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Objective The aim of this study was to compare the performance of alternative measures of cumulative lifetime vibration dose to predict the occurrence of low-back pain (LBP) outcomes in a cohort of 537 professional drivers investigated at baseline and over a two-year follow up period. Methods The exposure data obtained in the EU VIBRISKS project were used to calculate alternative measures of either acceleration- (external) or force- (internal) based lifetime vibration doses. Vibration was measured in representative samples of machines and vehicles used by the drivers. Internal lumbar forces were calculated by means of anatomy-, posture-, and anthropometry-based finite element models. The relations of LBP outcomes to alternative measures of lifetime vibration doses were assessed by the generalized estimating equations method. Results Metrics of cumulative vibration exposure constructed with either acceleration- or force-based methods were significantly associated with the occurrence of LBP outcomes. A measure of model fitting suggested that force-based doses were better predictors of LBP outcomes than acceleration-based doses. Models with force root-mean-square doses provided a better fit to LBP outcomes than those with force-peak doses. Conclusions Measures of internal lumbar forces were better predictors of LBP outcomes than measures of external vibration acceleration although the exposure metrics constructed with the acceleration-based method have the advantage of greater simplicity compared to the force-based method. The differences between the models with force-based doses suggest that the cumulative health effects on the lumbar spine might depend on the integrated resulting total force over the entire exposure time rather than primarily on the force peaks.

Purpose: In the 30 years since the Stockholm Workshop Scale (SWS) was published, the scientific literature on hand-arm vibration syndrome (HAVS) has grown and experience has been gained in its practical application. This research was undertaken to develop an up-to-date evidence-based classification for HAVS by seeking consensus between experts in the field. Methods: Seven occupational physicians who are clinically active and have had work published on HAVS in the last 10 years were asked to independently take part in a three-round iterative Delphi process. Consensus was taken when 5/7 (72%) agreed with a particular statement. Experts were asked to provide evidence from the literature or data from their own research to support their views. Results: Consensus was achieved for most of the questions that were used to develop an updated staging system for HAVS. The vascular and neurological components from the SWS are retained, but ambiguous descriptors and tests without adequately developed methodology such as tactile discrimination, or discriminating power such as grip strength, are not included in the new staging system. A blanching score taken from photographs of the hands during vasospastic episodes is recommended in place of self-recall and frequency of attacks to stage vascular HAVS. Methods with the best evidence base are described for assessing sensory perception and dexterity. Conclusions: A new classification has been developed with three stages for the clinical classification of vascular and neurological HAVS based on international consensus. We recommend it replaces the SWS for clinical and research purposes.

Background The serum level of dehydroepiandrosterone sulphate (DHEA-S) has been suggested as a biological marker of stress. Aims To assess the association between serum DHEA-S, psychosocial factors and musculoskeletal (MS) pain in university workers. Methods The study population included voluntary workers at the scientific departments of the University of Trieste (Italy) who underwent periodical health surveillance from January 2011 to June 2012. DHEA-S level was analysed in serum. The assessment tools included the General Health Questionnaire (GHQ) and a modified Nordic musculoskeletal symptoms questionnaire. The relation between DHEA-S, individual characteristics, pain perception and psychological factors was assessed by means of multivariable linear regression analysis. Results There were 189 study participants. The study population was characterized by high reward and low effort. Pain perception in the neck, shoulder, upper limbs, upper back and lower back was reported by 42, 32, 19, 29 and 43% of people, respectively. In multivariable regression analysis, gender, age and pain perception in the shoulder and upper limbs were significantly related to serum DHEA-S. Effort and overcommitment were related to shoulder and neck pain but not to DHEA-S. The GHQ score was associated with pain perception in different body sites and inversely to DHEA-S but significance was lost in multivariable regression analysis. Conclusions DHEA-S was associated with age, gender and perception of MS pain, while effort-reward imbalance dimensions and GHQ score failed to reach the statistical significance in multivariable regression analysis.

Nickel nanoparticles (NiNPs) represent a new type of occupational exposure because, due to the small size/high surface, they can release more Ni ions compared to bulk material. It has been reported a case of a worker who developed sensitization while handling nickel nanopowder without precautions. Therefore there is the need to assess whether the skin absorption of NiNPs is higher compared to bulk nickel. Two independent in vitro experiments were performed using Franz diffusion cells. Eight cells for each experiment were fitted using intact and needle-abraded human skin. The donor phase was a suspension of NiNPs with mean size of 77.7 ± 24.1 nm in synthetic sweat. Ni permeated both types of skin, reaching higher levels up to two orders of magnitude in the damaged skin compared to intact skin (5.2 ± 2.0 vs 0.032 ± 0.010 μg cm(-2), p = 0.006) at 24 h. Total Ni amount into the skin was 29.2 ± 11.2 μg cm(-2) in damaged skin and 9.67 ± 2.70 μg cm(-2) in intact skin (mean and SD, p = 0.006). Skin abrasions lead to doubling the Ni amount in the epidermis and to an increase of ten times in the dermis. This study demonstrated that NiNPs applied on skin surface cause an increase of nickel content into the skin and a significant permeation flux through the skin, higher when a damaged skin protocol was used. Preventive measures are needed when NiNPs are produced and used due to their higher potential to enter in our body compared to bulk nickel.

PURPOSE: To provide an updated epidemiological validation for a supplementary method for assessing the risk of vascular disorders from hand-transmitted vibration. METHODS: The occurrence of vibration-induced white finger (VWF) in the vibration-exposed workers of the Italian cohort of the EU VIBRISKS study was related to measures of daily vibration exposure expressed in terms of r.m.s. acceleration magnitude normalised to an 8-h day, frequency weighted according to either the frequency weighting Wh defined in international standard ISO 5349-1:2001 [Ah(8) in ms- 2] or the hand-arm vascular frequency weighting Wp proposed in the ISO technical report (TR) 18570:2017 [Ap(8) in ms- 2]. To estimate a threshold value for vascular hand-arm vibration risk, the Wp-weighted vibration exposure value Ep,d (in ms- 1.5) was calculated according to the ISO/TR document. The difference in the predictions of VWF between the exposure measures calculated with the frequency weightings Wh or Wp was investigated by means of logistic modelling. RESULTS: Measures of daily vibration exposure constructed with the frequency weighting Wp [Ap(8) and Ep,d], which gives more importance to intermediate- and high-frequency vibration, were better predictors of the occurrence of VWF in the vibration-exposed workers than the metric derived from the conventional ISO frequency weighting Wh [Ah(8)]. There was some epidemiological evidence for a threshold value of Ep,d for the onset of VWF in the vibration-exposed workers. CONCLUSIONS: Measures of daily vibration exposure evaluated with the vascular weighting Wp performed better for the predictions of VWF than those obtained with the frequency weighting Wh recommended in ISO 5349-1.

Objectives. To compare a local cohort of 2,488 men occupationally exposed to asbestos and enrolled in a public health surveillance program with the 1995 – 2009 cancer incidence of the general population of Friuli Venezia Giulia (FVG) region, Northeast Italy, we conducted a historical cohort study. Methods. Standardized incidence ratios (SIRs), with 95% confidence interval (95%CI), for specific cancer sites were estimated in the cohort and in subgroups of workers employed in shipbuilding between 1974-1994. For internal comparisons, we estimated incidence rate ratios (IRRs) for all cancers, lung cancer and mesothelioma, by level of exposure to asbestos and sector of employment adjusted for smoking habits and age at start of follow-up. Results. Among cohort members the SIR was 8.82 (95%CI 5.95-12.61) for mesothelioma and 1.61 (95%CI 1.26-2.04) for lung cancer. In subgroup analyses, the SIR for lung cancer in subjects hired in shipbuilding between 1974-1984 was 2.09 (95%CI 1.32-3.13). In the overall cohort, a borderline increased incidence was also found for stomach cancer (SIR=1.53 95%CI 0.96-2.31). Internal comparisons within the cohort show that among men with high asbestos exposure level the relative risk was almost three-fold for lung cancer (IRR=2.94 95%CI 1.01-8.57). Conclusions. This cohort experienced an excess in the incidence of both mesothelioma and lung cancer, showing increasing incidence rates at higher level of asbestos exposure. For lung cancer, the relative incidence was highest among workers hired in shipbuilding between 1974-1984.

Titanium dioxide nanoparticles (TiO2NPs) suspensions (concentration 1.0 g/L) in synthetic sweat solution were applied on Franz cells for 24 h using intact and needle-abraded human skin. Titanium content into skin and receiving phases was determined. Cytotoxicity (MTT, AlamarBlue® and propidium iodide, PI, uptake assays) was evaluated on HaCat keratinocytes after 24 h, 48 h, and seven days of exposure. After 24 h of exposure, no titanium was detectable in receiving solutions for both intact and damaged skin. Titanium was found in the epidermal layer after 24 h of exposure (0.47 ± 0.33 ?g/cm2) while in the dermal layer, the concentration was below the limit of detection. Damaged skin, in its whole, has shown a similar concentration (0.53 ± 0.26 ?g/cm2). Cytotoxicity studies on HaCaT cells demonstrated that TiO2NPs induced cytotoxic effects only at very high concentrations, reducing cell viability after seven days of exposure with EC50s of 8.8 × 10-4 M (MTT assay), 3.8 × 10-5 M (AlamarBlue® assay), and 7.6 × 10-4 M (PI uptake, index of a necrotic cell death). Our study demonstrated that TiO2NPs cannot permeate intact and damaged skin and can be found only in the stratum corneum and epidermis. Moreover, the low cytotoxic effect observed on human HaCaT keratinocytes suggests that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure. © 2015 by the authors; licensee MDPI, Basel, Switzerland.

Skin absorption and toxicity on keratinocytes of cobalt oxide nanoparticles (Co3O4NPs) have been investigated. Co3O4NPs are commonly used in industrial products and biomedicine. There is evidence that these nanoparticles can cause membrane damage and genotoxicity in vitro, but no data are available on their skin absorption and cytotoxicity on keratinocytes. Two independent 24 h in vitro experiments were performed using Franz diffusion cells, using intact (experiment 1) and needle-abraded human skin (experiment 2). Co3O4NPs at a concentration of 1000 mg/L in physiological solution were used as donor phase. Cobalt content was evaluated by Inductively Coupled–Mass Spectroscopy. Co permeation through the skin was demonstrated after 24 h only when damaged skin protocol was used (57 ± 38 ng·cm−2), while no significant differences were shown between blank cells (0.92 ± 0.03 ng cm−2) and those with intact skin (1.08 ± 0.20 ng·cm−2). To further investigate Co3O4NPs toxicity, human-derived HaCaT keratinocytes were exposed to Co3O4NPs and cytotoxicity evaluated by MTT, Alamarblue® and propidium iodide (PI) uptake assays. The results indicate that a long exposure time (i.e., seven days) was necessary to induce a concentration-dependent cell viability reduction (EC50 values: 1.3 × 10−4 M, 95% CL = 0.8–1.9 × 10−4 M, MTT essay, 3.7 × 10−5 M, 95% CI = 2.2–6.1 × 10−5 M, AlamarBlue® assay) that seems to be associated to necrotic events (EC50 value: 1.3 × 10−4 M, 95% CL = 0.9–1.9 × 10−4 M, PI assay). This study demonstrated that Co3O4NPs can penetrate only damaged skin and is cytotoxic for HaCat cells after long term exposure.

Objective The aim of this study was to investigate the performance of four frequency weightings for hand-transmitted vibration to predict the incidence of vibration-induced white finger (VWF). Methods In a longitudinal study of vibration-exposed forestry and stone workers (N=206), the incidence of VWF was related to measures of vibration exposure expressed in terms of 8-hour frequency-weighted energy-equivalent root-mean-square (rms) acceleration magnitude [A(8)] and years of follow-up. To calculate A(8), the rms acceleration magnitudes of vibration were weighted by means of four frequency weightings: (i) W(subscript h) (the frequency weighting specified in ISO 5349-1:2001); (ii) W(subscript h-bl) (the band-limiting component of W(subscript h)); (iii) W(subscript hf) (a frequency weighting based on finger vibration power absorption); and (iv) W(subscript hT) (a frequency weighting based on a Japanese study of VWF prevalence). The relations of VWF to alternative measures of vibration exposure were assessed by the generalized estimating equations (GEE) method to account for the within-subject dependency of the observations over time. Results Data analysis with a GEE logistic model and a measure of statistical fit suggested that calculating A(8) by weighting the tool rms accelerations with W(subscript h-bl) gave better predictions of the cumulative incidence of VWF than the other alternative measures of daily vibration exposure. Values of A(8) derived from the currently recommended ISO frequency weighting W(subscript h) produced poorer predictions of the incidence of VWF than those obtained with frequency weightings W(subscript hf) or W(subscript hT). Conclusions This prospective cohort study suggests that measures of daily vibration exposure which give relatively more weight to intermediate and high frequency vibration are more appropriate for assessing the probability of VWF.

The objective of this study was to investigate the relation between alternative measures of exposure to whole-body vibration (WBV) and low back pain (LBP) in professional drivers.The incidence of 12-month LBP, high pain intensity (numerical rating scale score5), and disability in the lower back (Roland and Morris disability scale scoreor=12) was investigated in a cohort of 537 drivers over a 2-year follow-up period. LBP outcomes, individual characteristics, and work-related risk factors were investigated by direct interview using a structured questionnaire. Daily vibration exposure was expressed in terms of either equivalent acceleration over an 8-h reference period [A(8), root-mean-square (r.m.s.) method] or vibration dose value [VDV, root-mean-quad (r.m.q.) method]. From the vibration magnitudes measured on vehicles and total exposure duration, seven alternative measures of cumulative vibration exposure were calculated for each driver, using expressions of the form Sigma a (i)(m)t(i), where a (i) is the frequency-weighted r.m.s. or r.m.q. acceleration magnitude on vehicle i(a(ws) or a (wq), respectively), t(i) is the lifetime exposure duration for vehicle i, and m = 0, 1, 2, or 4.In the drivers' cohort, the cumulative incidence of LBP outcomes were 36.3% for 12-month LBP, 24.6% for high pain intensity, and 19.2% for disability in the lower back. A transition model, which takes into account the temporal sequence of cause and effect and captures the longitudinal part of the relationship, showed that VDV performed better than A(8) for the prediction of LBP outcomes. After adjusting for potential confounders, test for trends suggested an increased risk for developing high pain intensity and disability over time (and, to a lesser extent, 12-month LBP) with the increases of cumulative vibration doses computed from lifetime exposure duration and r.m.q. vibration magnitude (i.e. Sigma[a (wqi)(m)t(i)]). Measures of exposure duration, either daily or lifetime, also provided good indications of risk for LBP outcomes over time. Physical work load, but not psychosocial environment, was significantly associated with the occurrence of LBP outcomes over time.Measures of vibration exposure derived from exposure duration (daily or lifetime) and r.m.q. acceleration magnitude (VDV, Sigma[a(wqi)(m)t(i)]) were better predictors of LBP outcomes over time than measures of vibration exposure including r.m.s. acceleration (A(8), summation operator[a(wsi)(m)t(i)]). Patterns of exposure-response relationship were more evident for the outcomes high pain intensity or disability in the lower back than for the binary response 12-month LBP.

Objectives To assess the usefulness of color charts for the diagnosis of finger whiteness in vibration-exposed workers. Methods A group of 146 forestry and stone workers exposed to hand-transmitted vibration (HTV) were examined twice over 1 year follow up period. The anamnestic diagnosis of finger whiteness was made on the basis of (a) a medical history alone, and (b) the administration color charts which showed changes in the skin color of fingers and hands. The cold response of digital arteries was assessed by measuring the change in finger systolic blood pressure (FSBP) after local cooling from 30 to 10C (FSBP%10). Results Assuming the administration of color charts as the gold standard, the sensitivity and specificity of the medical history alone to diagnose finger whiteness was 88.2 and 93.8%, respectively, at the initial cross-sectional study and 94.4 and 97.7% at the end of the follow-up. Random-intercept linear regression analysis of follow up data showed that after adjustment for several covariates, FSBP%10 was significantly associated with finger whiteness assessed by either medical history alone (P\0.005) or the color charts (P\0.001). However, a statistical measure of overall fit of regression models (Bayesian Information Criterion) suggested that the color chart method performed better than medical history alone for the prediction of the cold response of digital arteries. Conclusion The administration of color charts seems to reduce the proportion of false positive responses for finger whiteness in a population of vibration-exposed workers. The color chart method was a more significant predictor of digital arterial hyperresponsiveness to cold than medical history alone. These findings suggest that the use of color charts in clinical and epidemiological studies may be of help to assist in the diagnosis of finger whiteness in vibration-exposed workers.

Objectives To investigate the relation between manipulative dexterity and vibration exposure, ergonomic risk factors, and upper limb disorders in a group of workers exposed to hand-transmitted vibration (HTV). Methods Manipulative dexterity was investigated on 115 HTV workers (82 forestry workers and 33 stone workers) and 64 control men over 1-year follow-up period. The Purdue pegboard method was used to test manipulative dexterity which was scored for the dominant hand, nondominant hand, and both hands. Information about individual, work and health history was obtained by means of a standardised questionnaire. Vibration exposure was assessed in terms of tool vibration magnitudes, daily and total exposure duration, and cumulative vibration dose. Results On the cross-sectional investigation, Purdue pegboard scores were significantly lower in the HTV workers than in the controls (0.001 \ P \ 0.05). Over 1-year follow-up period, Purdue pegboard scores were found to be inversely related to age, smoking and use of vibratory tools (0.001 \ P \ 0.05). Moreover, deterioration of some measures of manipulative dexterity was significantly associated with sensorineural and vascular symptoms in the fingers of the HTV workers. Randomintercept linear regression analysis showed that Purdue pegboard scores decreased with the increase of vibration exposure. The reduction of assembly score (i.e. number of pins, collars, and washers assembled in a 60-s period) was significantly associated with the increase in vibration exposure and ergonomic stress (neck-upper arm posture, hand-intensive work, and total ergonomic score). Purdue pegboard scores tended to improve over the follow-up period in both the controls and the HTV workers, suggesting a possible learning effect over time. Conclusion The findings of this longitudinal study suggest an association between deterioration of manipulative dexterity and neurovascular symptoms in the fingers of HTV workers. There was evidence for a significant relation between loss of precise manipulation and exposures to hand-transmitted vibration and ergonomic risk factors.

OBJECTIVE: This cohort study aims to compare the performance of alternative frequency weightings of hand-transmitted vibration (HTV) for the assessment of the exposure–response relationships for neurosensory disorders and reduced work ability among HTV-exposed workers. METHODS: In a 3-year follow up study, the occurrence of neurosensory symptoms and reduced work ability, and the response to quantitative sensory testing (grip force, manipulative dexterity, touch sensation) were investigated in 249 HTV-exposed workers and 138 healthy controls. Among the HTV-exposed workers, the sensory outcomes were related to measures of daily vibration exposure expressed in terms of 8-hour energy-equivalent frequency-weighted acceleration magnitude [A(8)]. To calculate A(8), the acceleration magnitudes of vibration were weighted by means of four alternative frequency weightings of HTV. RESULTS: The occurrence of neurosensory symptoms, reduced work ability, and abnormalities of sensory tests was greater among the HTV-exposed workers than the controls. Among the HTV-exposed workers, the deterioration of neurosensory outcomes and the reduction of work ability increased on par with the measures of vibration exposure. Exposure–response models revealed that the four alternative frequency weightings of HTV provided the same predictions for the probability of finger numbness among the exposed workers (observed 36% versus predicted 32%). CONCLUSIONS: The findings of this study revealed significant dose–response relationships between measures of vibration exposure, sensory disorders, and reduced work ability among the HTV-exposed workers. There were no differences in the prediction of finger numbness between measures of vibration exposure calculated with alternative frequency weightings of HTV.

To investigate whether prior exposure to hand-transmitted vibration on the day of a cold provocation test affects the cold response of digital arteries.Each of ten healthy men attended two experimental sessions in which their right hands were exposed for 60 min to either contact force alone (5 N) or a combination of contact force (5 N) and 125-Hz vertical vibration with an acceleration magnitude of 64 m s(-2) r.m.s. (unweighted). Finger systolic blood pressure (FSBP) during local cooling to 10 degrees C was measured in the second right finger (exposed hand) and the second left finger (unexposed hand) before exposure and at 30 and 70 min after the end of both exposure conditions.Analysis of repeated measures of FSBP during local cooling by means of an autoregressive model revealed no significant difference in cold-induced vasoconstriction of the digital arteries between exposure to contact force alone and combined exposure to contact force and vibration. There were no significant changes in the cold response of digital arteries over time in either the right or the left hand after exposure of the right hand to either the contact force alone or the combined contact force and vibration.The results of this experimental study of the influence of prior vibration exposure on the cold test results suggest that in healthy men recent exposure to contact force and moderate levels of hand-transmitted vibration does not affect the response of finger circulation to cold provocation. These findings may be of practical importance for the definition of test conditions in the field, especially the length of time required between the last occupational exposure to tool vibration and the commencement of objective vascular testing.

Objectives: To investigate the prevalence of vascular, neurological and musculoskeletal disorders of the upper limb in a group of female workers performing either mechanical or hand sanding in the furniture industry (n=100) and in a control group of female office workers (n=100). A further aim was to study the possible adverse effects of exposure to a combination of vibration and ergonomic risk factors in female workers. Methods: All female workers underwent a medical interview and a complete physical investigation. The clinical diagnoses of Raynaud’s phenomenon and carpal tunnel syndrome (CTS) were made according to international consensus criteria. Hand-transmitted vibration from orbital sanders was measured according to International Organization for Standardization (ISO) recommendations. Daily vibration exposure was assessed in terms of 8-h energy-equivalent frequency-weighted acceleration [A(8)] according to the European Directive on physical agents. Ergonomic load on the upper limbs was estimated by means of strain index methodology. Results: There was no significant difference in the prevalence of Raynaud’s phenomenon between the furniture workers (4%) and the controls (8%). The prevalence of CTS, peripheral sensorineural disturbances (after exclusion of CTS cases) and upper-limb musculoskeletal complaints was significantly greater in the furniture workers than in the controls. CTS was clinically diagnosed in 19% of the furniture workers and 8% of the controls. A log-binomial regression analysis showed that the occurrence of soft-tissue disorders of the upper limb increased significantly with the increase of both daily vibration exposure and the strain index score. It was estimated that the risk for CTS increased by a factor of 1.30 (95% CI 1.11–1.53) for each unit of increase in A(8) (ms−2), and by 1.09 (95% CI 1.02–1.15) for each unit of increase in the strain index score. Conclusions: Even though the cross-sectional design of this epidemiological study does not allow aetiological considerations, our findings suggest a significant association between occupational use of vibratory tools and soft-tissue disorders in the upper limbs of female workers. Quantitative estimation of vibration exposure and ergonomic stress showed that these physical risk factors seem to contribute in a multiplicative way to the occurrence of chronic nerve and musculoskeletal disorders in female workers operating hand-held vibrating tools in the furniture industry.

To compare the acute response of finger circulation to continuous and intermittent vibration having the same total duration of vibration exposure and the same energy-equivalent acceleration magnitude.Finger blood flow (FBF) was measured in the middle and little fingers of both hands of ten healthy men. Finger skin temperature (FST) was measured in the middle right finger. With a static load of 10 N, the middle finger of the right hand was exposed to 125 Hz at 44 m s(-2) root mean square (r.m.s.) in five conditions: (1). 30 min continuous exposure, (2). two periods of 15 min, separated by a 15 min period with no vibration, (3). four periods of 7.5 min, separated by 7.5 min periods with no vibration, (4). eight periods of 3.75 min, separated by 3.75 min periods with no vibration, (5). 16 periods of 1.88 min, separated by 1.88 min periods with no vibration. All five exposures correspond to an 8 h energy-equivalent frequency-weighted acceleration magnitude of 1.4 m s(-2) r.m.s. according to International Standard ISO 5349-1 (2001). Finger circulation was measured in all four digits before the application of vibration and at fixed intervals during vibration exposure and during a 45 min recovery period.The FST did not change during vibration exposure, whereas all vibration conditions produced significant reductions in FBF of the vibrated finger when compared with the pre-exposure FBF. During vibration exposure, the vibration caused a similar degree of vasoconstriction in the vibrated finger without evidence of cumulative effects during intermittent exposure. After the end of exposure to 30 min of continuous vibration there was a progressive decrease in the FBF, whereas there was no statistically significant reduction following exposure to intermittent vibration.For the vibration stimuli investigated (exposure durations varying from 1.88 min to 30 min, with rest periods varying from 1.88 min to 15 min), the reduction of FBF during exposure was the same for continuous and intermittent vibration. The after effect of vibration was greater following the continuous vibration exposure. Although some evidence from this study is consistent with the notion that intermittent vibration has a less severe effect than continuous vibration, this evidence is not yet conclusive.

Objectives: To identify the current state of knowledge, current uncertainties and future needs related to the diagnosis of disorders associated with the use of vibratory hand-held tools. Method: An international workshop was convened with invited experts, medical doctors, scientists and engineers familiar with hand-transmitted vibration and the diagnosis of vascular, neurological and musculoskeletal disorders. This paper records the general conclusions from four panel discussions. Results: For the most common vascular disorder (vibration-induced white finger), the principal symptom and sign involves attacks of well-demarcated finger blanching (Raynaud's phenomenon); low finger systolic blood pressure following cooling is indicative of vibration-induced white finger and zero finger systolic blood pressure can confirm an attack of Raynaud's phenomenon. For neurological disorders, some symptoms can exist without detectable signs and some signs can exist without symptoms; numbness and tingling are commonly reported but neurological changes may be present without these symptoms. The pathogenesis of musculoskeletal disorders in users of vibratory tools is not clear; symptoms may include pain that may not be associated with abnormal results in objective tests. For both neurological and musculoskeletal disorders, a thorough neuromuscular and skeletal examination is required; diagnosis must consider the work history and medical history, the results of physical examination and any objective tests in addition to other factors (e.g. age, smoking, alcohol, systemic disorders, medication and neurotoxic agents) that might have contributed to symptoms, signs and test results. Conclusions: While vibration-induced white finger is caused by vibration, some neurological and musculoskeletal disorders are the result of work with vibratory tools where the separate roles of vibration, repetitive movements, grip and push forces, non-neutral postures and any other ergonomic stressors are often unclear. Such disorders may be more easily identified as being caused by the work rather than by exposure to hand-transmitted vibration per se. A person found to have developed disorders induced by either vibration or the work situation should not be returned to the same vibration exposure or work without any changes expected to lessen the risks.

Objectives This study investigated the effect of hand elevation on reductions in finger blood flow (FBF) induced by hand-transmitted vibration. Methods Fourteen males attended six sessions on six separate days, with a control sessions and a vibration session (125-Hz vibration at 44 ms 2 r.m.s.) with the right hand supported at each of three elevations: 20 cm below heart level (HL), at HL, and 20 cm above HL. Finger blood flow on the left and right hand was measured every 30 s during each 25-minute session comprised of five periods: (i) no force and no vibration (5 minutes), (ii) 2-N force and no vibration (5 minutes), (iii) 2-N force and vibration (5 minutes), (iv) 2-N force and no vibration (5 minutes), and (v) no force and no vibration (5 minutes). Results Without vibration, FBF decreased with increasing elevation of the hand. During vibration of the right hand, FBF reduced on both hands. With elevation of the right hand, the percentage reduction in FBF due to vibration (relative to FBF on the same finger at the same elevation before exposure to vibration) was similar on the middle and little fingers of both hands. After cessation of vibration, there was delayed return of FBF with all three hand heights. Conclusions Vibration of one hand reduces finger blood flow on both exposed and unexposed hands, with the reduction dependent on the elevation of the hand. The mechanisms responsible for vibration-induced reductions in FBF seem to reduce blood flow as a percentage of the blood flow without vibration. Tasks requiring the elevation of the hands will be associated with lower FBF, and the FBF will be reduced further if there is exposure to hand-transmitted vibration.

Purpose – To investigate the relationships between low back symptoms and alternative measures of external dose and internal spinal dose in professional drivers exposed to whole body vibration (WBV). Methods – The occurrence of low back symptoms were investigated in a cohort of 537 drivers over a two-year follow up period. Low back pain (LBP), individual characteristics, and work-related risk factors were investigated with a structured questionnaire. Exposure to WBV was evaluated by means of measures of external dose (daily vibration exposure in terms of either equivalent continuous acceleration over an eight-hour period (A(8)) or vibration dose value according to the EU Directive on mechanical vibration) and measures of internal lumbar load (daily compressive dose Sed and risk factor R according to ISO/CD 2631-5 2014). Results – In the drivers’ cohort, the cumulative incidence of 12-month low back outcomes was 16.8% for LBP, 9.3% for chronic LBP, and 21.8% for sciatic pain. The measures of internal spinal load were better predictors of the occurrence of low back symptoms than the measures of daily vibration exposure. A two-fold increase in the risk estimates for low back outcomes was found in the upper quartile of the R factor (0.41-0.72 units) compared to the lower one (0.07-0.19 units). Conclusions – In this prospective cohort study, measures of internal spinal dose performed better than measures of daily vibration exposure (external dose) for the prediction of low back outcomes in professional drivers. The ISO boundary values of the risk factor R for low and high probabilities of adverse health effects on the lumbar spine tend to underestimate the health risk in professional drivers.

To evaluate whether residential radon exposure explains the excess mortality for lung cancer in an Italian alpine valley with high natural radioactivity, the authors conducted a population-based case-control study on 138 deceased cases and 291 sex- and year-of-birth-matched controls. Year-long alpha-track measurements of radon were performed in the most recent residence, and information about occupational history and lifetime smoking habits was obtained. The authors adjusted for smoking, and radon was associated with lung cancer risk among men: compared with a radon level of < 40 becquerels (Bq) per cubic meter (m3), the odds ratios for 40-76 Bq/m3, 77-139 Bq/m3, 140-199 Bq/m3, and 200+ Bq/m3 were 2.1, 2.0, 2.7, and 1.4, respectively. The association between radon and lung cancer, as determined with a multiplicative model, was found only among male smokers.

OBJECTIVES—To investigate the acute effects of the frequency of hand transmitted vibration on finger circulation. A further aim was to investigate whether the frequency weighting assumed in current standards for hand transmitted vibration reflects the haemodynamic changes which occur in the fingers exposed to vibration with different frequencies but with the same frequency weighted acceleration magnitude. METHODS—Finger skin temperature (FST) and finger blood flow (FBF) were measured in the middle fingers of both hands of 10 healthy men. With a static load of 10 N, the right hand was exposed for 15 minutes to the following root mean square (rms) acceleration magnitudes and frequencies of vertical vibration: 5.5 m/s2 at 16 Hz; 11 m/s2 at 31.5 Hz; 22 m/s2 at 63 Hz; 44 m/s2 at 125 Hz; and 88 m/s2 at 250 Hz. These exposures to vibration produce the same frequency weighted acceleration magnitude (5.5 m/s2 rms) according to the frequency weighting included in the international standard ISO 5349. A control condition consisted of exposure to the static load only. Finger circulation was measured before application of the vibration and static load and at fixed intervals during exposure to vibration and a 45 minute recovery period. RESULTS—No significant changes in finger circulation were found with only the static load. The FST did not change significantly during or after acute exposure to vibration. In the vibrated right finger, exposures to vibration with frequencies of 31.5-250 Hz provoked a greater reduction in FBF than did vibration of 16 Hz or the static load only. In the non-vibrated left finger, the FBF measured with vibration at each frequency of 63-250 Hz was significantly lower than that measured with static load only. The reduction in FBF during exposure to vibration with any frequency was stronger in the vibrated finger than in the non-vibrated finger. In both fingers, there was a progressive decrease in FBF after the end of exposure to vibration with frequencies of 31.5-250 Hz. The higher the frequency of vibration, the stronger the decrease in FBF in both fingers during recovery. CONCLUSIONS—Acute exposures to vibration with equal frequency weighted magnitude reduce the FBF in both vibrated and non-vibrated fingers for frequencies between 31.5 and 250 Hz. The extent of digital vasoconstriction after exposure to vibration increases with increasing frequency. The frequency weighting given in current standards tends to overestimate the vasoconstriction associated with acute exposures to vibration frequencies around 16 Hz. Keywords: finger circulation; frequency weighted acceleration magnitude; vibration frequency

The aim of this study is to update the information on the epidemiologic evidence of the adverse health effects of whole-body vibration (WBV) on the spinal system by means of a review of the epidemiologic studies published between 1986 and 1997. In a systematic search, using several databases, of epidemiologic studies of low back pain (LBP) disorders and occupations with exposure to WBV, 45 articles were retrieved. The quality of each study was evaluated according to criteria concerning the assessment of vibration exposure, assessment of health effects, and methodology. The epidemiologic studies reaching an adequate score on each of the above-mentioned criteria were included in the final review. A meta-analysis was also conducted in order to combine the results of independent epidemiologic studies. After applying the selection criteria, 17 articles reporting the occurrence of LBP disorders in 22 WBV-exposed occupational groups reached a sufficient score. The study design was cross-sectional for 13 occupational groups, longitudinal for four groups and of case-control type for one group. Two studies included both cross-sectional and follow-up data on the occurrence of LBP disorders in four occupational groups. The main reasons for the exclusion of studies were insufficient quantitative information on WBV exposure and the lack of control groups. The findings of the selected studies and the results of the meta-analysis of both cross-sectional and cohort studies showed that occupational exposure to WBV is associated with an increased risk for LBP, sciatic pain, and degenerative changes in the spinal system, including lumbar intervertebral disc disorders. Owing to the cross-sectional design of the majority of the reviewed studies, this epidemiologic evidence is not sufficient to outline a clear exposure-response relationship between WBV exposure and LBP disorders. Comparing the epidemiologic studies included in this review with those conducted before 1986, it is concluded that research design and the quality of exposure and health effect data in the field of WBV have improved in the last decade.

This study investigated the relation between vibration exposure, the prevalence of white fingers, and the cold response of digital arterial vessels in workers using vibrating tools.The change in finger systolic blood pressure (FSBP) at 15 and 10 degrees C as the percentage of the pressure at 30 degrees C (FSBP%) was measured in 455 healthy referents and 822 workers exposed to hand-transmitted vibration. Exposure to hand-transmitted vibration was assessed in terms of 8-hour energy-equivalent frequency-weighted acceleration [A(8)] and total operating time with vibrating tools.The prevalence of white fingers was 1.1% for the referents and ranged from 9.0% to 51.6% for the vibration-exposed groups. The estimated mean value of A(8) ranged between 1.6 (referents) and 8.3 (quarry drillers) m/s2. After adjustment for age, smoking, and drinking habits, the FSBP% was significantly lower in the vibration-exposed groups than in the reference group. Groupwise, the FSBP%(10 degrees) was inversely related to the prevalence of white fingers, the estimated A(8), and total operating time. With FSBP%(10 degrees)70% or60% as the lower normal limit, the sensitivity of the cold test varied from 86% to 100%, with a specificity of 90% to 94%, and a positive predictive value of 68% to 74%.FSBP measurement during cold provocation is a useful laboratory test for white fingers. A quantitative relationship between cold-induced digital arterial hyperresponsiveness and occupational exposure to hand-transmitted vibration was suggested.

This paper provides an overview of the exposure-response relationship for the vascular component of the hand-arm vibration syndrome, called vibration-induced white finger (VWF). Over the past two decades, several epidemiological studies have shown a poor agreement between the risk for VWF observed in various occupational groups and that predicted by models included in annexes to International Standard ISO 5349 (ISO 5349:1986, ISO 5349-1:2001). Either overestimation or underestimation of the occurrence of VWF have been reported by investigators. It has been argued that the current ISO frequency-weighting curve for hand-transmitted vibration, which assumes that vibration-induced adverse health effects are inversely related to the frequency of vibration between 16 and 1250 Hz, may be unsuitable for the assessment of VWF. To investigate this issue, a prospective cohort study was carried out to explore the performance of four alternative frequency weightings for hand-transmitted vibration to predict the incidence of VWF in groups of forestry and stone workers. The findings of this study suggested that measures of vibration exposure which give relatively more weight to intermediate and high frequency vibration produced better predictions of the incidence of VWF than that obtained with the frequency weighting currently recommended in International Standard ISO 5349-1:2001.

Objectives This study investigated whether reductions in finger blood flow (FBF) during and after vibration are similarly dependent on the magnitude and duration of vibration. Methods FBF on the left and right hand was measured every minute during, and for 1 hour following, exposure of the right hand to one of three magnitudes of 125-Hz sinusoidal vibration (0, 22, or 88 ms 2 r.m.s.) for one of two durations (7.5 or 15 minutes). Each session comprised five periods: (i) no force and no vibration (5 minutes), (ii) 2-N force and no vibration (5 minutes), (iii) 2-N force and vibration (7.5 or 15 minutes), (iv) 2-N force and no vibration (5 minutes), and (v) no force and no vibration (60 minutes). Results Both magnitudes and durations of vibration reduced FBF in the exposed and unexposed hands, both during and after vibration. With increased magnitude of vibration, there was increased vasoconstriction in all fingers during and after exposure, and longer recovery times after vibration exposure. With increased duration of vibration, there were no changes in vascular responses during exposure but increased vasoconstriction after exposure and prolonged recovery times. With the higher vibration magnitude, the reduction in FBF during exposure was correlated with the time taken to recover after exposure. Conclusions Subjects with greater reduction in blood flow during vibration exposure also have stronger and longer vasoconstriction during subsequent recovery. The correlation between vascular changes during and after vibration exposure suggests similar mechanisms control FBF during and after vibration exposure.

Objectives Finger blood flow is reduced by hand-transmitted vibration but there has been little study of the peripheral vascular response to repetitive mechanical shocks. This study investigated how reductions in finger blood flow depend on shock repetition rate and the peak and rms magnitude of acceleration. Methods Subjects attended seven sessions: six with repetitive mechanical shocks and a control session with no shocks. Each session comprised five successive 5-min periods: (1) no force and no vibration, (2) force and no vibration, (3) force and vibration, (4) force and no vibration and (5) no force and no vibration. During the second– fourth periods, the palm of the right hand applied 2-N force to a vibrator. During the third period, a 125-Hz mechanical shock was applied with one of four repetition rates (1.3, 5.3, 21 or 83.3/s) and one of three acceleration magnitudes (2.5, 5 or 10 ms-2 rms, unweighted). Finger blood flow was measured every 30 s in the middle and little fingers of the right (exposed) hand and the left (unexposed) hand. Results Different repetition rates (1.3–83.3 s-1) and different peak magnitudes (10–88 ms-2 peak) but the same rms acceleration (10 ms-2 rms) caused similar decreases in blood flow in fingers on exposed and unexposed hands. Shocks with a 83.3 s-1 repetition rate, peak magnitude of 10 ms-2 and rms acceleration of 10 ms-2 provoked greater reduction in finger blood flow than shocks with the same peak magnitude but lower repetition rate (21 or 5.3 s-1) and lower rms acceleration (5 or 2.5 ms-2). Conclusions For shocks similar to those based on 125-Hz oscillations with repetition rates between 1.3 and 83.3 s-1, acute reductions in finger blood flow can be predicted from the rms acceleration.

OBJECTIVES--To investigate the occurrence of disorders associated with the hand arm vibration syndrome in a large population of stone workers in Italy. The dose-response relation for vibration induced white finger (VWF) was also studied. METHODS--The study population consisted of 570 quarry drillers and stonecarvers exposed to vibration and 258 control stone workers who performed only manual activity. Each subject was interviewed with health and workplace assessment questionnaires. Sensorineural and VWF disorders were staged according to the Stockholm workshop scales. Vibration was measured on a representative sample of percussive and rotary tools. The 8 h energy equivalent frequency weighted acceleration (A (8)) and lifetime vibration doses were calculated for each of the exposed stone workers. RESULTS--Sensorineural and musculoskeletal symptoms occurred more frequently in the workers exposed to vibration than in the controls, but trend statistics did not show a linear exposure-response relation for these disorders. The prevalence of VWF was found to be 30.2% in the entire group exposed to vibration. Raynaud's phenomenon was discovered in 4.3% of the controls. VWF was strongly associated with exposure to vibration and a monotonic dose-response relation was found. According to the exposure data of this study, the expected percentage of stone workers affected with VWF tends to increase roughly in proportion to the square root of A(8) (for a particular exposure period) or in proportion to the square root of the duration of exposure (for a constant magnitude of vibration). CONCLUSION--Even although limited to a specific work situation, the dose-response relation for VWF estimated in this study suggests a time dependency such that halving the years of exposure allows a doubling of the energy equivalent vibration. According to these findings, the vibration exposure levels currently under discussion within the European Community seem to represent reasonable exposure limits for the protection of workers against the harmful effects of hand transmitted vibration.

In a six year follow up study of the handarm vibration syndrome, 62 stoneworkers operating hand held vibrating tools in 10 travertine quarries and mills were first investigated in 1985 and then in 1991. The frequency weighted acceleration of vibration from the rock drills and stone hammers used by the travertine workers exceeded 20 m/s2, indicating a hazardous work activity according to the proposal of the EC directive for physical agents. A clinical examination and a cold provocation test were repeated with the same procedures as those adopted at the time of the first survey. The stoneworkers were divided into groups according to current work state: active stoneworkers who continued to use powered tools during the follow up (n = 21, median exposure time 22 years), and ex-stoneworkers with retirement vibration free intervals of three years (n = 22, median exposure time 27.5 years) and of six years (n = 19, median exposure time 20 years). In the group of active stoneworkers, a 38% onset a new cases of vibration-induced white finger (VWF) was found during the follow up (p < 0.01). Among the retired stoneworkers affected with VWF (n = 24), one recovered from VWF, one showed improvement, 20 remained stationary, and two deteriorated. The ex-stoneworkers experienced no significant change in sensorineural disturbances and a decrease in musculoskeletal symptoms of the upper limbs. At the cold provocation test, the currently active stoneworkers with VWF showed, on a group basis, a delayed finger rewarming time between the two examinations (p = 0.002). An abnormal response to cold provocation persisted in the fingers of the ex-stoneworkers with VWF, even in those reporting subjective improvement. These findings indicate a tendency towards the irreversibility of sensorineural and VWF symptoms in a group of ex-stoneworkers with prolonged exposure to high vibration levels in the past. The increased occurrence of VWF in the active stone workers after a few extra years of vibrating tool usage argues for an urgent implementation of preventive measures in the stone industry.

To investigate prospectively the relation between vibration-induced sensory dysfunction and measures of daily exposure to hand-transmitted vibration (HTV). Thermal perception thresholds for warmth and cold (TPT in °C) and vibrotactile perception thresholds (VPT in dB) at 31.5 and 125 Hz were measured at the fingertips of digit II (for the median nerve) and digit V (for the ulnar nerve) of both hands in 27 male controls and 29 naval engine workers exposed to HTV. In the HTV workers, peripheral sensory function was investigated over a follow-up period of 1–3 years. Vibration exposure was expressed in terms of equivalent frequency-weighted acceleration [A h(eq,T) in ms−2 rms], duration of exposure (T in hours), and frequency-weighted acceleration normalised to a period of 8 h [A(8) in ms−2 rms]. At baseline, the HTV workers showed significantly higher TPT for warmth and lower TPT for cold than the controls, while no differences in the VPTs at both frequencies were observed between the two groups. After adjustment for several confounders, data analysis with the generalised estimating equations method and a transition model showed that the changes over time in the TPTs of the HTV workers were significantly related to all measures of daily vibration exposure [A h(eq,T), T, A(8)]. No significant associations were observed for VPTs at either 31.5 or 125 Hz. The findings of this longitudinal study suggest a significant exposure–response relationship between thermal sensory impairment over time and measures of vibration exposure. The measurement of TPT may be a useful testing method to assess vibration-induced neuropathy at an early stage.

A case-control study of lung cancer and occupational exposure was conducted in a coastal area of Northeastern Italy where metallurgical and mechanical industries, docks and shipyards are located. Cases comprised 756 men who died of primary lung cancer in a 5-year period. Controls comprised 756 male subjects dying from other causes during the same period. Occupational exposures to lung carcinogens were assessed according to a job title-based approach, using two separate lists of industries/occupations recognized as being causally associated (list A) or suspected of being causally associated (list B) with lung cancer in humans. Exposure to asbestos was classified as absent, possible, or definite. After adjustment for cigarette smoking and place of residence, a significant association was found between lung cancer and occupations in both list A [relative risk (RR) = 2.25, 95% confidence interval (CI) = 1.68–3.03] and list B (RR = 1.33, 95% CI = 1.03–1.71). A significant excess risk was found for workers with definite exposure to asbestos as compared to those with no exposure to lung carcinogens (RR = 1.98, 95% CI = 1.42–2.75). Among occupations with recognized exposure to lung carcinogens other than asbestos, a significant excess risk for lung cancer was observed in iron and metalware workers. In occupational groups with definite exposure to asbestos, elevated risk estimates were found for shipyard workers, dockworkers, carpenters, and electricians. The combined effect of smoking and asbestos was found to be compatible with that expected under a multiplicative model. The overall population-attributable risk (ARp) for cigarette smoking was found to be 87.5%. The ARp estimate for occupations in list A was 16.0%. The estimate increased to 25.3% (95% CI = 16.2–34.4) when occupations in list B were included. The ARp estimate for possible or definite exposure to asbestos was 20.0% (95% CI = 11.5–28.5). With regard to the histologic types of lung cancer, significant associations were found between definite exposure to asbestos and squamous cell carcinoma (RR = 2.00, 95% CI = 1.28-–3.11), small cell carcinoma (RR = 2.11, 95% CI = 1.31–3.39), and adenocarcinoma (RR = 2.16, 95% CI = 1.32–3.53).

OBJECTIVES: To examine the association between two job stress models-the job strain (JDC) and the effort-reward imbalance (ERI) model-and ambulatory blood pressure monitoring in call handler operators. METHODS: Participants included 74 women (age, 34.9 ± 9.9 years) and 26 men (age 36.0 ± 10.8 years) who were monitored on 2 workdays for ambulatory blood pressure. Measures of both job stress models were related to blood pressure by the generalized estimating equations (GEE) method while adjusting for potential confounders (gender, age, cigarette smoking, alcohol consumption, educational level, marital status, time of day, and work schedule). RESULTS: Workshifts were associated with an increase of 3-4 and 14 mmHg in mean arterial pressure (MAP) compared with diurnal activities out of work and sleeping period, respectively (P < 0.001). Ambulatory blood pressure was also significantly related with work schedule preference: unpleasant work schedule was associated with an increase of 2 mmHg in MAP compared with pleasant work schedule (P = 0.013). In the ERI model, subjects scoring high in work stress have higher ambulatory blood pressure at work, at home, and during sleep. Work stress by time interaction was not longer significant when controlling for potential confounders: generalized estimating equations revealed that MAP was influenced by BMI (>25 vs.

Objectives: To investigate prospectively the relation between vibration-induced white finger (VWF) and measures of cumulative (lifetime) exposure to hand-transmitted vibration (HTV). Methods: Two hundred and forty-nine HTV workers and 138 control men of the same companies participated in a 3-year follow-up study. The diagnosis of VWF (Raynaud’s phenomenon in the controls) was based on the medical history, the administration of colour charts and the results of a cold test. Tool vibration magnitudes were expressed as root-mean-square (r.m.s.) acceleration, frequency-weighted according to international standard ISO 5349-1 and also unweighted over the frequency range 6.3–1250 Hz. From the vibration magnitudes and exposure durations, alternative measures of cumulative vibration dose were calculated for each HTV worker, according to the expression: dose = Σ a i m t i , where a i is the acceleration magnitude on tool i , t i is the lifetime exposure duration (hours) for tool i , and m = 0, 1, 2 or 4. Results: The incidence of VWF varied from 5 to 6% in the HTV workers versus 0 to 1.5% for Raynaud’s phenomenon in the controls. After adjusting for potential confounders, measures of cumulative vibration dose derived from total operating hours and high powers of unweighted acceleration (ie, , with m >1) gave better predictions of the occurrence of VWF than dose measures calculated from frequency-weighted acceleration (ie, ). These findings were observed in the entire sample of HTV workers, in those with no VWF at the initial investigation, and in those with normal cold test results at baseline. Conclusions: This prospective cohort study suggests that measures of cumulative vibration doses constructed from unweighted r.m.s. acceleration perform better for the prediction of VWF than dose measures calculated according to the recommendations of current standards. These findings should contribute to the improvement of the ISO frequency weighting for evaluating the severity of hand-transmitted vibration.

The aim of this study was to investigate the relation between low back pain (LBP) outcomes and measures of daily exposure to whole-body vibration (WBV) in professional drivers. In a study population of 202 male drivers, who were not affected with LBP at the initial survey, LBP in terms of duration, intensity, and disability was investigated over a two-year follow-up period. Vibration measurements were made on representative samples of machines and vehicles. The following measures of daily WBV exposure were obtained: (i) 8-h energy-equivalent frequency-weighted acceleration (highest axis), A(8)(max) in ms(-2) r.m.s.; (ii) A(8)(sum) (root-sum-of-squares) in ms(-2) r.m.s.; (iii) Vibration Dose Value (highest axis), VDV(max) in ms(-1.75); (iv) VDV(sum) (root-sum-of-quads) in ms(-1.75). The cumulative incidence of LBP over the follow-up period was 38.6%. The incidence of high pain intensity and severe disability was 16.8 and 14.4%, respectively. After adjustment for several confounders, VDV(max) or VDV(sum) gave better predictions of LBP outcomes over time than A(8)(max) or A(8)(sum), respectively. Poor predictions were obtained with A(8)(max), which is the currently preferred measure of daily WBV exposure in European countries. In multivariate data analysis, physical work load was a significant predictor of LBP outcomes over the follow-up period. Perceived psychosocial work environment was not associated with LBP.

To investigate prospectively the relation between vibration-induced vascular disorders and measures of daily exposure to hand-transmitted vibration (HTV).Two hundred and forty-nine HTV workers and 138 control men of the same companies participated in a 3-year follow-up study. The diagnosis of vibration induced white finger (VWF) in the HTV workers and that of Raynaud's phenomenon in the controls was based on the medical history, the administration of color charts and the results of a cold test with measurement of finger systolic blood pressures. Vibration magnitudes from the tools were measured as r.m.s acceleration, frequency weighted according to international standard ISO 5349-1, and also unweighted over the frequency range 6.3-1,250 Hz. Daily vibration exposure was expressed in terms of daily exposure duration and frequency-weighted or unweighted r.m.s. acceleration normalized to a reference period of 8 h (Aw(8) or Auw(8), respectively).The incidence of VWF varied from 5 to 6% in the HTV workers versus 0-1.5% for Raynaud's phenomenon in the controls. After adjusting for potential confounders, Auw(8) gave better predictions of the incidence of VWF and the cold response of the digital arteries over time than Aw(8) or daily exposure duration. These findings were observed in the entire sample of HTV workers, in those with no VWF at the initial investigation, and in those with normal cold test results at baseline.The findings of this longitudinal study suggest that a measure of daily vibration exposure calculated from unweighted r.m.s. acceleration over the frequency range 6.3-1,250 Hz performs better for the prediction of vascular disorders in users of vibratory tools than a measure derived from r.m.s. acceleration frequency weighted according to ISO 5349-1. This study provides epidemiological evidence that more weight should be given to intermediate and high-frequency vibration for evaluating the severity of hand-transmitted vibration.

Background Carpal tunnel syndrome (CTS) is a socially and economically relevant disease caused by compression or entrapment of the median nerve within the carpal tunnel. This population-based case-control study aims to investigate occupational/non-occupational risk factors for surgically treated CTS. Methods Cases (n = 220) aged 18-65 years were randomly drawn from 13 administrative databases of citizens who were surgically treated with carpal tunnel release during 2001. Controls (n = 356) were randomly sampled from National Health Service registry records and were frequency matched by age-gender-specific CTS hospitalization rates. Results At multivariate analysis, risk factors were blue-collar/housewife status, BMI ≥ 30 kg/m2, sibling history of CTS and coexistence of trigger finger. Being relatively tall (cut-offs based on tertiles: women ≥165 cm; men ≥175 cm) was associated with lower risk. Blue-collar work was a moderate/strong risk factor in both sexes. Raised risks were apparent for combinations of biomechanical risk factors that included frequent repetitivity and sustained force. Conclusion This study strongly underlines the relevance of biomechanical exposures in both non-industrial and industrial work as risk factors for surgically treated CTS.

Introduction Nanotechnologies are among the fastest growing areas of scientific research and have important applications in a wide variety of fields. The data suggest that in the future workers and consumers exposed to nanoparticles will significantly increase. Dermal absorption and toxicity of nanoparticles At now there are gaps in understanding about the human and environmental risk that manufactured nanoparticles pose for occupational exposed people and for consumers. There is a need for assessing the health and environmental impacts, the nanoparticles life cycle, the human exposure routes, the behavior of nanoparticles in the body, and the risk for workers. Possible routes of entry into the body include inhalation, absorption through the skin or digestive tract, injection, and absorption or implantation for drugs delivery systems. In particular, dermal absorption and skin penetration of nanoparticles needs a better evaluation because few and contradictory data are present in the literature, mainly on titanium dioxide. Conclusions There are limited data on carbon-based nanoparticles and very few data on other metal nanoparticles increasingly used in industry. The article reviews the literature on the percutaneous absorption of nanoparticles and their effect on skin.

Background Experimental and clinical evidence suggest that stress can lead to ill-health through the disregulation of the hypothalamic–pituitary–adrenal (HPA) axis. Studies to date have produced equivocal results likely due to different methodologies and failure to account for confounding factors. This investigation aimed to assess the relation between self-reported work-related stressors and salivary cortisol and to clarify the role of the potential confounders. Methods Thirty-six call-handlers completed a self-administered job content questionnaire and collected seven daily salivary samples on two workdays and a weekend. The diurnal salivary cortisol output was expressed as cortisol awakening response (CAR), and cortisol output in the rest of the day. Salivary cortisol data were normalized by means of square root transformation. The generalized estimating equations method was used to assess the relation between job strain and cortisol levels after adjusting for gender, weekdays and adherence to the sampling schedule. Results Job strain significantly influenced the total amount of cortisol response to waking (high strain vs. low strain: 1.1 (0.3–2.0) nmol/L). The cortisol response to waking showed gender-specific differences [women excreting greater cortisol than men: 1.1 (0.3–1.9) nmol/L], and weekday differences [workdays vs. weekend: 1.0 (0.3–1.6) nmol/L]. Noncompliance with the sampling protocol was associated with lower salivary cortisol than in adherent subjects. Conclusions Our results provide further evidence for the HPA axis involvement in the physiological response to work stress. The measure of the CAR showed to be the sensitive index to assess the physiological response to psychosocial factors. Gender, weekday, and protocol compliance were confounding factors. Am. J. Ind. Med. 52:251–260, 2009. 2008 Wiley-Liss, Inc.

To investigate the association between two job stress models—the job demand-control model and the effort-reward imbalance model—and repeated measures of salivary cortisol among male and female call-centre operators. Daily cortisol profiles consisting of seven time points were measured across two workdays and one leisure day to determine the cortisol awakening response and the cortisol output in the day in 104 volunteers. The employees completed two self-administered questionnaire—the Karasek’s demand-control questionnaire and the Siegrist’s effort-reward imbalance questionnaire—to assess psychosocial hazards at work. The relations between the perceived workload measures and salivary cortisol levels were analyzed by means of generalized estimating equations method after adjusting for potential confounders (gender, age, educational level, marital status, morning awakening time, sleep duration and quality, weekdays, work schedule, adherence to sampling procedure). The total cortisol amount excreted in the awakening period was positively associated with the job strain measures (high strain vs. low strain: 1.4 (2.4–0.3) nmol/l). In contrast, individuals scoring higher in effort-reward imbalance at work had both lower cortisol awakening response (high imbalance vs. low imbalance: −0.7 (−1.3 to −0.2) nmol/l) and lower diurnal secretory activity (−9.2 (−17.7 to −0.7) nmol/l). Gender, weekday and adherence to sampling schedule significantly influenced the cortisol excretion in the morning period. Our results indicate that the two work stress models differentially affect salivary cortisol output. This finding suggests that combining the information from two complementary job stress models results in improved knowledge on the psychobiological correlates of the psychosocial work environment.

Objectives This study investigated the relation between salivary endothelin, vibration exposure, and vascular disorders in a group of forestry workers. Methods Altogether 54 forestry workers and 52 controls underwent a medical examination and a cold test with measurement of the percentage of change in finger systolic blood pressure after finger cooling from 30°C to 10°C (FSBP% 10° ). Salivary endothelin concentration (ET 1–21 , in fmol/ml) was measured by a commercially available enzyme-linked immunosorbent assay before and after the cold challenge. The anamnestic diagnosis of vibration-induced white finger (VWF), assisted by color charts, was based on the Stockholm Workshop criteria. Results Six forestry workers (11%) and one control (2%) reported white fingers. Before the cold challenge, the salivary ET 1–21 concentration was significantly greater in the VWF workers than in the controls (P=0.036). The cold response of digital arteries was stronger in the VWF workers than in the controls (P

The authors report the first results of a global survey on the working conditions in the forests of the Italian Alps, where the mechanization of the operations is limited, owing to the difficult geomorphological conditions. First, an organizational analysis was performed in all the phases of forest work by using the method of organizational congruences. The physiological cost of each task was evaluated by measuring oxygen consumption, lung ventilation during work, and the heart rate through 24-hour continuous dynamic electrocardiograph recording. The postural load on the lumbar disks for the main logging tasks was evaluated by means of a biomechanical analysis that estimated the compressive force applied to disk L3 in different positions. The vibrations transmitted to the worker's hand/arm system during the cutting activities were also measured. The results of the analysis suggest that potentially hazardous situations can be reduced by training operators in safer work practices and that the work organization must be improved since most tasks are physically too demanding, from both the metabolic and the cardiac point of view. The postures habitually assumed by workers during cutting exert a load on intervertebral disks that is much higher than if they assumed an ergonomically correct position. The health risk from vibrations requires a careful control of both the working conditions and the worker's state of health.

To investigate the occurrence of vibration-induced white finger (VWF) and the cold response of digital arteries in a group of forestry workers, most of whom had used anti-vibration (AV) chain saws solely.One hundred and twenty-eight forestry workers underwent initially a medical examination and a standardized cold test with measurement of the change in finger systolic blood pressure after finger cooling from 30 to 10 degrees C (FSBP%(10 degrees )). They were re-examined two or three times over the calendar period 1990-1999. Seventy-one forestry workers were active over the entire follow up period, while 57 retired after 1-8 years from the initial investigation.The initial prevalence and the cumulative incidence of VWF over the follow up period were 26.6 and 11.7%, respectively. In the retired workers, the new cases of VWF occurred before their retirement, that is when they were still active. There were no significant changes in FSBP%(10 degrees ) in the active forestry workers over the follow up period. A significant increased in FSBP%(10 degrees ) (i.e. improvement) was observed in the retired workers at the end of the follow up. FSBP%(10 degrees ) at the cross-sectional investigation was significantly lower in the forestry workers who developed VWF during the follow up than in those who never experienced finger blanching over the study period.The findings of this follow up study suggest that forestry workers with work experience limited to AV chain saws are still at risk of developing VWF. Cessation of vibration exposure in the retired workers was associated with a beneficial effect on the cold response of digital arteries. Cold-induced digital arterial hyperresponsiveness at the initial investigation was a predictive factor for the onset of VWF over time.

To investigate prospectively the relation between vibration-induced white finger (VWF), exposure to hand-trasmitted vibration (HTV) and the cold response of digital arteries in users of vibrating tools. Two-hundred and sixteen HTV workers and 133 control men of the same companies underwent initially a medical examination and a standardised cold test with measurement of the change in finger systolic blood pressure (FSBP) after finger cooling from 30 to 10°C. They were re-examined 1 year later. Tool vibration magnitudes were expressed as frequency-weighted and unweighted r.m.s. accelerations. From the vibration magnitudes and exposure durations, alternative measures of cumulative vibration dose were calculated for each HTV worker, according to the expression: $$ \text{dose} = \sum a_i^m t_i$$ , where a i is the acceleration magnitude on tool i, t i is the lifetime exposure duration for tool i, and m = 0, 1, 2 or 4. Among the HTV workers, the initial prevalence and the 1-year incidence of VWF were 18.1 and 1.7%, respectively. At the first examination, the HTV workers with moderate or severe score for VWF showed a significantly increased cold reaction in the fingers when compared with the controls and the HTV workers with no vascular symptoms. At the follow-up, the controls, the asymptomatic HTV workers, and the prevalent cases of VWF did not show significant changes in the cold response of digital arteries. A deterioration of cold-induced digital vasoconstriction was found in the incident cases of VWF. In the HTV workers, vibration doses with high powers of acceleration (i.e., $$ \text{dose} = \sum a_i^m t_i$$ with m > 1) were major predictors of the vasoconstrictor response to cold at the follow-up examination. The measurement of FSBP after local cooling may be a helpful objective test to monitor prospectively the change in vibration-induced vascular symptoms. The findings of this longitudinal study suggest a dose–effect relationship between cold-induced digital arterial hyperresponsiveness over time and measures of cumulative vibration exposure. In the controls, the cold response of the digital arteries was stable over 1-year follow-up period.

Many millions of workers are exposed to hand‐transmitted vibration from powered tools and are at risk of developing disorders in the fingers, hands, or arms.1,2,3,4 One consequence of prolonged regular exposure to hand‐transmitted vibration is impaired circulation in the fingers, often evident during or following exposure to cold. The symptoms may be first noticed as abnormally cold fingers, but disorder is often diagnosed from reports of attacks of blanching on the distal, middle, or proximal phalanges. The condition is named “vibration‐induced white finger” from the characteristic attacks of blanching that are assumed to be caused by vibration damage, although the attacks are most often provoked by cold.4 The mechanisms involved in this heightened sensitivity to cold are not known, and so there is uncertainty as to the range of symptoms and signs that characterise the disorder. Although it is clear that hand‐transmitted vibration causes vibration‐induced white finger, there is limited evidence as to the characteristics of vibration that are responsible for the injury. To obtain a number indicating the severity of an exposure to vibration (that is, evaluate the vibration), it is necessary to make assumptions as to the importance of the vibration magnitude, the vibration frequency, the vibration direction, the daily exposure duration, and life‐time exposure duration. Various standards have made such assumptions so as to define uniform methods for evaluating the vibration on powered tools. Having defined a measure of vibration severity, it is possible to assess the acceptability of the vibration, in terms of the probability or severity of disorder. In International Standard 5349‐1 (2001), the evaluation is performed using the root‐mean‐square value of the vibration acceleration after it has been frequency‐weighted (using a weighting called Wh), assuming all directions of vibration to be equally important and all locations of contact with the hand to be equally likely to lead to problems.5 The assessment of vibration severity uses the 8‐hour energy equivalent daily exposure (called A(8)) to predict the years of exposure before 10% of persons are likely to develop the first signs of finger blanching. The frequency weighting inherent in current standards and directives did not evolve from epidemiological studies of the conditions causing vibration‐induced white finger, or from experimental studies of the effects of different frequencies of vibration on relevant physiological responses.6,7 The frequency weighting was largely based on a study of how the discomfort produced by hand‐transmitted vibration depends on the frequency of vibration.8 Some recent epidemiological studies suggest that the frequency weighting may not be optimum and that, at least for the vibration on some groups of common tools, the onset of finger blanching may be predicted with greater accuracy without using frequency weighting Wh.9 The frequency weighting has a large effect on the relative importance of vibration on different tools and, consequently, on the risks of injury and the responsibilities of employers. Improved understanding of the importance of vibration frequency therefore has considerable importance. Contact with the vibration on a tool involves the application of force to the fingers. There are tasks that involve the application of a force without exposure to vibration which do not result in the characteristic symptoms of vibration‐induced white finger, so force alone cannot explain the disorder. However, force may be expected to have some direct mechanical effect on circulation within the fingers. Furthermore, force may alter the transmission of vibration into the fingers and hand: increased force will tend to stiffen the tissues, which will change resonance frequencies and tend to increase the transmission of vibration from the area of contact with vibration. Occupational exposures to hand‐transmitted vibration result in symptoms of vibration‐induced white finger after many months, usually years, of regular exposure to vibration. Laboratory studies have found reductions in blood flow during and following exposure of a finger to vibration. The effects are not restricted to the vibrated finger but are also observed in other fingers, including those on a hand not exposed to vibration. Previous experimental studies by the current authors have explored the effects of the magnitude, frequency, and duration of vibration on finger blood flow using controlled contact areas and controlled contact force.10,11,12 The effects of variations in contact force on finger blood flow have not previously been investigated. This study was designed to investigate whether the force applied by a finger affected finger blood flow and whether the effects of force interacted with the acute effects of vibration. Specifically, it was hypothesised that finger blood flow would be affected by the application of force and that the effects of vibration frequency would be dependent on the force applied to the finger.

Objectives: To evaluate process and outcome of a multifaceted occupational health intervention programme on whole-body vibration (WBV) in forklift truck drivers. Methods: An experimental pretest/post-test control group study design. The authors trained occupational health services (OHS) in the experimental group in the use of the programme. OHS in the control group were asked to deliver care as usual. In total, 15 OHS, 32 OHS professionals, 26 companies, and 260 forklift drivers were involved. Post-test measurements were carried out one year after the start of the programme. Results: Baseline data before the start of the programme showed no difference between experimental and control group. Results of the outcome evaluation indicate a slight, although not statistically significant, reduction of WBV exposure in the experimental group (p = 0.06). Process evaluation revealed a positive influence on company policy toward WBV, attitude and intended behaviour of forklift drivers, and a trend towards an increase in knowledge of OHS professionals and company managers. The number of observed control measures with a major impact (levelling of surface and reduction of speed) was rather low. In those cases where control measures had been taken, there was a significant reduction in WBV exposure. This limited effect of the programme might be caused by the short period of follow up and the dropout of participants. The feasibility and the usefulness of the programme within the OHS setting were rated good by the participants. Conclusions: This programme to decrease WBV exposure was partially effective. Significant effects on intermediate objectives were observed. More research on the effectiveness of intervention in the field of WBV is needed.

Job hazards and preventive measures for workers Since the beginning of the Christian era, the Apuanian Alps between the provinces of Massa Carrara and Lucca in Tuscany, have been a centre for the excavation of white marble, venato and arabescato, and Cardoso stone. Marble is a metamorphic rock composed of calcium carbonate with a quartz content of less than 1%. Cardoso stone (from the name of the village of Cardoso) is a dark grey metamorphic sandstone made up of alternate thin layers of microgranular quartz and carbonate, as well as lamellas of disorientated mica, for example muscovite, with a quartz content of 60%. They are precious materials, used in Italy and worldwide to cover surfaces and flooring or as an architectural or structural element in building and for the realisation of sculptures. To prevent, as much as possible, the alteration or breakage of the material, the methods used for extracting this stone are different to those adopted for the extraction of rocks used in the building or chemical industry. The quarrying industry in the Apuanian Alps directly employs about 1000 workers in the area of Massa Carrara and 200 in Alta Versilia (a small mountainous area in the Province of Lucca), including the transporters of the extracted material from the quarries to the processing and commercialisation locations. The workers are exclusively male. To be a quarryman, specific professionalism is required, only attained with a long apprenticeship in the local quarries. In Alta Versilia the average age of the quarrymen is about 40 years and the specific length of service is high (over 10 years). In the same area, the excavation, or to use the formal term “exploitation”, is carried out at an altitude between 200 and 1600 metres above sea level. Because of the altitude some quarries close during the …

Aims: To follow up vibration induced white finger (VWF) in a selected group of 73 vibration exposed workers who claimed unsuccessfully for VWF compensation at a first examination. Methods: The VWF claimants were sent to our unit by the National Insurance Institute. The basic compensatory criteria included a positive history of VWF and abnormal cold response of the digital arteries. Following the first unsuccessful examination, over a mean time period of 4.1 (range 1–11) years the National Insurance Institute requested a second examination for all 73 claimants and a third examination for 29. During the follow up period, all subjects continued to work with vibratory tools. Results: There were 14 new cases who reported white finger during the follow up period. In the new VWF cases, finger blanching attacks became visible after about 3.5 years since the first examination. All incident cases of anamnestic VWF showed an abnormal cold response in the digital arteries and obtained compensation according to the basic compensatory criteria. In the entire sample of VWF claimants, there was a discrepancy between positive history of VWF symptoms at medical interview (55%) and abnormal cold provocation outcomes (19%). Digital arterial hyperresponsiveness to cold was associated with both VWF symptoms and the duration of vibration exposure since the first examination. Over the follow up period, a significant increase in the vasoconstrictor response to cold was observed in the vibration exposed workers with no symptoms of finger whiteness. Abnormal cold response was not associated with either age or smoking habit. Conclusions: Cold test measuring finger systolic blood pressure may be considered a useful laboratory method to confirm objectively VWF symptoms and to disclose abnormal cold induced vasoconstrictor response in vibration exposed workers with a negative history of VWF. Medical interview outcomes should be interpreted with caution in medicolegal situations involving VWF claimants.

Objectives: A case–control study was conducted in Verona, Italy, to assess the relationship between occupation, occupational exposures and systemic sclerosis (SSc). Methods: Fifty-five cases (46 female and nine male) and 171 controls were recruited. Interviews provided work histories, including job titles, industry and likelihood of occupational exposure to silica, hand– arm vibration, organic solvents, and other chemicals. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated. Results: Female teachers (OR 3.4, 95% CI 1.2–10.1) and textile workers (OR 2.1, 95% CI 1.0–4.6) were at an increased risk of SSc. Compared with those never exposed, age-adjusted and gender-adjusted ORs were 2.3 (95% CI 1.0–5.4) among subjects exposed to organic solvents, 2.5 (95% CI 0.8–8.0) for exposure to selected chemicals, 1.7 (95% CI 0.4–7.6) for exposure to silica, and 1.5 (95% CI 0.5–4.8) for usage of vibrating tools. When data analysis was stratified according to gender, only men showed a significant increase in risk for exposure to solvents and selected chemicals. Conclusions: The findings of this study tend to support the role of organic solvents and certain chemicals in SSc causation. The association with teaching and working in the textile industry suggests that other exposures are involved in the aetiology of SSc among women. However, because of the small number of subjects, particularly in stratified analyses, chance cannot be ruled out as an explanation of some findings of this study.

Aims: To investigate alternative relations between cumulative exposures to hand-transmitted vibration (taking account of vibration magnitude, lifetime exposure duration, and frequency of vibration) and the development of white finger (Raynaud's phenomenon). Methods: Three previous studies have been combined to provide a group of 1557 users of powered vibratory tools in seven occupational subgroups: stone grinders, stone carvers, quarry drillers, dockyard caulkers, dockyard boilermakers, dockyard painters, and forest workers. The estimated total operating duration in hours was thus obtained for each subject, for each tool, and for all tools combined. From the vibration magnitudes and exposure durations, seven alternative measurements of cumulative exposure were calculated for each subject, using expressions of the form: dose = ∑amiti, where ai is the acceleration magnitude on tool i, ti is the lifetime exposure duration for tool i, and m = 0, 1, 2, or 4. Results: For all seven alternative dose measures, an increase in dose was associated with a significant increase in the occurrence of vibration-induced white finger, after adjustment for age and smoking. However, dose measures with high powers of acceleration (m > 1) faired less well than measures in which the weighted or unweighted acceleration, and lifetime exposure duration, were given equal weight (m = 1). Dose determined solely by the lifetime exposure duration (without consideration of the vibration magnitude) gave better predictions than measures with m greater than unity. All measures of dose calculated from the unweighted acceleration gave better predictions than the equivalent dose measures using acceleration frequency-weighted according to current standards. Conclusions: Since the total duration of exposure does not discriminate between exposures accumulated over the day and those accumulated over years, a linear relation between vibration magnitude and exposure duration seems appropriate for predicting the occurrence of vibration-induced white finger. Poorer predictions were obtained when the currently recommended frequency weighting was employed than when accelerations at all frequencies were given equal weight. Findings suggest that improvements are possible to both the frequency weighting and the time dependency used to predict the development of vibration-induced white finger in current standards.