Respiratory illness in agricultural workers

Respiratory diseases have long been recognized in association with work in farming. Overall, only a small proportion of the population is employed in agriculture, so respiratory disease in farmers is not a major public health issue. However, farmers are known to have high morbidity and mortality from certain respiratory diseases, as shown by routinely collected statistics. Despite this, knowledge of the frequency, nature and risk factors for some respiratory disorders in agricultural workers is incomplete. Multiple exposures are common and some exposures can give rise to more than one specific disease. Moreover, the most common respiratory symptoms reported by farm workers (wheeze, dyspnoea and cough) are relatively non-specific and can be associated with several occupational respiratory disorders. This review describes the main occupational respiratory illnesses in farming and summarizes the current literature about epidemiology and prevention. The most important diseases are rhinitis and asthma, which, although common, are not usually fatal. Some non-allergic conditions, e.g. asthma-like syndrome and organic toxic dust syndrome, are not yet fully understood, but appear to be common among farm workers. The most serious respiratory diseases are hypersensitivity pneumonitis and respiratory infections, but these are rare. Most importantly, respiratory diseases are preventable by controlling harmful exposures to organic dust, toxic gases and chemicals on farms through improvements in animal rearing techniques, ventilation of animal accommodation, careful drying and storage of animal feed-stuffs, crops and other products, and use of personal protective equipment.     

队列研究中对照组的选择问题

职业流行病学调查时，对照组是非常重要的，因为使用不同折对照组将得到不同的结果。为了选择一个较好的有可比性的对照组，本文调查了某煤矿工人死亡率，调查对象共２５８９例生矿工，追踪２１年（１９７２年１月１日￣１９９２年１２月３１日），采用５个对照组，即内对照、工厂组、３个居民组（当地、某城区和全国）进行分析，探讨队列研究中如何选择恰当对照，使其结果更能反映客观事实。结果表明：不同对照其结果不同。分析了各     

Increased risk of asthma among Finnish construction workers

AIM: To determine the risk of asthma among 7891 Finnish construction workers in the Pirkanmaa Region of southern Finland. METHOD: Retrospective cohort study of hospital records of the Tampere University Hospital. A population of Pirkanmaa paper mill workers (n=2686) and the Pirkanmaa working age population (n=252,500) served as reference populations. RESULTS: There were 147 new cases of asthma among the construction workers in 1991-1995. The annual rate was 37 per 10,000 workers and the odds ratio was 2.1 [95% confidence interval (CI)=1.2-3.6] for the women and 1.8 (95% CI=1.5-2.2) for the men when compared with the general working age population. In general, the risk of asthma among the paper mill workers did not differ from the risk of asthma among the general working age population. The construction workers had an increased risk for asthma, although the number of reported cases of occupational asthma was lower for the construction workers than for the paper mill workers or for the working population. CONCLUSION: Construction work, especially dusty tasks, was associated with an elevated risk of asthma. Thus the effect of exposure to irritant agents may have a role in the development of asthma among construction workers. For the most part, these cases of asthma do not meet the criteria for occupational asthma because the specified causal agent can not be defined. The aetiologic agents and mechanisms of asthma in construction work should be clarified for preventive measures.     

Lead toxicity

Lead is one of the oldest known and most widely studied occupational and environmental toxins. Despite intensive study, there is still vigorous debate about the toxic effects of lead, both from low-level exposure in the general population owing to environmental pollution and historic use of lead in paint and plumbing and from exposure in the occupational setting. The majority of industries historically associated with high lead exposure have made dramatic advances in their control of occupational exposure. However, cases of unacceptably high exposure and even of frank lead poisoning are still seen, predominantly in the demolition and tank cleaning industries. Nevertheless, in most industries blood lead levels have declined below levels at which signs or symptoms are seen and the current focus of attention is on the subclinical effects of exposure. The significance of some of these effects for the overt health of the workers is often the subject of debate. Inevitably there is pressure to reduce lead exposure in the general population and in working environments, but any legislation must be based on a genuine scientific evaluation of the available evidence.     

Occupational exposure and health problems in small-scale industry workers in Dar es Salaam, Tanzania: a situation analysis

BACKGROUND: Workers in informal small-scale industries (SSI) in developing countries involved in welding, spray painting, woodwork and metalwork are exposed to various hazards with consequent risk to health. Aim To assess occupational exposure and health problems in SSI in Dar es Salaam, Tanzania. METHODS: Focused group discussions (FGD) were conducted among SSI workers. Participants were assessed for exposure to occupational and environmental hazards, the use of protective equipment and health complaints by interview. The findings were discussed with participants and potential interventions identified. RESULTS: Three hundred and ten workers were interviewed (response rate 98%). There was a high level (>90%) of self-reported exposure to either dust, fumes, noise or sunlight in certain occupational groups. There was low reported use of personal protective equipment. There was a high level of self-reported occupational health problems, particularly amongst welders and metalworkers. Workers reported their needs as permanent workplaces, information on work related hazards, water and sanitation, and legislation for SSI. CONCLUSIONS: In SSI in Tanzania, our study suggests that workers have high levels of exposure to multiple health hazards and that use of protective equipment is poor. This group of workers warrants improved occupational health and safety provision.     

Characteristics of the healthy worker effect

The healthy worker effect (HWE), which can mask mortality excesses resulting from occupational exposures, poses a methodological problem for those who study occupational cohorts. This problem is further complicated by the fact that the strength of the HWE may vary from one occupational cohort to another. Understanding the HWE is particularly important for investigators of nuclear worker cohorts, because screening associated with the security clearance process may amplify the HWE among certain subpopulations of nuclear workers. This review suggests that the HWE is modified by a number of factors, including gender, race, age at hire, occupational class, length of employment, monitored status, length of follow-up, and cause of death. In general, these factors operate similarly in nuclear and other occupational cohorts. Given that many of these factors may be highly correlated with exposure, or proxy measurements for exposure, it is important for investigators to understand how these factors relate independently with mortality. Continuing to document the HWE and its changes over time is essential to the proper interpretation of exposure effects in occupational cohorts in general, and in nuclear cohorts in particular.     

The scale of perceived occupational stress

This article reviews previous research on the scale of occupational stress and describes in detail the Bristol Stress and Health at Work study. This study had three main aims: firstly, to determine the scale and severity of occupational stress in a random population sample; secondly, to distinguish the effects of stress at work from those of stress in general life; and finally, to determine whether objective indicators of health status and performance efficiency were related to perceived occupational stress. These aims were investigated by conducting an epidemiological survey of 17,000 randomly selected people from the Bristol electoral register, a follow-up survey 12 months later, and detailed investigation of a cohort from the original sample. The results revealed that approximately 20% of the sample reported that they had very high or extremely high levels of stress at work. This effect was reliable over time, related to potentially stressful working conditions and associated with impaired physical and mental health. The effects of occupational stress could not be attributed to life stress or negative affectivity. The cohort study also suggested that high levels of occupational stress may influence physiology and mental performance. The prevalence rate obtained in this study suggests that 5 million workers in the UK have very high levels of occupational stress.     

Occupational health in general practice in an industrial area of Singapore

The aim of this study was to estimate the caseload with regard to the proportion of work-related medical cases in factory workers and to survey knowledge of and attitudes to occupational medicine among doctors in an industrial area in Singapore. To this end, a self-administered questionnaire was given to 74 general practitioners in the industrial district of Jurong in Singapore. Overall, there was an 89.2% response rate. Thirty-three of the 66 respondents were males. Mean age was 40.8 years (range 27-64 years). Twenty-four (36%) had some postgraduate training in occupational medicine (GP-OM) while the rest did not (GP). The caseload for all doctors was similar with regard to the number of adult patients and, more specifically, the number of factory workers seen per day. The majority of doctors (76.6%) felt that <10% of factory workers seen had work-related problems. Most (70%) felt confident in dealing with the occupational problems that arose. However, a large percentage (78% of GPs, 45.8% of GP-OMs) felt that training in occupational medicine was inadequate. This is reflected in the knowledge questions, where GPs did not score as well as GP-OMs. It was concluded that GPs working in this industrial area see a good proportion of factory workers, in a fair number of cases for work-related problems. However, only a third of the GPs are qualified in occupational medicine. These factors highlight the need for more emphasis on occupational medicine training among general practitioners, especially those working in industrial areas.     

Occupational dental erosion from exposure to acids: a review

Objective Dental erosion is characterized as a disorder witha multifactorial aetiology including environmental acid exposure.The purpose of this article was to summarize and discuss theavailable information concerning occupational dental erosion. Methods Information from original scientific papers, case reportsand reviews with additional case reports listed in PubMed, Medlineor EMBASE [search term: (dental OR enamel OR dentin) AND (erosionOR tooth wear) AND (occupational OR worker)] were included inthe review. References from the identified publications weremanually searched to identify additional relevant articles. Results The systematic search resulted in 59 papers, of which42 were suitable for the present review. Seventeen papers demonstratedevidence that battery, galvanizing and associated workers exposedto sulphuric or hydrochloric acid were at higher risk of dentalerosion. For other industrial workers, wine tasters and competitiveswimmers, only a few clinical studies exist and these do notallow the drawing of definitive conclusions. Conclusion Occupational acid exposure might increase the riskof dental erosion. Evidence for occupational dental erosionis limited to battery and galvanizing workers, while data forother occupational groups need to be confirmed by further studies.     

Solar ultraviolet radiation and skin cancer

Background Incidence rates of skin cancer, both non-melanomaskin cancer and (malignant/cutaneous) melanoma, are rising inGreat Britain. It is widely accepted that solar ultravioletradiation (UVR) is the main causal factor for these neoplasms.Many people are occupationally exposed to solar UVR, includingfarmers, construction workers and some public service workers. Aim The aim of this article is to review the key epidemiologicpapers on occupational solar exposure and skin cancer and discussthe relationships found. Method A literature search was conducted using online databasesand article bibliographies. A full review of all available studieswas not carried out, as only key studies on occupational exposurewere required. Results There is a clear association between solar radiationand skin cancer. The mechanisms for induction vary between thetypes of skin cancer and these cannot be solely attributed tooccupational exposures. Conclusions There is great difficulty in separating the effectsof occupational and recreational solar UVR exposure; therefore,any results discussed in this review should be interpreted withcaution. However, it is clear that solar UVR exposure does induceskin cancer and protective measures should be taken in an attemptto reduce the burden of occupational skin cancer in Great Britain.     

Hepatitis C virus: an important occupational hazard?

Infection with Hepatitis C virus (HCV) is estimated to affect 3% of the world's population and is an important cause of liver disease. It is most commonly transmitted by percutaneous exposure. Although current evidence does not suggest an increased prevalence of HCV infection among healthcare workers, transmission of infection following occupational exposure has been demonstrated. An average transmission rate of 1.8%, following percutaneous injury, has been reported. The risk of transmission is higher from patients with viraemia, as measured by a positive polymerase chain reaction for HCV RNA. After exposure to HCV, healthcare workers should be actively followed up, initially using a test to detect viral RNA. This may facilitate earlier diagnosis and treatment. Recent reports in the UK, of transmission of infection to patients from HCV infected healthcare workers, have prompted a review of the appropriateness of HCV infected individuals undertaking exposure prone procedures.     

Occupational health services in the UK--challenges and opportunities

BACKGROUND: A small minority of the UK workforce currently has access to an occupational physician. Reduction in the size of enterprises, the emergence of atypical work patterns and problems recruiting and training occupational health specialists risk making this minority even smaller. AIM: This paper considers the challenges currently facing occupational medicine and how we can improve access to occupational health services (OHS). It aims to highlight some of the diverse internal and external factors that restrict the UK's ability to provide all workers access to OHS. METHOD: A literature review was carried out and combined with awareness of current trends in business and new legislation together with provision of occupational medicine in other countries. RESULTS: Potentially controversial solutions that might help to make OHS more widely accessible were identified and are discussed. It is hoped that these will provoke further debate. CONCLUSION: Individually and organizationally, we must examine and improve capabilities if we are to improve worker access to OHS and deliver targets to reduce occupational ill-health. It is suggested that this requires a strategic shift to apply resources differently. There is need to explore delegation of tasks traditionally performed by doctors to nurses and other staff together with the outsourcing of non-core work. The increased use of telemedicine and the enhanced use of information technology for training, risk assessments, wellness programmes and questionnaire-based health assessments are other developments that should be explored.     

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.     

Prevention of occupational asthma--practical implications for occupational physicians

BACKGROUND: Occupational factors have been estimated to contribute to approximately 10% of adult-onset asthma and occupational asthma (OA) is one of the most common occupational lung diseases in industrialized areas. Persistent asthma frequently occurs with significant socio-economic impacts. METHODS: A literature search was performed using PubMed. The key term searched was occupational asthma combined with prevention. RESULTS: Primary prevention has been effective for OA related to natural rubber latex, and may have reduced the incidence of diisocyanate-induced asthma. Medical health surveillance has been effective in settings such as the detergent enzyme industry, workers exposed to complex platinum salts and likely for diisocyanate workers in Ontario. Tertiary prevention is still required for workers with OA and can improve prognosis. CONCLUSIONS: OA is potentially preventable. Sufficient studies have demonstrated the rationale and benefit of primary preventive strategies. Medical health surveillance programs combined with occupational hygiene measures and worker education have been associated with improved outcomes but further studies are needed to understand the optimum frequency and measures for such programs and to identify the separate contribution of the components. Until primary and secondary prevention is better understood and implemented, there will also remain a need for tertiary preventive measures.     

Occupational health in the Andalusian Fisheries Sector

BACKGROUND: The conditions of work in the fisheries sector are arduous with high rates of occupational accidents. Numerous factors are known that can directly influence the health of the sailor or fisherman both in fishing and merchant fleets. AIM: To evaluate the health status, safety and working conditions in the Andalusian fishing sector. METHODS: Cross-sectional questionnaire study with proportional sampling of the health and lifestyles of fishery workers in 19 of the 23 Andalusian ports. RESULTS: A total of 247 workers employed on 202 craft fishing boats responded. In all 87% of workers reported a current medical condition. The main problems reported were musculoskeletal disorders, respiratory diseases, diseases of the digestive system, eye problems and skin problems. A total of 72% reported taking some self-prescribed medication, and 60% of fishery workers smoked. Nine per cent of fishery workers admitted taking illicit drugs and 3% reported using illicit drugs on board. Diets on board were poorly balanced. While on board, 62% of crews reported a subjective significant worsening of previous health. The lifetime prevalence of accidents was 76%. CONCLUSIONS: Fishery workers had a high prevalence of self-reported medical problems, a high prevalence of self-medication, poor diets and frequently smoked. Self-medication and some medical conditions (diabetes, angina and depression) may reflect a potential failing of health checks and pre-employment checks. National health services and insurance companies dealing with occupational health should focus more on appropriate health checks, illness prevention and health promotion activities for this population.     

Hand-arm vibration syndrome in South African gold miners

BACKGROUND: Hand-arm vibration syndrome (HAVS) is associated with the use of hand-held vibrating tools. Affected workers may experience symptoms of tingling, numbness, loss of grip strength and pain. Loss of dexterity may impair everyday activities, and potentially increase the risk of occupational accidents. Although high vibration levels (up to 31 m/s(2)) have been measured in association with rock drills, HAVS has not been scientifically evaluated in the South African mining industry. AIMS: The aim of this study was to determine the prevalence and severity of HAVS in South African gold miners, and to identify the tools responsible. METHODS: A cross-sectional study was conducted in a single South African gold-mine. Participants were randomly selected from mineworkers returning from annual leave, comprising 156 subjects with occupational exposure to vibration, and 140 workers with no exposure. Miners who consented to participate underwent a clinical HAVS assessment following the UK Health and Safety Laboratory protocol. RESULTS: The prevalence of HAVS in vibration-exposed gold miners was 15%, with a mean latent period of 5.6 years. Among the non-exposed comparison group, 5% had signs and symptoms indistinguishable from HAVS. This difference was statistically significant (P < 0.05). All the cases of HAVS gave a history of exposure to rock drills. CONCLUSIONS: The study has diagnosed the first cases of HAVS in the South African mining industry. The prevalence of HAVS was lower than expected, and possible explanations for this may include a survivor population, and lack of vascular symptom reporting due to warm-ambient temperatures.     

An evaluation of occupational health services within the NHS in London

AIMS: To establish the nature, extent and organization of occupational health service provision for employees within the National Health Service (NHS) in London and to review the systems for monitoring performance. METHODS: Human resources directors and occupational health managers were contacted from a random selection of NHS trusts in the London area and invited to complete an interviewer-led questionnaire. RESULTS: All seventeen trusts interviewed claimed to provide an occupational health service to their employees, with 88% providing this service in-house. The organization of the services varied, although most resided within the human resources function. Only 29% of the trusts could provide a written occupational health policy. Teaching hospital trusts had the most qualified and the highest numbers of medical staff. District/General hospital trusts had the least qualified clinical staff. Although most trusts were able to provide a comprehensive range of services, 87% of occupational health managers felt they could only provide a reactive service. Income was generated from non-NHS sources by 88% of the trusts and all were aware of NHS Plus. There was an indication that some trusts assigned NHS Plus status did not meet the standard of NHS Plus, although the survey took place only 3 months after the launch of NHS Plus. CONCLUSIONS: There was a significant variation in the nature and extent of occupational health services in the NHS trusts. As a consequence, there may be differences in the level of occupational health service available to staff across the NHS in London.     

Occupational asthma prevention and management in industry--an example of a global programme

Isocyanates are widely used in the manufacture of polyurethane foams, plastics, coatings and adhesives, and are known to cause occupational asthma in a proportion of exposed workers. Substitution as a prevention strategy is not currently a feasible option. For this reason, health and safety professionals working together in an automotive coatings business created a proactive global programme to address the known potential effects of isocyanates on its workers. The goals of the programme are prevention, early detection and mitigation of effect of key endpoints, especially asthma and to a lesser degree dermatitis, in people who are occupationally exposed, or potentially exposed, to isocyanates and products containing isocyanates. The surveillance programme for isocyanates has several important components, which include assessment of exposure, pre-placement questionnaire and spirometry, training and education of employees, regularly administered periodic questionnaires, medical assessment for abnormal questionnaire responses, process for early reporting and investigation of symptomatic employees and incidents, group data review and management reporting. Although regional differences exist regarding availability of specialized services, we have successfully implemented this programme in parts of North America, Europe and Latin America, and are currently implementing elsewhere. These simple control measures are relatively inexpensive and can be applied in even small business settings. It is recommended that all employers who manufacture, handle or use isocyanate-containing products consider such a strategy.     

Occupational electrocutions in Jefferson County, Alabama

Few studies have presented the general epidemiology of electrocution deaths using local medical examiner data. Data were obtained from coroner/medical examiner's files for electrocution deaths occurring between 1981 and 1998. All 27 occupational electrocutions were among men; 92.6% were white and 7.4% were black, with a mean age of 33.1 years. The rates of high- and low-voltage electrocution were similar. Low-voltage deaths showed a seasonal pattern, with the largest numbers in July, August and October. Deaths occurred most frequently among electricians and electrical helpers. The level of detail available from medical examiner records permits more complete evaluation of injury patterns than is possible using death certificate data; however, even more detailed studies, exploring worker activity at the time of injury, education, experience and training, are needed.     

Frequent musculoskeletal symptoms and reduced health-related quality of life among industrial workers

The high percentage of musculoskeletal symptoms (MSS) found in studies of general populations and various occupational groups underlines the need to distinguish between severely and mildly affected individuals. To investigate associations between MSS and quality of life, we examined the frequency of MSS on a five-point scale, health-related quality of life (SF-36) and sickness absence among 5654 workers in the aluminium industry. High frequencies of MSS from all body parts were related to lower scores on the SF-36 and increased sickness absence. This relationship was strongest for MSS from the lower back. Workers who reported low back MSS 'very often' had a mean role--physical score equivalent to that of the 15th percentile of the general population. These results show that workers who reported MSS often or very often were severely affected, and this scale can therefore be used to distinguish individuals at high risk for reduced health-related quality of life and sickness absence.