Importance of psychosocial work factors on general health outcomes in the national French SUMER survey

AIM: To examine the associations between psychosocial work factors and general health outcomes, taking into account other occupational risk factors, within the national French working population. METHODS: The study was based on a large national sample of 24 486 women and men of the French working population who filled in a self-administered questionnaire in 2003 (response rate: 96.5%). Psychosocial work exposures included psychological demands, decision latitude, social support, workplace bullying and violence from the public. The three health indicators studied were self-reported health, long sickness absence (>8 days of absence) and work injury. Adjustment was made for covariates: age, occupation, work status, working hours, time schedules, physical, ergonomic, biological and chemical exposures. Men and women were studied separately. RESULTS: Low levels of decision latitude, and of social support, and high psychological demands were found to be risk factors for poor self-reported health and long sickness absence. High demands were also found to be associated with work injury. Workplace bullying and/or violence from the public also increased the risk of poor health, long sickness absence and work injury. CONCLUSION: Psychosocial work factors were found to be strong risk factors for health outcomes; the results were unchanged after adjustment for other occupational risk factors. Preventive efforts should be intensified towards reducing these psychosocial work exposures.     

A review of studies on maternal occupational exposures and birth defects, and the limitations associated with these studies.

The proportion of pregnant women who work during pregnancy is increasing as more women move into previously male-dominated occupations. With this move, occupational exposure to chemical or physical factors during pregnancy could be further increased. In the last decade, there have been many reports on the causes of birth defects. Unfortunately, most reported associations between occupational exposures and adverse reproductive outcomes in epidemiological studies are equivocal and often controversial. Many reported associations are only suggestive. More information is needed before firm conclusions can be drawn. The major reasons for ambiguous findings are due to limitations of study methodology, e.g. inappropriate endpoints, multiple confounders, low study power and inadequate analysis methods. It must also be noted that maternal work, and therefore exposure, may also differ greatly from country to country.     

Occupational exposures to metals, solvents and pesticides: recent evidence on male reproductive effects and biological markers

This review is based primarily on the recent epidemiological studies conducted in occupational settings in order to explore the relationship between exposures to chemical agents and the possible effects on male reproductive function. The paper examines evidence of the effects of metals, solvents, pesticides and dioxin. The effects considered are primarily the possible alterations of sperm quality and reduction of fertility. Many studies have identified small groups of workers with exposures to these agents, presenting some alteration in the spermatological or fertility profile, but the results are difficult to replicate in other settings with different individuals and different levels of exposure. From examination of the concentrations of environmental and occupational pollutants in the blood and in the seminal fluid of exposed individuals, it appears that, in general, the concentrations are much lower in the seminal fluid and in sperm cells, making this a less useful marker of exposure.     

Parental occupational exposures and risk of childhood cancer: a review

We reviewed the literature in order to summarize the present knowledge on the association between parental occupational exposures to chemicals and the risk of childhood malignancy. The 32 studies pertaining to this topic were evaluated by considering various study qualities such as sample size, specificity of outcome, confounding, exposure specificity, and control selection. When evaluating the findings from any epidemiologic study, the potential sources of bias have to be considered. The selection of subjects, misclassification of exposure or outcome, and confounding from extraneous factors can contribute to a biased estimate of effect. Studies done to minimize these potential biases will be more valid, and these studies should be given the most weight when parental occupational exposures are evaluated as risk factors for childhood malignancy. We conclude that the preponderance of evidence supports the hypothesis that occupational exposure of parents to chemicals increases the risk of childhood malignancy. The parental occupational exposures implicated in childhood malignancy risk are exposure to chemicals including paints, petroleum products, solvents (especially chlorinated hydrocarbons) and pesticides, and exposure to metals. The available data do not allow the identification of specific etiologic agents within these categories of compounds. Future epidemiologic and toxicologic studies should be designed to pursue these leads.     

The influence of occupational exposure on male reproductive function

Recently, many studies have found a decrease in semen quality which has increased the focus on male reproductive health. Occupational hazards are by far the best documented in reproductive epidemiological research. Generally, occupational exposures have been divided into physical exposures (heat and radiation), chemical exposures (solvents and pesticides), psychological exposures (distress), exposure to metals and welding. The recent and/or most important epidemiological studies exploring the effect of occupational exposures on semen quality and fecundity, the ability to conceive, are reviewed. The evidence for an adverse effect on male reproduction of several occupational and environmental exposures and toxicants, such as heat, ionizing radiation, inorganic lead, dibromochloropropane, ethylene dibromide, some ethylene glycol ethers, carbon disulfide and welding operations, is strongly supported in well-designed epidemiological studies. For other agents, the association is only suspected or suggested and needs further evaluation before conclusions can be drawn. It is also important to bear in mind that many workers in the non-Western world still are exposed to substances that are banned in the Western world, sometimes in high concentrations.     

Occupational factors associated with low back pain in urban taxi drivers

BACKGROUND: Urban taxi drivers differ from other professional drivers in their exposures to physical and psychosocial hazards in the work environment. Epidemiological data on low back pain (LBP) of this occupational group are very scarce. AIMS: To examine LBP in taxi drivers and its association with prolonged driving and other occupational factors. METHODS: We analyzed the cross-sectional data from the Taxi Drivers' Health Study. Standardized instruments were used to collect information on personal factors, work-related physical and psychosocial factors and driving time profiles. LBP prevalence was assessed using the modified Nordic Musculoskeletal Questionnaire. Multiple logistic regression models were employed for statistical analyses. RESULTS: Of 1242 drivers, 51% reported LBP in the past 12 months, significantly (P < 0.001) higher than other professional drivers (33%) in Taiwan. After adjusting for the effects of demographic characteristics, lifestyle factors, anthropometric measures and socioeconomic positions, we found that driving time >4 h/day [prevalence odds ratio (POR) 1.78; 95% CI 1.02-3.10], frequent bending/twisting activities while driving (adjusted OR 1.86; 95% CI 1.15-2.99), self-perceived job stress (POR 1.75; 95% CI 1.20-2.55), job dissatisfaction (POR 1.44; 95% CI 1.05-1.98) and registration type were the major occupational factors significantly associated with higher LBP prevalence in taxi drivers. CONCLUSIONS: We have identified that long driving time and several physical and psychosocial factors are associated with high prevalence of LBP in taxi drivers. This should be further investigated in prospective studies. Future studies are needed to examine the potential adverse effects of prolonged exposure to low levels of whole-body vibration.     

Occupational toxicology and the control of exposure to pharmaceutical agents at work

BACKGROUND: The pharmaceutical industry employs >350 000 people worldwide in operations including research and development (R&D), manufacturing, sales and marketing. Workers employed in R&D and manufacturing sectors are potentially exposed to drug substances in the workplace that are designed to modify physiology and also to chemical precursors that are potentially hazardous to health. Pharmaceutical workers are at risk from adverse health effects, including occupational asthma, pharmacological effects, adverse reproductive outcomes and dermatitis. AIM: This study aimed to describe the approaches taken by pharmaceutical companies for identifying and communicating potential adverse health effects that may result from workplace exposures and in setting 'in-house' exposure control limits and to highlight the challenges in controlling workplace exposures to increasingly potent compounds. METHOD: The literature was reviewed by searching the Medline and HSELine databases. RESULTS: The findings are presented in five sections, covering: test methods and approaches to occupational toxicology; hazard communication; approaches to setting health-based occupational exposure limits for pharmaceutically active agents; recent approaches to risk control; and occupational hygiene and exposure controls. CONCLUSION: Significant efforts have been directed at predicting and evaluating potential occupational health hazards in the pharmaceutical industry. The pharmaceutical industry has provided leadership in controlling exposure to hazardous substances. Much of this work has been driven by a real need to control occupational exposures to substances that can have profound adverse health effects in exposed employees and that are becoming increasingly more potent.     

Occupational exposure to ionizing and non-ionizing radiation and risk of glioma

BACKGROUND: Although the aetiology of glioma is poorly understood, the higher incidence in males has long suggested an occupational cause. AIM: To investigate possible associations between occupational exposure to ionizing, ultraviolet (UV), radiofrequency (RF) and extremely low frequency (ELF) radiation and adult glioma risk. METHODS: Case-control study using histologically confirmed cases of glioma first diagnosed between 1987 and 1991 in Melbourne, Australia, matched by age, sex and postcode of residence. A detailed occupational history was obtained for each subject. Exposure to radiation was assessed using a Finnish job exposure matrix (FINJEM) for all the radiation types as well as self-reports and expert hygienist review for RF and ionizing radiation. For ELF and UV, gender-specific FINJEM analysis was performed. RESULTS: The study population consisted of 416 cases of glioma and 422 controls. The risk estimates given by FINJEM for ELF, RF and ionizing radiation were close to or below unity. Gender-specific analysis for UV showed odds ratios of 1.60 [95% confidence interval (CI) 0.95-2.69] and 0.54 (95% CI 0.27-1.07) for the highest exposed group of men and women, respectively (corresponding P value for trend was 0.03 and 0.04). CONCLUSIONS: We did not find evidence of an association between glioma and occupational exposure to ELF, RF and ionizing radiation. UV radiation was associated with increased glioma risk for men but this result could have been confounded by other predominantly male occupational and lifestyle exposures associated with high UV. Further investigation of UV radiation and glioma risk is suggested.     

Compensating occupationally related tenosynovitis and epicondylitis: a literature review

OBJECTIVES: To assess occupational associations with tenosynovitis and epicondylitis, we conducted a systematic literature review. We focused particularly on evidence that might support compensation of these disorders 'on the balance of probabilities'. METHODS: We searched the MEDLINE and EMBASE electronic biomedical databases to 1 January 2005 using combinations of keyword and medical subject headings, and also the references cited in two state-of-the-art reviews from the 1990s. Primary research reports were retrieved and checked for further relevant citations. From each paper, we abstracted a standardized set of information on study populations, exposure contrasts and estimates of effect. RESULTS: We found and summarized 18 papers. In the main, these based analysis on job titles rather than on directly assessed physical activities. Few occupations were studied more than once, however, and there was little consistent evidence of jobs or work activities that carried more than a doubling of risk for either disorder. CONCLUSION: Compensation of occupational illness can be problematic for disorders that are not specific to work and for which there are no distinctive clinical features in occupationally related cases. Attribution can, however, be made on the balance of probabilities if there is convincing evidence that risk is at least doubled in an occupational group. Our review highlights the relative lack of data to support such attribution for tenosynovitis and epicondylitis, and discusses the difficulty of compensating upper limb disorders.     

Occupational groups at risk of voice disorders: a review of the literature

BACKGROUND: Occupational voice health is becoming more important as more people rely on their voices for their work. A number of studies have identified certain occupational groups at increased risk of developing occupational voice disorders, namely teachers, singers and aerobics instructors. Aim The paper aims to review the literature on occupational groups at risk of voice disorders and identify areas for future research. METHOD: A literature review of key databases using key words such as 'occupational', 'voice health', 'voice loss', 'dysphonia' and 'work related' was undertaken. RESULTS: The review identified case reports, studies of attendees at hospital voice clinics and a few cross-sectional studies of occupational groups in the workplace. There were no longitudinal studies found or intervention studies looking at reduction of risk. CONCLUSION: Further research on occupational voice disorders needs to be based in the workplace, and to look at the risk factors for the development of voice problems and for the efficacy of controls.     

Occupational exposures and the risk of ovarian cancer in Sweden

BACKGROUND: Studies of occupational exposures and ovarian cancer, often limited by few subjects or proportionate mortality data, have yielded inconsistent results. METHODS: Swedish women employed in 1960, 1970, or during both years were followed from 1971 to 1989 using census data linked to nationwide cancer and death registries. A total of 9,591 ovarian cancer cases were identified among 1,670,517 women. Poisson regression was used to estimate the relative risk of ovarian cancer in specific occupational groups and in women exposed to particular occupational exposures defined by job exposure matrices. We lacked data on reproductive factors. RESULTS: Jobs associated with elevated ovarian cancer rates in this and previous studies include dry cleaning, telegraph and telephone work, paper packaging, and graphic and printing work. In contrast to results of some previous studies, we found that hairdressers and beauticians were not at increased risk of ovarian cancer. Organic dusts, aromatic amines, aliphatic and aromatic hydrocarbons are suggested as specific etiologic agents. CONCLUSIONS: In this large study, we have confirmed some results from smaller studies and identified some new relationships that need to be confirmed elsewhere.     

Reducing occupational exposure to chemical carcinogens

Strategies for controlling occupational exposure to chemicalcarcinogens are set out in the European Union Carcinogens Directiveand in national legislation such as the British Control of SubstancesHazardous to Health Regulations. While such legislative requirementsmust apply to all occupational chemical carcinogens, it is arguedthat priority should be given to controlling those agents thatcontribute most to the cancer burden. Examples of possible strategiesto reduce exposure to two agents (diesel exhaust particulateand paint emissions) are discussed. It is concluded that thereare no real technical difficulties in controlling exposuresto chemical carcinogens; however, for many of the key agents,we need to change attitudes to the potential risks and clearlydemonstrate to employers and employees how to reduce the exposures.     

Environmental pollutants and breast cancer

Breast cancer is the most common cancer in women and the leading cause of cancer death among women 35-54 years of age. Rising incidence, increased risk among migrants to higher risk regions, and poor prediction of individual risk have prompted a search for additional modifiable factors. Risk factors for breast cancer include reproductive characteristics associated with estrogen and other hormones, pharmaceutical hormones, and activities such as alcohol use and lack of exercise that affect hormone levels. As a result, investigation of hormonally active compounds in commercial products and pollution is a priority. Compounds that cause mammary tumors in animals are additional priorities. Animal models provide insight into possible mechanisms for effects of environmental pollutants on breast cancer and identify chemical exposures to target in epidemiologic studies. Although few epidemiologic studies have been conducted for chemical exposures, occupational studies show associations between breast cancer and exposure to certain organic solvents and polycyclic aromatic hydrocarbons (PAHs). Population-based studies have been limited to a few organochlorine compounds and PAHs and have been mostly negative. A variety of challenges in studies of breast cancer and the environment may have contributed to negative findings. Lack of exposure assessment tools and few hypothesis-generating toxicologic studies limit the scope of epidemiologic studies. Issues of timing with respect to latency and periods of breast vulnerability, and individual differences in susceptibility pose other challenges. Substantial work is needed in exposure assessment, toxicology, and susceptibility before we can expect a pay-off from large epidemiologic studies of breast cancer and environment.     

Lung cancer mortality at a UK tin smelter

BACKGROUND: An earlier study of mortality among male former employees at a tin smelter in Humberside, UK, had identified excess mortality from lung cancer, which appeared to be associated with occupational exposure. AIMS: The aim of the present study was to investigate the relationship between lung cancer mortality and quantitative measures of exposure. METHODS: Using available records of occupational hygiene measurements, we established exposure matrices for arsenic, cadmium, lead, antimony and polonium-210 ((210)Po), covering the main process areas of the smelter. We established work histories from personnel record cards for the previously defined cohort of 1462 male employees. Three different methods of extrapolation were used to assess exposures prior to 1972, when no measurement results were available. Lung cancer mortality was examined in relation to cumulative inhalation exposure by Poisson regression analysis. RESULTS: No significant associations could be found between lung cancer mortality and simple cumulative exposure to any of the substances studied. When cumulative exposures were weighted according to time since exposure and attained age, significant associations were found between lung cancer mortality and exposures to arsenic, lead and antimony. CONCLUSIONS: The excess of lung cancer mortality in the cohort can most plausibly be explained if arsenic is the principal occupational carcinogen (for which the excess relative risk diminishes with time since exposure and attained age) and if there is a contribution to excess mortality from an enhanced prevalence of smoking within the cohort. The implications of the dose-response for arsenic exposure for risk estimation merit further consideration.     

Estimating the relative risk of pancreatic cancer associated with exposure agents in job title data in a hierarchical Bayesian meta-analysis

OBJECTIVES: The study demonstrates the application of a hierarchical Bayesian meta-analysis of epidemiologic studies that show an association between pancreatic cancer risk and job titles, using a job-exposure matrix to estimate risks for occupational exposure agents. METHODS: Altogether 261 studies published from 1969 through 1998 on pancreatic cancer and job titles were identified. When proportional studies are excluded, 77 studies were informative for 9 selected occupational agents. These studies included more than 3799 observed pancreatic cancer cases. Hierarchical Bayesian models were used for job titles (lower-level data) and agents (higher-level data), the latter from a Finnish job-exposure matrix. Non-Bayesian random effects models were applied for job titles to check consistency with the Bayesian results. RESULTS: The results suggest that occupational exposures to chlorinated hydrocarbon compounds may increase the risk of pancreatic cancer; the meta-relative risk (MRR) was 2.21 [95% credible interval (CrI) 1.31-3.68]. A suggestive weak excess was found for exposure to insecticides (MRR 1.95, 95% CrI 0.51-7.41). CONCLUSIONS: Hierarchical models are applicable in meta-analyses when studies addressing the agent(s) under study are lacking or are very few, but several studies address job titles with potential exposure to these agents. Hierarchical meta-analytic models involving durations and intensities of exposure to occupational agents from a job-exposure matrix should be developed.     

Assessment of methods and results of reproductive occupational epidemiology: spontaneous abortions and malformations in the offspring of working women

Epidemiological studies relating occupational exposures of working women to spontaneous abortions and malformation are reviewed and some methodological considerations are presented. The reproductive epidemiology is less developed than epidemiology in general and seems to involve some specific problems. The ascertainment of exposure and of outcome may be problematic. The exposures may be reported differently by the women depending on the outcome of the pregnancy; thus confirmation of exposure from an independent data source would be an asset. The recognition of spontaneous abortions by women is variable and this should be considered in the study design. An access to medical records could provide objective data on the outcome, but it may introduce other types of asymmetries. The types of occupational exposures of the women, suggested to carry a risk of spontaneous abortions, include anesthetic agents, laboratory work, copper smelting, soldering, and chemical sterilization using ethylene oxide and glutaraldehyde. Maternal employment in laboratories and exposure to solvents has been linked to a risk of congenital malformations in the offspring in five studies. Data on the teratogenic effects of anesthetic gases has been conflicting. In one study, employment in copper smelting was associated with malformations in the offspring.     

Ergonomic methods for assessing exposure to risk factors for work-related musculoskeletal disorders

BACKGROUND: This review provides an overview of the range of methods that have been developed for the assessment of exposure to risk factors for work-related musculoskeletal disorders. METHODS: Relevant publications and material on exposure assessment techniques have been gathered for inclusion in this review. RESULTS: The methods have been categorized under three main headings: (1) self-reports from workers can be used to collect data on workplace exposure to both physical and psychosocial factors by using methods that include worker diaries, interviews and questionnaires; (2) observational methods that may be further subdivided between (a) simpler techniques developed for systematically recording workplace exposure that enable an observer to assess and record data on a number of factors using specifically designed pro-forma sheets for establishing priorities for workplace intervention; and (b) advanced techniques developed for the assessment of postural variation for highly dynamic activities that record data either on videotape or are computer analysed using dedicated software; (3) direct measurements using monitoring instruments that rely on sensors attached directly to the subject for the measurement of exposure variables at work. CONCLUSIONS: The choice between the methods available will depend upon the application concerned and the objectives of the study. General, observation-based assessments appear to provide the levels of costs, capacity, versatility, generality and exactness best matched to the needs of occupational safety and health practitioners (or those from related professions) who have limited time and resources at their disposal and need a basis for establishing priorities for intervention.     

Musculoskeletal disorders in farmers and farm workers

Farming is a physically arduous occupation and this places farm workers at potential risk of musculoskeletal disorders such as osteoarthritis (OA) of the hip and knee, low back pain (LBP), neck and upper limb complaints, and hand-arm vibration syndrome (HAVS). This review considers the epidemiological evidence concerning such risks. The strongest evidence relates to OA of the hip, for which the public health impact is likely to be considerable. There is also weaker, but suggestive evidence that farmers more often have knee OA and LBP than workers in occupations with fewer physical demands. Tractor drivers, in particular, seem to have more LBP. Relatively little information exists on the risks of soft tissue rheumatism in the limbs and neck. For some outcomes, the link with occupational risk factors (such as heavy loading of joints and whole-body vibration) is sufficient to suggest the course that future prevention should take, but for several outcomes more research is first needed.     

Occupational respiratory disease in mining

This review is based on research-based literature on occupational lung disease in the mining and related industries, focusing on conditions of public health importance arising from asbestos, coal and silica exposure. Both 'traditional' and 'new' concerns about occupational respiratory disease in miners are addressed, with the inclusion of practical evidence-based findings relevant to practitioners working in developed and developing countries. Mining is not a homogeneous industry since current miners work in formal and informal operations with numerous, and often multiple, air-borne exposures. A further occupational health challenge facing primary care practitioners are ex-miners presenting with disease only after long latency. The sequelae of silica exposure remain an occupational health priority, particularly for practitioners who serve populations with concomitant HIV and tuberculosis infection and even when exposure is apparently below the statutory occupational exposure level. Coal workers' pneumoconiosis, asbestos related diseases, lung cancer and other occupational respiratory diseases remain of considerable importance even after mining operations cease. While mining exposures contribute significantly to lung disease, smoking is a major factor in the development of lung cancer and chronic obstructive airways disease necessitating a comprehensive approach for prevention and control of mining-related occupational lung disease.