To Örebro University

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.

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.

BACKGROUND: Chronic kidney disease (CKD) is a growing health issue that is becoming more prevalent globally, increasing financial cost on healthcare systems. The purpose of this study is to investigate the incidence of eye diseases in patients diagnosed with CKD in Sweden and to evaluate which eye diseases are most likely to develop.

METHODS: A longitudinal population-based retrospective case-control study was conducted including all individuals diagnosed with chronic kidney disease during the time period 2001-2019. A total of 19 455 cases and 38 890 controls were included. For each case, two controls were matched with the same sex, age, and county of residence.

RESULTS: CKD patients had a significantly higher risk of contracting any eye disease compared to individuals without kidney disease HR 1.73 (CI 1.67-1.79), with an elevated risk for all blocks of diagnoses except for glaucoma HR 0.95 (CI 0.85-1.06). However, this condition developed earlier in cases than in controls. Subanalyses showed an increased risk for chronic eye disease patients to develop cataract HR 1.70 (CI 1.63-1.78), other retinal disorders HR 1.86 (CI 1.72-2.02), and retinal vascular occlusions HR 2.08 (CI 1.73-2.51). In general, diagnosis of an eye disease occurred earlier in cases than controls.

CONCLUSIONS: The results from this study suggest that CKD patients have an increased risk to develop eye disease. Ocular disease seems to develop considerably earlier in CKD, even without staging the severity of the disease, with particularly high risk of developing retinal diseases and cataracts. Screening for eye disease in CKD should be considered.

INTRODUCTION: Work-related exposure to silica is a global health hazard that causes diseases such as silicosis. Some studies have also reported that silica exposure is linked to elevated cardiovascular disease mortality. However, these diagnoses have not been investigated in detail and there have been few studies on morbidity. The aim of this study is to examine morbidity and mortality from different cardiovascular diseases among silica-exposed Swedish foundry workers.

METHODS: Historical and contemporary measurements (1968-2006) of respiratory silica exposure were matched to job categories, individual foundries, and 4 time periods (1968-1979, 1980-1989, 1990-1999, 2000-2006) using a mixed model. Morbidity and mortality data for the studied cohorts were matched against the General Population Registry. Statistical analyses were performed with SPSS and STATA, and the data were stratified by age, gender, and year.

RESULTS: Mortality from cardiovascular disease (SMR 1.3; 95% CI 1.2-1.4) and stroke (SMR 1.6, 95% CI 1.2-2.1) was significantly elevated among the studied population. The cohort also exhibited significantly elevated morbidity from stroke (SIR 1.34; 95% CI 1.2-1.5) but not myocardial infarction. The mean age at the time of first morbidity from stroke was 64 years, with 36% of the cases occurring before the age of 60.

CONCLUSIONS: Swedish foundry workers exposed to respirable silica exhibit elevated morbidity and mortality from stroke, but not from myocardial infarction. Our results also suggest a relationship between silica exposure and morbidity from stroke at a younger age than the general population.

OBJECTIVE: To determine whether occupational exposure to silica dust is associated with an increased risk of developing sarcoidosis.

DESIGN: Case-control study of all individuals between 20 and 65 years of age diagnosed with sarcoidosis (D86) in Sweden between 2007 and 2016. Controls were matched to cases (2:1) based on age, sex and county at the time of diagnosis. A Job Exposure Matrix was used to estimate the occupational silica exposure of all cases and controls.

SETTING: Medical and occupational data from the National Outpatient Register were used to implement a case-control analysis, while the two controls used for each case were selected from the National Register of the Total Population. Information about occupation and time of employment were collected from the Swedish Occupational Register.

PARTICIPANTS: All men and women aged 20-65 years old who were diagnosed sarcoidosis (D86) from 2007 to 2016 were included and assigned two controls.

MAIN OUTCOMES: Silica dust exposure correlates with an increased risk of developing sarcoidosis in men.

RESULTS: The prevalence of silica exposure at work was statistically significantly higher among male cases than controls (OR 1.27, 95% CI 1.13 to 1.43). For men of an age of 35 years or younger the correlation seems to be stronger (OR 1.48, 95% CI 1.1 to 1.87) than in older men (OR 1.21, 95% CI 1.05 to 1.39). For men older than 35 with exposure to silica the prevalence of sarcoidosis increased with the exposure time, with an OR of 1.44 (95% CI 1.04 to 2.00) for exposure of more than 10 years.

CONCLUSIONS: Occupational exposure to silica dust seems to increase the risk of sarcoidosis among men between 20 and 65 years of age. The risk is higher among exposed men 35 years or younger and older men with longer exposure (>6 years).

Vibration exposure from handheld tools can affect the hands with neurological symptoms and vibration-induced Raynaud's phenomenon (VRP). The underlying pathophysiological mechanisms are not fully known, however, changes in the composition of blood parameters may contribute to VRP with an increase in blood viscosity and inflammatory response. The aim of this study was to examine the effect on blood parameters in capillary blood from fingers that had been exposed to a vibrating hand-held tool. This study involved nine healthy participants who had been exposed to vibration and an unexposed control group of six participants. Capillary blood samples were collected before and after vibration exposure for the exposed group, and repeated samples also from the control group. The exposed groups were exposed to vibration for a 15-min period or until they reached a 5.0 m/s2 vibration dose. Analysis of blood status and differential counting of leucocytes was performed on the capillary blood samples. The results of the blood samples showed an increase in mean value for erythrocyte volume fraction (EVF), hemoglobin, red blood cell count, white blood cell count and neutrophils, as well as a decrease of mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration. The increase of EVF and neutrophils was statistically significant for samples taken from the index finger but not the little finger. Even though the study was small it showed that an acute vibration exposure to the hands might increase EVF and neutrophilic granulocytes levels in the capillary blood taken from index fingers.

OBJECTIVES: The most pronounced occupational exposure routes for lead (Pb) are inhalation and gastrointestinal uptake mainly through hand-to-mouth behaviour. Skin absorption has been demonstrated for organic Pb compounds, but less is known about inorganic Pb species. Several legislative bodies in Europe are currently proposing lowering biological exposure limit values and air exposure limits due to new evidence on cardiovascular effects at very low blood Pb levels. In light of this, all exposure routes in occupational settings should be revisited to evaluate how to lower the overall exposure to Pb.

METHODS: The aim of the study was to investigate the possible exposure routes in workers operating computer numerical control-machines in a brass foundry and specifically to understand if metal cutting fluids (MCFs) used by the workers could lead to skin absorption of Pb. The different bronze alloys at the facility may contain up to 20% Pb. After obtaining written informed consent from the workers (n = 7), blood, skin wipes, and personal air samples were collected. In addition, MCFs used on the day of exposure measurements were collected for in vitro skin absorption studies using stillborn piglet skin mounted in static Franz diffusion cells (n = 48). All samples were analysed for Pb content using inductively coupled plasma mass spectrometry.

RESULTS: Pb air concentration (<0.1-3.4 µg m-3) was well below the Swedish occupational exposure limit value. Blood Pb was in the range of <0.72-33 µg dl-1, and Pb on skin surfaces, after performing normal work tasks during 2 h, was in the range of 0.2-48 µg cm-2. Using the MCFs in diffusion cells showed that skin absorption had occurred at very low doses, and that up to 10% of the Pb content was present in the skin after 24 h exposure. Using these results in the US EPA adult lead model, we could estimate a contribution to blood Pb from the three exposure routes; where hand-to-mouth behaviour yielded the highest contribution (16 µg Pb dl-1 blood), followed by skin absorption (3.3-6.3 µg Pb dl-1 blood) and inhalation (2.0 µg Pb dl-1 blood).

CONCLUSIONS: This case study shows that MCF may lead to skin absorption of inorganic Pb and contribute to a systemic dose (quasi-steady state). Furthermore, even though good hand hygienic measures were in place, the workers' skin exposure to Pb is in all likelihood an important contributor in elevating blood Pb levels. Skin exposure should thus be monitored routinely in workers at facilities handling Pb, to help reducing unnecessary occupational exposure.

Introduction: Sarcoidosis is a systemic inflammatory disorder, with an unclear etiology, involving granuloma formation that in most cases affects the lungs and intrathoracic lymph nodes. Sarcoidosis occurs in an acute or chronic form, each with different clinical presentation and prognosis.

Methods: Case-control study of comorbidity and mortality in people diagnosed with sarcoidosis (ICD10 code D86) from 2007 through 2016 in Sweden. Controls were matched to cases (2:1) based on age, sex and county at the time of diagnosis. Data was collected from the Swedish National Patient Register and The Cause of Death Register. All men and women aged 20-65 years old who were diagnosed with sarcoidosis (D86, ICD10) during the years of study were included, resulting 7828 cases and 15656 controls.

Results: Patients with sarcoidosis had increased mortality compared to matched controls (hazard ratio 1.88; 95% CI 1.56 - 2.26) and the Swedish general population (standardized mortality ratios1.75; 95% CI 1.52 - 2.00). The sarcoid cases, compared to controls, also had a significantly greater number of inpatient visits within several different chapters of ICD10 e.g. cardiomyopathy, heart failure, pulmonary embolism and malignant neoplasm.

Conclusion: Individuals with sarcoidosis are at higher risk of comorbidities and mortality than matched controls as well as the general population of Sweden. These findings are important knowledge for healthcare professionals who meet sarcoid patients, to encourage identification and treatment of comorbidities to reduce the risk of impaired quality of life and, eventually, premature death.

OBJECTIVE: This study was to investigate the acute effects of hand-arm vibrations on the nerve functions of the hands, and the impact of the grip force applied to the vibrating tool during exposure.

METHODS: Grip strength and perception of vibration, touch, and temperature were evaluated using QST before and after vibration exposure in 21 occupationally unexposed individuals. The procedure was performed twice, with a higher grip force being applied during exposure on the second occasion.

RESULTS: Vibration perception was significantly impaired after both exposures. Grip strength, perception of touch and temperature were only significantly affected after the high grip force exposure.

CONCLUSIONS: Exposure to hand-arm vibrations has acute effects on hand nerve function that are sensitive to the grip force applied during exposure.

PURPOSE: To study the risk for eye diseases in individuals with Ulcerative Colitis (UC), and to assess whether silica dust-exposure could contribute to the development of inflammatory eye diseases.

METHODS: A case-control study was conducted using a patient register processed by the National Board of Health and Welfare (NBHW) and Statistics Sweden. Cases were diagnosed with UC between 2007 and 2016. Matching was done with two random controls having the same age, sex and county of residence, without a systemic inflammatory disease. Using a job-exposure matrix, cases and controls were assessed for work-related silica dust exposure. The risk for eye disease was estimated by Cox regression analysis with calculation of Hazard Ratio (HR).

RESULTS: A total of 58 989 individuals were included, comprising 19 663 cases and 39 326 controls. The sex distribution was similar. Overall, individuals with UC had an increased risk for eye disease, specified in ICD 10 chapter VII (H00-H59) with HR 1.25 (CI 1.20-1.32). The highest HR on block-level for cases was 1.52 (CI 1.36-1.70), (H15-H22), which includes episcleritis, keratitis and anterior uveitis. The risk for ocular disease was higher in silica dust-exposed than non-exposed with a HR of 1.44 (CI 1.16-1.78) and 1.25 (CI 1.19-1.31), respectively. Among cases, the risk for iridocyclitis (H20) was further elevated by silica dust exposure, with HR of 3.84 (CI 1.64-8.97) in exposed compared to 1.94 (1.57-2.41) in non-exposed.

CONCLUSION: UC is associated with an increased risk for eye diseases, including inflammatory conditions. Our findings highlight that silica dust-exposure may be of importance in the pathogenesis of uveitis.

OBJECTIVE: Occupational quartz exposure is a health risk, with increased risk of developing lung, autoimmune diseases, and elevated mortality in cardiovascular diseases.

METHODS: The population was obtained from the period 2005 to 2016 and consisted of 5237 cases of patients with atrial fibrillation (AF). Quartz exposure information was obtained through a Swedish job exposure matrix.

RESULTS: The risk of developing AF was increased for the quartz-exposed male population who were within a year of having commenced employment OR 1.54; (95% CI 1.06-2.24); this increased in the age group 20 to 55 (OR 2.05; CI 95% 1.02-4.10).

CONCLUSION: Our main conclusion is that quartz dust exposure may be related to increased risk of AF in high exposed (above 0.05 mg/m mean quartz dust) in men aged 20 to 55 years.

The literature on Raynaud's phenomenon (RP) in the feet is scarce, especially in the occupational setting. The primary aim of our study was to investigate the occurrence of RP in the feet of miners. As part of the MineHealth project, written surveys and clinical examinations were completed by 260 Arctic open-pit miners working in northern Sweden and Norway (participation rate 53.6%). Data on RP were collected using standardised colour charts and questionnaire items. Clinical examination included assessing the perception of vibration and pain in both feet. There were eight women and three men who reported RP in the feet. Four also had RP in their hands but none acknowledged any first-degree relatives with the condition. Nine reported exposure to foot-transmitted vibration and one to hand-arm vibration. Seven showed signs of neurosensory injury in the feet. To conclude, the occurrence of RP in the feet of miners was 4.4%. Most cases with RP in the feet did not report the condition in the hands and were exposed to vibration transmitted directly to the feet. There were no reports of a hereditary component. Most cases with RP in the feet also had clinical findings suggestive of peripheral neuropathy in the feet.

The primary aim of this study was to determine if occupational exposure to whole-body vibration (WBV) was associated with reporting neck pain. A cross-sectional study was conducted on a sample of the general population living in northern Sweden, aged 24 to 76 years. Data was retrieved through a digital survey that collected information on exposure to WBV and biomechanical exposures as well as subjectively reported neck pain. The study included 5,017 participants (response rate 44%). Neck pain was reported by 269 men (11.8%) and 536 women (20.2%). There was a statistically significant association between reporting occupational exposure to WBV half the time or more (adjusted OR 1.91; 95% CI 1.22-3.00) and reporting neck pain. In gender-stratified analyses, the same pattern was observed in men, while there were too few women to determine any association. We conclude that occupational exposure to whole-body vibration was associated with neck pain in men.

BACKGROUND: Cold exposure is an underrecognized occupational hazard that may increase the risk of peripheral nerve entrapment. The aim of this study was to determine if self-reported occupational exposure to contact and ambient cooling was associated with symptoms of carpal tunnel syndrome (CTS).

METHODS: In this mainly cross-sectional study, surveys were conducted on a population-based sample of men and women between 18 and 70 years of age, living in northern Sweden. Cold exposure and presence of symptoms suggestive of CTS were subjectively reported. Associations between exposure and outcome were evaluated using logistic regression.

RESULTS: The study included 2,703 women and 2,314 men, with a median age of 60 years (interquartile range 19). Symptoms of CTS were reported by 453 (9.2%). Being highly occupationally exposed (almost always) to contact cooling of the hands was associated with reporting CTS (OR 3.20; 95% CI 1.62-6.33), as was ambient cooling (OR 2.00; 95% CI 1.03-3.88) and severe ambient cooling (OR 4.02 95% CI 2.09-7.71), after adjusting for age, gender, body mass index, current daily smoking, diabetes mellitus, joint disease, and hand-arm vibration exposure. The point estimates increased with longer daily exposure duration. For workers exposed to severe ambient cooling for more than half of their working hours, in addition to performing heavy manual handling every day, the OR for reporting CTS was 7.25 (95% CI 3.88-13.53), with a positive additive interaction effect (expressed as relative excess risk due to interaction) of 4.67.

CONCLUSIONS: Self-reported occupational exposure to contact and ambient cooling was associated with symptoms suggestive of CTS. There were statistically significant positive exposure-response patterns for time spent exposed to contact and ambient cooling at work in relation to reporting symptoms of CTS. Positive additive interaction effects between cold exposure and heavy manual handling were also found. Since there was important potential uncontrolled confounding regarding repetitive wrist movements and forceful gripping, the results need to be confirmed by other studies, preferably with longitudinal design and more detailed exposure assessment.

Hand-arm vibration (HAV) is a common occupational exposure in Sweden and worldwide that causes both acute transient effects and persistent hand-arm symptoms. The health effects include vibration-induced Raynaud’s phenomenon, neuropathic symptoms, carpal tunnel syndrome (CTS), and musculoskeletal disorders. The overall aim of this thesis was to investigate vascular and neurological effects in the hands of workers exposed to hand-arm vibrations.

Methods: In study 1, the aim was to investigate the risk of CTS from hand-arm vibration. This study was conducted as a register study using the National Outpatient Register and a job exposure matrix to estimate HAV exposure. Study 2 aimed to investigate the acute effects of HAV on the nerve functions of the hands and the impact of grip force. Nerve function was evaluated before and after vibration exposure. In study 3, the aim was to identify low molecular organic biomarkers in blood samples from vibration-exposed workers using a novel metabolomics approach. HAV-exposed workers underwent medical examination and blood samples were collected and analysed before and after a work shift. In study 4, the aim was to investigate if arterial abnormalities in the hands could be identified in patients with VWF which also had a positive Allen’s test. In this case series, Doppler ultrasound and magnetic resonance angiography (MRA) investigations were performed to investigate the arterial status in the hands. 

Results: Study 1 showed that the risk of CTS for HAV exposed individuals increased with an OR of 1.61 (95% CI 1.46-1.77) for the whole population. The risk was highest in HAV exposed younger males. Study 2 showed that HAV exposure with high grip force affect nerve function different than with low grip force. In study 3, workers with VWF had metabolic profiles different from participants without VWF, both before and after vibration exposure. In study 4, ultrasound and MRA identified vascular abnormalities in all participants; these abnormalities were a predominantly missing or not complete superficial arch. 

Conclusion: The overall finding is that HAV exposure, even at levels under legislated values, can give negative health effects. These results add new knowledge about CTS, HAV exposure and gender. Both metabolomics and studies of acute effects of HAV could be further studied to find a level of exposure where no health effects appear. With the findings on MRA, there is the possibility that a subgroup of VWF can be subject for treatment.

OBJECTIVE: To study the impact of occupational silica exposure on the incidence rates of sarcoidosis and rheumatoid arthritis (RA) in a cohort of exposed workers in Swedish iron foundries.

DESIGN: The prevalence of sarcoidosis and RA in a cohort of silica exposed workers was compared with the prevalence in the general Swedish population in this register study. A mixed model was used to calculate silica exposure, and individual silica exposures were used to compute dose responses.

SETTING: Personnel records from 10 iron foundries were used to identify workers whose employment began before 2005 which was then linked to the national non-primary outpatient visits register.

PARTICIPANTS: The final cohort consisted of 2187 silica-exposed male workers who had been employed for at least 1 year and were still alive without having emigrated when the follow-up study began. The cohort's employment period covers 23 807 person-years at risk.

MAIN OUTCOME: The presented results indicate that moderate to high levels of silica exposure increase risks for sarcoidosis and seropositive RA.

RESULTS: Mean levels of airborne silica dust in the foundries decreased significantly between the 1970s and 2000s. Incidence rates of sarcoidosis (3.94; 95% CI 1.07 to 10.08) and seropositive RA (2.59; 95% CI 1.24 to 4.76) were significantly higher among highly exposed individuals.

CONCLUSION: Our results reveal increased risks for sarcoidosis and seropositive RA among individuals with high exposure to silica dust (>0.048 mg/m(3)) compared with non-exposed and less-exposed groups.

Work with vibrating tools is common in many industries. Exposure to hand-arm vibrations is associated with a risk of hand injury in the form of: Vascular disorders, nerve malfunction, and effects on the musculoskeletal system. The aim of this study was to investigate the prevalence of hand-arm vibration symptoms among employees at a mechanical company, as well as to follow-up with patients presenting symptoms and evaluate the effects of certain proposed measures. We found that 21% of the employees were judged to have vibration-related problems even though the exposure to vibrations was judged to be relatively low. There seems to be an over-representation of Carpal tunnel syndrome among participants; this may suggest that ergonomic conditions at the investigated company, such as grinding with flexed wrists, are unfavorable.

Relevance to industry: Regular screening for early signs of vibration-related damage, even if workers are subject to only moderate vibration exposure, is an important part of preventing the aggravation of health problems.

Objective: To investigate whether low molecular organic biomarkers could be identified in blood samples from vibration exposed workers using a metabolomics.

Methods: The study population consisted of 38 metalworkers. All participants underwent a standardized medical examination. Blood samples were collected before and after work shift and analyzed with gas chromatography time-of-flight mass spectrometry. Multivariate modeling (orthogonal partial least-squares analysis with discriminant analysis [OPLS-DA]) were used to verify differences in metabolic profiles.

Results: Twenty-two study participants reported vascular symptoms judged as vibration-related. The metabolic profile from participants with vibration-induced white fingers (VWF) was distinctly separated from participants without VWF, both before and after vibration exposure.

Conclusion: Metabolites that differed between the groups were identified both before and after exposure. Some of these metabolites might be indicators of health effects from exposure to vibrations. This is the first time that a metabolomic approach has been used in workers exposed to vibrations.

Hand-arm vibration is a common occupational exposure that causes neurological impairment, myalgia, and vibration-induced Raynaud's phenomena or vibration white fingers (VWF). The pathological mechanism is largely unknown, though several mechanisms have been proposed, involving both immunological vascular damage and defective neural responses. The aim of this study was to test whether the substances interleukin-33 (IL-33), macrophage-derived chemokine (MDC), interleukin-10 (IL-10), endothelin-1 (ET-1), C-C motif chemokine ligand 20 (CCL20), calcitonin, and thromboxane (TXA2) changed before and after occupational hand-arm vibration exposure. 38 full-time shift workers exposed to hand-arm vibration were recruited. All the participants underwent medical examinations regarding symptoms of Raynaud's phenomena. In 29 of the participants, the concentration of IL-33, MDC, IL-10, ET-1, CCL20, calcitonin, and TXA2 was measured before and after a workday. There was a significant increase in ET-1 and calcitonin concentration and a decrease in the CCL20 concentration after the work shift in all participants. In the group suffering from VWF, but not in the non-VWF group, MDC was statistically significantly lower before the work shift (p = .023). The VWF group also showed a significant increase in MDC after the work shift. Exposure to occupational hand-arm vibration is associated with changes in ET-1, calcitonin, and MDC concentration in subjects suffering from vibration white fingers, suggesting a role of these biomarkers in the pathophysiology of this condition.

Vibration white finger (VWF) is a complication from exposure to hand-arm vibrations. Poor knowledge of the pathophysiology of VWF means that making an accurate prognosis is difficult. Thus, a better understanding of VWF's pathophysiology is of importance.The purpose of this study was to investigate whether there were arterial abnormalities in the hands in patients with VWF and a positive Allen's test, using ultrasound and MRA imaging.This was a case series where arterial abnormalities in the hands were investigated in ten participants with VWF and using prolonged Allen's test (> 5 s). The participants had an average vibration exposure of 22 years and underwent Doppler ultrasound and Magnetic Resonance Angiography (MRA) to check for arterial abnormalities.The participants had VWF classified as 1-3 on the Stockholm workshop scale. Ultrasound and MRA identified vascular abnormalities in all participants, the predominant finding was missing or incomplete superficial arch. Also, stenosis was identified in four participants.This study reveals a high proportion of arterial stenosis and abnormalities in patients with VWF and a prolonged Allen's test.

OBJECTIVE: To investigate the increased risk for carpal tunnel syndrome (CTS) in men and women with hand-arm vibration (HAV) exposure.

DESIGN: Case-control study of CTS where 4396 cases was obtained from National Outpatient Register between 2005 through 2016. Cases were matched to controls and exposure was estimated using a job exposure matrix.

RESULTS: Exposure to HAV increased the risk of CTS with an OR of 1.61 (95% CI 1.46-1.77). The risk was highest in men <30 years of age and among women <30 years no increased risk was observed. The risk increased with a mean year exposure above 2.5 m/s2 to OR 1.84 (95% CI 1.38-2.46).

CONCLUSIONS: HAV exposure increase the risk of CTS in both genders, with highest risk increase in younger men. This emphasize identification of HAV exposure in patients with CTS.

PURPOSE: Cobalt exposure is known to cause adverse effects on health. A major use of cobalt is in the manufacture of hard metal. Exposure can lead to asthma, hard metal lung disease, contact allergy and increased risk of cancer. Cobalt is mainly absorbed from the pulmonary tract, however penetration through skin may occur. The relationships between exposure to inhalable cobalt in air and on skin and the uptake in blood and urine will be investigated, as well as the association between dermal symptoms and dermal exposure.

METHODS: Cobalt exposure in 71 workers in hard metal production facilities was measured as inhalable cobalt in the breathing zone and cobalt found on skin with acid wash. Uptake of cobalt was determined with concentrations in blood and urine. Correlations between exposure and uptake were analysed.

RESULTS: Inhalable cobalt in air and cobalt in blood and urine showed rank correlations with coefficients 0.40 and 0.25. Cobalt on skin and uptake in blood and urine presented correlation coefficients of 0.36 and 0.17. Multiple linear regression of cobalt in air and on skin with cobalt in blood showed regression coefficients with cobalt in blood (β = 203 p < 0.0010, and β = 0.010, p = 0.0040) and with cobalt in urine (β = 5779, p = 0.0010, and β = 0.10, p = 0.60).

CONCLUSIONS: Our data presents statistically significant correlations between exposure to cobalt in air with uptake of cobalt in blood and urine. Cobalt on skin was statistically significant with cobalt in blood but not with urine.

Objective: To determine whether occupational exposure to silica dust causes an increased risk of developing Crohn's disease (CD) and ulcerative colitis (UC).

Design: Case-control study of CD (K50) and UC (K51) from 2007 through 2016. Controls were matched to cases (2:1) based on age, sex and county at the time of diagnosis. A job exposure matrix was used to estimate the occupational silica exposure of all cases and controls.

Setting: Medical and occupational data from the National Outpatient Register were used to implement a case-control analysis, while the two controls used for each case were selected from the National Register of the Total Population.

Participants: All men and women aged 20-65 years old who were diagnosed with CD (K50) and UC (K51) during the years of study were included and assigned two controls, resulting in 58 136 cases and 116 272 controls.

Main outcomes: Silica dust exposure correlates with an increased risk of developing UC in men and CD in women.

Results: The prevalence of UC was significantly higher in the group exposed to silica dust (OR 1.13, 95% CI 1.06 to 1.21) than in controls, particularly in individuals with over 5 years exposure. When stratified by sex, a significantly increased OR was detected for men (OR 1.33, 95% CI 1.05 to 1.22). This trend was also consistent with longer exposure times. The prevalence of UC was not increased in exposed women. The prevalence of CD was significantly increased among exposed women (OR 1.29, 95% CI 1.01 to 1.65), but not for exposed men.

Conclusions: Silica dust exposure correlates with an increased risk of developing UC, especially in men, and the risk seems to increase with the duration and degree of exposure. Conversely, silica dust exposure correlates positively with the risk of developing CD in women.

OBJECTIVE: Rheumatoid arthritis (RA) is an inflammatory disease with unknown etiology. This study examines if silica dust exposure increases the risk for seropositive and seronegative RA.

METHODS: A nationwide registry case-control study was conducted that included all cases of RA in Sweden between 2005 and 2016. In total, 31,139 cases with two matched controls were included. A JEM was used to estimate exposure.

RESULTS: Silica dust exposure was associated with a statistically significant increase in odds ratio (OR) for seropositive (OR 1.22, 95% CI 1.05 to 1.40) and seronegative (OR 1.23, 95% CI 1.04 to 1.46) RA among men.

CONCLUSION: This study found an increased OR for RA in silica-exposed men. The OR was equal for seropositive and seronegative RA. These findings further support the hypothesis that silica dust may be a trigger for RA.