Environmental mycological study and allergic respiratory disease among tobacco processing workers.

This study presents the results of an investigation of respiratory symptoms, lung function, chest X-ray examinations, analysis of specific IgE antibodies and skin prick tests to fungi on 130 tobacco-processing workers and 112 control workers. Industrial hygiene survey and environmental mycological studies were also performed. The average dust concentrations ranged from 13.76 to 29.55 mg/m(3) in the tobacco processing workshops. Also, the numbers of fungi colonies in the processing environments were much higher than those in the control environments. The prevalences of chronic respiratory or nasal symptoms in exposed workers were significantly higher than those in control workers (p<0.05 or p<0.01). The prevalences of lung function abnormalities in the exposed workers were significantly higher than those in control workers (p<0.05). The positive prevalences of specific IgE reactions to fungi (26.92% for A.fumigatus and 51.54% for Rhizopus nigricans) in exposed workers were also significantly higher than those in control workers (p<0.01). The positive prevalences of the skin prick test showed that 18.46% of the exposed workers were positive to A. fumigatus and 23.85% were positive to Rhizopus nigricans. Our results suggested that tobacco processing workers may develop respiratory diseases related to tobacco dust and we consider that fungi might be one of the allergens causing allergic respiratory or nasal diseases in tobacco processing workers.

Environmental mycological study and respiratory disease investigation in fur-processing workers.

This paper presents the results of an investigation of respiratory symptoms, chest X-ray examinations, and analysis of antibodies to fungi of 138 fur-processing workers and 40 control workers. Industrial hygiene survey and environmental mycological studies were also conducted. The dust concentrations in fur processing workshops (1.8-6.7 mg/m3) were below the national health limit (10 mg/m3). Most dusts in all fur processing workshops contained less than 2.0% silica. Numbers of isolated fungi in fur processing workshops [629-3,681 cfu/m3 (colony forming unit/m3)] were significantly higher than those in control environments (63-503 cfu/m3). The prevalences of respiratory symptoms in fur processing workers were higher than those in control workers, especially among female exposed workers. The prevalences of the symptoms in female exposed workers were 37.9% with chronic cough, 28.4% with chronic phlegm, 10.5% with dyspnea, 22.1% with chest tightness, and 4.2% with fever. Seven cases showed abnormalities in chest X-ray examinations. The OD450nm values for antibodies to fungi in fur processing workers were significantly higher than those in control workers (P<0.05). The prevalences of positive anti-fungi antibodies in fur-processing workers were also significantly higher than those in control workers (p<0.01). The results suggested that fungi might be one of the main allergens in respiratory diseases in fur processing workers.

Environmental mycological study and respiratory disease investigation in tussah silk processing workers.

This study presents the results of an investigation of respiratory symptoms, pulmonary function and chest X-ray examinations, and analysis of antibodies to fungi of 197 tussah silk-processing workers and 40 control workers. An industrial hygiene survey and environmental mycological studies were also conducted. The dust concentrations in tussah silk processing workshops were less than 5.1 mg/m(3) on average, with a maximum of 7.8 mg/m(3) below the national health limit of 10 mg/m(3). Most dusts in all tussah silk processing workshops contained less than 1.2% silica. Numbers of isolated fungi in tussah silk processing workshops [755-6,544 cfu/m(3) (colony forming unit/m(3)), were significantly higher than those in control environments (63-472 cfu/m(3)). The prevalences of respiratory symptoms in tussah silk processing workers were higher than those in control workers. The prevalences of respiratory symptoms in exposed male non-smoking workers were 44.4% with chronic cough, and 38.9% with chronic phlegm respectively, which were significantly higher than those (12.5%, 12.5% respectively) in male non-smoking control workers (p<0.05). The prevalences in exposed male smoking workers were 42.9% with dyspnea, and 38.1% with chest tightness respectively, which were significantly higher than those (16.7%, 8.3% respectively) in male smoking control workers (p<0.01). The prevalences of respiratory symptoms in exposed female workers were 25.3% with chronic cough, 38.0% with chronic phlegm, 31.0% with dyspnea, and 29.1% with chest tightness respectively, which were significantly higher than those (10.0%, 10.0%, 10.0%, 5.0% respectively) in female control workers (p<0.01). Fifteen exposed workers often suffered from fever. Five X-rays were abnormal and four cases had nodular or patchy shadows. The prevalences of pulmonary function abnormalities in the exposed female group were significantly higher than those in control groups (p<0.01). The OD(450 nm) values for antibodies to fungi in tussah silk processing workers were significantly higher than those of control workers (p<0.05). The positive rates of anti-fungal antibodies in tussah silk-processing workers were also significantly higher than those of control workers (p<0.01). The results suggested that fungi might be one of the main allergens in respiratory diseases in the tussah silk processing workers.

Pulmonary function in fur-processing workers: a dose-response relationship.

Pulmonary function tests were conducted in 212 male workers exposed to fur dust in a fur-processing factory, and in 148 unexposed male workers. The authors used the cumulative dose of dust exposure (mg-yr) as an exposure index to relate to pulmonary function injury, as measured by pulmonary function tests, in exposed workers. The results showed that fur workers had lower percentages of predicted pulmonary function, as measured by forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1.0), and maximal flow rate of expiration at 50% and 25% of forced vital capacity (V50 and V25, respectively), compared with controls (p < 0.01). As the cumulative dose of fur dust exposure increased, average levels of pulmonary function declined significantly (p < 0.01), and pulmonary function abnormalities (i.e., < 80% of predicted FVC and FEV1.0, or < 70% of predicted V50 and V25) increased significantly (p < 0.05). Multiple-regression results identified fur dust exposure as the leading risk factor associated with the decline in pulmonary function in the exposed group. The results demonstrated a dose-response relationship between fur dust exposure and respiratory system injury, as measured by pulmonary function tests in fur-processing workers. On the basis of this dose-response relationship and the use of lifetables, the authors proposed an exposure limit of 4 mg/m3 for fur dust.

Relationship of jute dust to interstitial fibrosis in rat lung.

The relationship between jute dust and lung interstitial fibrosis was studied by instilling groups of rats, via trachea, with jute dust and comparing the results with those for positive (quartz) and negative (saline) controls. The rats were sacrificed at regular intervals and their lungs and hilar lymph nodes were analyzed for collagen content and morphologic changes. The earliest changes consisted of alveolar edema, increased numbers of intraalveolar macrophages, and marked thickening of the interalveolar septa, with mixed cellular infiltrates. Moderate thickening of the alveolar walls and the zones around the peribronchioles was seen in the test groups at 6 mo. After 12 mo, some fibrosis of the alveoli walls and peribronchiole zones occurred. Interstitial cellular nodules were observed occasionally, composed mainly of dust particles, fibroblasts, reticular fibers, and collagen fibers. The collagen content in the lungs of the jute dust groups was significantly higher than for the saline control group for all test periods. The authors conclude that jute dust may induce lung interstitial fibrosis.

Experimental study on fibrogenic effect of fur dust on rat lung.

OBJECTIVE: The fibrogenicity of fur dust was studied in rat lung tissues. METHODS: Intratracheal instillation of fur dust, morphologic examination of lungs and analysis of collagen content were performed in Wistar rats. RESULTS: Morphologic examination revealed that the earliest changes consisted of alveolar edema, increased numbers of intraalveolar macrophages, and marked thickening of interalveolar septa with mixed cellular infiltrate. After sixth months, there was moderate thickening of the alveolar walls and the peribronchioli. After 12 months, interstitial positive fibrosis of the alveolar wall and the peribronchioli were weakly seen. In the carding dust group (silica content 17.6%), interstitial nodules were observed composed of fibroblasts, reticular fibers, and collagen fibers. Electron microscopic examination also showed that alveolar walls became thickened and collagen fiber bundles were seen around bronchioles and small vessels in the carding groups after 12 months. At all stages of analysis, the collagen content in lungs of the fur dust groups was significantly higher than that of the control group. CONCLUSIONS: Our study suggested that fur dust might induce weak interstitial fibrosis in the lung.