Hand-arm Vibration Exposure Research Articles

Effective information campaign for management of exposure to hand–arm vibration in the metal and construction industries

European Directive 2002/44/EC defines employers' responsibilities in the risk management of hand–arm vibration (HAV). However, the directive is still not completely implemented in all risk industries. The aim of our study was to determine whether it is possible to improve the recognition and management of the risks of HAV at workplaces with a one-year information campaign. A questionnaire on opinions and measures for controlling HAV exposure at workplaces was sent to all occupational safety representatives and occupational safety managers in the construction and metal industry in Finland (n = 1887) and once again to those who responded to the first questionnaire (nn = 961) one year after the campaign. The campaign increased recognition of HAV in risk assessment from 57.0% to 68.3% (p=.001), increased measures to decrease exposure to HAV from 54.6% to 64.2% (p=.006) and increased the number of programmes to control the risks due to HAV (p<.001). The information campaign, which focuses on the construction and metal industries, proved to be effective in increasing the awareness of the risks of HAV and the measures needed to control exposure to HAV. A similar campaign can be recommended in the case of risks specific to certain occupations.

Noise-induced hearing loss and combined noise and vibration exposure.

While there is a wide body of literature addressing noise-induced hearing loss (NIHL) and hand-arm vibration syndrome (HAVS) independently, relatively few studies have considered the combined effects of noise and vibration. These studies have suggested an increased risk of NIHL in workers with vibration white finger (VWF), though the relationship remains poorly understood. To determine whether hearing impairment is worse in noise-exposed workers with VWF than in workers with similar noise exposures but without VWF. The Quebec National Institute of Public Health audiometric database was used in conjunction with work-related accident and occupational diseases data from the Quebec workers' compensation board to analyse differences in audiometry results between vibration-exposed workers in the mining and forestry industries and the overall source population, and between mining and forestry workers with documented VWF and those without VWF. The International Organization for Standardization (ISO) 7029 standards were used to calculate hearing loss not attributable to age. 15751 vibration-exposed workers were identified in an overall source population of 59339. Workers with VWF (n = 96) had significantly worse hearing at every frequency studied (500, 1000, 2000 4000 Hz) compared with other mining and forestry workers without VWF. This study confirms previous findings of greater hearing loss at higher frequencies in workers with VWF, but also found a significant difference in hearing loss at low frequencies. It therefore supports the association between combined noise and hand-arm vibration (HAV) exposure and NIHL.

Predicting Hand Grip Strength of Hand Held Grass Cutter Workers: Neural Network vs Regression

Exposure to hand transmitted vibration caused disability in term of hand grip strength force among hand held grass cutter workers. Objective: This current study develop prediction model of independent and dependent variable that induce to loss of grip strength using non-linear neural network and linear multiple regression prediction approach for both hands. Linear and non-linear approach was used the direct least square and activation sigmoid function, respectively. Method: 204 hand held grass cutter worker have been selected as the subject study due hand arm vibration exposure during operation which is significant to loss hand grip strength. The independent variables consist of age, height, weight, working experience and estimated vibration exposure per day while hand grip strength was selected as the dependent variables. Result: The performance indexes of regression are better fit for neural network compared to multiple regressions with 0.017 (right hand grip) and 0.066 (left hand grip) differences, respectively. The mean square error also stated near to “0” for non-linear compared to linear techniques. Conclusion: It concludes that the neural network model is superior to the linear model. However, best architecture of neural network algorithm could be implemented to increase performance index, hence produce the accurate prediction model for hand grip strength among grass cutter workers.

Risk of hearing loss among workers with vibration‐induced white fingers

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. 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. 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. 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.

Assessment of Hand-Arm Vibration Exposure among Motorcyclist in Malaysia

Motorcyclists are road users that highly exposed to hand-arm vibration that may contribute to body discomfort and fatigue that eventually will lead to road accidents and injuries. The two main objectives of this study are to identify the body parts that experience discomfort among motorcyclist and to understand the vibration exposure effect on different road types. In this study, two research methodologies were used; first, a survey questionnaire of 100 motorcyclists and second, an experimental study on hand-arm vibration (HAV) measurement exposed on motorcyclist using accelerometer mounted on the right side handlebars of the motorcycle. Two male respondents with a different weight range, 45-65 kg and &gt;70 kg are selected for this experiment. The experiment was conducted on two different types of roads: tarmac road and pave road within a speed limit of 20-40 m/s2. Results of the study showed that the motorcyclist usually experienced body discomfort at lower back, upper back, wrist, buttock and neck area. The root-mean-square (r.m.s) frequency-weighted acceleration on the handlebars of the motorcycles was in the range of 0.07 m/s r.m.s for the tarmac road and 0.42 m/s r.m.s for the pave road. This value shows that different road type is affecting the vibration exposed to the motorcyclist. Clearly there’s a vibration felt by the motorcyclist but not on the degree of causing pain but a prolonged exposure to this vibration may induce discomfort and injuries.

Work ability in vibration-exposed workers.

BackgroundHand–arm vibration exposure may cause hand–arm vibration syndrome (HAVS) including sensorineural disturbances.AimsTo investigate which factors had the strongest impact on work ability in vibration-exposed workers.MethodsA cross-sectional study in which vibration-exposed workers referred to a department of occupational and environmental medicine were compared with a randomized sample of unexposed subjects from the general population of the city of Gothenburg. All participants underwent a structured interview, answered several questionnaires and had a physical examination including measurements of hand and finger muscle strength and vibrotactile and thermal perception thresholds.ResultsThe vibration-exposed group (47 subjects) showed significantly reduced sensitivity to cold and warmth in digit 2 bilaterally (P < 0.01) and in digit 5 in the left hand (P < 0.05) and to warmth in digit 5 in the right hand (P < 0.01), compared with the 18 referents. Similarly, tactilometry showed significantly raised vibration perception thresholds among the workers (P < 0.05). A strong relationship was found for the following multiple regression model: estimated work ability = 11.4 − 0.1 × age − 2.3 × current stress level − 2.5 × current pain in hands/arms (multiple r = 0.68; P < 0.001).ConclusionsVibration-exposed workers showed raised vibrotactile and thermal perception thresholds, compared with unexposed referents. Multiple regression analysis indicated that stress disorders and muscle pain in hands/arms must also be considered when evaluating work ability among subjects with HAVS.

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.MethodsParticipants 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.ResultsThere 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.ConclusionsIn 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.

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

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. 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. 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. 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.

Noise and hand-arm vibration exposure in relation to the risk of hearing loss

The aim of this study was to examine the possible association of combined exposure of noise and hand-arm vibration (HAV) and the risk of noise-induced hearing loss. Workers in a heavy engineering industry were part of a dynamic cohort. Of these workers, 189 had HAV exposure, and their age and hearing status were recorded in the same year and were, therefore, included in the analysis. Data on HAV duration and acceleration was gathered through questionnaires, observations, and measurements. All available audiograms were categorized into normal and hearing loss. The first exposure variable included the lifetime HAV exposure. The lifetime HAV exposure was multiplied by the acceleration of HAV for the second and third exposure variable. Logistic regression using the Generalized Estimation Equations method was chosen to analyze the data to account for the repeated measurements. The analysis was performed with both continuous exposure variables and with exposure variables grouped into exposure quartiles with hearing loss as an outcome and age as a covariate. With continuous exposure variables, the odds ratio (OR) with a 95% confidence interval (CI) for hearing loss was equal to or greater than one for all exposure variables. When the exposure variables were grouped into quartiles, the OR with a 95% CI was greater than one at the third and fourth quartile. The results show that working with vibrating machines in an environment with noise exposure increases the risk of hearing loss, supporting an association between exposure to noise and HAV, and the noise-induced hearing loss.

Frequency Weightings for Hand-Transmitted Vibration ^|^ndash; Results of the Ottawa Workshop

In this collection of papers we have read about a range of research being applied to understanding the relationship between exposures to hand-transmitted vibration and injury to the hand and arm. These include laboratory studies designed to investigate specific human physiological and psychophysical responses or to determine biodynamic models for the hand and arm; animal surrogate studies to investigate damage mechanisms; and workplace studies seeking to demonstrate empirical relationships between exposures and apparent effects on the worker populations. The presentation of these papers, and the related workshop held in Ottawa in 2011, were brought about by a desire to improve the assessment of health risks from handarm vibration exposures. Currently these risks are evaluated in accordance with International Standard, ISO 5349– 1:20011), and key to the application of this Standard is the frequency weighting Wh as defined in ISO 8041:20052). Within the International Standards and research communities there has been for some time an acknowledgement that Wh did not represent risk well for some machine types, and a desire to develop a frequency weighting that was more effective, particularly for vascular injuries. For this reason the ISO working group responsible for the ISO 5349 Standards proposed some candidate weightings for consideration in October 2008. The Ottawa frequency weightings workshop, held as part of the 12th International Conference on Hand-Arm Vibration, and this special edition of Industrial Health represent the best information currently available to inform this debate.

アルミ鋳造品製造工程における作業者の手腕振動ばく露の実態

アルミ鋳造品製造における手腕振動ばく露を伴う四つの作業工程について，六種類の手持ち振動工具を通常使用した際の作業者の手腕振動ばく露量の測定を行った．また，普段の手持ち振動工具の一日当たりの使用時間や作業後の自覚症状の有無および手腕振動ばく露軽減のために自身が行っている対策について聞き取り調査を行った．その結果，鋳造品の仕上げ工程および最終検査工程における研磨作業では，日当たり等価振動ばく露量に基づいた一日当たりの振動ばく露限界時間が1時間強或いは1時間未満であった．これらの手腕振動ばく露作業は，通常一日当たり5時間程度行われており，当該振動ばく露作業業務改善の必要性が明らかになった．同作業工程の手腕振動ばく露作業者は特殊健康診断（いわゆる振動健診）を受けておらず，金型製造の仕上げ工程の作業者のみが振動健診を受診していた．聞き取り調査の結果，慢性的な自覚症状を訴える作業者はいなかったが，大半の作業者が所定の手腕振動ばく露作業中あるいは終了後の手指の疲労や痺れを訴えた．しかしながら，防振手袋の使用は見受けられなかった．手腕振動ばく露作業者の大半は，軍手と薄手のゴム手袋を重ねて装着するか防振性能を有していない革製手袋を装着していた．今回の調査の結果，当該現場において防振手袋等の保護具普及の啓蒙活動をはじめとする総合的な手腕振動ばく露低減のための作業管理の必要性が明らかとなった．本調査で測定対象とした振動工具は、鋳造品製造で一般的に用いられている工具である．今後、同様の工具に対する広範な手腕振動ばく露量の測定と作業管理方法に関する実態調査を進める必要がある．

Uptake and quality of health surveillance for noise and hand-arm vibration

Health surveillance (HS) is required for employees if noise or hand-arm vibration (HAV) exposures are likely to be above exposure action levels. The extent to which employers comply with Health and Safety Executive (HSE) regulations is unclear. To establish the uptake and quality of HS for noise and HAV in high-risk industries. A cross-sectional telephone-based questionnaire study involving employers in high-risk industries for noise or HAV. A total of 246 and 386 interviews were completed for noise and HAV, respectively. The uptake of HS in the cohorts was 17 and 10%, respectively. Selection of those companies thought to have 'higher risk' increased the uptake to 25 and 18%, respectively. The proportion of companies carrying out HS was strongly related to the size of the company, with smaller companies less likely to provide this for their employees. A large proportion of companies that reported having HS in place had formal procedures for managing exposed workers (90 and 83% for noise and HAV, respectively), received feedback on individual workers (81 and 80%) and some reported that they used this information to inform their risk management process (58 and 63%). The frequency of HS for HAV was in line with that suggested in HSE guidance in 70% of cases, however, for noise, it was often utilized more frequently. While many of the companies appear to be following HSE guidance, there is a significant number that are not. Further initiatives that engage with smaller companies may help increase HS provision.

The effect on the temporary threshold shift in hearing acuity from combined exposure to authentic noise and hand-arm vibration

This study examined and compared the effect on temporary threshold shift in hearing (TTS) in healthy subjects of noise and hand-arm vibration (HAV) combined and separately using controlled and authentic exposure conditions. This study also investigated the effect on TTS in hearing in relation to gender after such exposures. Twenty-two healthy subjects (11 men/women, mean age 22 years, range 18-31years) were exposed both separately and in combination with HAV (6.7m/s(2)), using vibrating handles and to noise (99dB(A)) using headphones, for 20min. The HAV and noise were reproduced from recordings from angular grinder in operation. Hearing thresholds at 1, 4, and 8kHz were measured before and up to 30min after exposure. Combined exposure to noise and HAV created significantly greater TTS in hearing than HAV exposure at 4 and 8kHz alone. After exposure to HAV, there was no significant change in hearing threshold. At 1kHz, there was a significant difference between noise and HAV exposure in TTS in hearing. There was no significant difference between combined exposure and noise exposure for any test frequency. There was no significant difference in TTS in hearing in relation to gender for 1, 4, and 8kHz for HAV, noise, or a combined exposure. The results indicate that there is no difference in the TTS in hearing after combined exposure compared to noise exposure alone. HAV exposure did not change the hearing threshold. The TTS in hearing did not differ significantly in relation to gender after HAV, noise, or combined exposure.

Variability in Hand–Arm Vibration During Grinding Operations

Measurements of exposure to vibrations from hand-held tools are often conducted on a single occasion. However, repeated measurements may be crucial for estimating the actual dose with good precision. In addition, knowledge of determinants of exposure could be used to improve working conditions. The aim of this study was to assess hand-arm vibration (HAV) exposure during different grinding operations, in order to obtain estimates of the variance components and to evaluate the effect of work postures. Ten experienced operators used two compressed air-driven angle grinders of the same make in a simulated work task at a workplace. One part of the study consisted of using a grinder while assuming two different working postures: at a standard work bench (low) and on a wall with arms elevated and the work area adjusted to each operator's height (high). The workers repeated the task three times. In another part of the study, investigating the wheel wear, for each grinder, the operators used two new grinding wheels and with each wheel the operator performed two consecutive 1-min grinding tasks. Both grinding tasks were conducted on weld puddles of mild steel on a piece of mild steel. Measurements were taken according to ISO-standard 5349 [the equivalent hand-arm-weighted acceleration (m s(-2)) averaged over 1 min]. Mixed- and random-effects models were used to investigate the influence of the fixed variables and to estimate variance components. The equivalent hand-arm-weighted acceleration assessed when the task was performed on the bench and at the wall was 3.2 and 3.3 m s(-2), respectively. In the mixed-effects model, work posture was not a significant variable. The variables 'operator' and 'grinder' together explained only 12% of the exposure variability and 'grinding wheel' explained 47%; the residual variability of 41% remained unexplained. When the effect of grinding wheel wear was investigated in the random-effects model, 37% of the variability was associated with the wheel while minimal variability was associated with the operator or the grinder and 37% was unexplained. The interaction effect of grinder and operator explained 18% of the variability. In the wheel wear test, the equivalent hand-arm-weighted accelerations for Grinder 1 during the first and second grinding minutes were 3.4 and 2.9 m s(-2), respectively, and for Grinder 2, they were 3.1 and 2.9 m s(-2), respectively. For Grinder 1, the equivalent hand-arm-weighted acceleration during the first grinding minute was significantly higher (P = 0.04) than during the second minute. Work posture during grinding operations does not appear to affect the level of HAV. Grinding wheels explained much of the variability in this study, but almost 40% of the variance remained unexplained. The considerable variability in the equivalent hand-arm-weighted acceleration has an impact on the risk assessment at both the group and the individual level.

Cost‐effective risk assessment of hand‐arm vibration exposure

PurposeAs a tool to help compliance with relevant health and safety legislation, a cost‐effective method of risk assessing construction workers' exposure to hand‐arm vibration (HAV) is presented that allows larger numbers of workers to be evaluated, either as a stratified sample of a population or as a population where numbers are not prohibitive.Design/methodology/approachThe method, developed and tested in the field with a national UK contractor, employs work study to collect exposure level data of workers undertaking real work and analyse these, to inform HAV management and risk control decisions.FindingsThe method benefits from economies of scale to efficiently risk assess large numbers of workers, without the need for specialist equipment or analysis software. It can be applied to sample strata defined by, for example, equipment used, types of work or classifications of worker.Research limitations/implicationsResults add to the growing body of academic knowledge relating to construction worker HAV exposure and its management.Practical implicationsThe method can easily be moulded to suit any type of construction organisation and help control cost associated with HAV legislation compliance.Social implicationsPotential benefits of controlled HAV exposure include reduced incidence of (HAV induced) medical conditions and concomitant personal financial gains to society.Originality/valueThe method and context are novel. The methodology of work study and sampling in a broader sense are well established.

Analysis of hand–arm vibration risk to highway utilities maintenance and repair operatives

Hand–arm vibration (HAV) is an occupational hazard to workers using hand-held mechanical equipment. Highway utilities maintenance and repair operatives (HUMRo) use an array of such equipment; their risk is assessed as a basis to inform health and safety management, in particular, as a first step in helping establish a semi-automated risk assessment system within a collaborating national (GB) utility contractor organisation. A work study regime is implemented with the collaborating contractor to record HUMRo's use of mechanical hand-held equipment during typical working days. Analyses on these data determine average daily HAV exposure levels and these are evaluated against UK legislative benchmarks. The majority of HUMRo are exposed below the legislative “action” level; while 15% were above this, of which 1.5% of these exceeded the defined legal maximum exposure. Workers performing “opening up/services” work type on “gas supply” equipment might be at most exposure risk; as are “alpha-males” who tend to use mechanical equipment more than their work colleagues.

Infrared thermometry in the diagnosis of hand-arm vibration syndrome

Clinicians need an accurate diagnostic test for hand-arm vibration syndrome (HAVS). To validate a simple thermometric method to diagnose HAVS-related Raynaud's phenomenon. Fifteen workers with photographically confirmed HAVS-related Raynaud's phenomenon were compared to controls without Raynaud's phenomenon and an occupational history of hand-arm vibration exposure. Digit temperatures were measured using an infrared thermometer before and after immersion in 5 degrees C water for 1 min. The HAVS patients differed significantly from the controls in terms of baseline temperature, rewarming time and rate. The fingertip-base temperature gradient was more commonly positive among the controls. The test method evaluated in this study is simple, cheap and accurate. If the pre-test probability is at least 35%, the best test variable to confirm the diagnosis of HAVS-related Raynaud's phenomenon is the time to rewarm to baseline of the first three fingertips providing the interval is > or =8-9 min.

Nerve conduction in relation to vibration exposure - a non-positive cohort study

BackgroundPeripheral neuropathy is one of the principal clinical disorders in workers with hand-arm vibration syndrome. Electrophysiological studies aimed at defining the nature of the injury have provided conflicting results. One reason for this lack of consistency might be the sparsity of published longitudinal etiological studies with both good assessment of exposure and a well-defined measure of disease. Against this background we measured conduction velocities in the hand after having assessed vibration exposure over 21 years in a cohort of manual workers.MethodsThe study group consisted of 155 male office and manual workers at an engineering plant that manufactured pulp and paper machinery. The study has a longitudinal design regarding exposure assessment and a cross-sectional design regarding the outcome of nerve conduction. Hand-arm vibration dose was calculated as the product of self-reported occupational exposure, collected by questionnaire and interviews, and the measured or estimated hand-arm vibration exposure in 1987, 1992, 1997, 2002, and 2008. Distal motor latencies in median and ulnar nerves and sensory nerve conduction over the carpal tunnel and the finger-palm segments in the median nerve were measured in 2008. Before the nerve conduction measurement, the subjects were systemically warmed by a bicycle ergometer test.ResultsThere were no differences in distal latencies between subjects exposed to hand-arm vibration and unexposed subjects, neither in the sensory conduction latencies of the median nerve, nor in the motor conduction latencies of the median and ulnar nerves. Seven subjects (9%) in the exposed group and three subjects (12%) in the unexposed group had both pathological sensory nerve conduction at the wrist and symptoms suggestive of carpal tunnel syndrome.ConclusionNerve conduction measurements of peripheral hand nerves revealed no exposure-response association between hand-arm vibration exposure and distal neuropathy of the large myelinated fibers in a cohort of male office and manual workers.

Can we explain the exposure variability found in hand-arm vibrations when using angle grinders? A round robin laboratory study

To quantify variance components of hand-arm vibration exposure from data collected in a laboratory study of four different angle grinders. Four different angle grinders were sent to seven laboratories for grinding tests by three operators at each laboratory. Vibration in both the throttle and support handles was measured. For one grinder, the experimental set-up was repeated and two measurements were collected for that specific grinder. At least one-third of the estimated variability is attributable to the wheel and less than one-third to the operator. In repeated experiments, between-occasion, operator and wheel factors explained 4, 29 and 17% of the total variability, respectively. Since measured vibrations in the support and throttle handles are significantly differed, measurements should be taken at both locations. Factors influencing vibration variability include the presence/absence of an auto balance unit, wheel and operator, but other factors remain to be elucidated.

Assessment of Peripheral Nervous Function in Hand-arm Vibration Exposure Experiments

Assessment of Peripheral Nervous Function in Hand-arm Vibration Exposure Experiments