Raynaud's phenomenon in the feet of Arctic open-pit miners.

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.

Silica Exposure and Cardiovascular, Cerebrovascular, and Respiratory Morbidity in a Cohort of Male Swedish Iron Foundry Workers.

OBJECTIVE: We present quantitative exposure-response data on silica exposure in male Swedish iron foundry workers for cardiovascular, cerebrovascular, and respiratory morbidity. METHODS: This 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. RESULTS: Increased 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/m 3 year is presented. CONCLUSIONS: The study presents a significantly increased COPD risk at cumulative silica exposures below the Swedish occupational exposure limit.

Occupational exposure to whole-body vibration and neck pain in the Swedish general population.

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 24-76 years. Data was retrieved through a digital survey that collected subjectively reported information on exposure to WBV and biomechanical exposures as well as 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.Practitioner summary: This cross-sectional, survey-based study investigated associations between self-reported occupational whole-body vibration and neck pain. It showed significant associations between frequent exposure to whole-body vibration and neck pain among men but not women. In occupational health care settings, whole-body vibration could be considered as a possible risk factor for neck pain.

Effects on blood parameters from hand-arm vibrations exposure.

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.

Occupational cold exposure and symptoms of carpal tunnel syndrome - a population-based study.

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.

Respirable Dust and Silica: Respiratory Diseases Among Swedish Iron Foundry Workers.

OBJECTIVE: The mortality and morbidity pattern for respiratory diseases was determined in a cohort of 1752 Swedish foundry workers, particularly for respirable silica dust exposure. METHODS: The morbidity follow-up in the Swedish National Non-primary Outpatient Register covered 2001 to 2017 (NPR; specialist not in care patients), the mortality from the National Causes of Death Register covered 2001 to 2017. Cumulative exposures to silica and dust were determined. RESULTS: The morbidity in COPD showed significantly increased risk for all exposure groups, as did silicosis in the high exposure group, these cases corresponded to silica exposure levels below 0.05 mg/m3. The mortality of all causes and respiratory diseases was significantly increased by cumulative silica exposure in the high exposure group. CONCLUSIONS: Significantly increased morbidity for respiratory diseases and COPD was determined at silica exposure levels below the current Swedish OEL.

Carpal Tunnel Syndrome and Hand-Arm Vibration: A Swedish National Registry Case-Control Study.

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.

Arterial abnormalities in the hands of workers with vibration white fingers - a magnetic resonance angiography case series.

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.

Silica Dust Exposure Increases Risk for Rheumatoid Arthritis: A Swedish National Registry Case-Control Study.

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.

Respiratory Health and Inflammatory Markers-Exposure to Cobalt in the Swedish Hard Metal Industry.

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, and medical examination including blood sampling was performed for 72 workers. Exposure-response relationships were 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. Nonsignificant exposure-response relationships were 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.

Sarcoidosis and increased risk of comorbidities and mortality in sweden.

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. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (2): 104-135).

Sarcoidosis and silica dust exposure among men in Sweden: a case-control study.

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).

Dermal and inhalable cobalt exposure-Uptake of cobalt for workers at Swedish hard metal plants.

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 (ß = 203 p < 0.0010, and ß = 0.010, p = 0.0040) and with cobalt in urine (ß = 5779, p = 0.0010, and ß = 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.

Serum Metabolites in Hand-Arm Vibration Exposed Workers.

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.

A Case Study of Brass Foundry Workers' Estimated Lead (Pb) Body Burden from Different Exposure Routes.

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.

Occupational Quartz Exposure in a Population of Male Individuals-Association With Risk of Developing Atrial Fibrillation.

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.

Risks of developing ulcerative colitis and Crohn's disease in relation to silica dust exposure in Sweden: a case-control study.

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.

Nerve Function Impairment After Acute Vibration Exposure.

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 quantitative sensory testing (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.

Silica exposure increases the risk of stroke but not myocardial infarction-A retrospective cohort study.

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.