| 1. |
- Andersson, Lena, et al.
(författare)
-
Estimating trends in quartz exposure in Swedish iron foundries : predicting past and present exposures
- 2012
-
Ingår i: Annals of Occupational Hygiene. - Oxford, United Kingdom : Oxford University Press. - 0003-4878 .- 1475-3162. ; 56:3, s. 362-372
-
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.
|
|
| 2. |
- Klasson, Maria, 1977-, et al.
(författare)
-
Occupational Exposure to Cobalt and Tungsten in the Swedish Hard Metal Industry : Air Concentrations of Particle Mass, Number, and Surface Area
- 2016
-
Ingår i: Annals of Occupational Hygiene. - Oxford, United Kingdom : Oxford University Press. - 0003-4878 .- 1475-3162. ; 60:6, s. 684-699
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 3. |
- Landberg, Hanna, et al.
(författare)
-
Comparison and Evaluation of Multiple Users' Usage of the Exposure and Risk Tool : Stoffenmanager 5.1
- 2015
-
Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 59:7, s. 821-835
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 4. |
- Liljelind, Ingrid, et al.
(författare)
-
Dermal and Inhalation Exposure to Methylene Bisphenyl Isocyanate (MDI) in Iron Foundry Workers
- 2010
-
Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 54:1, s. 31-40
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 5. |
- Westerlund, Jessica, 1983-, et al.
(författare)
-
Occupational Exposure to Trichloramine and Trihalomethanes in Swedish Indoor Swimming Pools : Evaluation of Personal and Stationary Monitoring
- 2015
-
Ingår i: Annals of Occupational Hygiene. - : Oxford University Press. - 0003-4878 .- 1475-3162. ; 59:8, s. 1074-1084
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Chlorination is a method commonly used to keep indoor swimming pool water free from pathogens. However, chlorination of swimming pools produces several potentially hazardous by-products as the chlorine reacts with nitrogen containing organic matter. Up till now, exposure assessments in indoor swimming pools have relied on stationary measurements at the poolside, used as a proxy for personal exposure. However, measurements at fixed locations are known to differ from personal exposure.Methods: Eight public swimming pool facilities in four Swedish cities were included in this survey. Personal and stationary sampling was performed during day or evening shift. Samplers were placed at different fixed positions around the pool facilities, at similar to 1.5 m above the floor level and 0-1 m from the poolside. In total, 52 personal and 110 stationary samples of trichloramine and 51 personal and 109 stationary samples of trihalomethanes, were collected.Results: The average concentration of trichloramine for personal sampling was 71 mu g m(-3), ranging from 1 to 240 mu g m(-3) and for stationary samples 179 mu g m(-3), ranging from 1 to 640 mu g m(-3). The air concentrations of chloroform were well below the occupational exposure limit (OEL). For the linear regression analysis and prediction of personal exposure to trichloramine from stationary sampling, only data from personal that spent > 50% of their workday in the pool area were included. The linear regression analysis showed a correlation coefficient (r (2)) of 0.693 and a significant regression coefficient beta of 0.621; (95% CI = 0.329-0.912, P = 0.001).Conclusion: The trichloramine exposure levels determined in this study were well below the recommended air concentration level of 500 mu g m(-3); a WHO reference value based on stationary sampling. Our regression data suggest a relation between personal exposure and area sampling of 1:2, implying an OEL of 250 mu g m(-3) based on personal sampling.
|
|
