Blood biomarkers for vibration-induced white fingers. A case-comparison study.

BACKGROUND: Vibration induced white fingers (VWF) is one form of secondary Raynaud's phenomenon (RP). METHODS: Vibration exposed workers with RP and vibration exposed controls without RP participated. Blood samples were collected before and after cold challenge exposure (COP). The concentration of von Willebrand factor (vonWf), thrombomodulin (TM), serotonin (SER), endothelin-1 (ET1 ), calcitonin gene-related peptide, or thromboxane A2 was calculated. The diagnostic usefulness of the substances for ruling in the diagnosis of Raynaud's was evaluated. RESULTS: The cases showed a significant lower concentration of vonWf before and after COP, a significant increase of ET1  and a decrease of TM after COP. The diagnostic usefulness of vonWf showed a likelihood of defining a true case by 35%. CONCLUSIONS: vonWf, TM, SER, or ET1 are suggested biomarkers for VWF. Diagnostic evaluation of vonWf showed a likelihood of defining a true case by 35% in the diagnosis of RP related to vibration.

Exposure to whole-body vibration and hospitalization due to lumbar disc herniation.

OBJECTIVE: The aim was to examine if exposure to whole-body vibration (WBV) increases the risk for hospitalization due to lumbar disc herniation. METHODS: The study basis is a cohort of 288,926 Swedish construction workers who participated in a national occupational health surveillance programme from 1971 until 1992. Job title, smoking habits, body weight, height and age were registered at the examinations. Assessment of WBV were made for each of the constituent occupations by constructing a job-exposure matrix (JEM). Exposure to WBV was graded on a scale from 0 to 5. In addition, the occurrence of hospitalization due to lumbar disc herniation from January 1st 1987 until December 31st 2010 was collected from a linkage with the Swedish Hospital Discharge Register. Poisson regressions were used to estimate relative risk with 95 percent confidence intervals (95% CI), adjusting for age, height, weight and smoking, using white-collar workers and foremen as a reference group. RESULTS: There was an increased risk for hospitalization due to lumbar disc herniation for workers in the construction industry exposed to medium to high WBV compared to white-collar workers and foremen 1.35 (1.12-1.63). When restricting the analyses to include workers 30-49 years of age at the time of the hospital admission the risk was 1.69 (95% CI 1.29-2.21). CONCLUSION: This study further supports that occupational exposure to whole-body vibration increases the risk for hospitalization due to lumbar disc herniation.

Hand-arm vibration and the risk of vascular and neurological diseases-A systematic review and meta-analysis.

BACKGROUND: Increased occurrence of Raynaud's phenomenon, neurosensory injury and carpal tunnel syndrome has been reported for more than 100 years in association with work with vibrating machines. The current risk prediction modelling (ISO-5349) for "Raynaud's phenomenon" is based on a few studies published 70 to 40 years ago. There are no corresponding risk prediction models for neurosensory injury or carpal tunnel syndrome, nor any systematic reviews comprising a statistical synthesis (meta-analysis) of the evidence. OBJECTIVES: Our aim was to provide a systematic review of the literature on the association between Raynaud's phenomenon, neurosensory injuries and carpal tunnel syndrome and hand-arm vibration (HAV) exposure. Moreover the aim was to estimate the magnitude of such an association using meta-analysis. METHODS: This systematic review covers the scientific literature up to January 2016. The databases used for the literature search were PubMed and Science Direct. We found a total of 4,335 abstracts, which were read and whose validity was assessed according to pre-established criteria. 294 articles were examined in their entirety to determine whether each article met the inclusion criteria. The possible risk of bias was assessed for each article. 52 articles finally met the pre-established criteria for inclusion in the systematic review. RESULTS: The results show that workers who are exposed to HAV have an increased risk of vascular and neurological diseases compared to non-vibration exposed groups. The crude estimate of the risk increase is approximately 4-5 fold. The estimated effect size (odds ratio) is 6.9 for the studies of Raynaud's phenomenon when including only the studies judged to have a low risk of bias. The corresponding risk of neurosensory injury is 7.4 and the equivalent of carpal tunnel syndrome is 2.9. CONCLUSION: At equal exposures, neurosensory injury occurs with a 3-time factor shorter latency than Raynaud's phenomenon. Which is why preventive measures should address this vibration health hazard with greater attention.

Musculoskeletal symptoms and exposure to whole-body vibration among open-pit mine workers in the Arctic.

OBJECTIVES: This cross-sectional questionnaire study was carried out at 4 open-pit mines in Finland, Norway, Russia and Sweden as part of the MineHealth project. The aim has been to compare the prevalence of musculoskeletal symptoms between drivers of mining vehicles and non-drivers. MATERIAL AND METHODS: The mine workers were asked whether they had suffered from any musculoskeletal symptoms during the previous 12 months in specified body regions, and to grade the severity of these symptoms during the past month. They were also asked about their daily driving of mining vehicles. RESULTS: The questionnaire was completed by 1323 workers (757 vehicle drivers) and the reported prevalence and severity of symptoms were highest for the lower back, followed by pain in the neck, shoulder and upper back. Drivers in the Nordic mines reported fewer symptoms than non-drivers, while for Russian mine workers the results were the opposite of that. The daily driving of mining vehicles had no significant association with the risk of symptoms. Female drivers indicated a higher prevalence of symptoms as compared to male drivers. CONCLUSIONS: The study provided only weak support for the hypothesis that drivers of vehicles reported a higher prevalence of musculoskeletal symptoms than non-vehicle drivers. There were marked differences in the prevalence of symptoms among workers in various enterprises, even though the nature of the job tasks was similar. Int J Occup Med Environ Health 2017;30(4):553-564.

Thermal perception thresholds among workers in a cold climate.

PURPOSE: To investigate whether exposure to cold could influence the thermal perception thresholds in a working population. METHODS: This cross-sectional study was comprised of 251 males and females and was carried out at two mines in the northern part of Norway and Sweden. The testing included a baseline questionnaire, a clinical examination and measurements of thermal perception thresholds, on both hands, the index (Digit 2) and little (Digit 5) fingers, for heat and cold. RESULTS: The thermal perception thresholds were affected by age, gender and test site. The thresholds were impaired by experiences of frostbite in the fingers and the use of medication that potentially could affect neurosensory functions. No differences were found between the calculated normative values for these workers and those in other comparative investigations conducted in warmer climates. CONCLUSIONS: The study provided no support for the hypothesis that living and working in cold climate will lead to impaired thermal perception thresholds. Exposure to cold that had caused localized damage in the form of frostbite was shown to lead to impaired thermal perception.

Association between Pain in Adolescence and Low Back Pain in Adulthood: Studying a Cohort of Mine Workers.

Purpose. To study the association of self-reported pain in adolescence with low back pain (LBP) in adulthood among mine workers and, also, study associations between the presence of LBP over 12-month or one-month LBP intensity during a health examination and daily ratings of LBP three and nine months later. Methods. Mixed design with data collected retrospectively, cross-sectionally, and prospectively. Data was collected using a questionnaire during a health examination and by using self-reported daily ratings of LBP three and nine months after the examination. Results. Pain prevalence during teenage years was 55% and it was 59% at age 20. Pain during teenage years had a relative risk of 1.33 (95% confidence interval 1.03-1.73) of LBP 12 months prior to the health examination, but with no associations with LBP intensity or LBP assessed by text messaging. Pain at age 20 years was not associated with any measure of LBP in adulthood. Daily ratings of LBP were associated with LBP during the health examination three and nine months earlier. Conclusions. There were no clear associations between self-reported pain in adolescence and LBP in adulthood. Self-reported daily ratings of LBP were associated with LBP from the health examination. Possible limitations for this study were the retrospective design and few participants.

Neurovascular hand symptoms in relation to cold exposure in northern Sweden: a population-based study.

PURPOSE: To describe the self-reported ambient cold exposure in northern Sweden and to relate the level of cumulative cold exposure to the occurrence of sensory and vascular hand symptoms. We hypothesize that cold exposure is positively related to reporting such symptoms. METHODS: A questionnaire about cold exposure and related symptoms was sent out to 35,144 subjects aged 18-70 years and living in northern Sweden. RESULTS: A total of 12,627 out of 35,144 subjects returned the questionnaire (response rate 35.9%). Subjects living in the rural alpine areas reported more extensive cold exposure both during work and leisure time compared to the urbanized coastal regions. Frostbite in the hands was present in 11.4% of men and 7.1% of women, cold sensitivity was present in 9.7 and 14.4%, and Raynaud's phenomenon was present in 11.0% of men and 14.0% of women. There was a positive association between cumulative cold exposure and neurovascular hand symptoms. CONCLUSION: The present study demonstrates that the cold environment in northern Sweden might be an underestimated health risk. Our hypothesis that cold exposure is positively related to reporting of neurovascular hand symptoms was supported by our findings. In addition, such symptoms were common not only in conjunction with an overt cold injury. Our results warrant further study on pathophysiological mechanisms and suggest the need for confirmatory prevalence studies to support national public health planning.

Is outdoor work associated with elevated rates of cerebrovascular disease mortality? A cohort study based on iron-ore mining.

BACKGROUND: A cohort study that examined iron ore mining found negative associations between cumulative working time employed underground and several outcomes, including mortality of cerebrovascular diseases. In this cohort study, and using the same group of miners, we examined whether work in an outdoor environment could explain elevated cerebrovascular disease rates. METHODS: This study was based on a Swedish iron ore mining cohort consisting of 13,000 workers. Poisson regression models were used to generate smoothed estimates of standardized mortality ratios and adjusted rate ratios, both models by cumulative exposure time in outdoor work. RESULTS: The adjusted rate ratio between employment classified as outdoor work ≥25 years and outdoor work 0-4 years was 1.62 (95 % CI 1.07-2.42). The subgroup underground work ≥15 years deviated most in occurrence of cerebrovascular disease mortality compared with the external reference population: SMR (0.70 (95 % CI 0.56-0.85)). CONCLUSIONS: Employment in outdoor environments was associated with elevated rates of cerebrovascular disease mortality. In contrast, work in tempered underground employment was associated with a protecting effect.

Exposure to whole-body vibration in open-cast mines in the Barents region.

OBJECTIVES: We aimed to measure and evaluate whole-body vibration (WBV) exposure among drivers of mining vehicles in the Barents region. STUDY DESIGN: In the period from November 2012 to August 2014, this cross-sectional study was carried out at 3 mines in Finland, Norway and Sweden as part of the MineHealth project. METHODS: Measurements of WBV were conducted on the surface of the driver's seat during normal work in accordance with international standards. Personal data on daily exposure times were collected by a questionnaire. RESULTS: Measurements were conducted on 95 different mining vehicles both as root mean square (RMS) value and vibration dose value (VDV) representing different manufacturers, models and capacities. Of the 453 miners who answered the questionnaire, 232 indicated that they were exposed to WBV during their working day. The results show that the mean daily exposure time varies between 1.9 and 6.7 h for different vehicles. The calculated mean A(8) could be found in an interval between 0.2 and 1.0 m/s(2) and the corresponding 8-h VDV fell between 7 and 17 m/s(1.75). CONCLUSIONS: Exposure to WBV among operators of mining vehicles may be a serious health and safety problem in the mines studied. The employers ought, therefore, take active steps to reduce exposure in accordance with the European vibration directive. Moreover, since some groups of drivers are exposed to vibration that is close to or exceeds the exposure limit values, the employer should take immediate action to reduce exposure below these values.

Neurosensory and vascular function after 14 months of military training comprising cold winter conditions.

OBJECTIVE: This study aimed to examine the effects of 14 months of military training comprising cold winter conditions on neurosensory and vascular function in the hands and feet. METHODS: Military conscripts (N=54) were assessed with quantitative sensory testing comprising touch, temperature, and vibration perception thresholds and finger systolic blood pressure (FSBP) after local cooling and a questionnaire on neurosensory and vascular symptoms at both baseline and follow-up. Ambient air temperature was recorded with body worn temperature loggers. RESULTS: The subjects showed reduced sensitivity to perception of touch, warmth, cold and vibrations in both the hands and feet except from vibrotactile perception in digit two of the right hand (right dig 2). Cold sensations, white fingers, and pain/discomfort when exposed to cold as well as pain increased in both prevalence and severity. There were no statistically significant changes in FSBP after local cooling. CONCLUSION: Fourteen months of winter military training comprising cold winter conditions reduced sensation from touch, warmth, cold, and vibrotactile stimulus in both hands and feet and increased the severity and prevalence of symptoms and pain. The vascular function in the hands, measured by FSBP after local cooling, was not affected.

Daily text messages used as a method for assessing low back pain among workers.

OBJECTIVES: To evaluate a method for collecting data concerning low back pain (LBP) using daily text messages and to characterize the reported LBP in terms of intensity, variability, and episodes. STUDY DESIGN AND SETTING: We conducted a cohort study of LBP among workers used by a mining company. The participants were asked to answer the question "How much pain have you had in your lower back in the last 24 hours on a scale from 0 to 10, where 0 = no pain and 10 = the worst pain imaginable" once a day for 5 weeks, with this process being repeated 6 months later. RESULTS: A total of 121 workers participated in the first period of data collection, and 108 participated in the second period. The daily response rate was 93% for both periods, and cluster analysis was shown to be a feasible statistical method for clustering LBP into subgroups of low, medium, and high pain. The daily text messages method also worked well for assessing the episodic nature of LBP. CONCLUSION: We have demonstrated a method for repeatedly measuring of LBP using daily text messages. The data permitted clustering into subgroups and could be used to define episodes of LBP.

Whole-body vibration and the risk of low back pain and sciatica: a systematic review and meta-analysis.

PURPOSE: The aim of this systematic literature review was to evaluate the association between whole-body vibration (WBV) and low back pain (LBP) and sciatica with special attention given to exposure estimates. Moreover, the aim was to estimate the magnitude of such an association using meta-analysis and to compare our findings with previous reviews. METHODS: The authors systematically searched the PubMed (National Library of Medicine, Bethesda), Nioshtic2 (National Institute for Occupational Safety and Health (NIOSH, Morgantown), and ScienceDirect (Elsevier, Amsterdam) databases for records up to December 31, 2013. Two of the authors independently assessed studies to determine their eligibility, validity, and possible risk of bias. RESULTS: The literature search gave a total of 306 references out of which 28 studies were reviewed and 20 were included in the meta-analysis. Exposure to WBV was associated with increased prevalence of LBP and sciatica [pooled odds ratio (OR) = 2.17, 95% confidence interval (CI) 1.61-2.91 and OR 1.92, 95% CI 1.38-2.67, respectively]. Workers exposed to high vibration levels had a pooled risk estimate of 1.5 for both outcomes when compared with workers exposed to low levels of vibration. The results also indicate that some publication bias could have occurred especially for sciatica. CONCLUSIONS: This review shows that there is scientific evidence that exposure to WBV increases the risk of LBP and sciatica.

Quantitatively measured tremor in hand-arm vibration-exposed workers.

OBJECTIVES: The aim of the present study was to investigate the possible increase in hand tremor in relation to hand-arm vibration (HAV) exposure in a cohort of exposed and unexposed workers. METHODS: Participants were 178 male workers with or without exposure to HAV. The study is cross-sectional regarding the outcome of tremor and has a longitudinal design with respect to exposure. The dose of HAV exposure was collected via questionnaires and measurements at several follow-ups. The CATSYS Tremor Pen(®) was used for measuring postural tremor. Multiple linear regression methods were used to analyze associations between different tremor variables and HAV exposure, along with predictor variables with biological relevance. RESULTS: There were no statistically significant associations between the different tremor variables and cumulative HAV or current exposure. Age was a statistically significant predictor of variation in tremor outcomes for three of the four tremor variables, whereas nicotine use was a statistically significant predictor of either left or right hand or both hands for all four tremor variables. CONCLUSIONS: In the present study, there was no evidence of an exposure-response association between HAV exposure and measured postural tremor. Increase in age and nicotine use appeared to be the strongest predictors of tremor.

Risk of hearing loss among workers with vibration-induced white fingers.

BACKGROUND: We examined the risk of hearing loss for workers who use hand-held vibrating tools with vibration-induced white fingers (VWF) compared to workers without VWF. METHODS: Data on 184 participants from a 21-year cohort were gathered with questionnaires and measurements. The effects on hearing status of VWF, hand-arm vibration exposure, smoking habits, age and two-way interactions of these independent variables were examined with binary logistic regression. Analyses were made for the right hand and ear as well as for the hand with VWF and the ear with worse categorized hearing status. RESULTS: Workers with VWF in their right hand had an increased risk of hearing loss (odds ratio 2.2-2.3) in the right ear. Workers with VWF in any hand did not have any increased risk of hearing loss in the ear with worse hearing status. CONCLUSIONS: This study supports the hypothesis that VWF increases the risk of hearing loss among workers who use hand-held vibrating tools in a noisy environment.

Raynaud's phenomenon among men and women with noise-induced hearing loss in relation to vibration exposure.

Raynaud's phenomenon is characterized by constriction in blood supply to the fingers causing finger blanching, of white fingers (WF) and is triggered by cold. Earlier studies found that workers using vibrating hand-held tools and who had vibration-induced white fingers (VWF) had an increased risk for hearing loss compared with workers without VWF. This study examined the occurrence of Raynaud's phenomenon among men and women with noise-induced hearing loss in relation to vibration exposure. All 342 participants had a confirmed noise-induced hearing loss medico legally accepted as work-related by AFA Insurance. Each subject answered a questionnaire concerning their health status and the kinds of exposures they had at the time when their hearing loss was first discovered. The questionnaire covered types of exposures, discomforts in the hands or fingers, diseases and medications affecting the blood circulation, the use of alcohol and tobacco and for women, the use of hormones and whether they had been pregnant. The participation rate was 41% (n = 133) with 38% (n = 94) for men and 50% (n = 39) for women. 84 men and 36 women specified if they had Raynaud's phenomenon and also if they had used hand-held vibrating machines. Nearly 41% of them had used hand-held vibrating machines and 18% had used vibrating machines at least 2 h each workday. There were 23 men/6 women with Raynaud's phenomenon. 37% reported WF among those participants who were exposed to hand-arm vibration (HAV) and 15% among those not exposed to HAV. Among the participants with hearing loss with daily use of vibrating hand-held tools more than twice as many reports WF compared with participants that did not use vibrating hand-held tools. This could be interpreted as Raynaud's phenomenon could be associated with an increased risk for noise-induced hearing loss. However, the low participation rate limits the generalization of the results from this study.

Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury.

BACKGROUND: Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients. OBJECTIVE: To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions. DESIGN: Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury. RESULTS: QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e.g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury. CONCLUSIONS: Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury.

A prospective cohort study investigating an exposure-response relationship among vibration-exposed male workers with numbness of the hands.

OBJECTIVE: The aim of this study was to investigate the exposure-response relationship of hand-arm vibration exposure to neurological symptoms (numbness) of the hand in a cohort of vibration-exposed workers. METHODS: The baseline cohort comprised 241 office and manual workers with and without exposure to hand-arm vibration. Numbness (the symptom or event) in the hand was assessed for all subjects at baseline and follow-ups after 5, 10, and 16 years. The workers were stratified into quartiles with no exposure in the first quartile and increasing intensity of exposure in quartiles 2-4 (groups 1-3). Data analysis was performed using survival analysis (time to event). Information on cumulative exposure and years of exposure to event was collected via questionnaires. Measurements were performed in accordance with the International Organization for Standardization (ISO) 5349-1. RESULTS: The hazard ratio (HR) of risk of event (numbness) differed statistically significantly between the non-exposed group (group 0) and the two higher exposure groups (groups 2 and 3). There was also a significant ratio difference between the lowest exposure group (group 1) and the two higher groups. The ratio for group 1 was 1.77 [95% confidence interval (95% CI) 0.96-3.26] compared with 3.78 (95% CI 2.15-6.62) and 5.31 (95% CI 3.06-9.20) for groups 2 and 3, respectively. CONCLUSION: The results suggest a dose-response relationship between vibration exposure and numbness of the hands. This underlines the importance of keeping vibration levels low to prevent neurological injury to the hands.

Determinants explaining the variability of hand-transmitted vibration emissions from two different work tasks: grinding and cutting using angle grinders.

BACKGROUND: There are numerous factors including physical, biomechanical, and individual that influence exposure to hand-transmitted vibration (HTV) and cause variability in the exposure measurements. Knowledge of exposure variability and determinants of exposure could be used to improve working conditions. We performed a quasi-experimental study, where operators performed routine work tasks in order to obtain estimates of the variance components and to evaluate the effect of determinants, such as machine-wheel combinations and individual operator characteristics. METHODS: Two pre-defined simulated work tasks were performed by 11 operators: removal of a weld puddle of mild steel and cutting of a square steel pipe. In both tasks, four angle grinders were used, two running on compressed air and two electrically driven. Two brands of both grinding and cutting wheels were used. Each operator performed both tasks twice in a random order with each grinder and wheel and the time to complete each task was recorded. Vibration emission values were collected and the wheel wear was measured as loss of weight. Operators' characteristics collected were as follows: age, body height and weight, length and volume of their hands, maximum hand grip force, and length of work experience with grinding machines (years). The tasks were also performed by one operator who used four machines of the same brand. Mixed and random effects models were used in the statistical evaluation. RESULTS: The statistical evaluation was performed for grinding and cutting separately and we used a measure referring to the sum of the 1-s r.m.s. average frequency-weighted acceleration over time for completing the work task (a(sa)). Within each work task, there was a significant effect as a result of the determinants 'the machine used', 'wheel wear', and 'time taken to complete the task'. For cutting, 'the brand of wheel' used also had a significant effect. More than 90% of the inherent variability in the data was explained by the determinants. The two electrically powered machines had a mean a(sa) that was 2.6 times higher than the two air-driven machines. For cutting, the effect of the brand of wheel on a(sa) was ~0.1 times. The a(sa) increased both with increasing wheel wear and with time taken to complete the work task. However, there were also a number of interaction effects which, to a minor extent, modified the a(sa). Only a minor part (1%) of the total variability was attributed to the operator: for cutting, the volume of the hands, maximum grip force, and body weight were significant, while for grinding, it was the maximum grip force. There was no clear difference in a(sa) between the four copies of the same brand of each machine. CONCLUSIONS: By including determinants that were attributed to the brand of both machine and wheel used as well as the time taken to complete the work task, we were able to explain >90% of the variability. The dominating determinant was the brand of the machine. Little variability was found between operators, indicating that the overall effect as due to the operator was small.

Quantitative neurosensory findings, symptoms and signs in young vibration exposed workers.

BACKGROUND: Long-term exposure to hand-held vibrating tools may cause the hand arm vibration syndrome (HAVS) including vibration induced white fingers and sensorineural symptoms. The aim was to study early neurosensory effects by quantitative vibrotactile and monofilament tests in young workers with hand-held vibration exposure. METHODS: This cross-sectional study consisted of 142 young, male machine shop and construction workers with hand-held exposure to vibrating tools. They were compared with 41 non-vibration exposed subjects of the same age-group. All participants passed a structured interview, answered several questionnaires and had a physical examination including the determination of vibrotactile perception thresholds (VPTs) at two frequencies (31.5 and 125 Hz) and Semmes Weinstein's Monofilament test. RESULTS: In the vibration exposed group 8% of the workers reported episodes of tingling sensations and 10% numbness in their fingers. Approximately 5-10% of the exposed population displayed abnormal results on monofilament tests. The vibrotactile testing showed significantly increased VPTs for 125 Hz in dig II bilaterally (right hand, p = 0.01; left hand, p = 0.024) in the vibration exposed group.A multiple regression analysis (VPT - dependent variable; age, height, examiner and five different vibration dose calculations - predictor variables) in dig II bilaterally showed rather low R2-values. None of the explanatory variables including five separately calculated vibration doses were included in the models, neither for the total vibration exposed group, nor for the highest exposed quartile.A logistic multiple regression analysis (result of monofilament testing - dependent variable; age, height, examiner and five vibration dose calculations - predictor variables) of the results of monofilament testing in dig II bilaterally gave a similar outcome. None of the independent variables including five calculated vibration doses were included in the models neither for the total exposed group nor for the highest exposed quartile. CONCLUSION: In spite of the fairly short vibration exposure, a tendency to raised VPTs as well as pathologic monofilament test results was observed. Thus, early neurophysiologic symptoms and signs of vibration exposure may appear after short-term exposure also in young workers.