A report of the gross and microscopic appearances in the lungs and the weights of the cardiac ventricles in 43 subjects receiving industrial benefit for byssinosis is presented. In 27 (63%) there was no significant emphysema, in 10 (23%) there were varying amounts of centrilobular emphysema, and panacinar emphysema was found in six (14%). Other changes were of non-specific nature, but most cases showed heavy black dust pigmentation, often associated with centrilobular dilatation of distal air spaces. (+info)
A longitudinal observation of early pulmonary responses to cotton dust.
(10/80)
AIMS: To examine early adverse pulmonary effects of exposure to cotton dust, and to identify potential risk factors, including atopy for pulmonary responses to cotton dust. METHODS: Spirometry, methacholine challenge testing, and questionnaire; performed among 101 non-smoking newly hired textile workers at baseline (prior to starting work), and at 3, 12, and 18 months after starting work. Concentrations of airborne cotton dust in various work areas were measured at each follow up survey using vertical elutriators. RESULTS: The incidence of non-specific respiratory symptoms was 8% at three months, then diminished afterwards. Substantial acute cross shift drops in FEV(1) at each follow up survey, and longitudinal declines in FVC and FEV(1) after 12 months of exposure were observed. Airway responsiveness to methacholine increased with follow up time, and was more pronounced among atopics. Increasing airway responsiveness was strongly correlated with cross shift drops in FEV(1). In addition, one or more respiratory symptoms at three months was significantly, and pre-existing atopy marginally significantly, associated with cross shift drops in FEV(1) after adjusting for other covariates and confounders. CONCLUSION: Results suggest that non-specific respiratory symptoms, decreasing lung function, and increasing airway responsiveness are early pulmonary responses to cotton dust. In addition, the occurrence of respiratory symptoms and increasing airway responsiveness, as well as atopy, may be important predictors for acute changes in lung function among cotton textile workers. (+info)
Additive effect of smoking and cotton dust exposure on respiratory symptoms and pulmonary function of cotton textile workers.
(11/80)
One hundred and sixty-nine and 175 cotton textile workers (CTWs) were enrolled in the first (1991) and second (1996) surveys to investigate the prevalence of byssinosis. The synergistic effect of smoking on cotton dust exposure was also evaluated. Although the difference in prevalence of abnormal pulmonary function between the first (38.5%) and second study (38.9%) was not statistically significant, smokers had significantly higher frequency than nonsmokers in both surveys. A significant trend existed between the cotton dust levels and the frequency of abnormal lung function. The significant trend was also noted in both smokers and nonsmokers. The frequency of respiratory symptoms and the prevalence of severe byssinosis in the second survey (14.9% and 12.6%, respectively) were significantly lower than that in the first survey (39.7% and 21.9%, respectively). The reduction of symptoms was due to remodeling of this old cotton mill. The prevalences of respiratory symptoms and byssinosis in smokers being significantly higher than in nonsmokers only found in the first survey, but not found in the second survey. These results indicate that smoking potentiates the effect of cotton dust exposure on respiratory symptoms and byssinosis. The second study reveals high prevalence of byssinosis still existed in Taiwanese cotton mill, although the prevalence was declining. Smoking was found to show an additive effect on cotton dust exposure. Anti-smoking campaign, occupational health program to reduce the dust exposure, and periodical medical examination are measures to prevent from byssinosis. (+info)
Byssinosis among jute mill workers.
(12/80)
Although byssinosis in jute mill workers remains controversial, studies in a few jute mills in West-Bengal, India, revealed typical byssinotic syndrome associated with acute changes in FEV1 on the first working day after rest. The present study on 148 jute mill workers is reported to confirm the occurrence of byssinosis in jute mill workers. Work related respiratory symptoms; acute and chronic pulmonary function changes among exposed workers were studied on the basis of standard questionnaire and spirometric method along with dust level, particle mass size distributions and gram-negative bacterial endotoxins. The pulmonary function test (PFT) changes were defined as per the recommendation of World Health Organization and of Bouhys et al. Total dust in jute mill air were monitored by high volume sampling, technique (Staplex, USA), Andersen cascade impactor was used for particle size distribution and personal exposure level was determined by personal sampler (Casella, London). Endotoxin in airborne jute dust was analysed by Lymulus Amebocyte Lysate (LAL) "Gel Clot" technique. Batching is the dustiest process in the mill. Size distribution showed that about 70-80% dust in diameter of < 10 microm, 40-50%, < 5 microm and 10-20%, < 2 microm. Mean endotoxin levels found in hatching, spinning and weaving, and beaming were 2.319 microg/m3, 0.956 microg/ m3, 0.041 microg/m3 respectively and are comparable to the values obtained up to date in Indian cotton mills. Respiratory morbidity study reported typical byssinotic symptoms along with acute post shift FEV1 changes (31.8%) and chronic changes in FEV1 (43.2%) among exposed workers. The group with higher exposure showed significantly lower FVC, FEV1, PEFR and FEF25-75% values. The study confirmed the findings of the earlier studies and clearly indicated that the Indian jute mill workers are also suffering from byssinosis as observed in cotton, flask and hemp workers. (+info)
Respiratory symptoms and cotton dust exposure; results of a 15 year follow up observation.
(13/80)
AIMS: To determine chronic effects of long term exposure to cotton dust and endotoxin on incidence of respiratory symptoms and the effect of cessation of exposure. METHODS: Respiratory health in 429 Chinese cotton textile workers (study group) and 449 silk textile workers (control group) was followed prospectively from 1981 to 1996. Byssinosis, chest tightness, and non-specific respiratory symptoms were assessed by means of identical standardised questionnaires at four time points. Exposures to cotton dust and endotoxin were estimated using area samples collected at each survey. Incidence and persistence of symptoms were examined in relation to cumulative exposure and exposure cessation using generalised estimating equations (GEE). RESULTS: Among cotton workers, the cumulative incidence of byssinosis and chest tightness was 24% and 23%, respectively, and was significantly more common in smokers than in non-smokers. A high proportion of symptoms was found to be intermittent, rather than persistent. Among silk workers, no typical byssinosis was identified; the incidence of chest tightness was 10%. Chronic bronchitis, cough, and dyspnoea were more common and persistent in the cotton group than in the silk group. Significantly lower odds ratios for symptoms were observed in cotton workers who left the cotton mills; risk was also related to years since last worked. Multivariate analysis indicated a trend for higher cumulative exposure to endotoxin in relation to a higher risk for byssinosis. CONCLUSION: Chronic exposure to cotton dust is related to both work specific and non-specific respiratory symptoms. Byssinosis is more strongly associated with exposure to endotoxin than to dust. Cessation of exposure may improve the respiratory health of cotton textile workers; the improvement appears to increase with time since last exposure. (+info)
Agglutination of lung surfactant with glucan.
(14/80)
Respirable cotton dust, implicated in the pathogenesis of byssinosis, contains a number of bioactive compounds. These include lipopolysaccharide (LPS), tannins, bacterial peptides, byssinosin, iacinilene C, and 1,3-beta-D-glucan. The exact aetiological agent of byssinosis in such dust has not been definitively identified nor has its mechanism of action on lower lung surfaces been determined. In the present study 1,3-beta-D-glucan, Enterobacter agglomerans LPS, and ovine pulmonary surfactant were mixed in varying combinations. After incubation, their characteristics were determined by sucrose density centrifugation, TLC, and carbohydrate analysis. Precipitates were found in mixtures containing surfactant-glucan and surfactant-glucan-LPS, but not in surfactant-LPS. Precipitates were not seen in the surfactant, LPS, and glucan controls. The formation of a precipitate did not increase the density of the surfactant glucan mixture when compared by density gradient centrifugation with the surfactant control. The interaction between surfactant and glucan was analysed by molecular modelling. The energy of a surfactant-glucan complex (60.07 kcal/mol) was calculated to be much lower than the sum of glucan (47.09 kcal/mol) and surfactant (30.98 kcal/mol) when added separately. The results indicate that 1,3-beta-D-glucan does interact with surfactant and this complex may play a part in the pathogenesis of byssinosis by altering lung physiology maintained by pulmonary surfactant. (+info)
Diffuse lung disease caused by cotton fibre inhalation but distinct from byssinosis.
(15/80)
A 66 year old man had inhaled cotton fibre for 50 years at his workplace. He did not have any respiratory symptoms. Chest CT scans revealed diffuse centrilobular and peribronchovascular interstitial thickening. Lung biopsy specimens confirmed the presence of string-like foreign bodies as well as granulomas and fibrosis in the peribronchial region. Infrared spectrophotometry confirmed that the foreign bodies were composed of natural cellulose. This is the first study to show directly by examination of biopsy samples that cotton fibre inhalation can cause diffuse lung disease. The clinical features of the disease were entirely different from those of byssinosis. (+info)
Airway responses to the inhalation of cotton dust and cotton bract extracts.
(16/80)
BACKGROUND: Exposure to dust in the cotton industry is associated with respiratory dysfunction. Healthy subjects challenged with cotton bract extract (CBE) develop transient airway hyperresponsiveness. CBE, a major component of cotton dust, is potentially an important agent for studying byssinosis. OBJECTIVES: To compare airway responses to cotton dust extract (CDE) and CBE in healthy subjects. METHODS: In 21 healthy, non-smoking subjects we compared the effects of CBE and CDE in a double-blind random order, following a 10-min aerosol inhalation. The response to methacholine (MCh) 2 h following CBE or CDE was measured. Lung function was recorded using maximal (MEFV) and partial expiratory flow volume (PEFV) curves, measuring MEF at 60% of baseline vital capacity below total lung capacity [MEF40%(P)] on the PEFV curve. Responders were subjects who developed a 20% or greater fall in MEF40%(P) following extract challenge. Endotoxin levels were low for CBE (5.71 EU/mg) and CDE (31.88 EU/mg). RESULTS: There were 18 responders to CBE and 17 responders to CDE. The average maximal falls in MEF40%(P) were 70 +/- 4.9 and 70 +/- 4.4% of baseline (nonsignificant) following CBE and CDE, respectively. All subjects enhanced their MCh response following CBE or CDE. The MCh dose which reduced MEF40%(P) by 40% was identical for CBE and CDE (1.3 microg/ml). CONCLUSIONS: We conclude that CBE and CDE exert similar physiologic effects. (+info)