Witek Tj

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.

Immunological and respiratory findings in spice-factory workers

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.

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 associated with sulfur dioxide exposure

SummaryExposures 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 (< 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.

Immunological findings in hemp workers

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.

The effect of cotton bract extract on respiratory glycoconjugate secretion from human airways in vitro

In vivo and in vitro studies with a water-soluble extract of cotton bracts (CBE) suggest that CBE may be responsible for some of the clinical manifestations of byssinosis. Since chronic bronchitis has been repeatedly documented as a major feature of byssinosis, we studied the effect of CBE on respiratory glycoconjugate (RGC) release from human airways (HAs) in vitro. HAs were incubated with [3H]glucosamine to label RGC molecules. CBE in increasing concentrations was added to radiolabeled HAs, and the release of 3H-RGC, histamine, and other mediators was measured. CBE in concentrations of 1 to 7 mg/ml caused a dose-related increase in RGC, as well as histamine release (RGC, 14% to 45% increase above control; histamine, 12 to 70 ng/ml released concurrently). Additionally, CBE in a dose of 5 mg/ml caused a more than threefold increase in peptidoleukotriene production above baseline. The effect of histamine H1 and H2 (pyrilamine and cimetidine), cyclooxygenase pathway inhibitor (indomethacin), leukotriene (LY 171883 and FPL 55712), and lipoxygenase pathway (BW nordihydroguaiarectic acid) blocking agents on CBE-induced RCG secretion was studied. In addition to histamine-H1 blockers, lipoxygenase inhibitors (nordihydroguaiarectic acid and BW 755C) and leukotriene blockers (FPL 55712 and LY 171883) are also potent inhibitors of CBE-induced RGC secretion. This suggests that CBE may act via the release of several mediators (histamine and leukotrienes), possibly from airway cells, such as mast cells, macrophages, or epithelial cells, to stimulate RGC secretion.