Respiratory abnormalities among male foundry workers in central Taiwan

The objectives of this study were to determine the relationship between exposure levels and respiratory abnormalities, to measure FVC and FEV1(1) changes per year based on work duties and to investigate the prevalence of and factors related to pneumoconiosis. A total of 583 male workers from 50 iron foundries in central Taiwan were investigated. First, workers' respiratory symptoms were categorized using a modified American Thoracic Society (ATS) questionnaire and then were verified by physician's examination. Next, pulmonary function tests were performed including: forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced expiratory flow rate. A chest radiograph was used to diagnose pneumoconiosis according to ILO criteria. Furnace workers were found to have the highest prevalence of chronic phlegm, thoracic disorders and chronic bronchitis. In general, smokers had a higher prevalence of respiratory symptoms as compared with non-smokers. Pulmonary function abnormalities and pneumoconiosis were closely linked to smoking and work duration. After adjusting for age, height and smoking there was a significant decrease based on work duration in FVC and FEV1 for furnace and moulding workers compared with after-processing and administrative workers. The overall prevalence of pneumoconiosis was 8.8%, highest among furnace (16.3%) and after-processing workers (11.4%) and lowest among administrative workers (2.5%). Using multiple logistic regression, the risk of developing pneumoconiosis (as compared with the administrative workers) for furnace workers was highest (8.98 times greater risk), followed by after-processing workers (6.77 times greater risk) and moulding workers (5.41 times greater risk). Prolonged exposure to free silica, and smoking habits, can result in respiratory abnormalities among foundry workers.     

Respiratory function in shoe manufacturing workers

A study of respiratory findings was performed on 376 female workers employed in a shoe manufacturing plant. The mean age of the workers was 32 years and the mean duration of their employment was 12 years. These workers were predominantly nonsmokers. Acute and chronic respiratory symptoms were recorded for each worker, and lung function was measured before and after the work shift. Maximum expiratory flow-volume (MEFV) curves were performed on which forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁), and flow rates at 50% and the last 25% (FEF₅₀, FEF₂₅) were measured. Significantly higher prevalences of all chronic respiratory symptoms were recorded in exposed compared to control workers; in particular, chest tightness (exposed: 44.7%; control: 0%), dyspnea (exposed: 42.6%; control: 2.0%), and rhinitis (exposed: 46.3%; control: 2.4%) were far more prevalent in workers than in controls. Among the shoe workers, there was also a high prevalence of acute symptoms that developed during the work shift, being most pronounced for nose and throat irritation (61.4%). The prevalence of acute and chronic respiratory symptoms increased with duration of employment. Statistically significant across-shift reductions were recorded for all ventilatory capacity tests for the group as a whole. In comparison to predicted, the measured ventilatory capacity parameters were significantly lower for all workers (p < 0.01). Lung function abnormalities increased with duration of employment. Environmental measurements demonstrated that benzene, fur, and synthetic fibers were found at higher than allowable maximal concentrations (Croatian standards). The data suggest that work in the shoe manufacturing industry may be responsible for the development of acute and chronic respiratory impairment. Am. J. Ind. Med. 31:50–55 © 1997 Wiley-Liss, Inc.     

Respiratory function in sewage workers

Respiratory symptoms and ventilatory capacity were studied in a group of 74 sewage workers employed in cleaning the city sewage system of Zagreb, Croatia. Workers were studied by their work stations: closed channels (N + 26), drainage (N + 31), and other sewage workers (N + 17). The prevalence of chronic respiratory symptoms was higher in closed channel and drainage workers than in controls, particularly for chronic cough (range: 41.9–46.2% vs. 14.3%), chronic phlegm (range: 38.7–46.2% vs. 14.3%), chronic bronchitis (range: 32.3–42.3% vs. 8.6%), and chest tightness (range: 29.0–53.8% vs. 0%). In the first two groups of sewage workers there was a high prevalence of acute symptoms which developed during the work shift, being particularly pronounced for eye irritation (range: 16.1–26.9%), dyspnea (16.1–23.1%), dizziness (range: 6.5–23.1%), throat burning (9.7–19.2%), and skin irritation (range: 22.6–26.9%). Baseline ventilatory capacity was significantly decreased compared to predicted values in sewage workers; in particular, values for FEF50 and FEF25 were reduced, suggesting obstructive changes in smaller airways. Our data indicate that sewage workers experience frequent acute and chronic respiratory symptoms and exhibit objective evidence of respiratory dysfunction. © 1993 Wiley-Liss, Inc.     

Respiratory findings in synthetic textile workers

We studied 308 female and 92 male textile workers employed in a factory that produced synthetic fiber hosiery. The mean age of the women was 38 years, their mean duration of employment 16 years. The mean age of the men was 39 years with a mean duration of employment of 16 years. A control group of 160 female and 78 male nonexposed workers was also studied. Chronic and acute work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves from which the forced vital capacity (FVC), the 1-sec forced expiratory volume (FEV₁) and maximum expiratory flow rates at 50% and the last 25% (FEF₅₀, FEF₇₅) were read. There was a higher prevalence of all chronic respiratory symptoms in exposed than in control workers, although the differences were statistically significant only for dyspnea, sinusitis, and nasal catarrh (P < 0.01) in female synthetic textile workers, and for nasal catarrh (P < 0.01) in male synthetic textile workers. Occupational asthma was recorded in 3 (0.9%) of the women textile workers, and in 1 (1.1%) of male textile workers. There was a high prevalence of acute symptoms during the work shift, which was greatest for cough (female: 46%; male: 59%), dryness of the throat (female: 49%; male: 40%), dryness of the nose (female: 53%; male: 43%) and eye irritation (female: 46%; male: 36%). Ventilatory capacity data among the synthetic textile workers demonstrated significantly decreased FEF₇₅ compared to predicted (P < 0.05). Our data suggest that inhalation of dust in synthetic textile plants causes the respiratory impairment. Am. J. Ind. Med. 33:263–273, 1998. © 1998 Wiley-Liss, Inc.     

Respiratory findings in pharmaceutical workers

BACKGROUND: Pharmaceutical workers may be at risk for the development of respiratory problems as a result of their work environment. METHODS: This study investigated 163 female and 35 male workers, employed in a pharmaceutical plant processing different types of medication, primarily antibiotics, in order to characterize the risk of this environment. Chronic respiratory symptoms were recorded by using the British Medical Research Council questionnaire. Acute symptoms, which developed during the work shift, were also recorded. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves on which FVC, FEV1, FEF50, and FEF25 were measured. Controls (113) were selected from a food packing facility. RESULTS: A significantly higher prevalence of chronic respiratory symptoms was recorded among workers (compared to controls), the highest being for sinusitis, nasal catarrh, and dyspnea. There was also a high prevalence of acute symptoms recorded during the workshift. Odds ratio showed that the most significant risk factors for these respiratory findings were smoking and length of time worked in the pharmaceutical industry, particularly in men. Pulmonary function testing demonstrated significantly decreased measured values in comparison to predicted European pulmonary function measurements (P < 0.01). This was particularly pronounced for FEF50 and FEF25, suggesting obstructive changes in smaller airways. CONCLUSIONS: Our data suggest that workers employed in the pharmaceutical industry may develop respiratory symptoms accompanied by ventilatory impairment.     

Respiratory function in workers employed in the glassblowing industry

A group of 80 men employed in the glassblowing industry was studied in order to investigate the effect of this occupational exposure on respiratory function. Eighty nonexposed workers were included in the study as a control group. Glassblowers had a significantly higher prevalence of chronic bronchitis, nasal catarrh, chronic sinusitis, and nasal bleeding than control workers; length of employment in the industry did not affect the prevalence of symptoms. Many of the glassblowers complained of work shift related symptoms. Measurement of lung function among glassblowers showed there were significant increases in the forced vital capacity (FVC) and the maximum flow rates at 50% and 25% of FVC on maximum expiratory flow volume (MEFV) curves (FEF₅₀, FEF₂₅) across the work shift. Glassblowers had significantly larger preshift FVC and forced expiratory volume in 1-second (FEV₁) measurements when compared to controls. Additionally, residual volume (RV) and RV/TLC% for the glassblowers were significantly increased while the diffusing capacity (DLCO) was normal (when compared to predicted values). Our data indicate that employment in the glassblowing industry contributes to the development of chronic respiratory findings. © 1993 Wiley-Liss, Inc.     

Respiratory symptoms and pulmonary function in mill workers exposed to wood dust

This study surveyed wood dust exposure levels and pulmonary hazards among wood mill workers. Dust concentrations as measured by six-stage cascade impactors were high in work areas of grinding and screening. Total dust concentrations for these dusty activities ranged from 4.4 to 22.4 mg/m³, and the respirable proportions were between 2.4% and 50.2%. The dust level in the sawing work was 2.9 mg/m³. Although symptoms of cough and phlegm were higher in smoking workers than in nonsmoking workers, the prevalence of respiratory symptoms in the exposed workers was not significantly higher than in the controls. However, the incidence of symptoms such as chronic phlegm and chronic bronchitis in the nonsmoking high-exposure workers was significantly higher than in nonsmoking controls. The mean values of MMF, PEFR, and FEF25% were significantly lower in the exposed workers than in controls for both smokers and nonsmokers. The pulmonary function deficits, with the exception of FEV1.0/FVC, also showed a significant trend with increasing levels of wood dusts exposure classified by job titles for both smokers and nonsmokers. After adjustment for age, sex, height, and smoking status, all parameters of pulmonary function were significantly lower in exposed workers than in controls and showed a declining trend with increasing exposure levels classified by job titles. These results indicate that high level of wood dust exposure in the wood mill industries may lead to pulmonary hazards. Engineering control and industrial hygiene are mandatory for dusty activities. © 1996 Wiley-Liss, Inc.     

Respiratory symptoms and lung function in wool textile workers

Our study investigated a group of 216 wool textile workers (158 women and 58 men). Respiratory symptoms were assessed by questionnaire in wool textile workers and in 130 not exposed (control) workers. Ventilatory capacity was measured in wool workers by recording maximum expiratory flow-volume (MEFV) curves on Monday before and after the work shift. Forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁), and flow rates at 50% and the last 25% of the vital capacity (FEF₅₀, FEF₂₅) were measured on the MEFV curves. Analysis of the data demonstrated a significantly higher prevalence of all chronic respiratory symptoms in wool workers than in controls. being the highest in wool workers for nasal catarrh (M: 63.8%; F: 44.9%) and for sinusitis (M: 62.1%; F: 43.0%). A high prevalence of acute symptoms, associated with the work shift, was also noted in wool workers. Exposure to wool dust caused significant across-shift reductions of ventilatory capacity varying from 1.4% for FEV, to 9.1% for FEF₅₀. Textile workers exposed to wool for > 10 years in the workplace had similar across-shift reductions of ventilatory capacity tests as those with shorter exposures. In a large number of these wool workers, FEF₅₀ and FEF₂₅ were below 70% of predicted normal values. Smokers had acute and chronic lung function changes similar to those of nonsmokers, indicating that smoking did not account for all the respiratory effects seen in wool processing workers. Our data suggest that dust exposures in wool textile mills may be associated with the development of chronic respiratory symptoms and impaired lung function.     

Asbestos-related x-ray changes in foundry workers

Michigan has a statewide mandatory occupational disease reporting system. As part of that system, reports are received from hospitals, physicians, death certificates, the workers' compensation bureau, and company medical departments. Based on this reporting, the State of Michigan has a special emphasis program for the surveillance of silicosis, a known disease outcome among foundry workers. From 1985–1996, 115 cases reported to the State Surveillance System as silicosis, pneumoconiosis not specified, or pulmonary fibrosis were reclassified as having asbestos related x-ray changes after a B-reader interpretation of each case's chest x-ray. During this same period there were an additional 697 reports confirmed as silicosis and 6,724 cases reported to the surveillance system as asbestosis. Among the 115 reports reclassified as having asbestos-related x-ray changes without evidence of silicosis-related x-ray changes, 54 had worked in foundries. Only 7 (14.8%) of these individuals had their primary work in maintenance in the foundry; 40 (85.1%) had their primary foundry work in a production job; and for 10 individuals the occupation was not known. Asbestos has been used in foundries on pipe laggings, boiler coverings, as insulation in fan housings, in gloves, aprons and curtains, as insulation in cupolas, and in ladles and insulation in sand molds. Clinicians caring for foundry workers need to be aware that asbestos-related x-ray changes are not uncommon in this population and asbestos exposure should be considered as one of the carcinogens contributing to the known increased risk of lung cancer among foundry workers. Am J. Ind. Med. 34:197–201, 1998. © 1998 Wiley-Liss, Inc.     

A respiratory epidemiological survey of workers in a small South African foundry

A cross-sectional study to assess prevalence of respiratory abnormality was conducted among 107 South African foundry workers. The prevalence of pneumoconiosis was 10.3% overall, increasing to 38% for workers with more than 15 years of service. Dyspnea was present in 38% of workers, chronic simple bronchitis in 15.9%, and asthmatic symptoms in 27%. Pneumoconiosis was not associated with higher prevalence rates of other respiratory abnormalities. The high overall prevalence of respiratory symptoms might be explained by exposure to environmental pollutants other than dust.     

Spirometric function in non-smoking workers exposed to aluminum

BACKGROUND: Exposure to aluminum (Al) causes the onset of respiratory disorders. This study is aimed at providing further information on how occupational exposure to Al affects the respiratory apparatus in healthy non-smokers, with particular attention to respiratory function. METHODS: A group of 50 male shipyard workers who were exposed to Al underwent medical examination, standard chest X-rays and spirometry in accordance with the C.E.C.A. protocol. The data were compared with those of a homogeneous group of controls, all with blood aluminum (AlB) levels below 7.5 ng/ml. Statistical analysis was performed on the following spirometric parameters: vital capacity (VC), forced vital capacity (FVC), maximum forced expiratory volume in 1 s (FEV1), and mean forced expiratory flow during mid-half of FVC (FEF(25-75%)). Environmental Al levels were also measured at the various workstations. RESULTS: Fifty male workers with an average age 31.82 +/- 5.05 years, occupational exposure of 11.81 +/- 3.71 years, presented with average AlB levels of 32.64 +/- 8.69 ng/ml. Environmental monitoring displayed Al levels higher than TLV TWA for all the workstations studied. None of the sample displayed significant pathological conditions. Statistical comparison of the spirometric parameters showed a decrease in the examined values in exposed workers. This decrease was found to be directly proportional to the AlB level. CONCLUSION: The authors conclude that Al affects respiratory function and that limit values should be reassessed.     

Respiratory function in vineyard and orchard workers

A group of 174 male vineyard and orchard workers was studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. In addition, 115 male control workers were studied for the prevalence of chronic respiratory symptoms. There was a significantly higher prevalence of dyspnea and chest tightness in exposed compared to control workers. In particular, exposed nonsmokers had significantly higher prevalences of dyspnea and chest tightness than controls; this was found for exposed nonsmokers with both short (≤10 years) and long (>10 years) exposure. Smokers exposed for more than 10 years had significantly higher prevalences of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than smokers with shorter exposures (p < 0.01 or p < 0.05). Workers employed for more than 10 years had higher prevalences of most of the acute (shift-related) symptoms than those workers with shorter employment; however, the differences were significant only for cough in smokers (p < 0.05). Significantly lower than predicted FVC values were measured in smokers and nonsmokers after both short and long duration of employment. Differences between measured and predicted FEV₁, FEF₅₀, and FEF₂₅ were significant for workers employed for more than 10 years. A separate analysis of individual data as a percent of predicted values demonstrated that many workers had FVC (5.2%), FEV₁ (6.3%), FEF₅₀ (27.6%), and FEF₂₅ (40.2%) lower than 70% of predicted values. These data suggest that vineyard and orchard workers may develop acute and chronic respiratory symptoms and lung function changes which are, in part, related to environmental factors and to cigarette consumption. Am. J. Ind. Med. 31:250–255, 1997. © 1997 Wiley-Liss, Inc.     

A cohort mortality study of foundry workers

Since the 1970s, hygienic improvements have led to a reduction in the level of airborne pollutants in Danish foundries. This mortality study reflects the exposure situation prior to 1970, and the findings may be used as a baseline for future evaluations of the preventive impact of reduced exposure. Mortality data were derived from a historical cohort study in which 3,056 foundry workers were compared with 43,024 workers employed in other industries. The foundry workers' life-long risk of dying from pneumoconioses averaged 2% and the corresponding standardized mortality ratio (SMR) equaled 7,368 (95% confidence interval (95% CI): 4,029–12,363). Excess mortality was also seen for chronic bronchitis and emphysema (SMR = 132, 95% CI: 98–185). Nonsignificant increases were seen for buccal cancer, stomach cancer, colon cancer, and urothelial cancer. In conclusion, Danish foundry workers exposed prior to 1970 seem to suffer an excess risk of devastating lung disease of occupational origin. Am. J. Ind. Med. 32:223-233, 1997. © 1997 Wiley-Liss, Inc.     

Respiratory function and immunological status in workers employed in a latex glove manufacturing plant

A study was performed in 17 female workers employed in a latex glove manufacturing plant. The mean age of these workers was 42 years and the mean duration of their employment was 19 years. The employees were primarily nonsmokers or light smokers. The presence of chronic respiratory symptoms and acute work-related symptoms was recorded for these workers. Ventilatory capacity was measured during the morning work shift by recording maximum expiratory flow-volume curves from which forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁) and maximum expiratory flow at 50%, and the last 25% of the vital capacity (FEF₅₀, FEF₇₅) were measured. A control group of 17 nonexposed women workers was also studied. The prevalence of chronic respiratory symptoms was greater among latex workers than among control confectionry packer workers, varying from 5.9% (vs. 0% in controls) for occupational asthma to 58.8% (vs. 0% in controls) for dyspnea grades 3 or 4. There was also a high prevalence of acute work-related symptoms in this industry, in particular, eye irritation (76.5%), dryness of the nose (70.6%), throat burning (70.6%), dryness of the throat (64.7%), and cough (58.8%). Among exposed workers, measured ventilatory capacity data were significantly lower than among controls, particularly FEF₇₅ (75.1% ± 10.5%). One of the 17 studied workers (5.9%) had a positive skin reaction to latex and had symptoms compatible with occupational asthma. Our data suggest that in addition to occupational asthma, the manufacture of latex gloves is associated with frequent, nonspecific respiratory findings. Am. J. Ind. Med. 33:175–181, 1998. © 1998 Wiley-Liss, Inc.     

Respiratory function and immunological status in cocoa and flour processing workers

Respiratory function and immunological status were studied in 40 cocoa and 53 flour processing workers employed as packers in a confectionry industry and in 65 unexposed control workers in the same industry. A high prevalence of chronic respiratory symptoms was recorded in exposed workers, varying from 5.0% to 30.0% in cocoa workers and from 5.7% to 28.3% in flour workers. Occupational asthma was diagnosed in 2 (5%) of the cocoa workers and in 3 (5.7%) of the flour workers. None of the control workers suffered from occupational asthma. The prevalence of almost all chronic respiratory symptoms was significantly greater in cocoa and flour workers than in control workers. There was also a high prevalence of acute symptoms that developed during the work shift, being highest for cough (cocoa: 57.5%; flour: 50.9%) and eye irritation (cocoa: 50.0%; flour: 54.7%). Significant across-shift reductions of ventilatory capacity were recorded in exposed workers, being largest for flow rates at 50% and the last 25% of the vital capacity on maximum expiratory flow-volume (MEFV) curves (FEF₅₀, FEF₇₅). The prevalence of positive skin tests for cocoa (60.2%) was significantly higher than the prevalence of positive skin tests for flour (25.8%) among the 93 exposed workers (p < 0.05). Control workers had significantly lower prevalences of positive skin tests to cocoa (4.6%) and flour (12.3%) than exposed workers (p < 0.01). Increased total serum IgE levels were found in 17.5% of cocoa and in 18.7% of flour workers; none of the control workers had increased IgE levels. Bronchoprovocation testing demonstrated significant decreases in lung function following inhalation of cocoa dust extract and flour dust in workers with respiratory symptoms and large across-shift reductions in lung function. Dust concentrations in the working environment were higher than those recommended by Croatian standards. These data suggest that workers employed in the processing of cocoa and flour may be at a high risk for the development of allergic sensitization and respiratory impairment. Am. J. Ind. Med. 33:24–32, 1998 © 1998 Wiley-Liss, Inc.     

Respiratory function in active firefighters.

BACKGROUND: Exposure to environmental pollution during firefighting may results in the development of respiratory disorders in firefighters. METHODS: The health effects of firefighting on respiratory function was investigated in a group of 128 active firefighters by recording respiratory symptoms and measuring lung function. In addition, 88 control workers, not exposed to known pollutants were studied for the prevalence of acute and chronic respiratory symptoms. RESULTS: Significantly higher prevalences of dyspnea, nasal catarrh, sinusitis, and hoarseness were recorded in firefighters compared to control workers (P < 0.01). One subject developed asthma symptoms following two intense firefighting episodes. A high prevalence of acute symptoms experienced during and after fire extinguishing was also documented among these firefighters. Eye and throat irritation as well as headache were prominent. A logistic regression analysis of chronic respiratory symptoms demonstrated that odds ratios were significant for both duration of work exposure and for smoking. Lung function testing demonstrated a decrease in FEF75 in relation to predicted suggesting obstructive changes in the smaller airways. A regression analysis of ventilatory capacity tests indicated a positive relationship of forced vital capacity with length of employment, 1 s forced expiratory volume as well as FEF50 were related to smoking, and FEF75 was related to both smoking and length of employment. CONCLUSIONS: Our data suggest that firefighters are at risk for developing acute and chronic respiratory symptoms as well as obstructive airway changes.     

Respiratory health of automobile workers exposed to metal-working fluid aerosols: Respiratory symptoms

A total of 1,811 automobile workers at three General Motors facilities were evaluated by questionnaire for possible respiratory effects resulting from airborne exposures to metal-working fluids (MWF): 1,042 currently worked as machinists and were exposed to one of three types of MWF aerosols (straight mineral oils, soluble oil emulsions, or water-based synthetic fluids that contained no oils); 769 assembly workers, without direct exposure, served as an internal reference group (of these, 239 had never worked as machinists). Symptoms of usual cough, usual phlegm, wheezing, chest tightness, and breathlessness, as well as physician-diagnosed asthma, and chronic bronchitis were the primary outcomes examined. Machinists as a whole had higher prevalence of cough, phlegm, wheezing, and breathlessness than that of assembly workers. Adjusting for confounding, phlegm and wheeze were associated with increasing levels of current exposure to straight oils; cough, phlegm, wheeze, chest tightness, and chronic bronchitis were associated with increasing levels of current exposure to synthetics. In models that included both past and current exposure, only current exposures to straight and synthetic fluids were associated with current symptoms. Am. J. Ind. Med. 32:450–459, 1997. © 1997 Wiley-Liss, Inc.