Epidemiological investigation of occupational hand-arm vibration disease caused by handheld workpiece polishing / 中国职业医学

ObjectiveTo explore the influencing factors of occupational hand-arm vibration disease (OHAVD) caused by handheld workpiece polishing. Methods A total of 222 OHAVD patients (case group), 275 hand-transmitted vibration-exposed workers (exposed group) and 243 healthy workers without hand-transmitted vibration exposure (control group) in a sports equipment manufacturing enterprise were selected as the study subjects using the convenience sampling method. Worksite survey of occupational health was conducted on these three groups, and the human vibration measurement equipment was used to measure the vibration exposure level of handheld vibration among the study subjects. The 8-hour energy equivalent frequency-weighted vibrating acceleration ［A(8)］ and cumulative vibration exposure level (CVEL) were calculated. Results The prevalence of coldness, numbness, tingling fingers, and vibration-induced white finger was higher in the exposed group and the case group compared with the control group (all P<0.05). The prevalence of the above-mentioned hand symptoms was higher in the case group compared with the exposed group (all P<0.05). The A(8) and CVEL levels of the study subjects in the case group were higher than those in the exposed group (all P<0.05). Binary logistic analysis result showed that age and CVEL were both influencing factors of OHAVD (all P<0.05). According to the restricted cubic spline models, CVEL of the study subjects in the exposed group had a positive nonlinear dose-response relationship with the risk of OHAVD (overall trend P<0.01, nonlinear P<0.01), indicating an increasing risk of OHAVD with increasing CVEL. Conclusion Hand-transmitted vibration exposure is a risk factor for OHAVD. Early intervention should be carried out for hand-transmitted vibration-exposed individuals to reduce vibration-exposed levels and control vibration exposure time.

Analysis of the effect of hand-transmitted vibration on hearing loss in male noise-exposed workers / 中国职业医学

Objective To investigate the combined effect of noise and hand-transmitted vibration on hearing loss in male noise-exposed workers. Methods A total of 952 male noise-exposed workers from an automobile manufacturing enterprise were selected as the research subjects using judgment sampling method. Occupational epidemiological surveys, assessments of occupational hazards in workplace, and pure-tone audiometry tests were conducted on the research subjects, and they were divided into low-level noise group, low-level combined group, high-level noise group, and high-level combined group according to whether the noise exposure level exceeded the national standard and whether they were jointly exposed to hand-transmitted vibration. The joint effects of noise and hand-transmitted vibration on hearing loss were analyzed. Results The detection rate of hearing loss in 952 noise-exposed workers was 21.7%. The detection rate of hearing loss of four groups, from high to low, was as follows： high-level combined group, high-level noise group, low-level combined group, and low-level noise group (44.9% vs 32.7% vs 12.9% vs 5.7%, P<0.01). The results of multivariate logistic regression analysis showed that the risk of hearing loss in the low-level noise group, the low-level combined group, the high-level noise group and the high-level combined group increased sequentially after adjusting for the confounding factors such as age, education level, smoking, drinking, listening to music with headphones, frequency of wearing noise-blocking earplugs and body mass index. The risk of hearing loss in the high-level noise group was 8.62 times more than that of the low-level noise group (P<0.01). The risk of hearing loss in the low-level noise combined group was 2.50 times more than that of the low-level noise group (P<0.01). The risks of hearing loss in the high-level combined group were 5.76 and 1.67 times more than that of the low-level combined group and the high-level noise group. Conclusion Combined exposure to noise and hand-transmitted vibration can increase the risk of hearing loss in male noise-exposed workers, and the higher the noise intensity, the greater the synergistic effect. Hand-transmitted vibration is a synergistic risk factor for occupational noise-induced hearing loss.

Effects of hand-transmitted vibration on upper limbs of workers: A meta-analysis / 环境与职业医学

Background Hand arm vibration disease (HAVD) is one of the legal occupational diseases in China, and its pathogenesis is not clear. Operators exposed to electric vibration tools for a long time have an increased risk of HAVD. Objective To conduct a systematic evaluation of the effects of vibration operations on workers' upper limb nerves, blood vessels, and muscles. Methods Relevant studies on the effects of hand-transmitted vibration on HAVD were searched and collected from the China Knowledge Infrastructure, Wanfang, and PubMed databases, and the literature was published from January 1974 to April 2021. The quality of cohort and case-control studies was assessed by the Newcastle-Ottawa Scale (NOS), and the quality of cross-sectional studies was by the evaluation criteria recommended by the Agency for Healthcare Quality and Research (AHRQ). Statistical analyses of outcome indicators (OR) in the included literature were performed using RevMan 5.4.1 software, effect sizes in the literature on vibration-induced white finger and neurosensory impairment were combined using a random-effect model, those that included carpal tunnel syndrome were combined using a fixed-effect model, and subgroup and publication bias analyses were also performed. To explore sources of study heterogeneity, meta-regression was performed using Stata 16.0 software, and sensitivity analyses were performed on the included literature. Results A total of 716 papers were retrieved from the databases, and 18 articles were retrieved by manual searching. A total of 34 papers were included after excluding those not meeting the criteria. Of the papers, 11004, 7270, and 1722 subjects related to vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome, respectively. The results of meta-analysis showed that compared with the control group, the combined ORs of hand-transmitted vibration exposure were 4.25 (95%CI: 2.72−6.65) for vibration-induced white finger, 4.03 (95%CI: 2.46−6.61) for neurosensory impairment, and 2.44 (95%CI: 1.61−3.71) for carpal tunnel syndrome. Heterogeneity was identified in the original studies related to vibration-induced white finger (I2=81%, P < 0.001) and neurosensory impairment (I2=90%, P < 0.001), except carpal tunnel syndrome (I2=23%, P < 0.001). The results of sensitivity analysis showed that the combined effect sizes (ORs) were stable and reliable. The results of meta-regression showed that the factors contributing to high heterogeneity of combined vibration-induced white finger and neurosensory impairment were time of publication (t=−2.10, P=0.049) and working age (t=−2.40, P=0.032), respectively. Conclusion Hand-transmitted vibration is a risk factor for vibration-induced white finger, neurosensory impairment, and carpal tunnel syndrome in operators.

Hand-transmitted vibration and occupational health / 环境与职业医学

The hand-arm vibration disease due to widespread hand-transmitted vibration operations is difficult to cure and seriously affects the health and quality of life of patients. Focusing on the prevention and control of hand-transmitted vibration and its occupational hazards, advances in occupational health relevant to hand-transmitted vibration were reviewed from the aspects of occupational hazard status, health impact, exposure monitoring, prevention and control of hand-transmitted vibration, as well as health surveillance, diagnosis, and treatment of hand-arm vibration disease. In addition, further suggestions on prevention and control of occupational hazards related with hand-transmitted vibration were prospected.

Peripheral circulation and peripheral nerve injury in workers exposed to vibration at two different frequencies / 环境与职业医学

Background Hand-arm vibration disease is harmful to human body, but there are no effective diagnosis and treatment so far, and current occupational exposure limits underestimate the health damage caused by high-frequency vibration exposure. Objective To evaluate and compare the damage to workers' peripheral circulation and peripheral nerve caused by different frequencies of vibration operation. Methods Drilling workers (n=187) from a mining company in Shandong Province and golf club head grinding workers (n=228) from a sports equipment factory in Guangdong Province were selected as study subjects. Hand symptoms were investigated. SV106 vibration meter was used to measure the target operation-associated vibration frequency spectrum. The 8 h energy-equivalent frequency weighted acceleration, cumulative vibration exposure level (CVEL), and the working age related to causing white finger in 10% of an exposed group were calculated. Result The study subjects were all male. More grinding workers reported hand symptoms than the drilling workers, e.g. peripheral circulation injury (52.6% vs 19.3%), peripheral nerve injury (71.5% vs 23.0%), hand stiffness (64.0% vs 7.0%), and deformed fingers (69.7% vs 4.3%) (all P<0.001). The main vibration frequencies of grinding operation (500-800 Hz) were much higher than those of drilling operation (125~160 Hz). CVEL and working age of vibration exposure showed a linear rising relationship with the cumulative prevalence rate of peripheral circulation and peripheral never injury, the fitting lines all showed good fitting effects (R2=0.812-0.988), and the slope of the fitting line of the grinding workers was larger than that of the drilling workers. The working age of vibration exposure associated with 10% cumulative prevalence of white finger was shorter in the grinding workers than in the drilling workers (6.81 years vs 10.27 years). According to the ISO prediction formula, the working age of vibration exposure was associated with 10% white finger prevalence shorter in the drilling workers than in the grinding workers (3.12 years vs 8.23 years). Conclusion Both the vibration exposure level and the prevalence of hand symptoms are high in two groups of workers with different vibration frequencies, and vibration exposure at a higher frequency tends to have severer damage to workers' hands.

Vibration attenuation and dexterity of different types of protective gloves / 环境与职业医学

Background Wearing anti-vibration gloves is a simple and effective way to prevent hand-arm vibration disease. The requirements for vibration damping gloves are varied by types of operations exposed to vibration. Objective To study the vibration attenuation and dexterity of different types of protective gloves, and to provide reference for scientific wearing of vibration damping gloves for people working with vibration exposure. Methods Nine kinds of common protective gloves (A and B were dipping gloves; C, D, and E were rubber gloves; F and G were textile and fabric gloves; H was cotton gloves; I was leather gloves) used by workers exposed to vibration in 28 factories in Guangdong Province were selected as research objects by typical case sampling method, and the basic parameters of included protective gloves were investigated and measured. According to ISO 10819:2013, a glove vibration transmissibility (GVT) test system was used to detect the vibration transmissibility values and analyze vibration attenuation characteristics of the subjects wearing different protective gloves. The dexterity was tested by Minnesota Manual Dexterity Test. Pearson test was used to analyze the correlations among glove thickness, vibration transmissibility, dexterity score, and grip strength score. Results For rubber gloves (C, D, and E), the associated average adjusted vibration transmissibility at middle and low frequencies \begin{document}$ {\overline T _{\text{M}}} $\end{document} and average adjusted vibration transmissibility at high frequency \begin{document}$ {\overline T _{\text{H}}} $\end{document} were lower than those of other gloves (0.89-0.91 and 0.59-0.80 respectively), the vibration transmissibility values of 50-200 Hz frequency band was 0.81-0.97, and the vibration transmissibility values of 315-1250 Hz frequency band decreased with the increase of frequency (the minimum value was 0.13). For other types of gloves (A, B, F, G, H, and I), the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} were 0.95-0.98 and 1.03-1.11 respectively, the vibration transmissibility values of 50-200 Hz frequency band was 0.96-1.02, and the vibration transmissibility values of 400-1250 Hz frequency band increased (the maximum value was 1.29). The \begin{document}$ {\overline T _{\text{M}}} $\end{document}, \begin{document}$ {\overline T _{\text{H}}} $\end{document}, and vibration transmissibility values of 40-1250 Hz frequency band of rubber gloves with double-layer protective materials (C, D, and E) were significantly lower than those of gloves with single-layer protective materials. But the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} of gloves of other types with double-layer materials (F, H, and I) were still greater than 0.9 and 1.0 respectively. Compared with single-layer protective materials, the gloves of other types with double-layer materials showed no significant changes in the vibration transmissibility values of 25-200 frequency band (0.91-1.06), and an increase in the vibration transmissibility values of 250-630 Hz frequency band (the maximum value was 1.22). The dexterity scores and grip strength scores of dipping gloves (A and B) were the lowest. Rubber gloves C had the highest dexterity score and grip strength score. The thickness of protective gloves was negatively correlated with the vibration transmissibility values, and positively correlated with the dexterity score and the grip strength score (P < 0.05). The vibration transmissibility value was negatively correlated with the dexterity score and the grip strength score (P < 0.05). Conclusion Among the 9 kinds of gloves, cotton gloves and leather gloves have no damping effect. Rubber gloves have certain vibration reduction effect, and the vibration reduction effect on high frequency band is better than that on low frequency band. The thicker the damping material is, the better the damping effect is, but the less the dexterity is. Appropriate damping gloves should be selected according to actual vibration operations.

Effects of hand-transmitted vibration on fingertip terminal nerve: A meta-analysis / 环境与职业医学

Background Hand-transmitted vibration is one of the most common occupational hazards and is closely related to symptoms of fingertip terminal nerve damage. Objective To analyze the effects of hand-transmitted vibration on the terminal nerve of fingertips. Methods We systematically searched literature about the effects of hand-transmitted vibration on fingertip terminal nerve at home and abroad. The outcome index was the number (rate) of fingertip terminal nerve symptoms reported by the vibration group and the control group, such as finger numbness and finger tingling, and the search period was from database inception to December 2021. The quality of cross-sectional studies was assessed using the criteria recommended by the Agency for Healthcare Research and Quality (AHRQ), and the quality of cohort studies was assessed by the Newcastle-Ottawa Scale (NOS). NoteExpress 3.2 was used for literature management, and Excel 2003 was used for data collection and extraction. RevMan 5.4.1 software was used for statistical analysis, and random effect model was used to calculate the OR value of pooled effects and to draw forest plots. Subgroup analysis was carried out according to the working years with vibration exposure. At the same time, sensitivity analysis was performed after excluding studies with the largest weight and funnel plots were generated to evaluate publication bias. Results A total of 3619 articles were retrieved, and 39 articles were finally included, including 29 Chinese articles and 10 English articles; 36 cross-sectional studies and 3 cohort studies. In total, 8399 subjects were studied, including 5673 cases in the vibration exposure group and 2726 cases in the control group. Random effect model was used to merge the included literature. The results of meta-analysis showed that compared with the control group, hand-transmitted vibration was significantly associated with the self-reported occurrence of finger numbness (OR=8.29, 95%CI: 5.43-12.66), finger tingling (OR=7.50, 95%CI: 4.78-11.77), finger swelling (OR=8.25, 95%CI: 4.06-16.76), finger stiffness (OR=10.71, 95%CI: 3.60-31.87), finger trembling (OR=5.11, 95%CI: 2.60-10.04), hand weakness (OR=11.05, 95%CI: 3.98-30.68), hand sweating (OR=2.70, 95%CI: 1.64-4.43), hand coldness (OR=3.54, 95%CI: 2.42-5.18) (P<0.01). The subgroup analysis showed that the odds ratios of both finger numbness and finger tingling increased in the early and middle stages of vibration exposure (<5 years and 5-10 years of exposure duration）(finger numbness: OR=11.11, 19.07; finger tingling: OR=4.70, 16.55, respectively)(P<0.01), and decreased in the late stage of vibration exposure (10-15 years and ≥15 years of exposure duration) (finger numbness: OR=9.57, 2.30; finger tingling: OR=5.71, 6.00, respectively) (P<0.01). The results of sensitivity analysis showed a stable pooled effect (OR=13.96, 95%CI: 4.85-40.13, Z=4.89, P<0.01). The funnel plot results showed positive publication bias. Conclusion Occupational exposure to hand-transmitted vibration can cause finger numbness, finger tingling, finger swelling, finger stiffness, finger trembling, hand weakness, hand sweating, and hand coldness.

Advances on nervous system impairment induced by hand-transmitted vibration / 环境与职业医学

Hand-transmitted vibration is one of the most common physical harmful factors in the workplace，and the hand-arm vibration syndrome caused by it lacks effective treatment, and seriously affects the physical and mental health of the involved workers. As an important target for hand-transmitted vibration, the nervous system has attracted increasing attention from scholars, and much progress has been made in recent years in studying the effects of hand-transmitted vibration on nervous system function. Based on related literature at home and abroad, this paper introduced the hand-transmitted vibration-associated damage in peripheral, autonomic, and central nervous systems, and then explored the associated influence factors, like vibration frequency, environment temperature, and individual factors. The potential directions for further research were also proposed.

Analysis of the vibration reduction effect of three common protective gloves / 中国职业医学

OBJECTIVE: To test and analyze the vibration transmissivity of three common kinds of protective gloves, and to determine their actual protecting effect. METHODS: Three kinds of protective gloves were selected as test materials, and five healthy volunteers were selected as subjects using typical sampling methods. According to the ISO 10819:2013 Mechanical Vibration and Shock--Hand-arm Vibration--Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand(hereinafter referred to as ISO 10819:2013), investigation and measurement of basic parameters of protective gloves. The gloved vibration transmission(GVT) test system was used to test the vibration transmission of different protective gloves worn by the subjects, and the spectrum analysis of vibration reduction characteristics was carried out. RESULTS: The thickness of damping material of all the three kinds of protective gloves met the standard requirements. The mean value for the corrected frequency-weighted glove vibration transmissibility values at 25.0-200.0 Hz were 0.91, 0.75 and 0.94, and 1.05, 0.85 and 1.10 at 200.0-1 250.0 Hz, for the protective gloves A, B and C, respectively. The results of anti-vibration characteristic spectrum analysis show that there has no vibration reduction effect at the frequency of 25.0-200.0 Hz when wearing these three kinds of gloves. Wearing gloves A and B on part of the 200.0-1 250.0 Hz frequency vibration has an amplifying effect. Wearing glove C has a partial vibration reduction effect at the 200.0-1 250.0 Hz frequency, and the vibration reduction efficiency is the highest at the frequency of 1 250.0 Hz.CONCLUSION: According to the ISO 10819:2013 standard, the mean value of GVT measured when wearing the three kinds of protective gloves does not meet the relevant requirements, and the anti-vibration effect is poor. These gloves cannot be defined as anti-vibration gloves.

Analysis of influencing factors of fingertip thermotactile perception threshold in healthy young adults / 中国职业医学

OBJECTIVE: To analyze the stability of test results of fingertip thermotactile perception threshold(TPT) among healthy individuals and the influencing factors of the TPT test. METHODS: Fifty healthy young volunteers aged 20-25 were selected as the study subjects using the convenience sampling method. The HVLab thermal aesthesiometer was used to perform the fingertip TPT test under the standard condition. Right index, middle, ring, little, left index and little fingers were tested. According to the method of random number table, we selected 25 subjects to receive second test after the interval of two weeks. RESULTS: Intraclass correlation coefficient(ICC) for cold threshold of right little finger was bigger than 0.75, suggesting the test-retest reliability was excellent. The ICC for hot threshold of six test fingers, cold threshold of right and left index fingers, right middle and left little finges was in the range of 0.60-0.74, indicating the test-retest reliability was good. However, the ICC for cold threshold of right ring finger was less than 0.40, and the test-retest reliability was poor. The hot threshold of right middle, ring and little fingers, and the cold threshold of left little finger of males were higher than those of females(all P<0.05). The cold threshold of right index and little fingers were lower than those of left hand in males(all P<0.05). The cold threshold of right middle and ring fingers were lower than that of the right index finger in females(all P<0.05). The cold threshold of right little finger was lower than those of right index, middle and ring fingers in females(all P<0.05). CONCLUSION: The stability of the fingertip TPT result is good in healthy young adults aged 20-25. The fingertip TPT test could be used for occupational health surveillance of workers exposed to hand-transmitted vibration. We should take into account the influence of gender, the right or left hand and different fingers when developing TPT reference values.

Application of finger systolic blood pressure in the diagnosis of vibration-induced vascular injury / 中国职业医学

OBJECTIVE: To evaluate the application value of finger systolic blood pressure(FSBP) in the diagnosis of vibration-induced vascular injury. METHODS: Thirty patients with vibration-induced vascular injury [vibration-induced white finger(VWF)] were selected as the case group by a non-randomized concurrent controlled trial, and 30 hand-transmitted vibration workers without VWF were selected as the control group. The FSBP test was performed on the tested hands of all subjects, and the FSBP index of each Finger(F_( i)) was measured. RESULTS: The F_i of the index finger, middle finger, ring finger and tail finger of the tested hand in the case group were lower than that in the control group(all P<0.01). In the case group, the F_i of index finger was lower than ring finger and tail finger(all P<0.01). The abnormal rates of F_i on the index, middle and ring fingers in the case group were higher than those in the control group(86.7% vs 10.0%, 76.7% vs 13.3%, 43.3% vs 10.0%, all P<0.01). The area under the receiver operator characteristic curve of the measured F_i of the index finger, middle finger, ring finger and tail finger were 0.884, 0.843, 0.764 and 0.687 respectively. The diagnostic cut off value of the F_i of index finger was 80.2%. The sensitivity and specificity were 86.7% and 90.0%, respectively. CONCLUSION: FSBP test has a good application value in the diagnosis of vibration-induced vascular injuries. It is suggested that the F_i of index finger be the first choice as the diagnostic index, and the abnormal value can be set at 80.0%.

Effects of hand-transmitted vibration on subjective symptoms in mine drilling workers / 中国职业医学

OBJECTIVE: To investigate the effect of hand-transmitted vibration on the subjective symptoms of mine drilling workers. METHODS: A total of 117 mine drilling workers exposed to hand-transmitted vibration were selected as the exposure group, and 46 workers without hand-transmitted vibration exposure were selected as control group by judgment sampling method. The Occupational Epidemiology Questionnaire of Mine Drilling Workers was used to investigate their subjective symptoms. RESULTS: The prevalence of tinnitus, hearing loss, cough and sputum in the exposure group was higher than that in the control group(P<0.05). The occurrence rate of numbness, tingling, self-reported white fingers and cold hands in the exposure group was higher than that in the control group(P<0.05). The total rate of symptoms of hand in the exposure group was higher than that in the control group(38.5% vs 21.7%, P<0.05). The multivariate logistic regression analysis results indicated that hand-transmitted vibration exposure and service length were risk factors of abnormal hand symptoms(P<0.05). CONCLUSION: Occupational hand-transmitted vibration exposure can affect the hand subjective symptoms of mine drilling workers, and the length of service is a synergistic influencing factor.

Bibliometric analysis on occupational hand-arm vibration disease in China / 中国职业医学

OBJECTIVE: To study the literature characteristics and research status of occupational hand-arm vibration disease in China. METHODS: Literature information on occupational hand-arm vibration disease published before 2018 in China were searched and collected through the China National Knowledge Infrastructure(CNKI) and Wanfang Database. The bibliometrics was used to analyze the publication time, type, journal sources, authors and their institutions, citation situation, funds and high-frequency key words. RESULTS: From 1975 to 2018, a total of 349 papers on occupational hand-arm vibration disease were published. The main article type was monograph, with a total of 179 articles(accounting for 51.3%). The articles were distributed in 79 kinds of journals, among them, 10 journals including China Occupational Medicine and Industrial Health and Occupational Diseases were the main carriers to publish related articles(237 papers, accounting for 67.9%). The main research institutions of the literature were Jining Medical College and Guangdong Province Hospital for Occupational Disease Prevention and Treatment, with 134 papers(accounting for 38.4%) published. Among the 5 core authors of the literature, 4 were from the above 2 research institutions. A total of 121 articles(accounting for 34.7%) were cited, and 77 articles(accounting for 22.1%) were supported by research fund. The top 3 high-frequency key words used were arm vibration disease, hand-transmitted vibration/local vibration and occupational disease. CONCLUSION: Occupational hand-arm vibration disease has attracted the attention of Chinese researchers, however, follow-up research, literature quality and funding support still need to be improved.

Characteristics of nailfold capillaroscopy in fine sanding workers / 中国职业医学

OBJECTIVE: To analyze the effects of hand-transmitted vibration operation on nailfold capillaroscopy( NFC) in fine sanding workers. METHODS: A total of 57 fine sanding workers of one golf ball production enterprise in Guangdong Province were selected as vibration exposure group and 30 workers without exposure to hand-transmitted vibration as control group by a judgement sampling method. NFC examination was carried out in workers of these two groups. RESULTS: The capillary haemorrhage detection rates,percentage of abnormal capillary loops and total capillary width in the vibration exposure group were higher than that in the control group [43. 9% vs 13. 3%,( 56. 6 ± 20. 9) % vs( 41. 2 ± 14. 5) %,( 44. 7 ± 4. 9) vs( 42. 4 ± 4. 9) μm,P < 0. 05]. The capillary density,capillary length and branch diameter in the vibration exposure group were lower than that in the control group [( 7. 7 ± 1. 0) vs( 8. 8 ± 1. 0) per mm,( 185. 1 ± 33. 9) vs( 205. 6 ± 23. 2) μm,( 18. 3 ± 1. 9) vs( 19. 6 ± 2. 6) μm,P < 0. 05]. No significant difference was found in the diameter of apical part and branch of capillaries between the two groups( P > 0. 05). In the vibration exposure group,the percentage of abnormal capillary loops in the left hand was lower than that in the right hand [( 53. 1 ± 20. 6) % vs( 61. 5 ±24. 2) %,P < 0. 01],the capillary length in the left hand of vibration exposure group was longer than that in the right hand [( 187. 2 ± 33. 5) vs( 179. 4 ± 35. 4) μm,P < 0. 05]. No significant difference was found in the capillary density,total capillary width,apical part diameter,output branch diameter and input branch diameter between two hands in the vibration exposure group( P > 0. 05). CONCLUSION: The hand-transmitted vibration can lower the nailfold capillary density,shorten and widen capillary loops, increase percentage of abnormal capillary loops and induce capillary haemorrhage. NFC could be used to assist early detection of microvascular damage induced by hand-transmitted vibration.

Evaluating the occupational exposure to hand-transmitted vibration in golf ball head grinding positions / 中国职业医学

OBJECTIVE: To evaluate the exposure status of hand-transmitted vibration(HTV)in golf ball head grinding workers.METHODS: The golf ball head grinding positions in a sports equipment factory were selected as the research subjects by the judgement sampling method.The HTV exposure level of the workers in 66 grinding positions was measured,the key control points for HTV hazards were identified,and the damage of HTV was classified.RESULTS: The median(M)of 4 hours energy equivalent frequency-weighted acceleration to vibration[a_(hw(4))]of grinding positions in this sports equipment factory was 4.21 m/s~2,and the a_(hw(4)) over standard rate was 50.0%(33/66).The a_(hw(4)) of rough grinding positions was higher than that of fine grinding positions(M:5.50 v.s 3.94 m/s~2,P<0.05).In both rough grinding positions and fine grinding positions,the a_(hw(4)) of different ball head grinding types from high to low were hollow titanium alloy ball heads, hollow stainless steel ball heads,and solid stainless steel ball heads(rough grinding positions M:7.41 vs4.43 vs 3.11 m/s~2,P<0.01; fine grinding p ositions M:5.24 vs 4.21 vs 2.93 m/s~2,P<0.01).For the hollow titanium alloy ball head grinding positions,the a_(hw(4)) of rough grinding was higher than that of fine grinding(M:7.47 vs 5.24 m/s~2,P<0.01).Rough grinding positions,especially hollow stainless steel ball heads and hollow titanium alloy ball head grinding positions were key control points for HTV hazards.In the 66 grinding positions,the HTV hazards were classified as grade 0,Ⅰ,Ⅱ,and Ⅲ in the grinding positions accounted for 3.0%,47.0%,40.9%,and 9.1%,respectively,and those with grade Ⅱ and above were 50.0%(33/66). CONCLUSION: The exposure level of HTV in golf ball head grinding workers is high,with a trend of exceeding the standard.The golf ball head grinding workers have a high occupational health risk.

Investigation and analysis on fingertip vibrotactile perception threshold at two frequencies in mine drilling workers / 中国职业医学

OBJECTIVE: To analyze the characteristic change of fingertip vibrotactile perception threshold(VPT) at two different frequencies among mine drilling workers. METHODS: A total of 48 mine drilling workers exposed to hand-transmitted vibration for at least 1.0 year were selected from mines in Hubei Province as the vibration exposure group by using the random number table method, and workers without hand-transmitted vibration exposure were selected as the control group. An HVLab vibrotactile perception meter was used to measure the fingertip VPT at 31.5 and 125.0 Hz in workers of these two groups. RESULTS: None of the workers in these two groups showed any clinical symptoms associated with occupational hand-arm vibration diseases. At 31.5 and 125.0 Hz, the fingertip VPT in the vibration exposure group was higher than that in the control group(P<0.01), the fingertip VPT of the little fingers was higher than that of the index fingers(P<0.01). At 125.0 Hz, the fingertip VPT of the fingers in dominant hands was higher than that in non-dominant hands in workers of the vibration exposure group(P<0.01). CONCLUSION: The mine drilling workers with hand-transmitted vibration exposure had higher fingertip VPT. There were differences of VPT in fingers and dominant hands.

A bibliometric analysis of literature on hand-transmitted vibration in China, 1990-2016 / 中华劳动卫生职业病杂志

Objective@#To investigate the features of literature on hand-transmitted vibration in China, 1990-2016.@*Methods@#In September 2017, the studies on hand-transmitted vibration in China, which were published in Chinese or English during 1990-2016, with "China" and "Taiwan" as the places where author affiliations were located, were retrieved. A bibliometric analysis was performed to investigate the type of articles, publication time, the journals in which articles were published, author affiliations, author regions, and funding.@*Results@#A total of 205 articles on hand-transmitted vibration were retrieved. There were 7.59 articles on average published annually from 1990 to 2016. In the 205 articles, 114 (55.61%) were published in the journals indexed in one or two core journal databases. In the 64 journals, 22 (34.38%) were indexed in one or two core journal databases. The first authors were from 22 provincial regions (provinces, autonomous regions, or centrally administered municipalities) in China, with 152 articles (74.15%) by the authors in the top five regions. There were a total of 876 authors, and the co-authorship degree was 4.27 (876/205). Most of the first authors (136 articles, 66.34%) were affiliated with universities or institutes for prevention and control of occupational diseases. Among the 205 articles, 103 (50.24%) were original articles or investigations, and 72 (35.12%) were funded.@*Conclusion@#The studies on hand-transmitted vibration fluctuated and increased from 1990 to 2016, with a relatively concentrated distribution in terms of sources, regions, and institutions. Interregional and international academic exchange should be strengthened.

Analysis on finger sensory examination among drill workers in a gold mine / 中国职业医学

OBJECTIVE: To analyze the effects of hand-transmitted vibration exposure on the finger vibratory and pain perception thresholds among drill workers in a gold mine. METHODS: By the judgement sampling method,134 male drill workers from a gold mine in the northern area of China were selected as the hand-transmitted vibration exposure group and102 fit-up workers without vibration exposure in the same mine were chosen as the control group. The finger vibratory perception thresholds,the pain perception thresholds and the occupational health examination were conducted and analyzed in these two groups. Based on the self-report with vibration-induced white finger( VWF),the workers of hand-transmitted vibration exposure group were divided into non-VWF subgroup( 105 workers) and VWF subgroup( 29 workers). RESULTS: The incidence of finger numbness,pain and self-reported white finger in the exposure group were significantly higher than those in the control group( P < 0. 05). Compared with the control group,the vibratory perception thresholds of the index finger,middle finger and ring finger of the right hand among the vibration exposure group workers were significantly higher( P < 0. 05),but there was no significant difference in the vibratory perception thresholds of the left ring finger between the two groups( P > 0. 05). The vibratory perception thresholds of both ring fingers,right index finger and right middle-finger in VWF subgroup were higher than those in control group( P < 0. 05). But no significant differences was found in the above 4 indexes in these two groups after compared to those of control group,respectively( P > 0. 05). The vibratory perception thresholds of left ring finger,right ring finger and right index finger in VWF subgroup were all higher than those in non-VWF subgroup( P < 0. 05),but the vibratory perception thresholds of right middle finger in these two groups showed no significant difference( P > 0. 05). The pain perception thresholds of index finger,middle finger and ring finger in both hands of the vibration exposure group workers were all higher than those in control group( P < 0. 05). The pain perception thresholds of middle finger and ring finger in both hands of the VWF subgroup and non-VWF subgroup were higher than those of control group( P < 0. 05). CONCLUSION: The hand-transmitted vibration can increase the thresholds of finger vibratory and pain perception in drill workers. The finger sensory perception examination could be used to assist the early detection of peripheral nerve damage induced by hand-transmitted vibration.

Essential characteristics of hand-arm vibration in hand-held workpiece polishing / 中国职业医学

OBJECTIVE: To study the occupational exposure characteristics of hand-transmitted vibration in hand-held workpiece polishing and to provide the basis for occupational hazard prevention and control technology research in this kind of job. METHODS: The questionnaire and on site occupational health investigation were used to study 4 typical enterprises of hand-held workpiece polishing. The study was conducted by filling forms by enterprise,personal interviews with administrative staffs and front-line workers,as well as on site visit. RESULTS: Among the 4 factories,there were 835workers( 22. 4%) engaged in the hand-held workpiece polishing assignment. The principal vibrating tools used in these 4factories were polishing machine,flint glazing machine and polishing wheel,and the workpiece polished by workers were button,toilet lid,thermos,mobile phone shell and golf head. The polishing workers were all equipped with noise reduction earplugs and anti-dust respirators, but they did not wear anti-vibration gloves. The hand-held workpiece polishing assignment has the characteristics including indirect and continuous vibration exposure and fine operation. Some workers used their knees and abdomens as the support to polish workpieces. The vibration exposure time was 6-11 h / d. The 4hours energy equivalent frequency-weighted acceleration to vibration [ahw( 4)]was 1. 9-19. 4 m/s~2,with the maximum which exceeded the occupational exposure limit( 5. 0 m / s~2),showing a wide range ahw( 4)in the same enterprise. CONCLUSION: Compared with the traditional vibrating tools,the hand-held workpiece polishing operation has different characteristics of hand-transmitted vibration such as more sophisticated machine structure,finer polishing ways,more influencing factors of vibration exposure level and more extensive body parts involved.

Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.