Schachter En

A study of respiratory effects from exposure to 2 ppm formaldehyde in healthy subjects.

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.

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 symptoms and lung function in hemp workers.

Respiratory symptoms and abnormalities of lung function were studied in 84 female and 27 male hemp workers employed in two textile mills (A and B) processing soft hemp (C sativa). In mill A 46 women and 27 men were investigated and 38 female workers were studied in mill B. Forty nine women and 30 men from a non-dusty industry served as controls. A significantly higher prevalence of almost all chronic respiratory symptoms was found in female hemp workers when compared to control workers. Among the men these differences were significant for nasal catarrh and sinusitis. A high prevalence of byssinosis was found among female hemp workers in both mills (group A, 47.8%; group B, 57.9%) as well as in the male workers (66.7%). Statistically significant across shift reductions in lung function were found for all ventilatory capacity measurements in female and male hemp workers varying from 7.1% for forced expiratory volume in one second (FEV1) to 15.1% for flow rates at 50% vital capacity (FEF50). Measured Monday baseline values before the work shift were significantly lower than expected for hemp workers, being particularly reduced for FEF25 and FEF50. The data suggest that occupational exposure to hemp dust is a significant risk factor for the development of acute and chronic lung disease in workers employed in this textile industry.

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 function in confectionery workers.

Respiratory symptoms and ventilatory capacity were studied in a group of 288 workers (259 women and 29 men) employed in a confectionery plant. A group of workers (96 women and 31 men) not exposed to confectionery manufacture were also studied as controls. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers, being greatest for confectionery workers exposed to the dust of flour, talc, and starch and the vapours of alcohol. Chronic bronchitis was reported by 7% of the women and 21% of the men, and chest tightness was reported by 27% of women and 66% of men. There was a high prevalence of acute irritative symptoms during the workshift in all groups of confectionery workers, especially for cough, dyspnoea, burning and dryness of the throat, and eye irritation. For all groups of confectionery workers there were statistically significant across shift reductions in ventilatory capacity, being most pronounced for maximum flow rate at 50% of the control vital capacity (FEF50; range 4.6-13.0%) and at 25% of the control vital capacity (FEF25; range 4.7-22.3%). Preshift values of FEF50 and FEF25 were significantly lower than predicted values. The data suggest that some workers employed in confectionery plants may develop acute and chronic respiratory symptoms associated with changes in lung function.