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.

[Ventilatory capacity and respiratory symptoms in brickyard workers]. / Ventilacijski kapacitet i respiracijski simptomi radnika u proizvodnji cigle.

We studied 233 male brickyard workers and 149 matched non-exposed control workers. The mean age of the brickyard workers was 35 years with the mean duration of employment in this industry of 16 years. Significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%) and chest tightness (24.0%) was found in the exposed workers than in controls (20.1%; 18.1%; 0%) (P < 0.05). A high prevalence of acute symptoms during work shift, particularly dry throat and eye and throat irritation, were found in the brickyard workers. The measured FVC and FEV1 values were significantly lower than predicted values. On the other hand, the measured FEF50 and FEF25 were not significantly lower than predicted. This was found in the exposed smokers and nonsmokers. Dust concentrations were considerably higher than recommended for dust which contains up to 70% of SiO2. Our data suggest that the brickyard workers display a high potential to develop acute and chronic respiratory symptoms and mostly restrictive changes of lung function.

[Respiratory findings in textile workers employed in dyeing wool and cotton]. / Respiracijski nalazi tekstilnih radnika zaposlenih na bojenju vune i pamuka.

The prevalence of acute and chronic respiratory symptoms and diseases and ventilatory capacity were studied in 97 textile workers employed in dyeing wool and cotton fibres and in 76 non-exposed control workers. The prevalence of chronic respiratory symptoms was significantly higher in the textile workers compared to controls. The symptoms of occupational asthma were recorded in 7.2 per cent of the textile workers. The prevalence of respiratory symptoms was higher in exposed smokers than in exposed non-smokers. The textile workers employed for more than 10 years had a higher prevalence of all respiratory symptoms than those with a shorter period of employment. The textile workers showed a high prevalence of acute symptoms which developed during work shift. Significant acute reductions of ventilatory capacity tests on maximum expiratory flow-volume curves (MEFV) in textile workers varied from 5.1% for FVC to 12.4% for FEF25. Ventilatory capacity tests in the textile workers before work shift were significantly diminished in comparison to the predicted values. Our data indicate that work in the textile dyeing industry may cause the development of respiratory symptoms and diseases as well as impairment of ventilatory capacity.

[Respiratory symptoms, diseases and ventilatory function in shoe industry workers]. / Respiracijski simptomi i bolesti te ventilacijska funkcija pluca radnica na izradi obuce.

The respiratory health status was studied in 376 female shoe workers. The mean age of workers was 32 years and the mean exposure 12 years. A significantly higher prevalence of all chronic respiratory symptoms and diseases was found in exposed compared to control workers. This was particularly pronounced for chest tightness (exposed: 44.7%; control: 0%), dyspnoea (exposed: 42.6%; control: 2.0%) and rhinitis (exposed: 46.3%; control: 2.4%). In exposed workers there was also a high prevalence of acute symptoms which developed during work shift, particularly irritation of the throat (56.6%), dryness of the throat (61.4%), dryness of the nose (56.4%), and eye irritation (63.6%). The prevalence of acute and chronic respiratory symptoms and diseases increased with duration of exposure. There were also statistically significant acute reductions in all ventilatory capacity tests (FVC, FEV1, FEF50, FEF25) during work shift. The measured ventilatory capacity values in exposed workers were significantly lower in comparison with the predicted values (P < 0.01). Lung function severity increased with duration of employment. The data suggest that occupational exposure to atmospheric pollution in the shoe manufacturing industry may be responsible for the development of acute and chronic respiratory impairment.

[Disorders of the respiratory tract in workers in the chemical industry]. / Poremecaji disnog sustava zaposlenih u kemijskoj industriji.

This paper studies the prevalence of chronic respiratory symptoms and diseases in 567 chemical workers and in 340 controls as well as their ventilatory capacity. The prevalence of all chronic respiratory symptoms was found to be significantly higher in the exposed workers than in controls (p < 0.01). Workers aged over 40 and those employed for over 10 years demonstrated higher prevalence of chronic respiratory symptoms than the workers up to 40 and those employed for up to 10 years, although the differences were not statistically significant. A large number of chemical workers complained of acute respiratory symptoms manifesting during the shift. The measured values of ventilatory capacity in chemical workers were significantly lower than those predicted. The findings were more pronounced in workers over 40 and in those employed for over 10 years. The measured values of gases and fumes in the working environment were mostly below the recommended values. Our data suggest that, in spite of low atmospheric pollution of the working environment, sensitive workers may develop respiratory impairments.

[Follow-up study of changes in respiratory function in the same workers after an additional 6 years of exposure to pollutants in the rubber industry]. / Ponovljeno ispitivanje promjena respiratorne funkcije istih radnika nakon daljnjih sest godina izlozenosti oneciscenjima u industriji gume.

Follow-up study of respiratory function was carried out in a group of 311 male workers employed in one rubber industry. The prevalence of respiratory symptoms and ventilatory capacity were recorded over te period of six years. Lung function was measured by recording maximum expiratory flow-volume (MEFV) curves on which forced vital capacity (FVC), one-second forced expiratory volume (FEVI) and flow rates at 50% and the last 25% of the vital capacity (FEF50, FEF25) were read. The prevalence of all chronic respiratory symptoms was higher during the follow-up study although not statistically significant (p > 0.05). During both studies smokers had significantly higher prevalence of chronic cough, chronic phlegm and chronic bronchitis than nonsmokers (p < 0.05 or < 0.025). Measured values of ventilatory capacity were significantly lower than predicted normal values during both studies (p < 0.01). Percentage of predicted values were lower during the follow-up study in comparison to that during the initial study. The mean lowest percentages were obtained for FEF25 (initial study: 77.4%; follow-up study: 70.5%). Smokers had larger mean annual decrease of FVC: 0.073 L; FEVI: 0.063 L; FEF50: 0.100 L/s; FEF25: 0.085 L/s than nonsmokers (FVC: 0.063 L; FEVI: 0.058 L; FEF50: 0.083 L/s; FEF25: 0.058 L/s). Workers exposed for more than 10 years had larger mean annual decrease of ventilatory capacity tests than hose with shorter exposure. Our data indicate that exposure to noxious agents in rubber industry may be responsible for the development of chronic respiratory symptoms and chronic lung function changes.

[Respiratory function in rubber-processing workers]. / Respiratorna funkcija radnika na preradi gume.

The prevalence of acute and chronic respiratory symptoms and diseases as well as lung function changes were studied in 409 rubber male workers and 172 nonexposed control male workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves on which forced vital capacity (FVC), one second forced expiratory volume (FEV1) and flow rates at 50% and the last 25% of vital capacity were calculated (FEF50, FEF25). A significantly higher prevalence of all chronic respiratory symptoms except asthma was found in rubber workers in comparison to the controls. Smokers had significantly higher prevalence of most of the chronic respiratory symptoms than nonsmokers. Rubber workers exposed for more than 10 years had also significantly higher prevalence of chronic respiratory symptoms than those with shorter exposure. A high prevalence of acute symptoms during work shift was recorded in rubber workers. Ventilatory capacity was mostly decreased during work shift, particularly FEF50 and FEF25. All acute reductions were greater in rubber workers exposed for more than 10 years as compared to those with shorter exposure. Alupent inhaled at the end of the work shift significantly improved decreased values. Rubber workers demonstrated significantly lower ventilatory capacity tests with respect to the controls. A large number of rubber workers showed a decrease in lung functions tests less than 70% of the predicted normal values. Our data suggest that rubber workers are exposed to numerous noxious agents which may lead to acute and/or chronic impairment of lung function.

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 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.

Longitudinal study of respiratory findings in rubber workers.

A cross-sectional assessment of respiratory function and symptoms was performed in 1985 on 409 male rubber workers and 172 unexposed control workers. A follow-up study in 311 of the original rubber workers was performed 6 years later. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. At the time of the initial study, significantly higher prevalences of all chronic respiratory symptoms, except for asthma, were found among the rubber workers compared to controls. Smokers had a significantly higher prevalence of most of the chronic respiratory symptoms compared with nonsmokers. A high prevalence of acute symptoms during the workshift was recorded among the rubber workers at both surveys. Rubber workers demonstrated significantly lower ventilatory capacity measurements compared to predicted. Ventilatory capacity measurements diminished significantly across the workshift, particularly FEF50 and FEF25. Metaproterenol inhaled at the end of the workshift significantly improved lung function in a small group of sensitive rubber workers. Annual lung function loss among both smokers and nonsmokers was in excess of predicted. Our data suggest that exposure to noxious agents in the rubber industry are associated with the development of acute and chronic respiratory impairment.