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Objectives: This study attempted to determine the prognostic indicators of low-back pain in an occupational health setting., Methods: The identification of prognostic factors of (i) functional disability after 3 months' follow-up, (ii) functional disability after 12 months' follow-up, and (iii) time to return to work among 120 workers who reported to an occupational health unit and were off work with low-back pain for at least 10 days. Crude and adjusted odds ratios and hazard ratios with 95% confidence intervals were estimated for the 3 outcome measures., Results: Factors related to a longer time to return to work were radiating pain, high functional disability at the beginning of the study, problems in relations with colleagues, and high work tempo and work quantity. High functional disability at the beginning of the study and a high avoidance coping style predicted functional disability at 3 months. Functional disability at 12 months was more accurately predicted by work-related and psychosocial factors., Conclusions: Especially radiating pain and functional disability predict a long duration of low-back pain in occupational health practice. Occupational physicians should also note work-related and psychosocial characteristics.

Objectives: To develop and apply a method for assessing the quality of the process of occupational health care for individual patients., Methods: The scientific literature was studied to develop a method to assess the quality of the process of occupational rehabilitation for workers with low back pain. The method was applied to health care and university workers with low back pain who were rehabilitated by their occupational physicians., Results: Assessment of quality of care is regarded as a four step approach. Firstly, guidelines should be developed and implemented. Secondly, indicators for quality and criteria to demarcate good and deviant quality were derived from the guidelines. Thirdly, a method for data collection was chosen. Finally, quality was scored. For occupational rehabilitation, there was some deviance from the guidelines for most cases, especially in continuity of care with a deviant rate of 47%. Other indicators deviated from 1.4%-17.4%. Occupational physicians agreed on the relevance of the indicators and criteria, but for three indicators they evaluated the criteria as too rigid. They did not agree with their own performance scores in 66% of the deviant cases., Conclusion: Assessing the quality of the process of occupational health care with this method is an asset to present methods, but more specific criteria are needed for a more sensitive assessment.

The objective was to review the literature on risk factors for musculoskeletal disorders related to pushing and pulling. The risk factors have been described and evaluated from four perspectives: epidemiology, psychophysics, physiology, and biomechanics. Epidemiological studies have shown, based on cross-sectional data, that pushing and pulling is associated with low back pain. Evidence with respect to complaints of other parts of the musculoskeletal system is lacking. Risk factors have been found to influence the maximum (acceptable) push or pull forces as well as the physiological and mechanical strain on the human body. The risk factors have been divided into: (a) work situation, such as distance, frequency, handle height, and cart weight, (b) actual working method and posture/movement/exerted forces, such as foot distance and velocity, and (c) worker's characteristics, such as body weight. Longitudinal epidemiological studies are needed to relate pushing and pulling to musculoskeletal disorders.

"The issue is addressed whether assistance to persons in need can be left to the ¿family' and the ¿community'. In that case people depend on their social networks. The support a person receives through a given network of social ties is examined. However, ties are diverse and subject to change. By means of a model of the dynamics of social ties, the conditions for adequate private support are analyzed. The sustainability of private support over time is examined by incorporating the impact on social ties of lending and receiving support. It is shown that support is only an effective alternative in a limited number of situations.", (excerpt)

Objectives: To (a) describe differences in the outcome of cross sectional and longitudinal analysis on musculoskeletal complaints relative to age and work demands, and (b) to assess the entrance and drop out selection on musculoskeletal complaints among groups of employees relative to age and work demands., Methods: A study population was selected on the basis of questionnaire data from periodical occupational health surveys of almost 45,000 employees collected between 1982 and 1993. From all companies within this data base that participated twice in company wide surveys four years apart, male employees were selected, and stratified for age and work demands. There were several populations: follow up (participation in both surveys); drop out (participation only in the first survey); entrance (participation only at the second survey); and two cross sectional populations (all participants at each survey). Prevalences of back complaints and turnover rates were analysed., Results: Reported back complaints in the cross sectional analysis declined over the oldest age groups in heavy physical work versus a small increase in the longitudinal analysis. The age group 50-9 and back complaints were identified as predictors at the first survey for not participating at the second survey. Neither age nor work demands at the first survey indicated drop out among those employees with back complaints at the first survey. The effects of entrance selection on estimated prevalences were small., Conclusions: The results indicate that musculoskeletal disorders lead to selection out of work, affecting the validity of both cross sectional and longitudinal epidemiological studies. In future studies analyses of turnover figures on musculoskeletal complaints relative to work demands and age are recommended.

Objectives: To examine changes in musculoskeletal complaints over four years in groups of employees relative to age and work demands., Methods: Repeated questionnaire data of male employees in heavy physical work (exposed group, n = 7324) and mental work (control group, n = 4686), stratified for age (20-9, 30-9, 40-9, 50-9), were analysed. For each employee, data on the occurrence of musculoskeletal complaints from two surveys with a mean interval of around four years were available. Changes in prevalences over the follow up interval were analysed. Proportions of new, recovered, and chronic cases as well as those free of complaints at both surveys were studied., Results: For most complaints, there were significantly greater increases in prevalences in the exposed group compared with the control group over the follow up interval particularly within the group aged 40-9 for back, neck, and several sites of the upper and lower limbs. The 20-9 year age group also had significantly greater changes for several musculoskeletal complaints. Within the oldest age group (50-9) exposure to heavy physical work demands only affected changes in prevalences of neck and upper arm complaints. After four years in the cohort free of complaints at the start of the follow up the group aged 40-9 had the highest prevalence of complaints of the back, neck, and the upper and lower limbs., Conclusions: Middle aged and younger employees develop musculoskeletal complaints as a result of exposure to heavy physical work. In the oldest age group health related selection seems to mask the occupational health risks under study. To prevent the expected increase in musculoskeletal disorders and related work disability in our aging workforce, preventive measures should be taken at all stages of a working life.

Guidelines for occupational rehabilitation of workers with low-back pain were developed as part of a larger study. We have formulated criteria for good practice of occupational rehabilitation on the basis of these guidelines. To assess the quality of occupational rehabilitation in the Netherlands, these criteria were subsequently used in an audit of medical records. The number of patients who received care consistent with the guidelines was compared to the number of patients eligible to receive that kind of care (performance rate). Six performance rates were calculated from the medical files of 40 workers with 48 new episodes of low-back pain. Two performance rates proved to be below 25% and two almost 50%. The highest performance rate, that for curative policy was 90%. These results are discussed in the light of the reliability of the original data. We recommend construction of guidelines as well as reliable registration of the occupational rehabilitation process to increase the possibilities of auditing and to raise the quality of occupational health care.

Objectives: To achieve a coherent programme of topics for research in occupational health and safety, with well founded priorities and to relate them to perceived gaps and needs in The Netherlands., Methods: In the first phase of the study 33 key informants were interviewed. In the second phase questionnaires were sent to 150 Dutch experts (including the key informants). Four groups were recruited, originating from: occupational health and safety services; scientific research institutes; governmental and other administrative bodies; and companies. Using the Delphi technique, the experts were asked to prioritize several topics, which were placed under different headings. In the third phase five workshops were organised to elaborate on the highly prioritized topics., Results: The response rates were 86% for the first and 81% for the second questionnaire. In the second round consistency was reached and consensus proved to be satisfactory; so that the Delphi process was stopped. There were surprisingly few differences in opinion between the four groups. The most important heading was "design/implementation/evaluation of measures", in which the topic cost-benefit analysis of measures had the highest score. "Assessment of relations between exposure and effect" was the second most important heading. Under this heading, topics on work stress were generally judged to be more important than topics on safety and biological, chemical, and physical hazards. The headings "occupational rehabilitation/sociomedical guidance" and "occupational health care/occupational health services" had about the sam priority, closely following the heading "assessment of relations between exposure and effect"., Conclusions: The general agreement on priorities should provide a sufficiently broad basis for decision makers to initiate a long term programme for occupational health research and development in The Netherlands.

Objective and Methods: Health gain, prevention of health loss, and avoidance of financial risk all seem to be driving forces for the use of pre-employment medical assessment. An attempt is made to measure the effect of implementing the pre-employment medical assessment on these end points. The anticipated maximum preventive effect (preventive effectiveness) of selection by means of pre-employment medical assessments for work related risks and the potential for disablement in individual workers can be calculated or estimated. Necessary parameters include test validity characteristics and epidemiological data for both the adverse outcome to be prevented, and risk factors of concern., Results: The preventive effectiveness can be expressed as the effort (number of actions) needed to prevent one adverse event-for example, one case of occupational disease or one case of long term disablement. Actions include: a pre-employment health assessment, rejection of the candidate, individual precautions, adjustments of the job, and adjustments of the job environment. It seems that the preventive effectiveness of many actions can be low, implying that large numbers of actions are needed to prevent one adverse outcome., Discussion: The medical assessment should consist of no more questions and tests than are required relevant to the stated aim. Particularly, when the pre-employment medical assessment is used to reject candidates at risk, the use of tests should be carefully weighed. If the preventive effectiveness is considered to be too low, then the question or test should not be incorporated for selection purposes. The application of a so called "expert judgment" should be based on professional guidelines wherever possible and should be made clear. The benefit of reducing the incidence of a serious adverse event by one may outweigh the costs of rejecting many candidates., Conclusions: The concept of preventive effectiveness may help to reach evidence based occupational medicine, which starts at the pre-employment medical assessment.

The use of job title as crude exposure measure in epidemiological studies is often inevitable when the available exposure data is scarce. In this study, an existing classification scheme of all job titles in the Netherlands into six categories of physical and mental work demands, constructed by expert judgement, was evaluated. Furthermore, a revision of this classification scheme for a research project on the relation between age, physical work demands, and musculoskeletal complaints was proposed and evaluated as well. For the evaluation, self-reported work demands, derived from questionnaire data of 38,921 employees and quantified by a scale of physical work demands and mental work demands, were used. Based on comparison of the mean scale scores of the several categories of work demands at group level, both classification schemes showed construct validity. Notwithstanding several limitations, the use of the presented classification schemes in epidemiological studies seems particularly challenging and rewarding when analysing data at group level from large and heterogeneous occupational populations. These kind of exploratory studies may generate new hypothesis on the basic patterns concerning work-related disorders, and can also be informative from a policy making perspective.

Objectives: This cross-sectional study was performed in order to elucidate the relationship of musculoskeletal complaints with age, gender and physically demanding work in the Netherlands., Methods: Questionnaire data of male (n = 36756) and female (n = 7730) employees, gathered as part of periodical occupational health surveys among active workers in the Netherlands, were stratified for age, gender, and type of work demands. For each stratified group prevalence rates (PR) were calculated for complaints of the back, neck, upper and lower extremities. Moreover, prevalence rate differences (PRD) were estimated as an absolute effect measure of exposure to various types of physical work demands, with active employees in mentally demanding work acting as a reference population., Results: Musculoskeletal complaints among workers in physically demanding occupations were found to increase with age for both sexes. For several complaints, substantially higher rates were reported for women than for men, with a relatively high number of complaints observed among the older female workers (around 40% for complaints of back, upper and lower extremities). Significant PRDs were present in particular for employees in heavy physically demanding occupations and in jobs with mixed mental and physical work demands., Conclusions: With the ageing of the workforce in mind, these findings stress the need for implementation of preventive measures. Special attention towards the susceptible group of female employees, the elderly age groups in particular, seems justified. In order to clarify the combined effects of age and physical work demands on musculoskeletal complaints, additional studies are required.

To determine priorities for ergonomic improvements in five maintenance departments of a steel company, a study was carried out to identify groups with a high prevalence of musculoskeletal problems or a high exposure to unfavourable musculoskeletal workload. All workers were asked to complete a standardized questionnaire on musculoskeletal symptoms and musculoskeletal workload. Response rate in the five departments varied between 60 and 80% (n = 436). Symptoms of low back and neck-shoulder (12-month prevalence rates of 53% and 36%, respectively) were most common, but not higher in comparison with a reference group of 396 non-sedentary workers. Self-reported exposure rates to physical and psychosocial loads as well as poor climatic conditions were comparable with the reference group; only exposure to vibration was higher. Significant differences were seen between the five departments as well as between task groups with the departments. Several task groups with relatively high symptom rates and high exposure levels could be identified. It is concluded that a questionnaire survey can constitute a valuable contribution to the selection of high-risk task groups that need ergonomic intervention.

Objectives: The main objective is to describe the potential health and work problems of the aging employees in the Dutch working population. In this way, we can identify groups at extra risk of specific health problems., Methods: In The Netherlands, occupational health services gather questionnaire data about work and health as part of periodical occupational health surveys (POHSs). These data from the POHSs of complaints about health and working conditions, aggregated into occupational groups and age categories, are used to provide indications for groups at extra risk of specific health problems. These problems are assessed by overviews of the relation between age and complaints about health and working conditions., Results: Almost all of the health questions show an increase in health complaints with increasing age. White collar workers, especially the high grade white collar workers, usually have lower complaint percentages on health questions than blue collar workers. Female employees have relatively high complaint percentages on the health questions. Differences between occupational groups in the complaints about work and working conditions reflect the differences in work demands and exposure. The relation between age and work complaints is generally inconsistent and weak. The complaint percentages on work questions of female employees tend to be equal to or lower than those of the male employees., Conclusions: The absence of a clear increase of work complaints with advancing age in the presence of a decrease in health and working capacity may be explained by a selective turnover in the working population, especially in demanding occupations. To enhance the work participation of older employees it may be necessary to reduce the work demands and to increase decision latitude.

Due to political priorities and benefit arrangements, prevention of work incapacity has played a minor role in employers' policies in the Netherlands. However, the comparatively high sickness absence rates and large numbers of disability benefit recipients in the Netherlands have fostered preventive policies and measures regarding unfavourable working conditions. Corresponding to recent changes in legislation, the role of occupational health and safety services will substantially increase in the coming years. Part of the new orientation will be a multi-disciplinary staff structure and more attention to tailor-made services and effectiveness. There is much debate about the precise role for occupational physicians in the control of sickness absenteeism in companies. This paper presents several instruments which are now being applied or which are still in a developmental stage. The issues of prevention of sickness absence and monitoring of long-term sick employees will remain a substantial part of the responsibilities of occupational health and safety services.

Internationally, the debate on aims for occupational health policy is expanding its horizons. Included among the issues are not only concerns about safety for workers, but also for their progeny. Equality among the sexes is also assuming a prominent position. In several countries, existing and proposed legislation already considers these matters. In the course of this article it is argued that this legislation and its implementation are inadequate. There are several reasons for this. Firstly, what constitutes health risks for workers exposed to chemical substances is subject to different interpretations. This is further complicated when one includes risks to reproductive function and to the progeny: the reproductive risks of toxicity. The different interpretations of the concepts of safety and equality are also discussed. There are differences in regulations and in standards about whether or not safety factors should be used when knowledge is uncertain. The operation of reasonable measures with a generic or sex specific policy also differs. Secondly, the current occupational exposure limits are set too high. These aspects are considered and it is probable that the policy aims should be made more specific. An elaborated approach that includes the "precautionary principle" in safety standards is proposed. To advise employers in their role as managers of reproductive risks of toxicity, a recently developed system for occupational health and safety services is described. This system is based on two criteria: effectiveness and reasonableness of proposed measures. The effectiveness criterion includes the precautionary principle; the reasonableness criterion includes equal rights and opportunities for men and women. Finally, a supportive governmental policy that is consistent with the most recent international development is recommended.

In the coming decades, demographic, economic and social changes will result in an increased proportion of elderly persons in the workforce in most industrialized countries. This trend is causing growing interest in the problems of the aging worker in current employment. The objective of this particular paper is to provide more insight into the impact of aging on the balance between physical work capacity and physical workload. To this end, the scientific literature in the field is reviewed and ordered by means of a specific conceptual model of "aging and physical workload". A progressive decline in physical work capacity, characterized by diminished aerobic capacity and muscular capacity, has consistently been reported. However, inter-individual differences appear to be considerable. The question of whether there are systematic differences in physical work demands between younger and older workers within occupations has been answered vaguely. Conflicting results in this matter bring into discussion the role of the actual working method as one of the determinants of the physical workload. An age-related imbalance between physical workload and physical work capacity is suggested to result in a chronic overload, increasing the risk of long-term health effects such as musculoskeletal complaints and disorders. For many aging workers in physically demanding occupations, extreme physical workloads, increasing the risk of disease or disablement, are still reported. The multiconceptual study of aging and physical workload in the present paper reveals several possibilities for preventive measures. However, as information is still lacking, additional research is needed, in particular on the onset and development of long-term effects on health in relation to age and work demands.

In this article, we describe methods which have been applied in the compilation of the Atlas of Health and Working conditions by Occupation. First, we discuss the need for information systems to identify problems concerning working conditions and health. Such information systems have an exploratory purpose, being deployed to identify work risks in companies, groups of occupations and sectors of industry, and can also be a starting point for the generation of hypotheses on the causes of adverse health effects. In the Netherlands, occupational health services gather questionnaire data about work and health as part of periodical occupational health surveys. In the atlas, aggregated questionnaire data for 129 occupations with male employees and 19 occupations with female employees are presented. In this article, we explain the methodology used to compare occupations with regard to each item in the questionnaire. We then discuss applications of these occupational ranking lists. The cross-sectional nature of the data collection, various forms of selection and the limited size of some occupational populations have to be taken into account when interpreting the results. Occupational ranking lists can be applied in the allocation of resources and in the design of scientific research. The overviews for each occupation, presented in the second half of the atlas, provide an occupational profile of existing problems with respect to work and health. These profiles are used as basic information to develop a practical policy on working conditions and health.

The results of the general Atlas of Health and Working Conditions by Occupation were compared with the results of the Atlas of Health and Working Conditions in the Construction Industry. Both are based on questionnaire data from periodical occupational health surveys [POHSs]. The scores on most of the items showed considerable differences between the two atlases, partly due to differences in the regional origin of the data. Therefore, direct comparisons between the atlases are biased by regional differences. To study the reliability and the generalizability of the results of both atlases, similarities between the data files with respect to occupations in the construction industry were studied. Most of the items on working conditions, especially those with a widespread distribution, showed a close resemblance between the data files in terms of the relative position of an occupation compared to other occupations in the construction industry. The items on health showed less resemblance, except for the items on musculoskeletal complaints, which showed results similar to those of the work items. These results indicate the reliability and generalizability of the judgements based on both atlases outside the regions of origin, as far as items with a widespread distribution are concerned. Therefore, we recommend the aggregation of POHS data on a national scale, taking regional differences into account. In that way, a greater number of occupations will be described and the reliability of the results will be enhanced.

Objectives: Many pregnant women have musculoskeletal complaints, the onset and aggravation of which are thought to be associated with their activity or work postures. The purpose of this paper was to obtain more insight into the influence of pregnancy on the load of the musculoskeletal system at work to provide a better basis for preventing complaints., Methods: To this end, literature pertinent to a model called "work load of the musculoskeletal system" was reviewed. The model was developed to describe how work contributes to musculoskeletal complaints., Results: It was found that pregnancy causes changes in a worker's characteristics. These changes can lead to changes in the work situation, activity pattern, and postural characteristics and possibly result in a change in work load. In addition, physical changes such as weight gain increase the work load in a given posture. The load-bearing capacity of the musculoskeletal system decreases due to pregnancy., Conclusions: The changes in load and the decrease in load-bearing capacity singly or simultaneously increase the risk of musculoskeletal complaints. The multifactorial cause of musculoskeletal complaints during pregnancy reveals various possibilities for prevention.

Among personnel of the city of Amsterdam the incidence of disability as a result of musculoskeletal problems amounts to 15 per 1000 person-years in the refuse collecting department. A disability prevention programme in accordance with literature was started to decrease this high incidence of disability. In the process-evaluation after 2 years from the start of the project it turned out that only three of the ten preventive measures advocated were realized. These meagre results were explained by strategic factors such as lack of motivation among management and the fact that policy on worker health protection was isolated from the overall company policy. Recommendations for future evaluation research are given.

Interest in the quality of instruments for occupational health services is growing as a result of European legislation on preventive services stressing, for example, risk identification and assessment. The quality of the services can be enhanced when the quality of the applied instruments can be judged and improved. To judge quality aspects of instruments, a basic draft scheme and criteria are presented. A first category of criteria covers measurement objective and study design and comprises for example sample strategy and data aggregation level. Technical quality aspects are validity, reliability, standardization and precision. Acceptability of an instrument by employees, employers and professionals belongs to the process quality. At last, strategic quality or presumed utility has to be assessed. As an illustration four instruments have been judged: periodic occupational health surveys, pre-employment medicals, the company audit on work and health, and specific working conditions assessment instruments. Finally the presented basic scheme and criteria are brought into discussion.

The outline of a study in occupational health services (OHS) on the prevention and control of effects of whole-body vibration is described and preliminary results are presented here. The study comprises an inventory of current activities of occupational health services in vibration-related issues, the development of a specific OHS-programme and evaluation of this programme, mainly on process level. Results of the inventory, a questionnaire survey in occupational health services (n = 112, response 67%), show that the impact of OHS in prevention and control of adverse health effects is small. The development and evaluation of a specific OHS-programme may be useful in setting up a preventive approach. Some methodologic problems are discussed also.

Five experienced occupational physicians independently reviewed the uniformly structured, concise records of 180 applicants who had applied for a job in one of three categories. All had undergone a preemployment medical examination by the Governmental Occupational Health and Safety Service. Agreement was assessed by calculating the percentage of disagreement and Cohen's kappa. Agreement between the five panel physicians and between the panel physicians and the Service appeared to be poor, with overall percentages of disagreement of 31 and 37%, respectively, and kappa values of 0.38 and 0.37, respectively. On the average 31% of the applicants judged as unfit by one physician had been assessed as fit by the others, whereas agreement was only marginally better when detailed medical criteria for fitness were available. Lack of consensus on the medical fitness of an applicant, as evidenced by this study, suggests that the validity of such a judgment may be questionable even when detailed fitness criteria are available.

The present experiments were designed to assess whether brain hypothermia can reduce the behavioral and histopathological deficits associated with global forebrain ischemia. Animals were subjected to 12.5 min of four vessel occlusion (4VO) with moderate hypotension, and brain temperature maintained at either 37 degrees C (4VO-37) or 30 degrees C (4VO-30). Behavioral tests designed to assess forelimb reflexes and sensorimotor function were given on post-operative weeks 2 and 4. Beginning in week 5, the rats were trained on a variety of navigation problems in the Morris water maze. Histopathological examination of the tissue 2 months following reperfusion revealed that 4VO-37 animals sustained substantial cell death in hippocampal region CA1 and moderate damage to the dorsolateral neostriatum. 4VO-30 animals showed minimal cell death in CA1 and neostriatum. There were no group differences for any of the sensorimotor measures, or for acquisition performance on either the simple place task or visible platform version of the water maze. In contrast, during acquisition of the learning set task, the performance of 4VO-37 animals was impaired relative to either of the other groups, whereas the performance of 4VO-30 animals was not significantly different from the sham controls. These data suggest that moderate intra-ischemic brain hypothermia provides long-lasting protection from behavioral deficits as well as neuronal injury following transient global ischemia.

Several hundreds of thousands of preemployment medical examinations are performed in The Netherlands each year, with the objective of screening for obvious risks for the applicants or others. Neither the efficacy of these examinations nor determinants for rejection are known. Altogether 101,754 preemployment medical examinations of applicants for governmental functions were analyzed. For one-fifth of the applicants some medical diagnosis was recorded. The overall rejection percentage was 0.6%, being highest for job categories involving public safety and high physical demands, but never exceeding 4%. Age was positively correlated with rejection percentage. Except for the diagnostic category "disorders of the musculoskeletal system" no relation between diagnostic category and job demands was apparent. Medical diagnoses frequently encountered among rejected applicants were also common among successful applicants. If selection aiming at reducing absenteeism or work disablement is considered to be the only goal of preemployment medical examinations, then their efficacy appears to be low for many job categories.

A literature review was performed on the subject of combined exposure to stressors in the working situation. A general, dynamic model of workload served as the theoretical framework for the study. In this model, every factor that triggers a physiological or psychological response in the worker is regarded as a stressor. Decision latitude plays an important role in the model. A quantitative and qualitative analysis was performed on the available literature. It was concluded that the stressors that appear in studies on combined exposure stem mostly from the physical, chemical and biological environment. The task contents, the labor conditions, social relationships at work and the decision latitude are considerably less often studied in relation to combined exposure. It is concluded that important concepts in the study of combined exposure (e.g. interaction, independence, synergism, antagonism) are often quite carelessly mentioned in the literature. Explicit definition of these concepts is lacking in many publications. Establishment of maximum exposure levels is not yet possible for most stressor combinations. Examples are given of combinations that do allow more or less definite conclusions. It is recommended that more studies should be interdisciplinary organized. More studies are necessary in the field, studying effects of long exposure periods in the working population instead of studying students in laboratory situations. Exposure of susceptible groups, such as older workers and partially disabled workers, deserves special attention.

Audiometry and casual blood pressure measurements were carried out among industrial workers exposed to noise levels exceeding 80 dB(A). Workers with long-term noise exposure had increased blood pressure, after correction for age. Only a weak correlation was observed between noise-induced hearing loss and the corrected blood pressure. The influence of other working conditions and of the relative body weight could not be evaluated.

A secondary analysis of data from a national survey was carried out in order to assess the number of industrial workers exposed to noise and other adverse working conditions. This permitted us to study correlations with parameters of health. More than half of the male blue collar workers in industry and building trades (sample n = 311) reported a great deal of noise. Dirty work and strenuous physical activity were also frequently mentioned. Noise exposure is often present together with exposure to stench and dirty and dangerous work. A weak correlation exists between reported noise exposure and experienced ill-being and diminished satisfaction with their own health. This observed relationship probably underestimates the true risks.

The results of epidemiological studies on non-auditory effects of noise in industry are commented upon. The present state of the art does not permit any definite conclusion to be drawn about the risk of hypertension. Annoyance by noise is widespread; it has many different aspects and it has been studied in detail in this project. Combinations of working conditions should be studied that produce interaction effects overloading psychological or physiological systems. Some examples are given. Standards and guidelines for industrial exposure to noise should also prevent wellknown, non-auditory effects, such as communication problems, which result in social isolation.

A review of the literature shows a growing interest in non-auditory effects of noise at work. Somatic, vestibular and psychological effects and different kinds of activity interferences are described. Suggestive evidence of an elevation of the blood pressure by noise exists, although the quality of the studies is limited. Many non-auditory effects can be described in a stress model. Annoyance and stress, however, were seldom the subject of field studies.

Workers of a shipbuilding and a machine shop department of a shipyard, with average noise levels of 98 dB(A) and 85.5 dB(A) respectively, were compared with respect to auditory and non-auditory effects. The distribution of years of noise exposure and of age was similar in both departments. No difference in blood pressure was observed after correction for age and relative body weight, however, the cross-sectional study design may have obscured a relationship. Analysis of other adverse working conditions could not explain the absence of a relationship between noise exposure and blood pressure. Noise-induced hearing loss and noise annoyance were observed far more frequently in the shipbuilding department in comparison with the machine shop. There were no differences in the consumption of pharmaceutical drugs, alcohol and tobacco.

Non-auditory effects of noise were studied among 539 male workers from seven industries. The LAeq, assessed by personal noise dosimetry, has been used to study acute effects. Various indices of total noise exposure, involving level and duration, were developed for long-term effect studies. In the analysis close attention was paid to prevent confounding, e.g. by other adverse working conditions. As expected, hearing loss increased with total noise exposure. Tinnitus was related particularly to hearing loss. Dizziness and hoarseness, however, were not related with noise exposure in this study. Also no correlation could be demonstrated between blood pressure and total noise exposure after correction for age, relative weight and various confounding variables. Use of hearing protection, selection processes and incomplete analysis of interactions between independent variables are suggested for possible explanation. About two-thirds of the workers reported noise annoyance. Various aspects were mentioned, such as irritation, surprise and impairment of communication and perception. Mentally stressful tasks appeared to be the most noise-sensitive. Particularly annoying noise sources, mental work load and time pressure had a relatively large impact on noise annoyance in comparison with the influence of noise level (LAeq) itself. Stress responses were not simply related to the noise exposure level, although consistent positive relations could be demonstrated between symptoms of stress and noise annoyance. Various findings led to the conclusion that noise exposure together with stressful mental activities may lead to disturbed concentration, irritation and annoyance. Experienced stress in turn may render workers more susceptible to noise. To overcome some limitations of this study, cohort studies and studies designed to assess interaction-effects are recommended.