Search

A group of 57 female workers employed in the processing of poultry food and 51 nonexposed control workers were studied to determine the possible relation between respiratory and immunological findings in poultry food workers. The prevalences of all chronic respiratory symptoms were significantly higher in exposed than in control workers (P < 0.01) except for occupational asthma. The highest prevalence of chronic respiratory symptoms in exposed workers was found for chronic cough (49.1%), followed by dyspnea (43.9%), rhinitis (38.6%), chronic phlegm (31.6%), and chronic bronchitis (26.3%). Occupational asthma was found in 5.3% of exposed workers. Exposed workers with a positive skin prick test to poultry food extract demonstrated higher prevalences of all chronic respiratory symptoms than those with negative skin tests, although the difference was statistically significant only for rhinitis (P < 0.05). The most frequent skin reactions were found for poultry food extract (exposed: 66.7%; control: 25.5%; P < 0.05). An increased IgE serum level was found in 19 (33.3%) of the exposed and in four (7.8%) of the control workers (P < 0.01). Three exposed workers with occupational asthma demonstrated an increased serum IgE level. Our data confirm previous results indicating that occupational exposure to poultry food dust may be associated with the development of chronic respiratory symptoms and immunological changes in exposed workers.

A prospective study of respiratory function was performed in a group of 70 jute and 40 control workers. At the initial study there were consistently higher prevalences of all chronic respiratory symptoms in jute workers compared to control workers; however, the differences were statistically significant only for dyspnea (P < 0.05). At the follow-up study 19 out of the original 70 jute workers were examined 19 years later. There was a significant increase in the prevalence of almost all chronic respiratory symptoms among these workers. Similar across-shift reductions of forced vital capacity (FVC) and the 1-s forced expiratory volume (FEV1) were recorded on Monday and the following Thursday at the initial study. In the 19 jute workers followed prospectively there were similar across-shift reductions of FVC and FEV1 at the first and the follow-up study, the reduction being slightly larger for FEV1 than for FVC. Only one jute worker (5.3%) and two control workers (5.7%) responded to skin testing with specific textile extracts. Two workers developed symptoms of occupational asthma. One of these workers had a positive response to skin testing with jute extract. Our data suggest that exposure to jute dust may cause the development of chronic respiratory symptoms in some workers.

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.

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.

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.

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 significantly 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.

Exposure to aerosols of organic dusts such as coffee, tea, spices, soy, fur, and animal food in an occupational setting can affect the respiratory health of industrial workers. Based on our experience with workers from many small industries processing organic materials, we discuss the clinical features and possible mechanisms responsible for the respiratory impairment associated with these types of dust exposure. Significantly higher prevalences for most chronic respiratory symptoms were found among exposed workers than among control workers. Smoking appears to aggravate these symptoms. A large number of exposed workers complained of acute symptoms which developed during the work shift. In exposed workers, significant across-shift reductions in lung function were recorded for all spirometric tests, but particularly for the flow rates at 50% and 25% of vital capacity on maximum expiratory flow-volume curves. Comparison of preshift measured ventilatory capacity tests with predicted normal values indicates that these workers demonstrate obstructive changes affecting primarily flow rate at low lung volumes. The data suggest that exposure to organic aerosols in industrial settings, particularly in conjunction with smoking, may be associated with the development of chronic obstructive lung disease.

A group of 117 women occupationally exposed in a pickling factory were studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. Workers were studied by task which included (1) pickling, (2) mustard making, and (3) packing. Similar prevalences for all respiratory symptoms were seen for the three workers groups, with all groups having significantly higher prevalences of chronic cough (P < 0.05), chest tightness, nasal catarrh, and sinusitis (P < 0.01) than a nonexposed control group from a bottling plant. Prevalences of acute symptoms were greater for pickling than for mustard or packing workers. Measured forced expiratory volume in 1 s and maximum flow rates at 50% and the last 25% of the control vital capacity were in general significantly lower than predicted values for the worker subgroups. Pickling workers exposed for more than 1 year in the industry had greater across-shift reductions for all spirometric parameters tested than those workers exposed for 1 year or less. Our data suggest that extended occupational exposure in the pickling industry results in acute exposure-related respiratory effects and ultimately may lead to the development of chronic respiratory symptoms and changes in baseline lung function.

Immunological status and its relation to respiratory findings were studied in 42 female textile workers occupationally exposed to hemp dust and in 49 female control workers. Skin prick tests with hemp or flax dust extracts from different parts of the mill in hemp workers demonstrated the following frequencies of positive tests to antigens: a mixture of hemp and flax extracts (64%), followed by flax extracts (48%), hemp from combing machines (41%), hemp from carding machines (38%), hemp from spinning and weaving machines (33%), and hemp from softening machines (20%). The prevalence of positive skin tests to hemp or flax allergens in control workers was consistently lower, ranging from 21 to 5%. Increased total serum IgE was recorded in 35.7% of hemp workers compared to only 5.0% of control workers (P < 0.05). Hemp workers with positive skin tests had significantly higher prevalences of chronic respiratory symptoms than those with negative skin tests. There were, however, no differences for acute symptoms between workers with positive and negative skin tests. Across-shift changes and baseline lung function were not different when compared by immunologic status. We showed additionally that a water-soluble extract of hemp dust causes a dose-related contraction of nonsensitized guinea pig tracheal smooth muscle when studied in vitro. Our results suggest that frequent immunologic abnormalities can be documented in hemp workers but, with the exception of chronic respiratory symptoms, in general, these do not correlate with respiratory findings.

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.

Immunological parameters were studied in a group of 24 cotton textile workers. These were volunteers from a cohort of 106 (83 women and 23 men) previously studied textile workers. A group of 30 employees from a bottle packing plant served as a control for the immunologic studies. The subgroup of volunteers undergoing immunologic testing did not differ from the original cohort of textile workers in age, sex, smoking history, or prevalence of most chronic respiratory symptoms, nor were there any significant differences in baseline lung function or across-shift changes. The 24 cotton worker volunteers underwent skin testing with extracts of cotton dust and cotton seed. Eight of these 24 (33.3%) had positive tests, and 5 of the 8 had elevated serum immunoglobulin E (IgE) levels. Only one of the 8 skin-test-positive workers had symptoms of byssinosis. Only 1 of 30 control workers' skin tested with cotton extract reacted, and none had an increased serum IgE level (P less than 0.01). Both baseline lung function and across-shift changes did not differ between workers with positive and negative skin test reactions or between workers with normal and elevated IgE levels. Additionally, we studied the response in vitro of nonsensitized guinea pig trachea to cotton bract extract and demonstrated a dose-dependent contractile response. These data suggest that while immunological findings are frequent in textile workers, they correlate poorly with respiratory symptoms and function and may not be the basis for the airway obstruction seen in this disease.

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.

The lung function response to inhalation of an extract of green coffee was studied in ten healthy subjects who were prescreened for airway hyperresponsiveness to an aerosol of green coffee extract. The effects of this provocation were evaluated at rest and following moderate exercise as well as with and without pretreatment with 80 mg of disodium cromoglycate (DSCG). There was a statistically significant decrement in lung function over time (P less than .001) following coffee provocation both at rest and following exercise. No significant protection against this response was observed with DSCG pretreatment. While the majority of these "healthy" coffee reactors exhibited baseline nonspecific airway hyperresponsiveness to methacholine (PC20 FEV1 less than 25 mg/mL in 7/10), there was no correlation in these ten subjects between baseline responsiveness to methacholine and the degree of lung function decrement following coffee (P greater than .05). Also, no correlation was observed between skin prick and lung function response to coffee extract. We conclude that inhalation of green coffee extract causes significant bronchoconstriction in selected healthy volunteers and that this response is not prevented by pretreatment with DSCG.

A follow-up study of respiratory function in cotton textile workers was performed 10 yr after the original cross-sectional study (1975 to 1985). There were 35 nonsmoking female and 31 smoking male textile workers restudied from the original group of 116. The majority of those lost to follow-up had left the industry. The prevalence of byssinosis among the female workers at the time of follow-up was 15/35 (42.9%) compared with 8/35 (22.9%) at the time of the initial study (p = 0.063). For men the byssinosis prevalence at follow-up was 16/31 (51.6%) compared with 8/31 (22.9%) at the time of the initial study (p = 0.03). Similarly, the prevalence of almost all other respiratory symptoms was significantly higher at the follow-up than at the time of the initial study. Significant across-shift decrements in FEV1 and FVC were documented at both surveys. The mean annual decline in ventilatory capacity was greater than expected for both female (FVC: -0.036 +/- 0.005 L/yr; FEV1: -0.059 +/- 0.009 L/yr) and male workers (FVC: -0.059 +/- 0.008 L/yr; FEV1: -0.068 +/- 0.006 L/yr) (Mean +/- SE). The mean total airborne dust concentration measured at the time of the follow-up study was 3.95 mg/m3 with an average respirable dust concentration of 0.97 mg/m3. We conclude that continued exposure to high dust concentrations in the cotton textile industry is associated with an increasing prevalence of respiratory symptoms and progressive impairment of lung function. The increase in respiratory impairment was seen both in smokers and nonsmokers.

Immunological and respiratory findings were studied in a group of 19 male soybean workers. Twenty control workers also participated in the immunological studies. All soybean workers had positive immediate skin reactions to soybean extract, as did 19/20 control workers. Similarly, 18/19 soy workers reacted to soy antigen prepared after separation from oil, but only 3/19 to soy lecithin antigen and 1 to soy oil antigen. A majority of soy workers (13/19) reacted to house dust. Only 3/19 soy workers had increased levels of soy-specific IgE. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being significantly different for dyspnea (P less than 0.01). Workers with increased specific serum IgE or positive skin tests to house dust did not have any more symptoms than workers with negative tests. Ventilatory function was significantly worse in soybean workers than expected. Nevertheless, workers with positive skin or serological tests to house dust had across-shift changes similar to those with negative tests. These data suggest that skin and airway responses to soybean components (particularly the non-lipid ones) are very frequent among soybean workers. In the current study specific (soy) and non-specific (house dust) skin tests and immunoglobulins did not allow us to identify the workers at risk of developing symptoms or lung function abnormalities. This suggests that in addition to any atopic mechanisms, the irritant effect of soy dust may play a role in this occupational airway disease.

The acute respiratory effects of exposure to low-level, short-term sulfur dioxide (SO2) were studied in ten asthmatic and ten healthy subjects. Subjects were exposed in an environmental chamber in a double-blind, random sequence to SO2) levels of 0.00, 0.25, 0.50, 0.75, and 1.00 ppm for 40 min. During the first 10 min subjects exercised on a cycloergometer at a level of 450 kpm/min. On separate days, subjects were exposed to 0 and 1.0 ppm SO2 in the absence of exercise. In exercising asthmatic subjects, breathing 1 ppm SO2 resulted in significant changes from baseline in airway resistance (Raw), forced expiratory volume in 1 sec (FEV1.0), maximal expiratory flow at 60% of the vital capacity (VC) below total lung capacity on the partial flow volume curve [MEF40% (P)] as well as reductions in flows at 50% of VC (Vmax50%). None of these parameters showed significant changes for exposures to 0.5 ppm or less, with the exception of small decreases (i.e., less than 0.2 L/sec) in Vmax50% at 0.25 and 0.5 ppm. Ten minutes after the end of exercise, there were no statistically significant differences from baseline, even though SO2 was still present in the chamber atmosphere. For asthmatic subjects, the average changes in Raw, FEV1.0, MEF40%(P), and Vmax50% increased as SO2 levels increased, suggestive of a dose-response relationship with a consistent effect first seen at 0.75 ppm. In individual exercising asthmatics, responses may occur at levels of SO2 below 0.75 ppm. No changes were seen in healthy individuals on any day, or in asthmatic subjects at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

A cohort of both active and retired older cotton textile workers was examined prospectively over a 6-year period to establish the nature and extent of chronic lung disease. Respiratory symptoms and lung function were studied in these workers and in a group of similarly aged controls. The cotton textile workers had higher prevalence and attack rates of respiratory symptoms than did controls even with smoking habits taken into account. Chronic bronchitis developed in 16% of all cotton textile workers compared to 1% of controls over the follow-up period (p less than 0.001). The cotton workers suffered a larger loss of lung function over 6 years than did controls. Male workers lost 42 mL/yr of forced expiratory volume in 1 second, although male controls lost only 25 mL/yr (p = 0.001). Similar differences were seen in women, and in both men and women who were nonsmokers. Retired cotton textile workers had more symptoms and disability than active workers. We conclude that chronic lung disease is not only irreversible but may progress even after exposure to cotton dust has ended.

The acute effect of herbal tea dust extracts on lung function was studied in 15 of 25 healthy subjects responding to the inhalation of these extracts. Bronchial inhalation challenge was performed with tea extracts (sage, dog rose and gruzyan) and with normal saline solution as a control substance to assess their baseline airway reactivity to an isotonic aerosol. Lung function testing was performed before exposure and at 0, 15, 30, and 60 minutes after the cessation of exposure. The same subjects were also tested by challenge with methacholine. Lung function was measured by recording FVC, FEV1, FEF50, FEF25, SGaw, and Raw. Subjects were skin tested by the skin prick method and serum IgE levels were determined. The findings suggested that neither baseline nonspecific airway reactivity nor specific markers of immediate sensitivity to tea predict airway responses to tea extracts. Further evaluation of immunologic markers may help to explain the onset and progression of airway disease in workers.

It has been suggested that fiberoptic bronchoscopy may induce life-threatening bronchospasm in persons with asthma. The safety of bronchoscopy and bronchoalveolar lavage (BAL) with bilateral installation of 300 ml of saline solution was assessed prospectively in ten adults with mild asthma as a part of a study of the lower respiratory tract in bronchospastic disease. Asthmatic subjects had pretreatment with intravenous aminophylline prior to bronchoscopy. Pulmonary function tests were performed prior to and immediately after the procedure, and values were compared to results in 12 normal adults undergoing bronchoscopy with BAL. One subject had mild bronchospasm (the third subject) before BAL could be performed. There were no major complications in the remaining asthmatic or normal subjects. Mean forced expiratory volume in one second (FEV1) did not change significantly in either group, and the mid-flow rate at 50 percent of vital capacity (Vmax 50%) decreased significantly only in normal subjects (p = 0.002). Moreover, none of the nine asthmatic subjects completing bronchoscopy with BAL had clinically significant bronchospasm. These results suggest that elective fiberoptic bronchoscopy and BAL can be performed safely in subjects with mild asthma.

Eleven of 48 (23%) patients diagnosed as having lung abscess or empyema presented diagnostic problems in the localization of infected material. All 11 patients were found eventually to have empyemas, all but one of which was complicated by bronchopleural fistulas. Difficulty in distinguishing abscess from empyema on a chest roentgenogram delayed diagnostic and therapeutic thoracentesis from 1 to 12 days. Pleural effusions were noted in all but one of the patients who did not initially have a bronchopleural fistula. In addition, once the bronchopleural fistula became established, the extension of the air-fluid level to the chest wall, the tapered borders of the air-fluid pocket, and the extension of the lesion across fissure lines were noted, in retrospect, to be suggestive of pleural localization. Delay in the evacuation of empyema fluid can lead to chronic complications and increased morbidity. Early identification and treatment of pleural effusions may avoid these diagnostic and therapeutic problems.

Exposures to sulfur dioxide (SO2) have been associated with progressive, dose-dependent bronchoconstriction in sensitive individuals. The clinical significance of such changes remains poorly characterized. We studied subjective responses following exposure to low level concentrations of SO2 (less than 1 ppm) in a group of 10 healthy and 10 asthmatic subjects. The number and severity of complaints associated with SO2 increased with concentrations in both healthy and asthmatic subjects. Asthmatics indicated progressive lower respiratory complaints, such as wheezing, chest tightness, dyspnea and cough with increasing levels of SO2 while healthy subjects complained more frequently of upper airway complaints such as taste and odor with increasing levels of SO2. Exercise increased the frequency of lower airway symptoms in asthmatics but led to no increases in symptoms in healthy subjects.

A patient with pulmonary veno-occlusive disease is described. Lung biopsy revealed noncaseating granulomas in conjunction with the typical vascular changes of this entity. This concurrence has not been previously described.

It is well established that cotton dust inhalation can compromise lung function in textile workers. Challenges with a water-soluble extract of cotton bract (CBE) can also induce reversible airway obstruction in healthy volunteers. We have examined the effect of inhaled CBE in nonhuman primates and have attempted to inhibit the bronchoconstrictive response with mediator modifying compounds. CBE (34 mg/ml or 100 mg/ml) was administered via IPPB for 15 minutes (15 breaths/min) in 12 intubated, anesthetized, adult male monkeys (Macaca fascicularis). Breath-by-breath determinations of pulmonary resistance, dynamic compliance (Cdyn), tidal volume, and breathing frequency were calculated from the transpulmonary pressure (esophageal balloon) and airflow signals and monitored for 2 hr postchallenge. Control challenges with distilled water were also performed in 3 monkeys with the greatest response from CBE. Five animals (42%) were found to respond to CBE with peak % changes in Cdyn greater than 45%. In 3 of these animals, we attempted to blunt the CBE response with chlorpheniramine (0.1 mg/kg i.v.) and a mast cell stabilizer lodoxamide (0.1 mg/ml aerosol). In these 3 animals the mean (+/- SD) peak % changes in Cdyn to CBE alone was -47.4 +/- 1.8. The CBE response following chlorpheneramine was -49 +/- 15.7 and following lodoxamide was -47.0 +/- 5.4. These data suggest that monkeys, like humans, can develop reproducible bronchoconstriction following an aerosol challenge with CBE. Furthermore, this bronchoconstriction in the monkey is probably not explained by the action of histamine or mediator release alone and an acute inflammatory reaction may be involved.

We studied the effect on airway function of chlorpheniramine maleate (C), an H1 antagonist, delivered as an aerosol to 12 asthmatic subjects, 40 minutes before submaximal exercise. The study consisted of three protocol days. A first day established that the asthmatic subjects had exercise-induced bronchospasm (EIB). On the remaining two protocol days, 10 mg of C or a saline placebo (P) were administered by aerosol nebulizer in a double-blind randomized fashion over a 5-minute period. Pulmonary function was measured immediately after the aerosol inhalation as well as 10 and 30 minutes later. A 5-7-minute period of exercise was then performed by each subject on a cycloergometer, and lung function was again measured immediately and 5 minutes after exercise. Thirty minutes after the inhalation of C there was a significant increase in lung function parameters (1.80 +/- 0.23 to 2.32 +/- 0.34/sec for MEF40%(P); Mean +/- 1 SE, P less than .05) but not for placebo. MEF40%(P) remained significantly higher on the C day than on the P day following exercise; however, this difference was no greater than the difference seen immediately before exercise. We suggest that C promotes mild bronchodilation of asthmatic airways, and that this effect in EIB may be interpreted as the result of an alteration of baseline airway caliber.

Purified aqueous extracts of cotton bract induce acute airway constriction in healthy volunteers never before exposed to cotton bract. The response is similar to that of textile workers who inhale cotton dust. Approximately 60% of volunteers respond to bract extract with significant decreases in lung function, and these volunteers show an increased number of lymphocytes present in their lungs. Following inhalation of bract, the percent of polymorphonuclear leukocytes increases. Macrophages obtained by bronchoalveolar lavage from volunteers pre-challenged with bract extract release increased amounts of chemotactic factor and superoxide anion. Efforts to detect release of histamine and leukotrienes in volunteers following challenge with bract show no increase in urinary histamine and no significant release of leukotrienes in lung lavage fluid. Purified extracts exhibit chemotactic activity in vitro. They also contract guinea pig ileal longitudinal muscle in vitro. This preparation contains mast cells but no basophils, and the H-1 blocker, mepyramine blocks the contraction. Purified bract extracts contain no histamine or endotoxin but other contractors of smooth muscle may be present. The purified extract exhibits spectral, fluorescent, and radioimmune assay properties similar to a leukotriene B-like component. Cotton bract appears to have direct as well as cell-mediated activities.

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.

We studied 89 patients in whom the clinical diagnosis of sarcoidosis was supported by the findings on tissue biopsy. A chest roentgenogram in 14 of the patients showed one of the following atypical features: large pulmonary nodules, an alveolar parenchymal pattern or a pleural effusion. Diagnoses of infection, malignancy or vasculitis were suggested by interpretations of atypical chest roentgenograms in eight of these 14 patients. Nonspecific and misleading clinical information contributed. The diagnosis of sarcoidosis was corroborated by extrathoracic tissue biopsies in 11 of the 14 patients. Over an average observation period of 38 months, the 14 patients remained classified as having sarcoidosis. This suggests that an extrathoracic tissue biopsy, whose findings are consistent with sarcoidosis, is often sufficient to support a clinical diagnosis of some forms of roentgenographically atypical pulmonary sarcoidosis.

It has been suggested that exposure to formaldehyde (FA) induces asthmatic symptomatology. We have previously studied healthy and asthmatic individuals and found that lung function was unaltered by controlled exposures to 2.0 ppm FA with and without mild exercise. Our present study extends these observations to a group of hospital laboratory workers routinely exposed to FA. Fifteen laboratory workers were exposed in double-blind, random sequence to 0 and 2 ppm FA for 40 min in an environmental chamber with temperature and relative humidity held constant at 23 degrees C and 50%, respectively. These exposures were repeated on two more occasions with a 10-min exercise regimen (450 kpm/min) after being in the chamber 5 min. In addition, a symptom diary and measurements of peak expiratory flow rate (PEFR) were recorded for 24 hr after exposure. Lung function remained unaltered for all 4 exposure days; e.g., mean FEV1.0 for the group did not change by more than 3% at any testing time on any exposure day. Also, there were no delayed obstructive changes as measured by PEFR recordings. Symptoms were mild and transient with unusual odor and eye irritation the most frequent complaint. No lower airway symptoms were reported. We conclude that this group of healthy laboratory workers did not experience any acute or delayed lung function changes from exposure to 2.0 ppm FA at rest and with exercise and that irritative symptoms were few.

Cotton textile workers have an increased prevalence of both obstructive and restrictive lung function patterns compared with control subjects. Similar abnormal patterns may occur with respiratory diseases of other etiologies, notably those associated with cigarette smoking. The shape of the maximum expiratory flow volume (MEFV) curve has been used to characterize patterns of lung function abnormality. To better evaluate the respiratory effects of cotton dust exposure and to contrast them with those of cigarette smoking, we defined a new functional parameter (angle beta) related to the shape of the MEFV curve. We compared 477 cotton textile workers, both current smokers and never smokers, 45 years and older, with 932 similarly aged control subjects from three communities. Smokers, regardless of their occupational exposure or sex, have smaller beta values than nonsmokers. Cotton textile workers, despite a greater prevalence of abnormal lung function, have beta values that do not differ from those of persons without occupational exposure to cotton dust. We suggest that morphologic patterns of flow volume curves reflect separate effects of cotton dust exposure and smoking and may be related to different sites of airway injury.

Maximum expiratory flow-volume curves have been used to characterize normal and abnormal respiratory function. Previous investigators have usually attempted to study whether any single lung function separately is most useful in characterizing lung dysfunction. Using stepwise discriminant analysis we sought to identify which combination of lung function parameters derived from maximum expiratory flow-volume curves could best discriminate between epidemiologic groups defined on the basis of smoking status and presence or absence of respiratory symptoms. We studied 5,031 whites, 2,271 males and 2,760 females, from three communities. In general, combinations of lung functions were no more useful than single lung functions to best discriminate between the groups studied. Flow rates at 50 and 25% of vital capacity remaining to be expired were most often selected as the best discriminating lung function, possibly suggesting obstruction of small airways in the smoking and symptomatic groups.

Cotton textile workers have an increased prevalence of both obstructive and restrictive lung function patterns when compared to control subjects. Similar abnormal lung function patterns may occur with other respiratory diseases, notably those associated with cigarette smoking. The shape of the maximum expiratory flow volume (MEFV) curve has been used to characterize patterns of lung function abnormality. We defined a new functional parameter (angle beta) related to the shape of the MEFV curve in order better to characterize the respiratory effects of cotton dust exposure. In this study, 477 cotton textile workers, both current smokers and never smokers 45 years and older, were compared to 932 similarly aged control subjects from three communities: Lebanon and Ansonia, CT, and Winnsboro, SC. Smokers, regardless of their occupational exposure of sex, have smaller values of beta than do nonsmokers. Cotton textile workers who have more abnormal lung function than do controls, cannot be distinguished from controls by beta. We suggest that such functional differences between cotton and smoking effects may reflect injury to different portions of the bronchial tree.

Most healthy subjects challenged with cotton bract extract demonstrate some degree of bronchospasm. This response has been associated with the endogenous production of histamine by the inhalation of cotton bract extract. We examined whether this responsiveness reflects increased sensitivity to histamine. Thirty-one healthy subjects were screened for sensitivity to cotton bract extract administered by nebulization. Pulmonary function was measured using partial expiratory flow-volume curves on which flows at 60% of the control vital capacity below total lung capacity were measured (MEF40%(P)). Responders were defined as subjects who exhibited a 20% or greater decrease in MEF40%(P) after 10 min inhaling cotton bract extract. Of those screened, 10 subjects were responders. From the remaining nonresponders, 11 consecutive subjects were selected. The maximal decrease in MEF40%(P) in responders was 40.5 +/- 5.1%, compared to 10.9 +/- 2.2% in nonresponders. The dose-response relationship for histamine was measured in all subjects, using inhalations of progressively more concentrated histamine solutions. The mean +/- SEM threshold for the responders was 38.4 +/- 7.4 mg of histamine per ml, compared to 42.2 +/- 6.8 mg of histamine per ml for responders (difference not significant). The percentage decrease in MEF40%(P) at the threshold dose was 27.6 +/- 3.7% for responders and 32.4 +/- 5.2% for nonresponders (difference not significant). We conclude that healthy subjects sensitive to cotton bract extract do not exhibit increased reactivity to histamine. This suggests that responders are not, in general, subclinical asthmatics, and that the difference between responders and nonresponders to CBE is not due to increased histamine sensitivity among responders.

Formaldehyde (FA) is a common indoor air pollutant with irritative properties. It has been suggested that FA may produce physiologic alterations of the respiratory system. To study such responses, 15 nonsmoking, healthy subjects were exposed in a double blind, random manner to 0 and 2 ppm FA for 40 min in an environmental chamber. In addition, the same exposures were repeated on a separate day with the subjects performing moderate exercise (450 kpm/min) for 10 min. Exposures were carried out under controlled environmental conditions (temperature = 23 degrees C, relative humidity = 50%). Pulmonary function was measured before, during, and after exposures using partial and maximal flow-volume curves and airway resistance. Symptom diaries were given to the subjects; upper and lower airway symptoms were recorded for up to 24 hr following exposures. No significant bronchoconstriction was noted in this group. In 3 subjects, sequential measurements of peak flow over a 24-hr period following FA exposure failed to reveal any delayed airway response. On a separate day, 6 healthy subjects failed to demonstrate changes from their baseline responsiveness to methacholine after exposure to 2 ppm FA. Respiratory symptoms were, in general, confined to the upper airways and were mild to moderate in severity. We conclude that short exposures to 2 ppm FA do not result in acute or subacute changes in lung function among healthy individuals either at rest or with exercise. Subjective complaints following such exposures are confined to irritative phenomena of the upper airways.

We performed a double-blind, random crossover study to investigate the respiratory effects of a single dose isoetharine mesylate (IM), administered by a metered aerosol canister in 19 subjects with mild, stable asthma. In addition, we studied the influence of the dose (number of actuations) and the mode of administration (delay between actuations) on these respiratory effects. The protocol consisted of a screening day and four test days: (1) one inhalation IM (2) two inhalations IM (3) one inhalation placebo (P), and (4) two inhalations P. In addition, the first nine asthmatics paused one minute between inhalations whereas the last ten paused five minutes between inhalations. Lung function was assessed using maximal and partial expiratory flow volume curves. Measurements were taken prior to aerosol delivery and for six hours after aerosol. Significant differences between IM and P were seen for up to two hours. The maximum effect was observed at 15 minutes, corresponding to a 23% and 25% increase in FEV1 from baseline with one and two puffs, respectively (P less than .001). The differences between one and two actuations were, in general, not significant. No significant differences were observed between individuals who waited one versus five minutes between inhalations. We conclude that IM aerosol results in significant improvement compared with placebo for two hours. Differences between one and two inhalations and the interval between two inhalations did not, in general, lead to enhanced effectiveness of this drug in the group of asthmatics studied.

Unlike asthmatics, healthy persons are relatively unresponsive to airway constrictors. By using partial expiratory flow-volume (PEFV) curves the authors have demontrated, in healthy subjects, dose-related decreases in flow rates following challenge with histamine and methacholine aerosols. With the use of semilogarithmic dose-response curves they have shown that 80 mg oral propranolol augmented, whereas oral pretreatment with 400 mg W10294A (an experimental bronchodilator) decreased, histamine and methacholine-induced airway constriction. However, 300 mg of orally administered aminophylline failed to modify the airway constrictor effects of histamine and methacholine. Moreover, variation was noted in induced airway constriction in healthy subjects with decreases in flow rates being greater in the morning than in the afternoon. The authors conclude that (1) propranolol augments whereas theophylline fails to prevent nonspecific induced airway constriction in healthy subjects. This suggests that the bronchodilator action of theophylline may be unrelated to its phosphodiesterase inhibitory activity, (2) control of volume history, by use of partial expiratory flow-volume curves, is useful in quantifying pharmacologic protection and augmentation of nonspecific induced airway constriction in healthy subjects and (3) conclusions resulting from observations of induced airway constriction in healthy subjects may be dependent upon the effects of diurnal variation.

Immunological and respiratory findings were studied in a group of 45 female spice-factory workers (mean age: 39 years; mean exposure: 17 years). In addition a group of 45 female control workers matched by sex, age, and smoking habit were also studied. Intradermal skin testing with mixed spice dust allergen demonstrated positive skin reactions in 73.3% of exposed and in 33.3% of control workers (P less than 0.001). Increased IgE serum levels were found in 36.8% of exposed and in 9.7% of the control workers (P less than 0.01). The prevalence of chronic respiratory symptoms was significantly higher in the exposed workers than in the control workers (P less than 0.01). There was, however, no consistent correlation between skin reactivity and chronic respiratory symptoms. There was a high prevalence of acute symptoms during the work shift. These complaints were more frequent in workers with positive skin tests for the symptoms of cough, chest tightness, and irritated and dry throat. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. There were statistically significant mean reductions during the work shift for all measured lung function parameters in workers with positive skin reactions. In those workers with negative skin reactions only FEF50 and FEF25 reached statistical significance. Aqueous extracts of different spices (chilli pepper, paprika, caraway, coriander leaves, coriander seeds, cinnamon, ginger, onion, curry, and parsley) caused a dose-related contractile response of isolated guinea pig tracheal smooth muscle. These data suggest that immunologic reactions to spices are frequent in spice workers and may be related to acute symptoms and lung function changes, but not to chronic changes. The data further suggest that, in addition to any immunologic response these spices may produce in vivo, they probably also provoke direct irritant reactions in the airways as suggested by in vitro data.

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.

A maximal lung inflation is known to alter airway tone in man. Recent investigations, examining how this phenomenon relates to bronchial provocation testing, suggest that a deep inspiration will decrease airway resistance and underestimate the subsequent decrement in lung function following airway challenge. Because the recovery of baseline tone is rapid following a deep inspiration, we evaluated the consistency of three consecutive partial and maximal expiratory flow-volume maneuvers performed at approximately 45- to 60-second intervals. Functional parameters including the forced expiratory volume in 1 s and the maximal expiratory flow at 60% of the vital capacity below total lung capacity on the partial curve (MEF40%P) were constant at each measurement point following induced bronchoconstriction or bronchodilation in both healthy and asthmatic subjects. We suggest that with 45 s between maneuvers, repeatable parameters can be attained from three consecutive flow-volume curves.

Fifteen asthmatic volunteers were exposed in a double-blind, random manner to room air and 2.0 ppm formaldehyde for 40 min in an environmental chamber. These exposures were repeated on a separate day during moderate exercise (450 kpm/min) for 10 min. Ambient and dew point temperatures were 23.0 +/- 0.0 degrees C and 11.5 +/- 1.0 degrees C, respectively. No significant airway obstruction as measured by flow-volume parameters and airway resistance was noted in this group during or immediately after exposure. Furthermore, sequential measurements of peak flow for 24 hr following formaldehyde exposure revealed no delayed airway response. In contrast, in comparison to the baseline methacholine inhalation challenge (MIC) test on the screening day, 8 of 12 asthmatics demonstrated a lower threshold to MIC following 2.0 ppm exposure for 40 min; however, the mean and median decrements of threshold in methacholine concentration of 10.4 mg/ml and 24.3 mg/ml were not significant (p = .12). Bad odor, sore throat, and eye irritation were common during exposure but symptoms were infrequent afterward.

This study examined nonspecific airway responsiveness to methacholine (MC) after inhalation of cotton bract extract (CBE). In a randomized double-blind, crossover trial, 13 healthy volunteers underwent an MC inhalation challenge test prior to inhalation of CBE and normal saline solution (NSS) aerosol sham as well as 2, 8, 24, and 168 h (7 days) later. The response parameter was the concentration of MC required to induce a 25% decrement in the maximal expiratory flow at 40% of the vital capacity below total lung capacity on the partial expiratory flow-volume curve (PC25MEF40%(P]. Five of 13 subjects demonstrated a ventilatory response to CBE with a 20% or larger decrement in the MEF40%(P); no subject demonstrated such change with NSS. For the group, the maximal decrement in MEF40%(P) was to 76.5 +/- 20.3% of baseline (mean +/- SD), occurring approximately 60 to 90 min after provocation, whereas the largest decrement after normal saline was to 88 +/- 10.6% of baseline, occurring immediately after inhalation. Changes in airway responsiveness to MC were transient. For example, the PC25MEF40%(P) for the group (mean +/- SD) was 51.3 +/- 41.1 mg/ml at baseline and 25.8 +/- 30.3 and 52.2 +/- 57.3 mg/ml at 2 and 8 h. After a pre-sham baseline of 50.4 +/- 43.2 mg/ml, PC25MEF40%(P) was 57.6 +/- 83.8 and 153.8 +/- 148 mg/ml at 2 and 8 h. Repeated measures ANOVA on these acute, same-day changes (i.e., 2 and 8 h after provocation) demonstrated a statistically significant effect of CBE on airway responsiveness (p = 0.048). These data demonstrate that inhalation of CBE, in addition to bronchospasm, causes a transient increase in airway responsiveness.

Sulfur dioxide (SO2) is a common air pollutant found in the workplace. Considerable variation exists in the airway responses of asthmatics to the inhalation of SO2. To determine if such variation among asthmatics is related to nonspecific airway reactivity, we compared the threshold doses of methacholine and SO2 required to produce significant changes in flow rates at 60% of the vital capacity below total lung capacity on the partial expiratory flow volume curve in a group of eight mildly asthmatic subjects. A significant correlation between the dose of SO2 and the dose of methacholine required to produce bronchoconstriction (r = .86, p less than .05) was observed, suggesting that there is a relationship between the response to SO2 and the response to methacholine in mildly asthmatic individuals. More generally, nonspecific airway hyperreactivity may help to predict untoward airway responses to inhaled SO2 in the workplace.

Epidemiology is the study of the distribution of disease in a population and of the factors that determine that distribution. Respiratory care practitioners encounter many aspects of epidemiology in training and practice and should become aware that most initial epidemiologic observations are made by clinicians. The determinations that excessive oxygen administration caused retrolental fibroplasia and that exposure to cotton bracts in the textile industry caused byssinosis resulted from the collaborative efforts of epidemiologists, laboratory workers, and clinicians. The three types of study designs in observational epidemiology are: (1) the cohort (incidence) study, in which a study factor is observed at the onset of the study and the study population is followed over time for the development of new cases of a disease; (2) the cross-sectional (prevalence) study, in which the presence or absence of risk factors is measured at one point in time in a study population and prevalence rates of disease among those with and without the risk factors are compared; and (3) the case-control study, in which the numbers of persons with and without a given disease who share certain background characteristics or exposure levels to risk factors are determined and compared. The epidemiologist's continued collaboration with the clinician and the laboratory scientist is important because epidemiology alone can rarely provide conclusive solutions to every aspect of a problem.

Air pollution is frequently incriminated as a risk factor in the development of chronic lung impairment and in the aggravation of existing disease. The federal government has set primary air quality standards to protect public health and secondary standards to protect public welfare (eg, to preserve vegetation and buildings). Much of the debate surrounding the development and evaluation of air standards focuses on the diseases of patients with whom the respiratory care practitioner has daily contact. We review the legislative efforts to protect the public from the effects of air pollution and provide insight into some of the scientific and medical dilemmas involved in this current public health issue.