| 1. |
- Andersson, Lena, et al.
(author)
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Estimating trends in quartz exposure in Swedish iron foundries : predicting past and present exposures
- 2012
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In: Annals of Occupational Hygiene. - Oxford, United Kingdom : Oxford University Press. - 0003-4878 .- 1475-3162. ; 56:3, s. 362-372
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Journal article (peer-reviewed)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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| 2. |
- Andersson, Lena, et al.
(author)
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Exposure assessment and modeling of quartz in Swedish iron foundries for a nested case-control study on lung cancer
- 2012
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In: Journal of Occupational and Environmental Hygiene. - Philadelphia : Taylor & Francis. - 1545-9624 .- 1545-9632. ; 9:2, s. 110-119
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Journal article (peer-reviewed)abstract
- Exposure assessment of quartz in Swedish iron foundries was performed based on historical and present measurement data. To evaluate the exposure response relationship between quartz exposure and lung cancer, we modeled quartz exposure from our database of measurements using determinants job title, time period and company. Based on these modeled exposure data, we conducted a nested case– control evaluation.In our database, the overall individual daily time-weighted average (TWA) quartz concentrations of current and historical data varied between 0.0018 and 4.9 mg/m3, averaging 0.083 mg/m3. The job titles with mean TWAs for the whole study period exceeding the European Union recommended occupational exposure limit of 0.05 mg/m3 were fettlers (0.087 mg/m3), furnace and ladle repair (0.42 mg/m3) and maintenance (0.054 mg/m3) workers.The mixed model analysis demonstrated significant determinants on the job level for furnace and ladle repair (β=4.06; 95% CI 2.78-5.93). For all jobs significantly higher exposure levels occurred only during the first time period, 1968-1979 (β=2.08; 95% CI 1.75-2.47), and a decreasing but not significant trend was noted for the three following 10 year time periods up to 2006 (β=1.0, 0.96 and 1, respectively). Two iron foundries had significantly higher quartz concentration levels than the others (β=1.31; 95% CI 1.00-1.71 and β=1.63; 95% CI 1.00-2.65, respectively). The individual cumulative quartz exposure measures were categorized in low, medium and high exposure (0.5-<1, 1-1.9 and ≥2 mg/m3 *years, respectively).In the nested case-control analysis, we found the highest odds ratios of lung cancer (OR 1.17; 95% CI 0.53-2.55) for the medium exposure group. No dose– response trend or significantly increased risk was determined for our high exposed group (≥2 mg/m3), representing 40 years of exposure at >0.05 mg/m3 of quartz. To conclude, certain foundry workers are still exposed to high levels of quartz, but an increased risk of lung cancer caused by quartz exposure in these Swedish iron foundries could not be confirmed at our exposure levels.
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| 3. |
- Andersson, Lena, 1965-, et al.
(author)
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Inflammatory and coagulatory markers and exposure to different size fractions of particle mass, number and surface area air concentrations in the Swedish hard metal industry, in particular to cobalt
- 2021
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In: Biomarkers. - : Taylor & Francis. - 1354-750X .- 1366-5804. ; 26:6, s. 557-569
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Journal article (peer-reviewed)abstract
- Purpose: To study the relationship between inhalation of airborne particles and cobalt in the Swedish hard metal industry and markers of inflammation and coagulation in blood.Methods: Personal sampling of inhalable cobalt and dust were performed for subjects in two Swedish hard metal plants. Stationary measurements were used to study concentrations of inhalable, respirable, and total dust and cobalt, PM10 and PM2.5, the particle surface area and the particle number concentrations. The inflammatory markers CC16, TNF, IL-6, IL-8, IL-10, SAA and CRP, and the coagulatory markers FVIII, vWF, fibrinogen, PAI-1 and D-dimer were measured. A complete sampling was performed on the second or third day of a working week following a work-free weekend, and additional sampling was taken on the fourth or fifth day. The mixed model analysis was used, including covariates.Results: The average air concentration of inhalable dust and cobalt were 0.11 mg/m3 and 0.003 mg/m3, respectively. For some mass-based exposure measures of cobalt and total dust, statistically significant increased levels of FVIII, vWF and CC16 were found.Conclusions: The observed relationships between particle exposure and coagulatory biomarkers may indicate an increased risk of cardiovascular disease.
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| 4. |
- Andersson, Lena, 1965-, et al.
(author)
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Respiratory health and inflammatory markers : Exposure to respirable dust and quartz and chemical binders in Swedish iron foundries
- 2019
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In: PLOS ONE. - : PLOS. - 1932-6203. ; 14:11
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Journal article (peer-reviewed)abstract
- PURPOSE: To study the relationship between respirable dust, quartz and chemical binders in Swedish iron foundries and respiratory symptoms, lung function (as forced expiratory volume FEV1 and vital capacity FVC), fraction of exhaled nitric oxide (FENO) and levels of club cell secretory protein 16 (CC16) and CRP.METHODS: Personal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Full shift sampling and examination were performed on the second or third day of a working week after a work free weekend, with additional sampling on the fourth or fifth day. Logistic, linear and mixed model analyses were performed including, gender, age, smoking, infections, sampling day, body mass index (BMI) and chemical binders as covariates.RESULTS: The adjusted average respirable quartz and dust concentrations were 0.038 and 0.66 mg/m3, respectively. Statistically significant increases in levels of CC16 were associated with exposure to chemical binders (p = 0.05; p = 0.01) in the regression analysis of quartz and respirable dust, respectively. Non-significant exposure-responses were identified for cumulative quartz and the symptoms asthma and breathlessness. For cumulative chemical years, non-significant exposure-response were observed for all but two symptoms. FENO also exhibited a non significant exposure-response for both quartz and respirable dust. No exposure-response was determined for FEV1 or FVC, CRP and respirable dust and quartz.CONCLUSIONS: Our findings suggest that early markers of pulmonary effect, such as increased levels of CC16 and FENO, are more strongly associated with chemical binder exposure than respirable quartz and dust in foundry environments.
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| 5. |
- Andersson, Lena, 1965-, et al.
(author)
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Respiratory Health and Inflammatory Markers : Exposure to Cobalt in the Swedish Hard Metal Industry
- 2020
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In: Journal of Occupational and Environmental Medicine. - : Lippincott Williams & Wilkins. - 1076-2752 .- 1536-5948. ; 62:10, s. 820-829
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To study the relationship between inhalable dust and cobalt and respiratory symptoms, lung function, exhaled nitric oxide in expired air and CC16 in the Swedish hard metal industry.METHODS: Personal sampling of inhalable dust and cobalt, medical examination including blood sampling was performed for 72 workers. Exposure-response relationships was determined using logistic, linear and mixed model analysis.RESULTS: The average inhalable dust and cobalt concentrations were 0.079 and 0.0017 mg/m, respectively. Statistically significant increased serum levels of CC16 were determined when the high and low cumulative exposures for cobalt were compared. Non-significant exposure-response relationships was observed between cross-shift inhalable dust or cobalt exposures and asthma, nose dripping and bronchitis.CONCLUSIONS: Our findings suggest an exposure-response relationship between inhalable cumulative cobalt exposure and CC16 levels in blood, which may reflect an injury or a reparation process in the lungs.
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| 6. |
- Andersson, Lena, 1965-, et al.
(author)
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Silica Exposure and Cardiovascular, Cerebrovascular, and Respiratory Morbidity in a Cohort of Male Swedish Iron Foundry Workers
- 2023
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In: Journal of Occupational and Environmental Medicine. - : Lippincott Williams & Wilkins. - 1076-2752 .- 1536-5948. ; 65:9, s. 731-739
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Journal article (peer-reviewed)abstract
- In this study, we present quantitative exposure-response data on silica exposure in male Swedish iron foundry workers receiving inpatient care for cardiovascular, cerebrovascular, and respiratory morbidity. The study show a significantly increased COPD risk at cumulative silica exposures that correspond to TWA silica below the Swedish OEL of 0.1 mg/m3. ObjectiveWe present quantitative exposure-response data on silica exposure in male Swedish iron foundry workers for cardiovascular, cerebrovascular, and respiratory morbidity.MethodsThis research is a cohort study of 2063 male Swedish iron foundry workers. From the Swedish National Patient Registers, data on morbidity incidence were retrieved. A historical measurement database of 1667 respirable silica exposure measurements from 10 Swedish iron foundries was used to calculate the cumulative exposure dose for each worker.ResultsIncreased morbidity risk for the whole group of foundry workers was determined for ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), bronchitis, and pneumonia. In addition, an increased risk for COPD at cumulative silica exposures ranging from 0.11 to 0.84 mg/m3 year is presented.ConclusionsThe study presents a significantly increased COPD risk at cumulative silica exposures below the Swedish occupational exposure limit.
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| 7. |
- Hedbrant, Alexander, 1987-, et al.
(author)
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Effects on white blood cell counts and the NLRP3 inflammasome due to dust and cobalt exposure in the hard metal industry
- 2022
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In: Biomarkers. - : Taylor & Francis. - 1354-750X .- 1366-5804. ; , s. 60-70
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Journal article (peer-reviewed)abstract
- INTRODUCTION: In light of potential negative health effects of cobalt exposure, a characterization of inflammatory mechanisms in exposed individuals is warranted. The current study investigated cobalt exposure in the Swedish hard metal industry and its relationship to inflammatory markers, including NLRP3 inflammasome activation and white blood cell (WBC) counts.MATERIAL AND METHODS: Inhalable cobalt and dust exposures, and systemic cobalt levels, were determined for 72 workers in the hard metal industry and linear regression models were applied to correlate exposure to markers of inflammasome activation and WBC counts.RESULTS: Mean exposures to inhalable dust (0.11 mg/m3) and cobalt (0.0034 mg/m3) were below the Swedish occupational exposure limits, and these low exposures did not correlate with any investigated outcomes. Instead, cobalt blood levels significantly correlated with a ca 10% decrease in IL-18 plasma levels per 10 nM cobalt increase. Furthermore, pre-shift cobalt blood and/or urine levels significantly correlated with some WBC measures, including decreased neutrophil-to-lymphocyte ratio, increased lymphocyte-to-monocyte ratio, and lymphocyte counts.CONCLUSION: The low inhalable particle exposures had no impact on WBC counts and inflammasome activation. Instead, systemic cobalt levels, which also include skin exposure, demonstrated possible suppressive effects on inflammatory responses in cobalt-exposed individuals in the hard metal industry.
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| 8. |
- Klasson, Maria, 1977-, et al.
(author)
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Biological monitoring of dermal and air exposure to cobalt at a Swedish hard metal production plant : does dermal exposure contribute to uptake?
- 2017
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In: Contact Dermatitis. - : John Wiley & Sons. - 0105-1873 .- 1600-0536. ; 77:4, s. 201-207
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Journal article (peer-reviewed)abstract
- Background: Occupational exposure to cobalt is well established in hard metal manufacture. Cobalt is known to cause contact allergy, asthma, hard metal lung disease, and lung cancer. The relationship between skin exposure and uptake determined in blood has not been extensively investigated.Objective: To examine whether skin and inhalable air exposure to cobalt contributes to uptake, determined as cobalt in blood, in a hard metal manufacturing factory.Methods: The amount of cobalt on the skin found with an acid wash technique, the air concentrations of inhalable cobalt and cobalt blood concentrations were determined and correlated in exposed workers.Results: We found a significant rank correlation for cobalt concentrations on the skin, in inhalable air, and in blood (0.376-0.498). Multiple linear regression showed significant regression coefficients for cobalt skin exposure and blood (B = 0.01, p < 0.05) and for inhalable cobalt in air and blood (B = 49.1, p < 0.001). According to our model based on data from the regression analyses, a twofold increase in skin exposure levels at different air concentrations caused a 3 - 14% increase in blood levels.Conclusions: Our data suggest that skin exposure to cobalt in the hard metal industry could affect the total uptake at the same order of magnitude as air exposure.
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| 9. |
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| 10. |
- Klasson, Maria, 1977-, et al.
(author)
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Dermal exposure to cobalt studied in vitro in keratinocytes : effects of cobalt exposure on inflammasome activated cytokines, and mRNA response
- 2021
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In: Biomarkers. - : Taylor & Francis. - 1354-750X .- 1366-5804. ; 26:8, s. 674-684
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Journal article (peer-reviewed)abstract
- BACKGROUND: Cobalt is a dermal sensitizer, and keratinocytes respond to cobalt exposure by releasing proinflammatory mediators, regulating the immune response.OBJECTIVE: To determine the effect of cobalt on the inflammasome associated cytokine- and gene expression in cultured human keratinocytes (HaCaT). Cultivation in low- or high calcium conditions model separate differentiation states of keratinocytes in the skin.METHOD: HaCaT cells in two different states of differentiation were exposed to cobalt chloride and caspase-1 activity as well as the production of IL-1 beta, IL-18 and gene expression of IL1B, IL18, NLRP3, CASP1, and PYCARD was quantified. RESULTS: High cobalt chloride exposure mediated significant increase in caspase-1 activity, cytokine levels, and IL1B and NLRP3 expression with a corresponding regulatory decrease for CASP1 and PYCARD expression. No difference between high- and low calcium culturing conditions modelling differentiation states was detected.CONCLUSIONS: Our data suggest that HaCaT cells respond with inflammmasome associated activity upon cobalt exposure in a concentration-dependent manner. These mechanisms could be of importance for the understanding of the pathophysiology behind allergic sensitization to dermal cobalt exposure.
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