Airborne endotoxin and its relationship to pulmonary function among workers in an Indian jute mill

Air samples from various processing areas of an Indian jute mill were examined for endotoxin. The authors assessed work-related respiratory symptoms and pulmonary function changes in the dust-exposed workers from the different processing areas using a standard questionnaire and spirometry. Endotoxin was estimated in water extract of jute dust from 3 milling areas, and in outside air, by the Limulus amebocyte lysate gel clot technique. The batching, spinning, and weaving areas of the jute mill showed endotoxin levels of 0.22-4.42 microg/m3, 0.04-1.47 microg/m3, and 0.01-0.07 microg/m3, respectively, values similar to those found in Indian cotton mills. Respiratory morbidities among the workers included typical byssinotic symptoms, along with acute changes in postshift forced expiratory volume in 1 s (FEV1.0) (31.8%). Results of this study demonstrated that increased exposure to bacterial endotoxin in airborne dust is related to byssinotic symptoms among Indian jute mill workers. Findings were similar to those reported previously for workers in the cotton, flax, and hemp industries.     

Respiratory disorders and atopy in cotton, wool, and other textile mill workers in Denmark.

A cross-sectional study of respiratory disorders and atopy in Danish textile industry workers was conducted to survey respiratory symptoms throughout the textile industry, to estimate the association of these disorders with atopy, and to study dose-response relationships within the cotton industry. Workers at cotton mills, a wool mill, and a man-made fiber (MMF) mill were examined. Four hundred nine (90%) of the 445 workers participated in this survey, i.e., 253, 62, and 94 workers at the cotton mills, the wool mill, and the MMF mill, respectively. An interview designed to assess the prevalence of common respiratory and allergic symptoms was given to all workers willing to participate, and blood samples were drawn. Lung function measurements determined a baseline FEV1, FVC and the change in FEV1 and FVC during work hours on a Monday. The working environment was examined for dust, bacteria, endotoxins, and molds, and the exposure was estimated for each participant. The mean personal samples of airborne respirable dust and respirable endotoxin were highest in the cotton industry, i.e., 0.17-0.50 mg/m3 and 9.0-126 ng/m3 respectively, whereas mold spores were found in the highest concentrations in the wool mill: 280-791 colony-forming units (cfu)/m3. Only small concentrations of microorganisms were found in the MMF mill. The mean change in FEV1% and FVC% was greatest among atopic individuals in both cotton and wool industry and other textile industries although the differences were not significant. FEV1% and FVC% in the cotton workers were significantly associated with the cumulative exposure to respirable endotoxin. Byssinosis was diagnosed only in the cotton industry. We found a dose-response relationship between endotoxin exposure and byssinosis, and a significant association between A-1-A serum concentrations less than or equal to 35 mumol/liter and byssinosis, a finding we are further evaluating in subsequent studies.     

A comparative environmental and medical study of dust exposure in jute and cotton mills in Burma

Jute is extensively cultivated and processed in Burma, as well as "lower-grade" cotton. This study was conducted there to compare dust exposure in jute and cotton mills, to study the acute and chronic effects of dust exposure on workers, and to establish exposure-response relationship. A sample of 799 male and female workers in two jute mills and two cotton textile mills, as well as a control group of 153 matching subjects, was examined, and dust exposure in the work environment was evaluated. Very high dust concentrations existed in the early stages of jute processing and sorting, which were reduced when jute fibers got cleaner, as in drawing and spinning, and were related to the grade of the processed fiber. Much lower concentrations of dust existed in the cotton mills, but exceeded the TLV (ACGIH) only in opening and cleaning and in carding operations. However, byssinosis occurred only in workers exposed to cotton dust, particularly among males, and its prevalence was related to the level and duration of dust exposure. Chronic bronchitis, cough and wheezing occurred at higher rates among all workers than in the control, while irritation to nose and throat, eyes and skin prevailed only among jute workers. A significant reduction in FVC, FEV1.0 and PEF (before and during shift) was observed in workers compared to control subjects, and was related to workers' exposure and age; however, this reduction was not related to symptoms of different respiratory conditions. "Cheroots" smoking was found to be an important potentiating factor in the occurrence of non-specific respiratory diseases and reduction in FEV1.0, particularly among jute workers.     

Byssinosis in Guangzhou, China.

OBJECTIVES--To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton. METHODS--All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer. RESULTS--The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure. CONCLUSION--It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis.     

Respiratory problems among cotton textile mill workers in Ethiopia.

This study was conducted to investigate the prevalence of respiratory problems, in particular byssinosis, and to explore factors associated with their occurrence among a group of 595 randomly selected workers representing 40.5% of those exposed to dusty operations in a typical Ethiopian cotton textile mill. A standard questionnaire on respiration was administered and pre and postshift forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were determined for each worker; workers found to have byssinosis and other respiratory diseases were compared with workers having no respiratory diseases in terms of the level and duration of exposure to cotton dust and other variables. Multiple area air samples from different sections were analysed for elutriated cotton dust concentrations (0.86-3.52 mg/m3). The prevalence of byssinosis was 43.2% among blowers and 37.5% in carders in comparison with four to 24% among workers in other sections. Prevalence of chronic bronchitis ranged from 17.6 to 47.7% and bronchial asthma from 8.5 to 20.5% across all sections. Significant across shift decrements in FEV1 and FVC were seen in those workers with respiratory tract diseases compared with those workers without such diseases. A significant dose response relation for pulmonary function and respiratory illnesses was also found by regression analysis. Preventive measures are proposed. Further research including a nationwide survey of textile mills is suggested. This is the first epidemiological study of the textile industry in Ethiopia.     

Respiratory problems among cotton textile mill workers in Ethiopia

This study was conducted to investigate the prevalence of respiratory problems, in particular byssinosis, and to explore factors associated with their occurrence among a group of 595 randomly selected workers representing 40.5% of those exposed to dusty operations in a typical Ethiopian cotton textile mill. A standard questionnaire on respiration was administered and pre and postshift forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were determined for each worker; workers found to have byssinosis and other respiratory diseases were compared with workers having no respiratory diseases in terms of the level and duration of exposure to cotton dust and other variables. Multiple area air samples from different sections were analysed for elutriated cotton dust concentrations (0.86-3.52 mg/m3). The prevalence of byssinosis was 43.2% among blowers and 37.5% in carders in comparison with four to 24% among workers in other sections. Prevalence of chronic bronchitis ranged from 17.6 to 47.7% and bronchial asthma from 8.5 to 20.5% across all sections. Significant across shift decrements in FEV1 and FVC were seen in those workers with respiratory tract diseases compared with those workers without such diseases. A significant dose response relation for pulmonary function and respiratory illnesses was also found by regression analysis. Preventive measures are proposed. Further research including a nationwide survey of textile mills is suggested. This is the first epidemiological study of the textile industry in Ethiopia.     

A study of the acute and chronic changes in ventilatory capacity of workers in Lancashire cotton mills

Berry, G., McKerrow, C. B., Molyneux, M. K. B., Rossiter, C. E., and Tombleson, J. B. L. (1973).Brit. J. industr. Med.,30, 25-36. A study of the acute and chronic changes in ventilatory capacity of workers in Lancashire cotton mills. A prospective study of workers in 14 cotton and two man-made fibre spinning mills in Lancashire was carried out over a three-year period. A questionnaire on respiratory symptoms was completed at the start of the survey and again two years later. Up to six measurements of ventilatory capacity were made at six-monthly intervals. From these measurements the rate at which the forced expiratory volume (FEV₁) was declining (annual decline in FEV) was evaluated for 595 subjects. Six of the mills were visited on Mondays and in 199 operatives the ventilatory capacity was measured at both the beginning and end of the shift to evaluate its acute fall during work (Monday fall in FEV).

The mean annual decline in FEV for cotton workers was 54 ml/year and it was only 32 ml/year for workers in the man-made fibre mills but this lower value was attributable almost entirely to one of the two mills. For the jobs near the carding engines the annual decline was 22 ml/year higher than for speed-frame tenters. The annual decline for cigarette smokers was 19 ml/year greater than for non- and ex-smokers. The annual decline in FEV was not found to be related to symptoms of byssinosis or bronchitis, nor to present dust levels, bioactivity of the dust or air pollution, although the expected effect attributable to byssinosis turned out to be less than that which the survey was designed to detect.

The mean Monday fall in FEV was higher in cotton mills than in man-made fibre mills among those without symptoms of byssinosis and was correlated with present dust levels. For those with symptoms of byssinosis an increased Monday fall was found only in those processing coarse cotton.

For those subjects who completed the respiratory questionnaire on two occasions the chronic and acute changes in FEV were examined in relation to the change in symptoms of byssinosis. No association was found for annual decline in FEV but the Monday fall in FEV was greater for those who developed byssinosis during the survey than for those who remained free of symptoms, and was less for those who lost their symptoms than for those who retained them.

     

The study of byssinosis in China: a comprehensive report

Cross-sectional studies were conducted during 1981-1983 among 861 textile workers in 3 cotton mills and 822 controls in 2 silk factories. Questionnaire and lung function tests were taken and inhalable dust concentrations were measured. Prevalence of byssinosis was 5.6%. Average dust concentrations were highest in carding rooms, 1.47-1.99 mg/m3. The correlations (r) between prevalence of byssinosis and dust concentrations was 0.64 (p less than 0.05). The prevalence of chronic bronchitis was 14.4% in cotton workers and 5.1% in controls (p less than 0.05). Acute FEV1 percent decrement (greater than 5%) was higher among cotton workers (32.1%) compared to controls (14.5%) (p less than 0.001). In one cotton blanket factory, the prevalence of byssinosis and chronic bronchitis was higher among workers in the high-dust work areas. Long-term effect studies included pulmonary function test among 173 cotton workers and 373 controls, retired 1-10 years, using the flow volume curve (FVC); chest X-rays of 140 pairs of cotton workers and controls with working tenures over 20 years; and examination of lobectomy specimens of 8 textile workers matched with 16 controls. In male cotton workers, only smokers had a prominent decrement of lung function indices, except FVC. For non-smoking females, there was no difference between the two groups. Additive effects were seen between smoking and dust exposure. According to the International Labor Organization (ILO) Pneumoconiosis Classification, the prevalence of abnormality (profusion greater than 1/0) was 4.3% and 8.7% in non-smoking controls and cotton workers. The interstitial changes on X-ray due to smoking would be much heavier. Additive effects also existed between smoking and dust exposures. No significant changes attributable to dust exposure were seen on pathological section of lobectomy specimens.     

The Relationship of Byssinosis to the Bacteria and Fungi in the Air of Textile Mills

The principal causative agent of byssinosis lies in the dust of cotton mills. This dust contains bacteria and fungi. An attempt has been made to determine whether any association could be established between the numbers of viable bacteria and fungi in the air of two cotton and two jute mills, and the prevalence of byssinosis. No association was found except between the numbers of live organisms of B. pumilus and B. subtilis, and the occurrence of byssinosis. This association does not establish a causal relationship, but it is suggested that an attempt should be made to produce typical symptoms in byssinotic subjects by means of organisms of the genus Bacillus. A subsequent paper presents the results of some observations of this kind.     

Mill effect and dose-response relationships in byssinosis.

Four hundred and eighty-six textile workers in three cotton mills and one wool/synthetic mill were studied for symptoms and functional effects of workroom exposure to dust. Byssinosis was found in 5.7% of 386 cotton workers, with an apparent threshold level of 0.5 mg cotton dust/m3 of air. Mean post-shift functional declines were greater in workers exposed to greater than or equal to 0.2 mg/m3. Workers with byssinosis were unequally distributed, however, with respect to job category and mill; and these variables, rather than current dust exposure levels, accounted for the observed distribution of byssinosis prevalence rates. Variation in biological potency of different samples of cotton dust could be responsible for 'mill effect', the residual variation in response rates by mill after controlling for variation due to dust exposure. A number of other potential influencing variables that are likely to be distributed unequally by mill should also be considered. Mill effect should be assessed in large-scale studies of byssinosis, most of which have analysed biological response rates by combining mill and other variables to examine first-order effects of dust dosage. In such analyses, much of the observed variability may be due to factors other than dust dosage.     

Mill effect and dose-response relationships in byssinosis

Four hundred and eighty-six textile workers in three cotton mills and one wool/synthetic mill were studied for symptoms and functional effects of workroom exposure to dust. Byssinosis was found in 5.7% of 386 cotton workers, with an apparent threshold level of 0.5 mg cotton dust/m3 of air. Mean post-shift functional declines were greater in workers exposed to greater than or equal to 0.2 mg/m3. Workers with byssinosis were unequally distributed, however, with respect to job category and mill; and these variables, rather than current dust exposure levels, accounted for the observed distribution of byssinosis prevalence rates. Variation in biological potency of different samples of cotton dust could be responsible for 'mill effect', the residual variation in response rates by mill after controlling for variation due to dust exposure. A number of other potential influencing variables that are likely to be distributed unequally by mill should also be considered. Mill effect should be assessed in large-scale studies of byssinosis, most of which have analysed biological response rates by combining mill and other variables to examine first-order effects of dust dosage. In such analyses, much of the observed variability may be due to factors other than dust dosage.     

Ocular and nasal irritation in operatives in Lancashire cotton and synthetic fibre mills.

OBJECTIVES--To document the prevalence of work related ocular (eyeWRI) and nasal (noseWRI) irritation in workers in spinning mills of cotton and synthetic textile fibres and to relate the prevalence of symptoms to atopy, byssinotic symptoms, work history, and measured dust concentrations in the personal breathing zone and work area. METHODS--A cross sectional study of 1048 cotton workers and 404 synthetic fibre workers was performed. A respiratory questionnaire was given to 1452 workers (95% of the total available population). Atopy was judged by skin prick tests to three common allergens. Work area cotton dust sampling (WAdust) was carried out according to EH25 guidelines in nine of the 11 spinning mills included in the study. Personal breathing zone dust concentrations were assessed with the IOM sampler to derive total dust exposure (PTdust) and a concentration calculated after the removal of fly (Pless). RESULTS--3.7% of all operatives complained of symptoms of byssinosis, 253 (17.5%) complained of eyeWRI and 165 (11%) of noseWRI. These symptoms did not relate to atopy or byssinosis, or correlate univariately with any measure of cotton dust exposure (noseWRI v WAdust r = 0.153, PTdust r = 0.118, eyeWRI v WAdust r = 0.029, PTdust r = 0.052). Both of these symptoms on logistic regression analysis were related to being of white origin (P < 0.001), female sex (P < 0.001), and younger age (P < 0.001). With regression analysis, there was a negative relation between dust concentration and prevalence of symptoms. CONCLUSION--Work related ocular and nasal irritation are the most common symptoms complained of by cotton textile workers. There was no relation between these symptoms and atopy, byssinosis, or dust concentration. It is likely that they relate to as yet unidentified agents unrelated to concentration of cotton dust.     

Prevalence of byssinosis in textile mills at Ahmedabad, India.

In an epidemiological study carried out in three textile mills at Ahmedabad, India, 929 workers were examined from the spinning departments. The mean prevalence of byssinosis in the blow section was 29.62%, whereas in the card section it was 37.83%. The concentrations of cotton dust (dust less fly) were high in the blow and card sections (4.00 mg/m3 in the blow and 3.06 mg/m3 in the card section). This study suggests that the prevalence of byssinosis is not low in the textile mills of India as reported in many earlier Indian studies.     

Prevalence of byssinosis in textile mills at Ahmedabad, India

In an epidemiological study carried out in three textile mills at Ahmedabad, India, 929 workers were examined from the spinning departments. The mean prevalence of byssinosis in the blow section was 29.62%, whereas in the card section it was 37.83%. The concentrations of cotton dust (dust less fly) were high in the blow and card sections (4.00 mg/m3 in the blow and 3.06 mg/m3 in the card section). This study suggests that the prevalence of byssinosis is not low in the textile mills of India as reported in many earlier Indian studies.     

Comparative study of the smooth muscle contractor activity of airborne dusts and of dustiness in cotton, flax, and jute mills.

A bioassay technique using isolated guinea-pig ileum was employed to compare the smooth muscle contractor activity of various dusts from mills in which the prevalence of byssinosis was known. The activity of dust from a mill spinning a coarse grade of cotton was several times greater than that in dust from a mill processing a fine grade of cotton. There was a similar order in the difference of the prevalence of byssinosis in these mills. However, the activities of fine cotton, flax, and jute dusts were very similar to each other, in spite of marked differences in the prevalence of byssinosis in these mills. For cotton dust, smooth muscle contractor activity was associated with all particle sizes, although the lowest level of activity was found in the largest sized fraction (less than 2 mm). Activity in the cotton dust extracts was not correlated with nitrogen, carbohydrate, or potassium content. However, about one-fifth of the activity of a cotton dust extract was associated with an insoluble particulate fraction. The possible chemical nature of the water-soluble contractor agent is discussed. It is concluded that, until the role of this agent in the pathogenesis of byssinosis has been established, the bioassay technique cannot be employed as a means of assessing the byssinogenic potential of cotton dust.     

Comparative study of the smooth muscle contractor activity of airborne dusts and of dustiness in cotton, flax, and jute mills.

A bioassay technique using isolated guinea-pig ileum was employed to compare the smooth muscle contractor activity of various dusts from mills in which the prevalence of byssinosis was known. The activity of dust from a mill spinning a coarse grade of cotton was several times greater than that in dust from a mill processing a fine grade of cotton. There was a similar order in the difference of the prevalence of byssinosis in these mills. However, the activities of fine cotton, flax, and jute dusts were very similar to each other, in spite of marked differences in the prevalence of byssinosis in these mills. For cotton dust, smooth muscle contractor activity was associated with all particle sizes, although the lowest level of activity was found in the largest sized fraction (less than 2 mm). Activity in the cotton dust extracts was not correlated with nitrogen, carbohydrate, or potassium content. However, about one-fifth of the activity of a cotton dust extract was associated with an insoluble particulate fraction. The possible chemical nature of the water-soluble contractor agent is discussed. It is concluded that, until the role of this agent in the pathogenesis of byssinosis has been established, the bioassay technique cannot be employed as a means of assessing the byssinogenic potential of cotton dust.     

Respiratory response in simultaneous exposure to flax and hemp dust

Žuškin, E., and Valíc, F. (1973).British Journal of Industrial Medicine,30, 375-380. Respiratory response in simultaneous exposure to flax and hemp dust. The effect of exposure to high concentrations of mixtures of hemp and flax dust was studied in 124 workers in two textile mills (mill A: 65-70% hemp and the rest flax, mean dust concentration 13·9 mg/m³; and mill B: about 35% hemp and the rest flax, mean dust concentration 15·8 mg/m³). A high prevalence of byssinosis was found in both mills (80% in mill B; 46·8% in mill A) after a mean exposure of no more than 13 years. In both mills, byssinotics had a higher prevalence of all chronic respiratory symptoms than non-byssinotics. This difference was more pronounced in mill A. Forty-eight percent of byssinotic women and 43% of byssinotic men had byssinosis of grade 2 or 3. Significant mean acute reductions in FEV_1·0 and ˙V_max 50% VC on Monday were recorded in subjects with and without byssinosis with a significantly larger mean reduction in byssinotics (FEV_1·0, P < 0·01; ˙V_max 50% VC, P < 0·05). ˙V_max 50% VC proved to be a more sensitive test for detecting acute effects of vegetable dust than FEV_1·0. The acute respiratory response of the subjects exposed to similar concentrations of flax and mixtures of two different proportions of flax and hemp dust was found to be equal.     

Differential Aerosol Challenge Studies in Byssinosis

Cotton textile mill workers with conditions diagnosed as byssinosis or not byssinosis by a modified Medical Research Council (MRC) questionnaire were challenged with extracts of cotton dust fractionated by filter membrane dialysis, and volatilization. Byssinotic subjects responded with a significant decrease in FEV_1.0 and with clinical symptoms to the inhalation of whole raw cotton extract and nonvolatile, nondialyzable cotton extract compared to saline, volatile extract, and dialyzable extract. Subjects without byssinosis responded the same to saline as to all other extracts. Comparison of responses of byssinotic and nonbyssinotic subjects showed no statistically significant differences with any extract. It was concluded that the active agent in cotton dust is water soluble, filterable at 0.22μ, nonvolatile at 40C, and nondialyzable but may not be active only in that group of patients identified as byssinotic by questionnaire.     

A comparative study of respiratory function in female non-smoking cotton and jute workers

Valić, F., and Žuškin, E. (1971).Brit. J. industr. Med.,28, 364-368. A comparative study of respiratory function in female non-smoking cotton and jute workers. To compare the effect of cotton and jute dust, respiratory symptoms were studied and respiratory function measured in 60 cotton and 91 jute non-smoking female workers of similar age distribution, similar length of exposure to dust, and exposed to similar respirable airborne dust concentrations. Cotton workers had a significantly higher prevalence of byssinosis, of persistent cough, and of dyspnoea (P < 0·01) than jute workers. Among cotton workers 28·3% were found to have characteristic symptoms of byssinosis, whereas none was found among jute workers.

Exposure to cotton but also to jute dust caused significant reductions of FEV_1·0, FVC, and PEF (P < 0·01) over the first working shift in the week. Functional grading of jute and cotton dust effects has shown that about 30% of cotton workers had functional grades F1 and F2, while only 13% of jute workers were found in the same grades (F1). It is concluded that cotton dust may be considered more active than jute though the latter cannot be considered inactive.

     

Effects of different vegetable dust exposures

Valić, F., and Žuškin, E. (1972).Brit. J. industr. Med.,29, 293-297. Effects of different vegetable dust exposures. In order to establish the rank of biological activity of vegetable dusts, five groups of non-smoking female workers exposed to similar concentrations of hemp, flax, cotton, sisal, and jute airborne dust, respectively, were compared as to the prevalence of byssinosis, chronic respiratory symptoms, and one-second expiratory volume changes over the Monday shift. The groups were selected in such a way as to differ in the distribution of age and length of exposure to the respective dust as little as possible.

The prevalence of byssinosis in hemp and flax workers was approximately equal (44% and 43% respectively), in cotton workers it was considerably lower (27%), while no byssinosis was caused by either sisal or jute dust. The highest prevalence of other chronic respiratory symptoms was recorded in hemp workers (39%), followed by flax (36%) and cotton workers (27%), while in sisal (13%) and jute workers (13%) it was the lowest.

Significant mean FEV_1·0 reductions over the shift were recorded in all the groups of textile workers with the largest reductions in hemp workers (19%) followed by flax (11%), cotton (8%), sisal (7%), and jute workers (5%). The application of orciprenaline before the shift diminished the mean acute FEV_1·0 falls over the work shift in all the groups studied.