Respiratory symptoms and lung function in jute processing workers: a primary investigation

This paper presents the results of an investigation of respiratory symptoms and lung function of 404 workers who had been exposed to jute dust in a jute mill. Measurement of total dust concentration and analysis of dust composition were also conducted. Most workers in the jute mill were exposed to jute dusts containing less than 5% silica, whereas a few workers were exposed to dusts containing approximately 10-15% silica. Male smokers and nonsmokers in the dust-exposed group had a higher prevalence of cough and chest tightness compared with those in the control group. Among dust-exposed workers, female nonsmokers had a significantly higher prevalence of cough, chronic bronchitis, chest tightness, and dyspnea than those in the control group. Lung function tests showed that dust-exposed workers had a greater incidence of abnormal lung function than did control workers, as measured by percentage of predicted forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and FEV1.0/FVC. Dust exposure was the main cause of respiratory symptoms and abnormal values of FEV1.0, but both cigarette smoking and dust exposure contributed to the abnormal values reported for FEV1.0.     

Respiratory function in animal food processing workers

A group of 71 men employed in animal food processing was studied to assess the prevalence of acute and chronic respiratory symptoms and the presence of lung function abnormalities. In addition, a control group of 55 unexposed men was studied for the prevalence of chronic respiratory symptoms. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed workers compared to the control workers. Those workers who smoked had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than the smokers in the control group. For nonsmokers, the differences between exposed and control workers were significant for chronic phlegm and chest tightness. The frequency of acute symptoms associated with the work shift was high among the animal food workers. There were significantly lower measured values for FVC, FEV1, and FEF50 in the exposed group (smokers and nonsmokers) compared to predicted lung function values. In smokers, all measured parameters of ventilatory capacity were significantly less than predicted; for nonsmokers, the FVC and FEV1 were less than normal. Our data indicate that exposure to dust in the animal food industry may be associated with the development of acute and chronic respiratory symptoms and the impairment of lung function. Smoking, in this setting, appears to aggravate these changes.     

Respiratory diseases, symptoms and ventilatory function in workers involved in processing food for livestock

The prevalence of chronic and acute respiratory symptoms and ventilatory capacity were studied in a group of 71 workers employed in animal food processing. A control group of 55 unexposed workers was also included in the study. A significantly higher prevalence for most of the chronic respiratory symptoms was found among the exposed than among control workers. Exposed smokers had a significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis and chest tightness than control smokers. The values for FVC, FEV1 and FEF50 measured in the exposed workers were significantly lower in comparison to predicted normal lung function values. In smokers all the measured parameters of ventilatory capacity were significantly lesser than predicted. For non-smokers only FVC and FEV1 were below normal. Our data indicate that occupational exposure to animal food may cause the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.     

Respiratory symptoms and ventilatory capacity in swine confinement workers.

A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes.     

Respiratory symptoms and ventilatory capacity in swine confinement workers.

A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes.     

Ventilatory function and allergic skin tests in cotton mill workers

Ventilatory capacity, chronic respiratory symptoms and respiratory diseases as well as intradermal skin tests were registered in a group of 112 cotton workers. The prevalence of chronic respiratory symptoms and respiratory diseases was higher among the exposed than among control workers although the differences were statistically significant only for chronic cough, nasal catarrh and byssinosis in women and for chronic cough, chronic phlegm and byssinosis in men. A similar prevalence of byssinosis was noted in women (29.4%) and in men (29.5%). Among textile workers mostly byssinosis grade 1/2 was found (women 22.1%, men 20.5%). There were statistically significant acute reductions over work shift for forced vital capacity (FVC) and one-second forced expiratory volume (FEV1). In men the values were somewhat lower than the expected normal values. A very small number of workers demonstrated positive intradermal skin tests to cotton allergen (exposed 8.2%, control 1.8%). Our data indicate that exposure to cotton dust may lead to the development of respiratory symptoms and diseases as well as to acute changes in ventilatory capacity but without an allergic reaction.     

Monitoring of respiratory symptoms and pulmonary ventilatory function in sisal processing workers]

The prevalence of acute and chronic respiratory symptoms and ventilatory capacity was studied in 50 textile workers exposed to sisal dust. A follow-up study was performed 19 years later and included 20 workers out of the 50. The first study showed a considerably higher prevalence of all chronic respiratory symptoms in the exposed than in control workers although the difference was statistically significant only for chest tightness (P < 0.01). Comparison of the prevalence in the first and the follow-up study in 20 textile workers revealed a statistically significant increase in the rate of chronic cough, dyspnea, chest tightness and nasal catarrh. During the follow-up study the prevalence of almost all chronic respiratory symptoms was significantly higher in exposed than in control workers. Results of ventilatory capacity in 50 sisal workers showed acute reductions of FVC and FEV1 during work shift on Monday and the following Thursday. Comparison of the measured and predicted normal values demonstrated lower values in the follow-up study in comparison to those in the first study. The mean annual fall of ventilatory capacity tests was 0.027 L for FVC and 0.036 L for FEV1. Data suggest that long-term exposure to sisal dust may cause the development of chronic respiratory symptoms and lung function impairment in sensitive subjects.     

Respiratory function and symptoms in workers exposed simultaneously to jute and hemp.

The environment and health of a working population exposed simultaneously to jute and hemp were studied. Classical symptoms of byssinosis were not present but 21 workers (7%) complained of atypical tightness of the chest. The prevalence of chronic bronchitis among the exposed workers was statistically significant in comparison with controls. Effects of dust concentrations, age and duration of exposure on the prevalence of chronic bronchitis were studied. A statistically significant reduction in FEV1.0 at the end of a work shift occurred in all the exposed workers. Bronchodilators given after the shift showed that acute reductions in forced expiratory volumes were nearly fully reversible in all exposed workers. Smokers and those with chronic bronchitis had greater reductions in FEV1.0 values at the end of the work shift.     

Respiratory health of plywood workers occupationally exposed to formaldehyde

This study was undertaken to enlarge our understanding of the adverse health effects of formaldehyde exposure in the workplace and community environment. The respiratory health status of 186 male plywood workers was evaluated by spirometric tests, respiratory questionnaires, and chest x-rays. Area concentrations of formaldehyde were measured in the work environment and found to range from 0.28 to 3.48 ppm. The average personal exposure was to 1.13 ppm of formaldehyde. Exposure to formaldehyde was associated with decrements in the baseline spirometric values, i.e., forced expiratory volume in 1 sec (FEV1.0), forced expiratory volume/forced vital capacity (FEV/FVC), and FEF25%-75%, and with several respiratory symptoms and diseases, including cough, phlegm, asthma, chronic bronchitis, and chest colds. The results of the study support the hypothesis that chronic exposure to formaldehyde induces symptoms and signs of chronic obstructive lung disease.     

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.     

Respiratory symptoms and pulmonary function in flour processing workers in the baking industry

Respiratory symptoms and ventilatory capacity were studied in 63 flour processing male bakery workers in Umtata, Transkei, Southern Africa. The controls were from a bottling plant in the same city. Both groups were black Africans from the Xhosa-speaking population. The studied population was nonsmoking and no significant difference was noted in age, race, sex, or height between the groups. The exposed workers had significantly lower forced expiratory indices than the control group. Mean percent predicted values of forced expiratory volume in one second (FEV₁), forced expiratory ratio (FEV₁/FVC x 100), forced mid-expiratory flow between 25% and 75% of FVC (FMF), forced expiratory flow between the first 200 ml and 1.200 ml of FVC (FEF 200-1,200), and peak expiratory flow rate (PEF) were, respectively, 11.2%, 20.0%, 31.0%, 27.4%, and 36.1% lower in the exposed group compared with the controls. The prevalence of forced expiratory ratio less than 70% in the exposed group was 37% while in the controls it was 8%. The prevalence of PEF rate less than 5 l/s in the exposed group was 32% while in the controls it was 11%. The exposed workers reported a significantly higher prevalence of respiratory symptoms compared to the controls. The prevalence of nasal symptoms, phlegm, and cough in the exposed workers was 53.9%, 30.1%, and 25.4%, respectively. The present study demonstrated that exposure to flour dust in flour processing workers in the baking industry is associated with significantly lower pulmonary functions and a higher prevalence of respiratory symptoms, and that these workers show signs of airway obstruction, compared to workers not exposed to flour. Flour processing workers have a significant occupationally related respiratory impairment.     

Respiratory Health of Plywood Workers Occupationally Exposed to Formaldehyde

This study was undertaken to enlarge our understanding of the adverse health effects of formaldehyde exposure in the workplace and community environment. The respiratory health status of 186 male plywood workers was evaluated by spirometric tests, respiratory questionnaires, and chest x-rays. Area concentrations of formaldehyde were measured in the work environment and found to range from 0.28 to 3.48 ppm. The average personal exposure was to 1.13 ppm of formaldehyde. Exposure to formaldehyde was associated with decrements in the baseline spirometric values, i.e., forced expiratory volume in 1 sec (FEV_(1.2) forced expiratory volume/forced vital capacity (FEV/FVC), and FEF_25%-75%, and with several respiratory symptoms and diseases, including cough, phlegm, asthma, chronic bronchitis, and chest colds. The results of the study support the hypothesis that chronic exposure to formaldehyde induces symptoms and signs of chronic obstructive lung disease.     

Respiratory function in greenhouse workers

Summary Respiratory 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 symptoms and lung function in furriers

Forty women who had been occupationally exposed in the fur coat manufacturing industry were studied. The mean age was 30 years; mean duration of exposure was 14 years. A group of 31 females who did not work in the furrier industry also was included in the study as the control group. A higher prevalence of all chronic respiratory symptoms was found among furriers when compared with controls; these differences were statistically significant for nasal catarrh (p less than 0.05) and sinusitis (p less than 0.01). Among the furriers, the highest prevalence of respiratory symptoms was recorded for chronic cough in 20 workers (50.0%), followed by sinusitis in 12 (30.0%), dyspnea in 10 (25.0%), and nasal catarrh in 8 workers (20.0%). Among the furriers, two (5.0%) had symptoms characteristic of occupational asthma. Most of the symptomatic furriers complained of acute symptoms during their work shifts. Statistically significant mean reductions in lung function over the work shift were recorded in furriers for forced vital capacity (FVC), -4.1%; one-second forced expiratory volume (FEV1), -5.2%; and flow rate at 50% vital capacity (FEF50%), -6.3%. Furriers demonstrated significantly lower mean Monday preshift measurements for FVC and flow rate at 25% (FEF25%) (p less than 0.05) when compared with those predicted. Preshift administration (by spinhaler) of 40 mg disodium cromoglycate in three workers reduced the intensity of acute respiratory symptoms and diminished the reductions in ventilatory capacity over the work shift. Data from six additional male workers demonstrated similar findings for symptoms and lung function. Our data suggest that furriers are at risk of developing both acute and chronic respiratory symptoms as well as ventilatory capacity impairment as a result of occupational exposure.     

Exposure to ammonia and acute respiratory effects in a urea fertilizer factory

Personal exposures to ammonia and acute respiratory effects were determined in workers at a urea fertilizer factory in Bangladesh. Full-shift personal exposure to ammonia was measured using a PAC III direct reading instrument and Drager diffusion tubes. Respiratory symptoms were elicited by a questionnaire study (n = 113), and preshift and postshift lung function (FVC, FEV1, and PEFR) were tested using spirometry (n = 88). Urea plant workers had higher mean exposure to ammonia and prevalence of acute respiratory symptoms than did workers in the ammonia plant. The symptoms with highest prevalence in the urea plant were chest tightness (33%) and cough (28%). FVC and FEV1 decreased significantly across the work shift among urea plant workers. The higher level of exposure to ammonia in the urea plant was associated with an increased prevalence of respiratory symptoms and an acute decline in lung function.     

Byssinosis in Guangzhou, China.

OBJECTIVES--To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton. METHODS--All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer. RESULTS--The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure. CONCLUSION--It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis.     

Respiratory findings in spice factory workers

The respiratory consequences of working in the spice industry were studied in 92 female spice factory workers (mean age, 36 yr; mean exposure, 12 yr). A control group of 104 female workers employed in a nondusty industry was also studied. The prevalence of chronic respiratory symptoms was significantly higher in the exposed than in the control group. In particular, the prevalence of dyspnea (57.6%), chronic cough (22.8%), chronic phlegm and chronic bronchitis (19.6%), nasal catarrh (37.0%), and sinusitis (22.2%) was high when compared to controls (p less than .01). Among spice factory workers, a high prevalence of acute symptoms during the workshift was recorded. Acute reductions in lung function were statistically significant over the workshift for forced vital capacity (FVC), -2.0%; forced expiratory volume in one second (FEV1.0), -3.0%; and for maximum expiratory flow rates at 50% (FEF50), -8.3% and at 25% (FEF25), -15.2% measured on maximum expiratory flow-volume (MEFV) curves. No difference was found in across-shift ventilatory function in workers with or without chronic respiratory symptoms, except for FEF25 (with symptoms, 16.7%; without symptoms, 9.6%). Preshift administration of 40 mg of disodium cromoglycate (DSC) inhaled 15 min before the workshift significantly diminished acute reductions in FEF50 and FEF25 in exposed workers. Monday preshift FEF50 and FEF25 in exposed workers were significantly lower than in control workers (p less than .01), which suggests an early irreversible component to this illness.     

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.     

接触棉尘工人呼吸系统早期反应──症状与肺功能改变

１６３名棉纺厂新工人（既往无棉麻粉尘接触史）入厂１０周后随访发现：４０人（２４．５％）出现呼吸道刺激症状，未观察到典型＂星期一症状＂。各车间症状阳性率呈现随可吸入棉尘浓度或内毒素水平升高而上升的趋势，γ＝０．９４，Ｐ＜０．０１。肺功能改变：入厂后ＦＶＣ比入厂前平均上升１２５．３ｍｌ，Ｐ＜０．０１；ＦＥＶ１平均上升８７．５９ｍｌ，Ｐ＜０．０１。ＦＥＶ１在入厂后占入厂前的比例平均为１０３．８％，其中仅１例低于８０％。班后ＦＶＣ比班前平均下降４６，０８ｍｌ，Ｐ＜０．０１；ＦＥＶ１平均下降１６．４６ｍｌ，Ｐ＜０．０５。班后ＦＥＶ１下降率≥５％者２２人（１３．５％），≥１０％者７人（４．３％）。上述改变与吸烟、暴露水平等因素无关。     

Epidemiological-environmental study of diesel bus garage workers: acute effects of NO2 and respirable particulate on the respiratory system

Personal samples of nitrogen dioxide (NO2) and respirable particulate (RP) were collected over the shift on 232 workers in four diesel bus garages. Response was assessed by an acute respiratory questionnaire and before and after shift spirometry. Measures of exposure to NO2 and RP were associated with work-related symptoms of cough; itching, burning, or watering eyes; difficult or labored breathing; chest tightness; and wheeze. The prevalence of burning eyes, headaches, difficult or labored breathing, nausea, and wheeze experienced at work were higher in the diesel bus garage workers than in a comparison population of battery workers, while the prevalence of headaches was reduced. Mean reductions in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), peak flow, and flows at 50 and 75% of FVC were not obviously different from zero. There was no detectable association of exposure to NO2 or respirable particulate and acute reductions in pulmonary function. Workers who often had respiratory work-related symptoms generally had a slightly greater mean acute reduction in FEV1 and FEF50 than did those who did not have these symptoms, but these differences were not statistically significant.