oxford University Press. - 0003-4878 .- 1475-3162. ; 56:3, s. 362-372
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Antonsson, Ann-Beth, 1956-, et al.
(författare)
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Fatal Carbon Monoxide Intoxication After AcetyleneGas Welding of Pipes
- 2013
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press. - 0003-4878 .- 1475-3162. ; 57:5, s. 662-666
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
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Exposure to parvalbumin allergen and aerosols among herring processing workers.
- 2013
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Ingår i: The Annals of occupational hygiene. - : Oxford University Press (OUP). - 1475-3162. ; 57:8, s. 1020-9
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Tidskriftsartikel (refereegranskat)abstract
- There are increasing reports of allergies and respiratory symptoms among workers in the fish processing industry, coinciding with an increasing use of high-pressure water in the processing plants. However, few studies have measured exposure in these work environments.
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| 5. |
- Freitag, Sonja, et al.
(författare)
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Frequent Bending-An Underestimated Burden in Nursing Professions
- 2012
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 56:6, s. 697-707
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Freitag, Sonja, 1968-, et al.
(författare)
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The effect of working position on trunk posture and exertion for routine nursing tasks : An Experimental Study
- 2014
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 58:3, s. 317-325
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Gustavsson, Marcus, et al.
(författare)
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Adsorption Efficiency of Respirator Filter Cartridges for Isocyanates
- 2010
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 54:4, s. 377-390
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Gylestam, Daniel, 1979-, et al.
(författare)
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Dry Sampling of Gas-Phase Isocyanates and Isocyanate Aerosols from Thermal Degradation of Polyurethane
- 2014
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 58:1, s. 28-49
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Gylestam, Daniel, 1979-, et al.
(författare)
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Sampling of Respirable Isocyanate Particles
- 2014
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 58:3, s. 340-354
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 10. |
- Hedmer, Maria, et al.
(författare)
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Exposure and Emission Measurements During Production, Purification, and Functionalization of Arc-Discharge-Produced Multi-walled Carbon Nanotubes.
- 2014
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 1475-3162. ; 58:3, s. 355-379
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Tidskriftsartikel (refereegranskat)abstract
- Background: The production and use of carbon nanotubes (CNTs) is rapidly growing. With increased production, there is potential that the number of occupational exposed workers will rapidly increase. Toxicological studies on rats have shown effects in the lungs, e.g. inflammation, granuloma formation, and fibrosis after repeated inhalation exposure to some forms of multi-walled CNTs (MWCNTs). Still, when it comes to health effects, it is unknown which dose metric is most relevant. Limited exposure data for CNTs exist today and no legally enforced occupational exposure limits are yet established. The aim of this work was to quantify the occupational exposures and emissions during arc discharge production, purification, and functionalization of MWCNTs. The CNT material handled typically had a mean length <5 μm. Since most of the collected airborne CNTs did not fulfil the World Health Organization fibre dimensions (79% of the counted CNT-containing particles) and since no microscopy-based method for counting of CNTs exists, we decided to count all particle that contained CNTs. To investigate correlations between the used exposure metrics, Pearson correlation coefficient was used.
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