The characteristics of formulating a diagnosis in diseases of the temporomandibular joint

Pulmonary diseases caused by dust occupy a leading place in occupational morbidity structure. Those diseases inspire much attention due to their high prevalence, especially in ecologically hazardous regions where the workers are under "double exposure". Upper respiratory tract diseases serve as a trigger for all respiratory disorders in workers exposed to dust. Early diagnosis of respiratory disorders includes history, clinical data, X-ray examination and assessment of pulmonary ventilation and together with concurrent cardiovascular diagnosis is necessary for well-justified prophylaxis.     

Immunogenetic basis of environmental lung disease: lessons from the berylliosis model

The role of genetic factors has been hypothesized in the pathogenesis of a number of chronic inflammatory lung diseases. The genes of the major histocompatibility complex (MHC) locus on human chromosome 6 have been identified as important determinants in diseases caused both by inorganic and organic compounds such as beryllium, gold, acid anhydrides, isocyanates and grass pollens. Since many environmental factors are the determinants of the immunopathogenesis of asthma, pulmonary granulomatous disorders, hypersensitivity pneumonitis and fibrotic lung disorders, an understanding of the interaction between environmental factors is crucial to epidemiology, prevention and treatment of these disorders. Berylliosis is an environmental chronic inflammatory disorder of the lung caused by inhalation of beryllium dusts. A human leukocyte antigen class II marker (HLA-DP Glu69) has been found to be strongly associated with the disease. In in vitro studies, the gene has been shown to play a direct role in the immunopathogenesis of the disease. In human studies, the gene has been shown to confer increased susceptibility to beryllium in exposed workers, thus suggesting that HLA gene markers may be used as epidemiological probes to identify population groups at higher risk of environmental lung diseases, to identify environmental levels of lung immunotoxicants that would be safe for the entire population and to prevent disease risk associated with occupation, manufactured products and the environment. Studies on the associations between human leukocyte antigens and chronic inflammatory lung disorders are reviewed in the context of the berylliosis model.     

Occupational and environmental exposures and nonspecific lung disease--a review of selected studies

Selected studies show that nonspecific lung diseases are a major occupational and environmental health hazard. Exposure to mineral dusts (such as cement and brown coal) and organic dusts (cotton, hemp and flour) as well as manganese and gaseous irritants causes significant upper respiratory tract injury. Possible additive effects of mixed exposures, combined exposure to dusts and gaseous irritants of the upper respiratory tract, individual susceptibility, and mechanisms of nonspecific respiratory effects of exposures are considered. Interpretation of the results is difficult due to uncontrolled confounding. Measures for preventing lung impairments include exposure reduction and preemployment examination of workers.     

Asbestos: current knowledge and perspectives

Diseases due to asbestos inhalation are not only a concern for occupational physicians, but also for general practicioners and pneumologists. The real or supposed risk has extended beyond the factories employing "primary asbestos workers" to thousands of people exposed to this material or simply working in buildings insulated with asbestos. The spectrum of asbestos-related diseases has changed: asbestosis (parenchymal fibrosis due to asbestos) tends to disappear, whereas the incidence of pleural lesions, which can be associated with lower cumulative exposures, increases. Patients with asbestos related diseases do not die any more from respiratory failure but from late neoplastic complications, such as mesothelioma and lung cancer. The lack of interest and of training in occupational medicine leads to an underrecognition and an underestimation of cancers due to asbestos by the physicians. Recent progresses in CT imaging and evaluations of exposure to fibers through mineralogical analysis of lung samples have led to improve the diagnostic approach of fiber-related diseases.     

A dual mechanism for impairment of GABAA receptor activity by NMDA receptor activation in rat cerebellum granule cells

It has been estimated that over three million workers in the USA are potentially exposed to silica or other mineral dusts. Results of epidemiological studies evaluating whether silica or glass fibers increase lung cancer risk to the exposed workers are inconclusive. Detection of DNA damage in cells exposed to genotoxic agents is being used to assess the carcinogenic potential of environmental agents. The alkaline (pH > 13) single cell gel/comet (SCG) assay was used to determine and compare DNA damage in cultured Chinese hamster lung fibroblasts (V79 cells) and human embryonic lung fibroblasts (Hel 299 cells) exposed to crystalline silica (Min-U-Sil 5), amorphous silica (Spherisorb), carbon black, and glass fibers (AAA-10). V79 or Hel 299 cells were exposed to these mineral dusts for 3 h at various concentrations. Min-U-Sil 5 and AAA-10, at almost all concentrations tested, caused a significant increase in DNA migration measured as tail length in both V79 and Hel 299 exposed cells. However, the increase was much higher in V79 then in Hel 299 cells for Min-U-Sil 5. Tail length was also increased relative to controls after amorphous silica treatment, but not to the same extent as that induced by crystalline silica. Exposure to carbon black did not induce DNA migration at any of the concentrations tested. These results indicate that silica and glass fibers, but not carbon black, can induce DNA damage in mammalian cells, and that crystalline silica has a higher DNA-damaging activity than amorphous silica. For glass fibers, induction of DNA damage in both V79 and Hel 299 cells was observed even at a concentration 10 times lower than silica and the response was similar in both cell lines. These results suggest that the SCG/comet assay is useful for the detection of DNA damage caused by occupationally related dusts/particles.     

Respiratory health of cigar factory workers

OBJECTIVES: To determine whether occupational exposure to raw tobacco causes respiratory or allergic diseases, an excess of respiratory symptoms, a decrease in lung function, or parenchymal changes in chest radiography among Finnish cigar workers. METHODS: This cross sectional study included all Finnish cigar workers (n = 106) exposed to raw tobacco and also a group of unexposed matched referents. Data were collected with a self administered questionnaire, flow volume spirometry, measurements of diffusing capacity of the lung for carbon monoxide, chest radiography and skin prick tests. A questionnaire was also sent to former workers of the factory. RESULTS: There were no significant differences between the groups in the prevalence of respiratory symptoms and chest radiography findings. Nine of 102 tobacco workers had pulmonary fibrosis of at least 1/0 (according to the International Labour Organisation (ILO) 1980 classification) and the corresponding figure was five for the referents. The tobacco workers tended to have a low forced vital capacity (FVC), and they had impaired forced expiratory volume in 1 second and lower means of the maximal expiratory flow at 25% of the FVC significantly more often than the referents. Diffusing capacity tended to be lower among the referents. The referents more often had atopy and earlier atopic diseases than the exposed workers. These results indicate the possibility of selection among the exposed workers. CONCLUSIONS: No excess of prevalence of respiratory symptoms in the tobacco workers was found. According to the questionnaire episodes of allergic alveolitis may have occurred in the cigar factory workers. However, in the absence of impairments in lung function and radiological changes it was not possible to distinguish humidifier fever and allergic alveolitis. In exposure conditions that include humidification of the air humidifier, fever and allergic alveolitis constitute a risk for tobacco workers. No effects were shown of exposure to tobacco dust on lung function.     

Evaluation of occupational diseases according to their risk and severity

Article covers approaches to evaluation and forecasting of occupational risk for workers exposed to occupational hazards, formulates a concept to evaluate occupational disease according to risk and severity categories, gives an integral parameter for qualitative and quantitative analysis of group risk for one occupational disease or their combination. Trials proved acceptability of the method for group risk evaluation according to WHO concept concerning occupational diseases.     

Occupational pathology: present and future

Formed 75 years ago, occupational pathology has defined structure of occupational morbidity, determined principles of occupational diseases' pathogenesis and pathomorphosis, demonstrated dependence of occupational entities on acting occupational hazards, described clinical manifestations of occupational diseases, emphasized informative diagnostic complexes. Diagnosis in occupational pathology now is established on basis of etiology. Manifold activities helped to form a system preventing health disorders caused by occupational hazards. Topical problem is to elaborate and put into practice some criteria for compensation of occupational damage with differential expert assessment of functional disorders caused either by occupational disease or by general one. Prospective trend could be to create a system organizing and managing workers' health on workplace and to put "protection by time" principle into practice with forecasting risk of occupational diseases and dose-effect dependence. Another prospect is to elaborate and put into practice a training in social and psychologic adaptation for occupational managers and industrial workers.     

Nested case-control study of esophageal cancer in relation to occupational exposure to silica and other dusts

BACKGROUND: Standardized proportionate mortality ratio (SPMR) was found to be 2.2 (95% CI = 1.3-3.5) for esophageal cancer (EC) among workers exposed to refractory brick dust in a large iron-steel complex in China. METHODS: A nested case-control design within a cohort of industrial workers. One hundred and twenty-five EC cases and 250 controls were identified from the death registry file. Interviews were conducted of the next of kin for past exposure information on job, domestic, and lifestyle factors. History of occupational exposure to various dusts was reconstructed from personnel files and by interviewing colleagues utilizing a job-exposure matrix. RESULTS: After adjusting for confounders, occupational exposure to silica dust was the most important risk factor among all variables investigated, with a 2.8-fold risk and a clear dose-response by length of exposure. Alcohol drinking (OR = 1.8) and coal cooking (OR = 2.0) were risk factors and high consumption of fruit diet (OR = 0.5) and meat diet (OR = 0.6) were protective factors. CONCLUSIONS: The relationship between occupational exposure to silica dust and the risk of EC found in an earlier SPMR study was confirmed. Ingestion of silica particles after lung clearance may increase the risk of EC among workers exposed to silica.     

Borderline mental disorders in workers exposed to poisons and their prevention

Studies covered psychic state in workers exposed to poisons. The authors represent clinical and epidemiologic principles of the disorders formation, the prevalence and structure of the disorders caused by various hazards. The article necessitates up-to-date data-processing system for occupational selection, clinical, psychophysiologic, biochemical and experimental psychologic evaluation of current state in workers engaged into liquidation of chemical weapons.     

Principles for assessment and diagnosis of work-related pulmonary and pleural diseases

Proposals for diagnostic methods and clinical evaluation of occupational lung and pleural diseases have been worked out by a Working Group appointed by the Norwegian Thoracic Society and the Norwegian Society of Occupational Medicine. The management of this group of diseases demands both an evaluation of occupational exposure and a specific pulmonary diagnosis. Recommendations were made especially for obstructive, interstitial, and malignant diseases.     

Mental disorders in workers exposed to chemicals at work

The article considers data on boundary psychic disorders in subjects exposed to chemicals of I-II jeopardy classes. Chemical factor appears to increase risk of psychiatric diseases. The authors suggest periodic psychiatric examination of workers engaged into hazardous chemical production for better occupational selection, early diagnosis and treatment of boundary psychic disorders.     

Retention of asbestos bodies in the lungs of welders

Examination of asbestos bodies (AB) retained in the lungs is a useful way of assessing past occupational exposure to this material. AB retention has been extensively studied in workers directly exposed to asbestos, but less so in those end users, such as welders, who use asbestos-containing products. We therefore retrospectively studied AB retention in 211 welders, for whom biological testing procedures had been requested by a chest physician, between 1988 and 1991. Optical microscopy of AB was performed on samples of sputum (40 subjects), bronchoalveolar lavage fluid (BAL) (147 subjects), and lung tissue obtained after thoracotomy (38 subjects). Information on previous jobs and exposure was obtained using a questionnaire (the mean duration of welding activities was 16.6 years). Eighty-two subjects (38.9%) had elevated lung retention of AB in all the samples studied. Significant AB retention occurred in only 30% of sputum samples, but in 40.1% of BAL samples and 39.5% of lung tissue samples. The duration of welding activities correlated with the density of AB in BAL or lung tissue (r = 0.31, p < 0.01 and r = 0.49, p < 0.05, respectively). On the basis of the questionnaire, only two of the welders with significant AB retention had other occupational exposure to asbestos. Our findings suggest that welding activities may increase lung retention of AB, and consequently might produce higher risks of fibrotic and/or malignant pulmonary diseases. These potential risks need to be brought to the attention of doctors; a longitudinal follow-up may also be warranted in such populations, even after individuals have ceased their welding jobs.     

The spectrum of respiratory disease associated with exposure to metal working fluids

Occupational respiratory diseases have been reported following exposure to metal working fluids. We report a spectrum of respiratory illnesses occurring in an outbreak in 30 workers of an automobile parts engine manufacturing plant. Workers presented with respiratory complaints and, after clinical and laboratory evaluations, were classified as those having hypersensitivity pneumonitis, occupational asthma, or industrial bronchitis, or those without occupational lung disease. Hypersensitivity pneumonitis affected seven workers, with six exhibiting serum precipitins to Acinetobacter Iwoffii. Occupational asthma and industrial bronchitis affected 12 and six workers, respectively. Oil-mist exposures were below current recommendations. Gram-negative bacteria, but no fungi, Thermophiles, or Legionella, were identified. Although specific agents responsible for each individual case could not be identified, probably both specific sensitizing agents and non-specific irritants from metal working fluids, additives, or contaminants contributed to this spectrum of occupational respiratory illness.     

Decree 626/94, section VII "Protection from carcinogenic agents": comparison of agents tested for evidence of carcinogenicity by the EEC and IARC

This paper reviews the assessments reported by the European Commission and the International Agency for Research on Cancer of evidence of carcinogenicity of agents. The aim was to identify the discrepancies in the classification of substances, jobs and occupational exposure situations considered by these two international bodies. This information can be of use in the risk evaluation of workers exposed to carcinogenic agents, as foreseen by Italian Decree No. 626/94.     

Air pollution in an industrial environment and occupational diseases

Most of the occupational diseases are related to air pollution at the work place. The distribution of gases and vapours and their human absorption are briefly described. The deposition of particles is a function of their physical properties, of the pattern of the respiratory airways and of pulmonary ventilation parameters. Several defence mechanisms also play a role. Illustrative examples are given of occupational diseases caused by solvents, carbon monoxide, metals, dusts (silicosis, asbestosis, pneumoconiosis due to dust of hard metals), allergens and carcinogens. The importance of prevention is emphasized.     

Lung cancer mortality in Casale Monferrato (Italy) and attributable risk to occupations in the asbestos-cement production

The study presents mortality rates for lung cancer in the town of Casale Monferrato, where the largest Italian asbestos cement-plant was located. Cases of lung cancer dying in 1989-94 were exhaustively searched for in the register of deaths. Each case of lung cancer has been identified as ever or never employed in the factory with a linkage to the rosters of employees in the plant. Women were also identified as ever or never married to an asbestos-cement worker. The number of person-years at risk for asbestos cement workers and their wives was measured on the basis of the most recent follow-up. Mortality rates were computed separately for those exposed (workers and wives of workers) and for those with no evidence of exposure. Mortality rates for non-exposed were similar to rates in Piedmont (the region where Casale is located). The relative risk (ever exposed vs. never exposed) was 2.8 among men and 2.1 among women. Attributable risk among the exposed was 64.5% for men and 53.1% for women while among the general population it was 18.1% for men and 13.2% for women. The study confirms the dramatic effect of occupational asbestos exposure in Casale Monferrato but does not suggest an increase in lung cancer mortality among people with no occupational activity in the asbestos-cement production.     

The adaptive reactions of the cardiorespiratory system in chronic bronchitis and its premorbid forms

AIM: Investigation of pulmonary ventilation, blood flow and cardiodynamics in subjects at risk of chronic nonspecific pulmonary disease (CNPD), prebronchitis (PB) and chronic bronchitis (CB). MATERIALS AND METHODS: 118 workers exposed to toxico-chemical factors underwent zonal rheography. RESULTS: At early stages of CB marked disorders of pulmonary ventilation and blood flow in the lungs were revealed. These disorders in subjects with threatened CNPD were regional and accompanied by a moderate increase in power inputs of the cardiorespiratory system. The maintenance of adequate pulmonary exchange in patients with PB entailed functional tension of the respiratory and cardiovascular systems that contributed to decompensation of adaptive mechanisms and occasionally to development of rheographic signs of pneumosclerosis in the lung zones with damaged ventilation and low perfusion of the pulmonary vessels. CONCLUSION: Overloading and decompensation of respiratory and cardial mechanisms of gas exchange regulation in the lungs in response to external damage may lead to development of myocardiodystrophy and pneumosclerosis which appear to be the "price of adaptation".     

Caries preventive services for children and adolescents in Denmark, Iceland, Norway and Sweden: strategies and resource allocation

Construction workers are exposed to considerable hazards carrying a health risk, e.g., dusts, fumes, noise and manual handling, yet there is often poor occupational health service provision particularly for subcontracted labourers. This paper presents seven case studies from large, engineering construction organizations, concerning current practice in occupational health management. The results supported the fact that data and records regarding health-related absence were limited and inconsistent, and that little existed in terms of medicals and health surveillance, particularly in the case of subcontracted workers. The main difficulties envisaged were reported to be the sizeable costs involved; the temporary and mobile work force; demonstrating cost-benefits to top management and a lack of interest amongst workers, perhaps exacerbated by the threat of lost livelihood. Managers also admitted limited health expertise and knowledge of the wider role health professionals could play in health management. Training and further research in this area are indicated.     

Exposure-response relationship in the hand-arm vibration syndrome: an overview of current epidemiology research

The complex of vascular, neurologic, and osteoarticular disorders occurring in the upper limbs of vibration-exposed workers is called hand-arm vibration syndrome. There is epidemiologic evidence for an increased occurrence of peripheral sensorineural disorders in occupational groups working with vibrating tools. An excess risk for wrist osteoarthrosis and for elbow arthrosis and osteophytosis has been reported in workers exposed to shocks and low-frequency vibration of high magnitude from percussive tools. However, there are too few epidemiology data to enable reliable conclusions to be drawn about exposure-response relationships for both sensorineural disturbances and bone and joint disorders caused by hand-transmitted vibration. Cross-sectional and longitudinal epidemiology studies have shown that occupational exposure to hand-transmitted vibration from a great variety of hand-held tools is significantly associated with an increased occurrence of digital vasospastic disorders called vibration-induced white finger (VWF). The proposal of an exposure-response relationship for VWF has been included in an annex to the international standard ISO 5349. The findings of several epidemiology studies have shown a poor agreement between the risk for VWF observed in various occupational groups and that predicted by the ISO 5349 model. Both overestimation and underestimation of the occurrence of VWF have been reported by investigators. It has been argued that the current ISO frequency-weighting curve for hand-transmitted vibration may be inappropriate for the assessment of vibration-induced adverse vascular effects. Alternative exposure-response relationships for VWF have been suggested in recent epidemiology studies. The epidemiology data used to construct current exposure-response relationships for vibration-induced injuries are primarily derived from cross-sectional studies. Future epidemiology research should be based on prospective cohort studies because the design characteristics of such studies permit the study of cause-effect relationships and the formulation of etiologic hypotheses.