Jadranka Mustajbegović

Respiratory Findings in Workers Employed in the Brick-manufacturing Industry

We studied 233 male workers employed in two brick-manufacturing plants and 149 matched control workers. The mean age of the brick workers was 35 years, with a mean duration of employment in this industry of 16 years. The prevalence of chronic respiratory symptoms as well as acute symptoms during the work shift were recorded. Lung function was measured on Monday during the work shift by recording maximum expiratory flow-volume (MEFV) curves, from which the forced vital capacity (FVC), the one-second forced expiratory volume (FEV1) and flow rates at 50% and the last 75% of the FVC (FEF50, FEF75) were measured. The results of periodic chest roentgenograms were reviewed. There was a significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%), and chest tightness (24.0%) in exposed workers, compared with control workers (20.1%; 18.1%; 0%) (P < 0.05). This increased symptom frequency was also documented among nonsmokers studied by age and by length of employment, suggesting a work-related effect. Among work shift-related symptoms, high prevalences were noted for upper respiratory tract symptoms (e.g., dry throat, eye irritation, throat irritation). The measured FVC and FEV1 were significantly lower than predicted for brick workers and suggested a restrictive pattern. The mean FVC (as a percent of predicted) was 78.1% and FEV1 was 88.1%. The FEF50 and FEF25 were not significantly decreased. A multiple regression analysis with age, exposure, and smoking as predictors and lung function parameters as response variables showed a significant effect between exposure and FVC. Significant chest roentgenographic abnormalities were not documented. These findings of a restrictive lung function pattern in brick workers with normal chest roentgenograms may suggest early interstitial disease. Additionally, a bronchitic component, as suggested by the respiratory symptoms, may also be present.

Respiratory function in greenhouse workers

SummaryRespiratory findings were studied in a group of 135 female and 32 male workers employed in greenhouses. In addition 51 women and 30 men were studied as a control group. Exposed women had significantly higher prevalences of chronic cough, dyspnea, chest tightness, and rhinitis (P < 0.01) than the controls. Among the men, only rhinitis was more prevalent in greenhouse workers (P < 0.01) than in controls. Smokers had higher prevalences of all chronic respiratory symptoms than nonsmokers, but the differences were statistically significant only for chronic cough and rhinitis in women and for chronic phlegm in men. There was a high prevalence of acute symptoms during work. A large number of greenhouse workers complained of skin reactions to plants and pesticides (women: 37.8%; men: 34.4%). Workers had significantly lower mean ventilatory capacity measurements (except in the case of forced vital capacity) when compared to standard predicted values. Smokers and nonsmokers had similar values of lung function expressed as percentages of the predicted values. Greenhouse workers exposed for more than 10 years had a significanty lower FEF25, measured as a percentage of the predicted value, than workers exposed for less than 10 years. Our data indicate that occupational exposure to greenhouses may be associated with the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.

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 confectionery 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.

Immunological and respiratory findings in swine farmers

The prevalence of respiratory symptoms and ventilatory capacity abnormalities in relation to immunological status was studied in 32 swine farmers and in 39 controls. A large number of swine farmers reacted to swine confinement building antigens (swine hair, 34%, swine confinement agents, 28%) but also to other extracts such as animal food (78%) and corn flour (37%). Control workers also reacted to these antigens in similar frequencies. Increased serum IgE levels were found in 3 swine farmers (9.4%) and all 3 had positive skin tests to at least one of the swine antigens. Among control workers one (2.6%) had an increased serum IgE level; this worker exhibited a positive skin reaction to swine food antigen. Swine farmers with positive skin reactions had across-shift reductions of FEF50 and FEF25 significantly larger than those with negative skin tests (P less than 0.01). Preshift measured ventilatory capacity data (FEV1, FEF50, FEF25) in swine farmers with positive skin tests were significantly lower (compared to predicted) than in those with negative skin tests. Additionally, we showed that a water-soluble swine confinement building antigen causes a dose-related contraction of nonsensitized guinea pig trachea smooth muscle studied in vitro. Our data indicate significant differences in lung function between swine workers with positive and negative skin tests. We suggest that skin testing may be helpful in identifying workers at risk for developing lung disease.

Respiratory Function and Immunologic Status in Workers Processing Dried Fruits and Teas

BACKGROUND Workers exposed to different organic aerosols may develop respiratory symptoms and lung function changes. OBJECTIVES To study the immunologic status and respiratory function in workers processing dried fruits and teas. METHODS The study was performed in 54 exposed and in 40 non-exposed female workers. Skin prick testing was performed with occupational allergens derived from the workplace. Respiratory symptoms were recorded for all workers. Lung function was measured in exposed workers by recording maximum expiratory flow-volume (MEFV) curves. RESULTS Significantly more exposed workers than controls reacted with positive skin tests to at least one of the occupational allergens (P < .01). Only the response to sage was significantly greater in exposed (60.0%) than in control workers (20.0%) (P < .01). Thirty percent of these workers had elevated IgE level (compared with 2.5% of control workers) (P < .01). Higher prevalences of all chronic respiratory symptoms were noted in exposed compared with control workers. The exposed workers with positive skin tests had significantly higher prevalences of dyspnea (P < .05) and nasal catarrh (P < .01) than those with negative skin tests. A large number of exposed workers complained of acute symptoms that developed during the work shift. In exposed workers there were statistically significant across-shift reductions of ventilatory capacity, particularly for FEF50 and FEF25 on Monday and the following Thursday. Skin test status was not associated with more severe changes in lung function. The mean FEF25 measured before the Monday shift was significantly lower than predicted (P < .01). CONCLUSION Our data suggest that following exposures to aerosols of dried fruits and teas some workers develop deleterious immunologic and respiratory changes.

Respiratory function of textile workers employed in dyeing cotton and wool fibers

A group of 135 textile dyeing workers (97 male and 38 female) was studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. Respiratory symptoms were elicited by a standardized questionnaire, and lung function testing was performed before and after the morning shift by recording maximum expiratory flow-volume (MEFV) curves. In addition, 103 nonexposed control workers were studied. The prevalence of all chronic respiratory symptoms was significantly higher in the exposed than in the control workers; in particular, the prevalence of occupational asthma was 6%. The exposed nonsmoking workers had more complaints than the controls who were nonsmokers. As expected, most of the symptoms were more prevalent in smokers than in nonsmokers. Nonsmokers with both long- and short-term work exposure had higher prevalences of dyspnea and rhinitis than control workers. Smokers exposed for 10 years or less had significantly higher prevalences of chronic phlegm than nonsmokers with the same duration of exposure (p < 0.05). In workers exposed for > 10 years, there were significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis in smokers than in nonsmokers (p < 0.01). A high prevalence of shift-related symptoms was found in exposed workers. Significant across-shift reductions of ventilatory capacity tests were documented in this cohort and varied from an average of 4.0% for FVC to 14.2% for FEF25. Preshift values of ventilatory capacity were significantly lower in this exposed population compared to predicted values suggesting a chromic effect. Our data suggest that textile dyeing workers develop acute and chronic respiratory impairment as a result of their exposures. These findings are exacerbated by cigarette smoking.

Respiratory findings in farmworkers.

This investigation was designed to study respiratory problems in farmworkers. To better define the consequences of this work environment on respiratory health, 814 farmworkers (738 male and 76 female) were studied . The mean age of the men in this study was 38 years, and the mean duration of their employment was 15 years. For women, the mean age was 44 years and the mean duration of their employment was 10 years. Of the men, 56.5% were regular smokers, and 23.7% of the women were regular smokers. A group of 635 control workers without significant exposure to air pollutants were matched by sex, age, employment, and smoking habit. The prevalence of chronic symptoms among male farmworkers was greater (P < 0.01) than among male control subjects for chronic cough (24.8% vs 11.4%), chronic phlegm (22.8% vs 9.1%), and chronic bronchitis (20.1% vs 7.4%). Among women farmworkers, a significant difference was noted with controls for chest tightness (farmworkers, 21.1%; control subjects, 0%;P < 0.001). There was a high prevalence of acute symptoms among male and female farmworkers. In particular, farmworkers complained of more frequent cough, eye irritation, dyspnea, and throat irritation than did control subjects. For respiratory symptoms in male and female farmworkers, odds ratios were generally significant for smoking, age, and duration of employment. Ventilatory capacity tests were significantly reduced for farmworkers compared with predicted values. Regression analysis of ventilatory capacity tests in male farmworkers as a percentage of predicted values demonstrated significant coefficients for employment and smoking. Our data suggest that farmworkers are exposed to noxious agents that cause respiratory symptoms and ventilatory capacity impairment.

Immunological and respiratory reactions in workers exposed to organic dusts

The relationship of skin reactivity and serum immunoglobulin E (IgE) levels to the prevalence of chronic respiratory symptoms and to ventilatory capacity is examined in workers exposed to different organic aerosols. The results from group of control workers similarly tested are also presented. Workers exposed to occupational allergens had positive skin tests more frequently than did controls, except for soy bean workers. Workers with positive skin tests to occupational allergens had a higher prevalence of almost all symptoms than those with negative skin tests although the differences did not always reach statistical significance. Workers with positive skin reactions in general had significantly higher serum IgE levels than did workers with negative skin reactions. There were across-shift reductions of ventilatory capacity in all groups of exposed workers, varying for forced vital capacity from 1.7% to 13.3%, for forced expiratory volume from 0.4%–21.9%, for maximum flow rates at 50% from 1.5% to 16.1% and for maximum flow rates at the last 25% of control vital capacity from 0% to 24.9%. There was, however, no correlation between acute and chronic lung function changes and skin reactivity or IgE values. Our data suggest that although exposure to organic aerosols may be associated with frequent immunologic reactions, these findings do not predict objective respiratory impairment.

Respiratory findings in livestock farmworkers

Inthis cross-sectional study, the prevalence of acute and chronic respiratorysymptoms and lung function were investigated in 236 (169 male and 67 female)livestock farmworkers raising domestic animals, including cattle and horses.The prevalence of acute and chronic respiratory symptoms was recorded byadministering a modified version of the British Medical Research Councilquestionnaire on respiratory symptoms. Lung function was measured by recordingthe maximum expiratory flow-volume curves from which the forced vitalcapacity, the one-second forced expiratory volume, and the maximum expiratoryflow rates at 50% and the last 25% were measured. There was a significantlyhigher prevalence of almost all chronic respiratory symptoms in farmerscompared with controls: highest among men for chronic cough (27.2%) andhighest among women for dyspnea (28.3%). Typical symptoms of occupationalasthma were diagnosed in 3.6% of the male and 1.5% of the female livestockfarmers. A logistic regression analysis performed on chronic respiratorysymptoms of livestock workers indicate significant effects of smoking(P < 0.001) on all symptoms exceptoccupational asthma. A large number of male and female livestock farmworkerscomplained of acute work-related symptoms: highest for dry cough (52.2%) andshortness of breath (44.9%). Lung function data among these workersdemonstrated a trend toward lower lung function in general. Multivariateanalysis of lung function parameters indicate significant effects of length ofemployment and smoking in male and length of employment in female livestockfarmworkers. The data suggest that employment in livestock farming may beassociated in a dose-dependent manner with the development of acute andchronic respiratory symptoms and lung functionchanges.: In this cross-sectional study, the prevalence of acute and chronic respiratory symptoms and lung function were investigated in 236 (169 male and 67 female) livestock farmworkers raising domestic animals, including cattle and horses. The prevalence of acute and chronic respiratory symptoms was recorded by administering a modified version of the British Medical Research Council questionnaire on respiratory symptoms. Lung function was measured by recording the maximum expiratory flow-volume curves from which the forced vital capacity, the one-second forced expiratory volume, and the maximum expiratory flow rates at 50% and the last 25% were measured. There was a significantly higher prevalence of almost all chronic respiratory symptoms in farmers compared with controls: highest among men for chronic cough (27.2%) and highest among women for dyspnea (28.3%). Typical symptoms of occupational asthma were diagnosed in 3.6% of the male and 1.5% of the female livestock farmers. A logistic regression analysis performed on chronic respiratory symptoms of livestock workers indicate significant effects of smoking (P < 0.001) on all symptoms except occupational asthma. A large number of male and female livestock farmworkers complained of acute work-related symptoms: highest for dry cough (52.2%) and shortness of breath (44.9%). Lung function data among these workers demonstrated a trend toward lower lung function in general. Multivariate analysis of lung function parameters indicate significant effects of length of employment and smoking in male and length of employment in female livestock farmworkers. The data suggest that employment in livestock farming may be associated in a dose-dependent manner with the development of acute and chronic respiratory symptoms and lung function changes.

Respiratory function and immunological status in paper-recycling workers

The respiratory function and immunological status of workers employed in the paper recycling industry were studied. The mean age of the 101 studied workers was 41 years, and the mean duration of their exposure was 17 years. A group of 87 unexposed workers of similar age, duration of employment, and smoking history was studied for the prevalence of chronic respiratory symptoms. Lung function in the paper workers was measured by recording maximum expiratory flow volume (MEFV) curves and recording forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and maximum expiratory flow rates at 50% and the last 25% of the FVC (FEF50, FEF25). Immunological studies were performed in all 101 paper workers and in 37 control workers (volunteers). These included skin-prick tests with paper-dust extracts and other nonoccupational allergens, as well as the measurement of total serum immunoglobulin E. Significantly higher prevalences of all chronic respiratory symptoms were found in paper compared with control workers (P < 0.01). The highest prevalences were found for chronic cough (36.6%), chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), and dyspnea (18.8%). Occupational asthma was diagnosed in four (4.0%) of the paper workers. A logistic regression analysis performed on chronic respiratory symptoms of paper workers indicated significant effects of smoking and exposure, with the smoking effect being the most important. Multivariate analysis of lung-function parameters indicate significant effects of exposure. For paper workers, the measured FEF50 and FEF25 were significantly decreased, compared with predicted values, suggesting obstructive changes located primarily in smaller airways. Among 101 tested paper workers, 16 (15.8%) had positive skin-prick tests to at least one of the paper extracts; none of the control workers reacted to these extracts. Increased serum IgE levels were found in 21% of the paper workers and in 5% of control workers (P < 0.05). Paper workers with positive skin-prick tests to any of the paper and/or other tested extracts had higher prevalences of chronic respiratory symptoms and lower measured lung-function tests compared with predicted than did those with negative skin-prick tests, but the differences were not statistically significant. The measured concentrations of total and respirable dust in this industry were higher than those recommended by Croatian standards. Our study suggests that work in the paper-recycling industry is associated with respiratory impairment and that sensitive workers employed in this industry may be at particular risk of developing chronic respiratory abnormalities.