Aluminum: impacts and disease

Aluminum is the most widely distributed metal in the environment and is extensively used in modern daily life. Aluminum enters into the body from the environment and from diet and medication. However, there is no known physiological role for aluminum within the body and hence this metal may produce adverse physiological effects. The impact of aluminum on neural tissues is well reported but studies on extraneural tissues are not well summarized. In this review, the impacts of aluminum on humans and its impact on major physiological systems are summarized and discussed. The neuropathologies associated with high brain aluminum levels, including structural, biochemical, and neurobehavioral changes, have been summarized. In addition, the impact of aluminum on the musculoskeletal system, respiratory system, cardiovascular system, hepatobiliary system, endocrine system, urinary system, and reproductive system are discussed.     

Effects of combined exposure to noise and toxic substances-critical review of the literature

A number of studies have been conducted in recent years investigating the potential effects on various health endpoints of the combination of noise and a variety of different industrial substances. This review indicates that the information available in both animals and humans on this subject is limited particularly with respect to assessing occupational risk. Most studies have focused on auditory effects in animals, although investigations have been performed for other toxicological endpoints. For some substances, notably toluene, the information from animals studies does suggest an interaction but these were performed only at exposure levels to both noise and chemicals which were each individually ototoxic. Single simultaneous exposure to noise and styrene did not result in any enhancement of auditory impairment above that produced by noise or styrene alone. Single simultaneous exposure to noise and carbon monoxide (CO), however, showed some evidence of enhancement of ototoxicity beyond that produced by noise or carbon monoxide alone, although only at high atmospheric concentrations of CO. When 1,3-dinitrobenzene was administered parentally at neurotoxic dose levels with continuous noise exposure, there was an increased severity of effects in the brain stem. Combined exposure to noise and lead and/or cadmium resulted in histopathological heart lesions of undefined severity, a finding which was not observed for either of those agents in isolation. Dermal exposure to dimethylformamide and noise or inhalation exposure to xylene and noise resulted in some biochemical changes in cardiac muscle which were of doubtful toxicological significance. In developing mice, there was evidence that combined exposure to cadmium sulphate and noise caused an increased incidence of external and skeletal malformations but only at dose levels of cadmium which would have induced developmental effects. Overall, for each of these chemicals and endpoints observed there is a suggestion of some interaction with noise exposure. From the data that are currently available, however, inferences cannot be drawn on whether or not interactions would have occurred at lower, more occupationally relevant, levels of exposure. A number of studies have investigated human populations exposed to both noise and industrial chemicals. Due to confounding factors, however, it was concluded that these data were inadequate for assessing the combined effects of noise and chemical exposure on hearing.     

Biomarkers and chemosensory irritations

OBJECTIVES: A literature review on studies in humans, applying physiological methods to monitor environmentally induced reactions in eyes and upper respiratory tract. The focus was on chemical exposures, but other occupational factors and indoor exposures were included. METHODS: Original articles were gathered from Medline until November 2000, combined with peer-reviewed publications from other sources. RESULTS: Ocular methods included measurement of tear film break-up time (BUT), blink frequency, detection of corneal damage, by vital staining, and cells or inflammatory markers in tear fluid. Nasal methods included acoustic rhinometry, rhinostereometry, and nasal peak expiratory flow. In addition, nasal lavage with isotonic sodium chloride solution was applied to measure concentrations of leucocytes, or biomarkers of secretion or inflammation in nasal lavage fluid (NAL). Most occupational studies were on nasal effects of organic or inorganic dust. There were few studies on occupational exposure to organic solvents or chemical irritants. Some studies demonstrated associations between ocular and nasal physiological response and the indoor environment. Finally, there were some exposure-chamber studies on effects of specific volatile organic compounds (VOCs). Little is known about adaptation at repeated ocular or nasal exposure to irritants. CONCLUSION: Physiological measurements can be valuable complements to symptom registration, but there is a need for standardised investigations. There is a lack of studies on ocular and nasal physiological responses in relation to specific chemical compounds. Experimental studies, with repeated exposure and longer follow-up time on biomarkers, are needed. Finally, there is a need for longitudinal epidemiological studies to elucidate if observed effects should be interpreted as variation within normal physiology, or as early signs of impaired ocular and respiratory health.     

Cross-protective immunity against o'nyong-nyong virus afforded by a novel recombinant chikungunya vaccine

Emerging mosquito-borne alphavirus infections caused by chikungunya virus (CHIKV) or o'nyong-nyong virus (ONNV) are responsible for sporadic and sometimes explosive urban outbreaks. Currently, there is no licensed vaccine against either virus. We have developed a highly attenuated recombinant CHIKV candidate vaccine (CHIKV/IRES) that in preclinical studies was demonstrated to be safe, immunogenic and efficacious. In this study we investigated the potential of this vaccine to induce cross-protective immunity against the antigenically related ONNV. Our studies demonstrated that a single dose of CHIKV/IRES elicited a strong cross-neutralizing antibody response and conferred protection against ONNV challenge in the A129 mouse model. Moreover, CHIKV/IRES immune A129 dams transferred antibodies to their offspring that were protective, and passively transferred anti-CHIKV/IRES immune serum protected AG129 mice, independently of a functional IFN response. These findings highlight the potential of the CHIKV/IRES vaccine to protect humans against not only CHIKV but also against ONNV-induced disease.     

Effect of conjugated linoleic acid on body composition and plasma lipids in humans: an overview of the literature

Studies in mice have indicated that feeding diets containing 0.5-1% conjugated linoleic acid (CLA) considerably reduces body fat. These findings have attracted much interest because of the potential use of CLA as a tool to promote weight loss in humans. Several CLA studies in humans have now been published, and the objective of the present review was to give an overview of these experiments. Most of the studies were done in free-living subjects and were not strictly controlled for nutrient and energy intakes. None of the studies found a significant reduction in body weight, and only 2 studies showed a significant but relatively small body fat-lowering effect. Some studies suggested that CLA may have a tendency to increase lean body mass. Furthermore, there are indications from animal studies that CLA may have effects on plasma lipids. However, only one study in humans showed a significant HDL-cholesterol-lowering effect of CLA; in all the other studies, there were no significant effects on plasma total, LDL-, and HDL-cholesterol concentrations or on plasma triacylglycerol concentrations. Thus, the results of the studies in humans indicate that the effect of CLA on body fat is considerably less than that anticipated from mice studies and that CLA has no major effect on plasma lipids.     

Salivary cortisol levels, subjective stress, and tinnitus intensity in tinnitus sufferers during noise exposure in the laboratory

Tinnitus, a chronic internal noise, is thought to increase in intensity during or following external noise exposure. Yet there is no empirical evidence for this complaint in the extant literature. Recently, cortisol has been advanced as a useful tool for studying the physiological effects of noise on stress, but few, if any, studies have examined the short-term effects of noise on cortisol levels in tinnitus sufferers. This study assesses the effects of noise exposure on cortisol levels and subjective stress in tinnitus participants and controls without tinnitus. Twenty tinnitus participants and 20 controls without tinnitus were exposed to a 20-min broadband noise with amplified low frequencies. Saliva samplings for cortisol analysis and subjective stress and tinnitus intensity ratings (for tinnitus participants) were performed at regular intervals throughout testing. Results show higher cortisol levels for both groups immediately before, immediately after, and 10min after the end of noise than at other time points. The tinnitus group had lower overall cortisol levels than controls. In contrast, subjective stress ratings were higher for the tinnitus group, and higher at midpoint and immediately after the noise ended. Tinnitus subjective intensity increased throughout testing, especially for the group with high tinnitus-related distress. Overall results show that noise exposure influences cortisol response, subjective stress, and tinnitus intensity.     

The effects of combined exposure to road traffic noise and whole body vibration on types of attention among men

Background: Noise and vibration are considered as harmful physical agents in the environment which have adverse effects on cognitive performance. One of the occupations at risk is driving, where there is a possibility of simultaneous exposure to road traffic noise and whole body vibration (WBV) transferred through the vehicle. This study aims to assess the effects of single and combined exposure to road traffic noise and WBV on different types of attention in men. Methods: The experiment was conducted on 24 men in 4 steps, executed on each participant inside an acoustic room. After recording a number of various attention scores at background conditions (27 dBA noise, no vibration) the participants were given single and combined exposure to noise levels at 55 and 85 dBA and vibration magnitude of 0.65 and 0.95 m/s² r.m.s. Results: As for combined exposure to noise and vibration, increasing vibration acceleration and noise levels at the same time compared to background condition caused a rise in the score of all visual attention types among groups exposed to low vibration acceleration and those exposed to medium acceleration and low noise. Nevertheless, when noise level and vibration acceleration is increased at the same time compared to background, auditory attention type scores mostly fell among groups with similar vibration accelerations. Conclusions:Overall, single and combined exposure to environmental stressors under investigation had a predominantly negative effect on auditory attention while the effects on visual attention were inconclusive. Definitive conclusions however require further systematic and comprehensive experiments.     

Measuring the noise attenuation of shotblasting helmets

Air-fed blasting helmets are used in abrasive blasting operations to provide essential face, eye and respiratory protection. BS EN 271: 1995 (equivalent to the European Standard EN 271: 1997), the standard that deals with the construction of blasting helmets, addresses the above matters and also the problem of noise generated by the breathing air supply. However it has no requirements for manufacturers to measure or report the helmet's ability to attenuate the very high levels of noise generated by the blasting process. The aim of the project was to develop a test method to measure the noise attenuation of shotblasting helmets. The method developed is an objective measurement, using a head and torso simulator (HATS), which provides a suitable means for helmet manufacturers to report their product's ability to attenuate blasting noise. The results from this project showed that the HATS currently prescribed by BS EN 271: 1995 can be used for measuring the noise attenuation of helmets against typical shotblasting noise. Using such a HATS in the proposed test method will give attenuation values that correlate well with those measured using human subjects. Therefore the HATS already used by manufacturers to show compliance of their product with BS EN 271: 1995 could also be used to provide information on the helmet's noise attenuation. Results from this project also showed that the same HATS can be used, in place of human subjects, to measure the air supply noise according to the method defined in BS EN 271: 1995. BS EN 271: 1995 is due for revision in 2000. The results from this work should be used to influence future revisions of the standard so that requirements to measure and report noise attenuation of shotblasting helmets are considered, a major omission in the present standard.     

Potential Effects of Sucralose and Saccharin on Gut Microbiota: A Review

Artificial sweeteners are additives widely used in our diet. Although there is no consensus, current evidence indicates that sucralose and saccharin could influence the gut microbiota. The aim of this study was to analyze the existing scientific evidence on the effects of saccharin and sucralose consumption on gut microbiota in humans. Different databases were used with the following search terms: sweeteners, non-caloric-sweeteners, sucralose, splenda, saccharin, sugartwin, sweet’n low, microbiota, gut microbiota, humans, animal model, mice, rats, and/or in vitro studies. In vitro and animal model studies indicate a dose-dependent relationship between the intake of both sweeteners and gut microbiota affecting both diversity and composition. In humans, long-term study suggests the existence of a positive correlation between sweetener consumption and some bacterial groups; however, most short-term interventions with saccharin and sucralose, in amounts below the ADI, found no significant effect on those groups, but there seems to be a different basal microbiota-dependent response of metabolic markers. Although studies in vitro and in animal models seem to relate saccharin and sucralose consumption to changes in the gut microbiota, more long-term studies are needed in humans considering the basal microbiota of participants and their dietary and lifestyle habits in all population groups. Toxicological and basal gut microbiota effects must be included as relevant factors to evaluate food safety and nutritional consequences of non-calorie sweeteners. In humans, doses, duration of interventions, and number of subjects included in the studies are key factors to interpret the results.     

Trends in research related to “Shinrin-yoku” (taking in the forest atmosphere or forest bathing) in Japan

“Shinrin-yoku”, which can be defined as “taking in the forest atmosphere or forest bathing”, has been receiving increasing attention in Japan in recent years for its capacity to provide relaxation and reduce stress. Since 2004, the authors of this paper have been involved in an investigation designed to ascertain the physiological effects of “Shinrin-yoku” within the framework of the “Therapeutic Effects of Forests” project. We have conducted physiological experiments, both in actual forests and in the laboratory, to elucidate the physiological effects on individuals of exposure to the total environment of forests or to only certain elements of this environment, such as the odor of wood, the sound of running stream water, and the scenery of the forest. We have obtained physiological measurements of central nervous activity, autonomic nervous activity, and biomarkers reflecting stress response that can be applied in this line of approach. Using these measurements, we have summarized the separate elements of forests in terms of the five senses. We have also reviewed a selection of field studies and introduced a number of results from ongoing projects as well as those from early studies. Future perspectives are also discussed.     

某矿山开采企业爆破、掘进和采矿作业工人听力损失的情况

目的减少矿山开采企业噪声对机体听觉损伤的危害,使工人听力损失率逐年下降。方法随机调查某矿山开采企业389名作业工人,询问工人的职业接触史、既往史、耳毒药物史、家族史、自觉症状等,并进行耳鼻喉科检查。对389人的气导纯音听阈测试结果进行评级。结果调查对象单耳或双耳听力异常337人,异常检出率为86．63％。单纯高频段听力损失286人,检出率为73．52％。语言频段合并高频段听力损失（包括单纯语言频段听力损失）51人,检出率为13．11％。经统计分析,采矿、爆破、掘进工种的听力异常检出率之间差异无统计学意义（P〉0．05）。语言频段听力损失异常检出率为13．11％。高频段（3、4．6kHz）听力损失依次加重,听力曲线呈斜坡下降型,符合噪声性听力损失特点。爆破组第50百分位数（P50）依次为25,32．5和40dBHL,掘进组为25,32．5和37．5dBHL。结论该企业作业工人听力异常检出率偏高,为此,用人单位不仅要重视职业健康和安全管理工作,坚持开展职业健康监护工作,更要监督指导工人正确使用个人防护用品。特别是对于从事爆破、掘进工作的矿业工人。     

The possible influence of noise frequency components on the health of exposed industrial workers--a review

Noise is a common occupational health hazard in most industrial settings. An assessment of noise and its adverse health effects based on noise intensity is inadequate. For an efficient evaluation of noise effects, frequency spectrum analysis should also be included. This paper aims to substantiate the importance of studying the contribution of noise frequencies in evaluating health effects and their association with physiological behavior within human body. Additionally, a review of studies published between 1988 and 2009 that investigate the impact of industrial/occupational noise on auditory and non-auditory effects and the probable association and contribution of noise frequency components to these effects is presented. The relevant studies in English were identified in Medknow, Medline, Wiley, Elsevier, and Springer publications. Data were extracted from the studies that fulfilled the following criteria: title and/or abstract of the given study that involved industrial/occupational noise exposure in relation to auditory and non-auditory effects or health effects. Significant data on the study characteristics, including noise frequency characteristics, for assessment were considered in the study. It is demonstrated that only a few studies have considered the frequency contributions in their investigations to study auditory effects and not non-auditory effects. The data suggest that significant adverse health effects due to industrial noise include auditory and heart-related problems. The study provides a strong evidence for the claims that noise with a major frequency characteristic of around 4 kHz has auditory effects and being deficient in data fails to show any influence of noise frequency components on non-auditory effects. Furthermore, specific noise levels and frequencies predicting the corresponding health impacts have not yet been validated. There is a need for advance research to clarify the importance of the dominant noise frequency contribution in evaluating health effects.     

Hearing threshold and heart rate in men after repeated exposure to dynamic muscle work,sinusoidal vs stochastic whole body vibration and stable broadband noise

Summary Changes in the temporary hearing threshold (TTS₂) and heart rate (HR) were examined in subjects exposed to stable noise, whole body vibration and dynamic muscular work at a dry-bulb temperature of 30°C. The exposure combinations consisted of three categories of dynamic muscular work with varying loads (2 W, 4 W, 8 W), of two categories of noise and of three categories of vibration. The noise categories were: (1) no noise, and (2) stable, broadband (bandwidth 0.2-16.0 kHz) A-weighted noise with an intensity of 90 dB. The vibration categories were: (1) no vibration, (2) sinusoidal whole body vibration (Z-axis) with a frequency of 5 Hz, and (3) stochastic broadband (bandwidth 2.8–11.2 Hz) whole body vibration. A single test consisted of a control period of 30 min, three consecutive exposure periods of 16 min, each followed by a 4-min post-exposure interval and a recovery period of 15 min. The results of the variance analyses indicated that noise had the most notable effect on the TTS₂ values at the hearing frequencies of both 4 and 6 kHz. Of the paired combinations, noise plus vibration and noise plus dynamic muscular work caused the most obvious combined effects. The combined effect of all three factors (noise, vibration and work) on the TTS₂ values after three consecutive exposure periods was significant at the 2.5% level at the 4 kHz hearing frequency and at the 5% level at the 6 kHz hearing frequency. The added effect of vibration on enhanced TTS₂ values was particularly clear when the vibration was stochastic and when the subjects had a low (2 W) working efficiency. Increasing the working efficiency, on the other hand, seemed to retard increases in the hearing threshold. Thus TTS₂ values seemed to reflect the changes in HR values. It is as if the low rate of cardiovascular activity during light dynamic muscular work had enabled the manifestation of the cardiovascular effects of noise and vibration; during strenuous dynamic muscular work, however, the high rate of cardiovascular activity aimed in some way at compensating for the effects of noise and vibration on blood circulation.A brief account of some of the results from the audiometric measurements has been given in San Francisco at the eleventh Inter-Noise Conference in May 17 to 19, 1982     

Effects of industrial solvents on hearing and balance: a review

Industrial hearing loss has generally been associated with noise exposure, but there is a growing awareness that industrial solvents can have an adverse effect on the auditory and vestibular systems in man. Both animal experiments and human studies point to an ototoxic effect of industrial solvents, as well as some central auditory and vestibular disturbances. This review examines the research from the last four decades in an attempt to get an overview of the available evidence. Research shows that industrial solvents are ototoxic in rats. The majority of the solvents studied cause a loss of auditory sensitivity in the mid-frequencies in rats, affecting outer hair cells in the order OHC 3 > OHC 2 > OHC 1 . Inner hair cells are generally unaffected. Spiral ganglion cells are most vulnerable to trichloroethylene. Simultaneous exposure to solvents and noise results in a synergistic effect; the pattern of trauma mirrors that due to solvent exposure rather than noise, but is more enhanced. There is a critical level when synergy occurs. The effects of solvents on the vestibular system are neurotoxic and influence the vestibulo-oculomotor system in both animals and humans; humans also present with problems in postural sway. There is a strong suggestion from human studies that solvents are ototoxic in man, but findings show that both the peripheral and central auditory pathways can be affected. Hearing losses can be in the high frequency region or can affect a wider range of frequencies. Hearing loss and balance disturbances can occur at levels below permitted levels of exposure. The synergistic effect of combined exposure to solvents and noise has also been noted in humans, resulting in greater hearing losses than would be expected from exposure to noise and solvents alone. The findings from both human and animal studies indicate that exposure to industrial solvents or to industrial solvents and noise can have an adverse effect on hearing and balance. The implications for industry and hearing conservation are far reaching.     

Effects of low frequency noise up to 100 Hz

This review concentrates on the effects of low frequency noise (LFN) up to 100 Hz on selected physiological parameters, subjective complaints and performance. The results of laboratory experiments and field studies are discussed in relation to the thresholds of hearing, of vibrotactile sensation and of aural pain. The effects of LFN may be mediated trough different ways. Temporary or permanent hearing threshold shifts seem to be due to acoustic stimuli above the individual hearing threshold. However, non-aural physiological and psychological effects may be caused by levels of low frequency noise below the individual hearing threshold. The dynamic range between the thresholds of hearing and of aural pain diminishes with decreasing frequency. This should be taken into account by the setting of limits concerning the health risks. Sufficient safety margins are recommended. The use of a frequency weighting with an attenuation of the low frequencies (e.g. G-weighting) does not seem to be appropriate for the evaluation of the health risks caused by LFN up to 100 Hz. It may be proposed to measure third octave band spectra or narrow band spectra. A comparison with the known human responses caused by the measured levels and frequencies could help to evaluate the health risks. Some proposals for further investigations were given: (1) experimental methods to discover the ways mediating the effects of low frequency noise, (2) consideration of the individual hearing threshold or hearing threshold shift and of the vibrotactile threshold in the low frequency range to be able to judge the effects, (3) consideration of combined body vibration caused by airborne low frequency noise or by other sources, (4) modelling to analyse the transmission of the acoustic energy from the input into the body to the structures containing sensors, (5) consideration of probable risk groups like children or pregnant women.     

Cardiovascular effects of environmental noise: research in the United Kingdom

Although the auditory effects of noise on humans have been established, the non-auditory effects are not so well established. The emerging links between noise and cardiovascular disease (CVD) have potentially important implications on public health and policy. In the United Kingdom (UK), noise from transport is a problem, where more than half of the population is exposed to more than the recommended maximum day-time noise level and just under three-quarters of the population live in areas where the recommended night-time noise level is exceeded. This review focuses on findings from studies conducted in the UK that examined environmental noise and cardiovascular disease. There were statistically no significant associations between road traffic noise and incident ischemic heart disease in the Caerphilly and Speedwell studies, but there was a suggestion of effects when modifying factors such as length of residence, room orientation, and window opening were taken into account. In a sample stratified by pre-existing disease a strongly increased odds of incident ischemic heart disease for the highest annoyance category was found compared to the lowest among men without pre-existing disease (OR = 2.45, 95%1.13 - 5.31), which was not found in men with pre-existing disease. In the Hypertension and exposure to noise near airports (HYENA) study, night time aircraft noise exposure (L night ) was associated with an increased risk of hypertension, in fully adjusted analyses. A 10-dB increase in aircraft noise exposure was associated with an odds ratio of 1.14 (95%CI, 1.01 - 1.29). Aircraft noise was not consistently related to raised systolic blood pressure in children in the road traffic and aircraft noise exposure and children's cognition and health (RANCH) study. There is some evidence of an association among environmental noise exposure and hypertension and ischemic heart disease in the UK studies; further studies are required to explore gender differences, the effects of day and night time exposure, and exposure modifying factors.     

某铀矿冶工程非放射性职业病危害及其关键控制点分析

目的 识别某铀矿冶工程在生产过程中产生的非放射性职业病危害及其关键控制点.方法 采用现场职业卫生学调查、工作场所职业病危害因素检测和职业健康监护相结合的方法 对该企业存在的职业病危害因素进行分析.结果 该铀矿冶工程作业场所中存在的职业病危害因素有粉尘、物理因素和化学毒物,其中粉尘包括矽尘、其他粉尘和电焊烟尘;物理因素包...     

Occupational morbidity due to the effects of vibration and noise in leading USSR industries and main objectives of its prevention

The article presents data on the prevalence and dynamics of noise and vibration related occupational morbidity in different regions of the USSR, branches of industry and professional groups. Diseases caused by noise and vibration present major and ever growing occupational pathology in the Soviet Union. Particularly high morbidity rates were traced in the Russian Federation, Ukraine, Kazakhstan and Lithuania, primarily in coal mining, metallurgy, machinery construction branches of industry, and, as to occupational hypoacusis,--in metallurgy, some branches of machinery construction, automobile construction and light industry. Vibration related risk factors were revealed in such professional groups as choppers, emery polishers, tool sharpeners, loggers, drill operators; noise related risk factors--in blacksmith's works, weaving and some others. Certain decrease in occupational morbidity rate was registered before 1985 with a tendency to increase in the last 4-5 years. Prevention of vibration and noise related morbidity should include complex measures, modernization of industrial sites and health services improvement.     

Gamma-hydroxybutyric acid An evaluation of its rewarding properties in rats and mice

Gamma-hydroxybutyric acid, an endogenous compound present in mammalian brain and supposed to be a neurotransmitter or neuromodulator, has been shown to affect several aspects of dependence from some drugs of abuse. It has been successfully used in clinical practice to alleviate both alcohol and opiate withdrawal symptoms. The aim of this study was to investigate whether gamma-hydroxybutyric acid possesses rewarding properties by means of conditioned place preference and intravenous self-administration paradigms. In the present study, gamma-hydroxybutyric acid induced conditioned place preference in rats, was intravenously self-administered by drug-naive mice, and altered cocaine intravenous self-administration in rats. Although to date the physiological role of this compound still remains unclear, there is no doubt that gamma-hydroxybutyric acid, in addition to its proved effect on alcohol and opiate dependence, possesses reinforcing properties of its own and may interfere with the neurochemical events in the rewarding effects produced by psychostimulant drugs. Our investigation points out the abuse liability of this drug, suggesting the use of particular precaution in handling gamma-hydroxybutyric acid as a clinically useful drug.     

Clinical assessment of musculoskeletal disorders in workers exposed to hand-arm vibration

OBJECTIVES: To describe the clinical assessment of musculoskeletal disorders among vibration-exposed workers and to review the experimental and epidemiological studies of the effects of vibration on the musculoskeletal system of the upper limbs. METHODS: A total of 212 references in English was found in Pub Med for the years 1980-2000 that dealt with clinical assessment. Many of these references were reviews and few were original research dealing with test performance in diagnostic procedures. RESULTS: The reported effects on bone are osteoporosis and cysts in the hands. Experiments have shown injuries to muscle cells in animals and additional physiological loading of muscles in humans by vibration. Low-frequency vibration exposure of high magnitude was associated with osteoarthrosis in the elbow, wrist and acromioclavicular joint and symptoms in the elbow and shoulder. Impacts, jerks and blows with high-energy transfer to the hands at low frequency might have the potential to result in musculoskeletal disorders considering the general model for injuries. Furthermore, the observed associations with vibration exposure and musculoskeletal disorders might result from the strong dynamic and static joint loading and the repetitive hand-arm motions required in tasks where hand-held machines are used. The clinical assessment of musculoskeletal disorders in workers exposed to hand-arm vibration consists of the clinical and exposure history and evaluation of the physical and laboratory findings. Since most patients with musculoskeletal disorders who are exposed to vibration are also exposed to other ergonomic stressors, accommodation of the injured worker has to take the whole work system into account (task, technology, environment and organisation). CONCLUSIONS: The scientific evidence that vibration per se is a risk factor for musculoskeletal disorders is still weak although there is strong evidence that job tasks with vibrating machines are associated with musculoskeletal disorders. The clinical assessment of musculoskeletal disorders in exposed patients imposes special requirements.