Occupational Causes Research Articles

Biological markers and occupational lung disease: mineral dust-induced respiratory disorders.

There is a need for methods to monitor early adverse effects, exposure, and/or susceptibility of individual subjects due to occupational and environmental causes. This paper discusses the experimental origin, value, and validity of several biological indicators, termed biomarkers, that were used to study coal dust-induced respiratory disorders. The findings are presented in a framework to visualize problems and challenges when developing biomarkers. Taking the framework of mineral dust-induced lung disorders as an example, it is demonstrated how carefully designed follow-up studies are a prerequisite to test the validity and use of events often put forward as biomarkers. It is concluded from the data that serum type III procollagen is neither an exposure nor an (early) effect marker, antioxidant enzyme expression is related to the early inflammatory response after mineral dust inhalation, while the evidence is accumulating that tumor necrosis factor-alpha is a susceptibility marker for progression in mineral dust-induced lung fibrosis.

Raynaud's phenomenon.

The classification of Raynaud's phenomenon has been complicated by various confusing labels, including Raynaud's disease and Raynaud's syndrome. To improve clarity and to allow for uniformity in reporting, most investigators agree that only the terms primary and secondary Raynaud's phenomenon should be used for patient classification. The prevalence of Raynaud's phenomenon seems to vary among different populations and different climates, suggesting genetic and environmental influences on its expression. The concept that Raynaud's phenomenon is the manifestation of a generalized vasospastic disorder has been addressed by studies of migraine headaches, variant angina, and the pulmonary vascular circulation. Current data suggest that the pathophysiology of Raynaud's phenomenon is complex and multifactorial, involving the endothelium, neuroreceptor expression, and locally produced mediators that affect vascular responses. New and old diagnostic tools used to measure digital circulation continue to be tested in an effort to define a better method of evaluating patients. Occupational causes of Raynaud's phenomenon continue to be an important health problem despite efforts to control vibratory tool usage. The role of beta-blockers in the induction of Raynaud's phenomenon has been questioned, but the use of chemotherapeutic agents is a definite risk factor. A new radical surgical approach for severe refractory Raynaud's phenomenon was described. Intravenous prostaglandins continue to appear helpful in the treatment of severe Raynaud's phenomenon, and oral prostaglandins are beginning to be studied.

Occupational causes of disorders in the upper limb.

Occupational causes of disorders in the upper limb.

Swedish occupational injury insurance: A laudable programme in need of reform

The Swedish occupational insurance system attributes an occupational cause to any injury or illness in the absence of overwhelming contrary evidence. Illnesses compensable under other sections of Sweden's welfare system are thereby shifted to the occupational programme. Examples are provided involving cases based upon ambient smoke and fumes in the workplace. The results greatly inflate the system's costs, discourage scientific evaluations of the causes of illnesses and injuries, and hinder programmes for the prevention of occupational maladies. A laudable effort to promote employee welfare thus has the actual consequence of reducing the system's overall benefits. The arrangement has provoked demands for reform, which warrant careful study to reduce the system's administrative burdens and potential for arbitrariness. Several possible approaches to reform are discussed

Mortality and incidence of cancer at four factories making phenoxy herbicides.

To assess the possible carcinogenicity of phenoxy herbicides and related chlorophenols and dioxins, the International Agency for Research on Cancer is coordinating an international collaborative study of workers exposed to these compounds in their production or use. Four British cohorts of chemical manufacturers which have been recruited to the survey are described. They comprise a total of 2239 men employed during 1963-85. These subjects were traced to 31 December 1987 through the National Health Service Central Register and the National Insurance Index, and their mortality compared with that in the national population. Two deaths were from non-Hodgkin's lymphoma with 0.87 expected. Both deaths occurred more than 10 years after first exposure to phenoxy compounds. One further non-Hodgkin's lymphoma was registered in a living subject with probable exposure to phenoxy compounds. No cases of soft tissue sarcoma or Hodgkin's disease were recorded. A nonsignificant excess of lung cancer (19 deaths observed, 14.2 expected) is probably attributable to chance or a confounding effect of smoking. In one cohort only there was increased mortality from circulatory disease (34 deaths observed, 20.4 expected). A nested case-control study did not point to any occupational cause for this excess, but further evaluation will be needed during continued follow up.

Occupation and leukemia mortality among men in 16 states: 1985‐1987

The relationship between leukemia and occupation was investigated in a case-control study using death certificates of 5,147 men who died of leukemia (ICD-9 codes 204-208) and 51,470 who died of other causes in 16 U.S. states from 1985 to 1987. Of six occupational activities identified previously as potentially increasing the risk of leukemia, only petroleum refining and rubber manufacturing had excess deaths for all leukemias combined (odds ratios (ORs) = 1.3, 95% confidence intervals (CI) = 0.6-2.8 and 0.9-1.8, respectively). Meat workers and wood workers had elevated mortality from acute lymphocytic leukemia (OR = 2.2, 95% CI = 0.7-7.0 and OR = 1.3, 95% CI = 0.8-2.2, respectively). There was no leukemia excess among farmers or auto mechanics. A survey of 43 other occupational groups indicated a widespread excess of leukemia among white collar occupations, primarily managers and professionals, but none among blue collar workers. This pattern was most pronounced for men under 65 years of age, and existed for all leukemia subtypes and among both blacks and whites. Despite the lack of specific exposure information and other limitations of death certificate data, these results encourage further examination of occupational causes of leukemia.

Effects of parental occupational exposures on spontaneous abortion and congenital malformation.

Human reproduction is a complex process and can be disturbed in many phases by both host and environmental factors. Therefore, it has been difficult to distinguish the occupational causes of spontaneous abortion and congenital malformations from other factors related to the parents' characteristics and their living environment. The extrapolation of results of animal studies to humans is often complicated because there are structural and functional differences between the species and the mechanisms of harmful effects are seldom known. There is also a lack of conclusive epidemiologic studies on the topic. At present knowledge on the potential reproductive toxicity of even rather common occupational exposures is limited and in many cases only suggestive. Paternal exposure to organic solvents before conception and maternal exposure during pregnancy may have adverse effects on the pregnancy and offspring. Heavy physical work during pregnancy may increase the risk of spontaneous abortion.

Carpal Tunnel Syndrome: The New ‘Industrial Epidemic’

1. Symptoms of carpal tunnel syndrome (CTS) include numbness, tingling, and decreased sensation in the fingers. 2. The main occupational causes of CTS include repetitive wrist flexion and extension, strong gripping with ulnar deviation, impact forces on the palm, and vibratory forces. 3. Conservative treatment includes a metal-reinforced splint that prevents flexion and extension of the wrist. Surgical treatment may be needed for severe symptoms. 4. Prevention of CTS requires early diagnosis, job reassignment, and tool redesign.

Occupational causes of low-back pain.

Associations between occupational activities and low-back pain (LBP) were examined in a retrospective postal survey of 545 randomly selected adults. Each subject gave a lifetime occupational history on six specified physical activities and also a lifetime history of LBP. Among the 436 subjects answering the questionnaire, the lifetime incidence of LBP was 63%. The occurrence of LBP was related by Cox's proportional hazards regression model to occupational activities in the year prior to the onset of symptoms. For the men the strongest associations were with heavy lifting and prolonged car driving. There was also an association with heavy lifting among the women. These risks were exaggerated in the subset of subjects whose LBP followed a chronic unremitting course. The findings are consistent with previous reports linking LBP with manual materials handling and driving at work. However, in this sample, less than 20% of the cases could be attributed to such activities.

Case-control study of lung cancer in Los Angeles county welders.

A case-control study of lung cancer in white male welders was undertaken to investigate possible environmental and occupational causes of a 50% excess of lung cancer observed in this occupational group. The subjects were identified from a population-based cancer registry in Los Angeles County. A standardized questionnaire was administered to either subjects or proxy informants of 90 lung cancer cases and 116 non-lung-cancer controls. Significantly increased risks of lung cancer were associated with tobacco smoking (odds ratio 7.6, p less than .005) and shipyard welding with at least a 10-year latency since first exposure (odds ratio 1.7, p less than .05). Although there were elevated risks associated with some specific welding processes, none were statistically significant. Control subjects were more likely to have had exposure to confined-space welding (odds ratio 0.6, 95% CI = 0.3-1.2), and this association was greatest where there had been at least a 20-year latency since first exposure (0.5, 95% CI = 0.3-1.0). We conclude that the excess of lung cancer in this welding population is contributed to by a higher frequency of smoking and probable exposure to asbestos in shipyards. Other factors may be important, but probably because of limited power and reliance on proxy information, this study failed to detect other statistically significant risks.

Investigation of lung cancer among female cosmetologists

Using a population-based cancer registry to identify subjects, a case-control study of female cosmetologists in Los Angeles County was conducted to investigate possible occupational and environmental causes for the elevated lung cancer risk found in this group. A standardized questionnaire was administered to proxy informants for decreased lung cancer patients and decreased nonpulmonary cancer control patients. No associations between lung cancer and specific beauty shop tasks, beauty product use, or environmental exposures were observed in the crude analysis or after controlling for smoking status. Case subjects had held more jobs outside of cosmetology than control subjects, but these jobs did not appear to be associated with any known hazardous exposures. Despite the elevated risk of lung cancer among female cosmetologists, researchers were unable to relate this excess to any specific occupational tasks or exposures. The excess of lung cancer in cosmetologists is most likely accounted for by a higher frequency of smoking in this occupational group.

Self-Reported Data on Spontaneous Abortions Compared with Data Obtained by Computer Linkage with the Hospital Registry

In a study of occupational causes of spontaneous abortions, based upon self-reported data and data from the hospital registry, evidence of differential misclassification was noted. Among those exposed a larger proportion of the self-reported spontaneous abortions were identified in the hospital registry, compared with what was found in the control group. This could be due to recall bias of the questionnaire data masking an effect of exposure, or a lower threshold for hospitalization among those exposed vis-à-vis controls, which would exaggerate the effect of exposure, if any. The analysis tended to support the idea of a less accurate recall of spontaneous abortions among controls, especially for abortion that occurred more than 3 years before the questionnaires were sent out. A second questionnaire was sent out to a subset of the participants 3 1/2 years after the first questionnaire. 17% reported fewer spontaneous abortions in this second questionnaire compared with the situation in the first questionnaire, for the period 1973 to 1980.

Economic and occupational causes of transit operator absenteeism: a review of research

Abstract Transit operator absence from work is a costly and pervasive problem within public transport organizations. This paper reviews over forty international studies in order to document significant factors related to this phenomenon. We begin with a brief assessment of the magnitude and costs of operator absence and isolate two major theories which have been proposed to explain operator absence behaviour: the income‐leisure trade‐off and occupational stress. Case study reports from three U.S. public transport organizations are used to illustrate the range of factors which influence employee absence behaviour. We conclude with suggestions for organizational changes which may serve to reduce operator absence and suggestions for further research.

Occupational causes of laryngeal cancer.

In a case-control study of all new cases of laryngeal cancer in Denmark from 1980 to 1982, 326 cases and 1134 community selected controls participated. Questionnaires were used to obtain information on education, occupation, and number of occupational exposures as well as smoking and drinking habits. High risk ratios for laryngeal cancer were found for semiskilled and unskilled workers, workers exposed to dust, out of doors workers, drivers, and people working in the cement industries and port services. The study hypothesis was that exposure to chromium or nickel increases the incidence rate of laryngeal cancer. No support for this was found concerning chromium, but exposure to nickel had a statistically significant risk ratio of 1.7.

Mortality from heart disease among workers exposed to solvents.

Several rubber industry jobs that are associated with cardiovascular disease (CVD) mortality involve the use of solvents and, since the only known occupational cause of atherosclerosis is a solvent (carbon disulfide), solvent exposures may contribute to the CVD excess observed among rubber industry workers. Detailed exposure estimates for 25 solvents were available for a cohort of 1,282 white male production workers in a large rubber- and tire-manufacturing plant, and a survivorship analysis compared the CVD mortality experience of exposed and nonexposed workers during a 15-year follow-up period. The known association between carbon disulfide exposure and ischemic heart disease (IHD) was apparent among these workers, and two other solvents, ethanol and phenol, were also found to be significant predictors of IHD. These exploratory findings suggest that solvents other than carbon disulfide may cause atherosclerotic disease.

Methods for detecting occupational causes of male infertility. Reproductive history versus semen analysis.

The use of semen and reproductive histories in epidemiologic studies is reviewed. Traditional parameters of semen quality are easily measured. A significant change may be positive proof of an effect on the reproductive tract and may occur within two or three months of the start of exposure. Conversely, semen specimens are difficult to obtain. The use of an appropriate reference group may be hard to ensure. A change in semen quality need not lead to abnormalities of reproduction. Past effects of exposure may not be detectable if exposure has been reduced or eliminated. Reproductive histories are readily obtained for fertility analysis. A reduction in fertility may be evidence of impaired health. Past effects of exposure are easily determined. For the detection of reduced fertility, however, two or three years of exposure may be needed. A change in fertility does not necessarily indicate an effect on the reproductive tract. The analysis of fertility requires considerable technical expertise. Since data for fertility analysis may be gathered in the workplace with little effort, suitable information should be obtained during employee medical examinations wherever potential exists for effects on reproduction.

Clinical Medicine for the Occupational Physician

The title of this book is somewhat misleading, as less than half of it is devoted to clinical topics. The other topics, however, such as ethics, epidemiology, and health of travelers are all pertinent. It is not a comprehensive text on occupational medicine, as many pertinent clinical and nonclinical topics are not discussed, eg, toxicology, industrial hygiene, exposure standards, ergonomics, role of the occupational health nurse, identification of occupational causes of disease, bladder carcinoma, ionizing radiation, shiftwork, and many harmful agents found in the workplace. The chapters on epidemiology, the health of working women, cancer, dermatoses, stress, and mental illness are good summaries that relate well to occupational problems. Most of the other clinical topics are limited to six organ systems: pulmonary, gastrointestinal, cardiovascular, musculoskeletal, nervous, and ear, nose, throat. These are good general reviews of the topics, but the occupational components are small. For example, noise and its effect

Examination of geriatric patients for carpal tunnel syndrome: results of surgical therapy.

Abstract: The carpal tunnel syndrome may be found in elderly patients who work at jobs entailing repetitive use of the hands. In a series of 13 such patients, after failure of corticosteroid therapy, surgical therapy (transection of the anterior carpal ligament) produced complete relief of symptoms in 8 cases, 75 per cent relief in 2 cases, 50 per cent relief in 1 case, and no relief in 2 cases.The occupational cause of carpal tunnel syndrome is frequently overlooked in favor of sometimes hasty diagnoses of cervical disease.

II. The use of Radiology in the Early Detection of Lung Cancer as an Industrial Disease

1. The known occupational causes of lung cancer are listed. 2. The results of routine radiology in two groups of men exposed in the past to the hazard of lung cancer in their occupations are discussed. 3. The fact that a few men have survived and been able to work for more than five years following operation indicates that routine radiology, combined with strict medical supervision of persons at risk, is of value in the diagnosis of lung cancer as an industrial disease.

Articular Manifestations of Erythema Nodosum

<h3>Introduction and objectives</h3> Occupational causes are thought to account for 20% of the global burden of asthma.¹ The gold standard test for identifying occupational asthma is a specific inhalational challenge (SIC) to the suspected occupational agent. However, there is little published data on real life outcomes of these challenges. We present the outcome of data from such challenges collected in one UK centre. <h3>Methods</h3> We performed a retrospective review of 46 consecutive SICs carried at the Occupational Lung Disease service between September 2010 and June 2019. Data was collected on demographics, occupation, OASYS score pre SIC, history of previous asthma, challenge agent tested, outcome of SIC and ongoing symptoms post SIC. <h3>Results</h3> Of the 46 SICs carried out during this period, 23 were negative, 19 were positive, 3 were equivocal and 1 test could not be completed (see figure 1). Median age of patients was 49.5yrs (IQR 42–58), 18 patients were female (39%). Fifty nine percent of SICs were carried out whilst patients were currently exposed at work. Fifty three percent of negative SICs had an OASYS score of &gt; 2.52 i.e. positive peak flow charts for work effect. The most common occupations were food industry work 11 (23%) and healthcare 9 (20%).In the positive SIC group 16% of patients had a prior history of asthma compared to none in the negative SIC group. Almost twice as many patients with negative SICs had ongoing symptoms compared to those with positive SICs (43 vs 26%). <h3>Conclusions</h3> Our data suggests that patients with a positive SIC were more likely to have a prior history of asthma documented and even when patients have a negative SIC a high proportion have ongoing symptoms. <h3>Reference</h3> Vandenplas O, Suojalehto H, Aasen TB, Baur X, Burge PS, de Blay F, <i>et al</i>. Specific inhalation challenge in the diagnosis of occupational asthma: consensus statement. <i>The European respiratory journal</i>. 2014;43(6):1573–87.