The health investigation of cotton textile workers in Beijing

This study reports findings from a survey of byssinosis among 289 cotton workers in certain cotton textile mills in Beijing. Incidence of byssinosis was 4.2% (12 cases). It decreased with a lower concentration of cotton dust and increased with yearly increment of cotton dust exposure. An elevation in body temperature over 37 degrees C was present among 14.2% of the workers on the first working day after rest. Acute lung function decrement was related to high dust concentration in the rooms. The higher the dust concentration in the rooms, the more evident was the chronic lung function decrement. Chronic bronchitis in cotton workers was higher than in controls. Incidence of byssinosis in smoking cotton workers was higher than in nonsmoking cotton workers.     

Relationships between dust level and byssinosis and bronchitis in Lancashire cotton mills

Berry, G., Molyneux, M. K. B., and Tombleson, J. B. L. (1974). British Journal of Industrial Medicine,31, 18-27. Relationships between dust level and byssinosis and bronchitis in Lancashire cotton mills. A prospective survey of workers in 14 cotton and two man-made fibre spinning mills was carried out. A questionnaire on respiratory symptoms was completed at the start of the survey by 1 359 cotton workers and 227 workers in man-made fibre mills and again two years later by about half of these workers. Dust measurements were available for 772 women and 234 men cotton workers.

The prevalence of bronchitis was found to be unrelated to dust level but for women was related to years of exposure. The change in symptoms of bronchitis was unrelated to dust level or to length of exposure. There was, however, an increased prevalence of bronchitis in the cotton mills when compared with the man-made fibre mills, and also over the two-year period a greater proportion of symptom-free workers developed symptoms and a lower proportion of those with symptoms lost their symptoms in the cotton mills than in the man-made fibre mills.

The prevalence of byssinosis was related to smoking habits, the smokers having about 1·4 times as much byssinosis as the non- and ex-smokers after allowing for exposure. Byssinosis was associated with the dust level and years of exposure, more so for the women, and an association between the incidence of new cases over the two years and dust level was also found. After allowing for dust level, years of exposure, and smoking there were still differences between the occupational groups in byssinosis prevalence. Strippers and grinders had the highest prevalence followed by drawframe tenters. Speedframe tenters, card tenters, and comber tenters had similar prevalences and ring spinners the lowest.

     

Respiratory disease in cotton textile workers in the People's Republic of China. I. Respiratory symptoms

The prevalence of byssinosis and nonspecific respiratory symptoms was studied in 887 textile workers with at least two years of employment in two cotton mills and one silk mill in Shanghai, the People's Republic of China. A standardized respiratory questionnaire was used, and environmental sampling was performed with vertical elutriators and colorimeter grading. Eight percent of the cotton textile workers complained of byssinosis. The reports of byssinosis were mostly mild (grade 1/2), more prevalent among women, and unrelated to duration of employment or elutriator dust levels. Nonspecific respiratory symptoms were significantly more prevalent among cotton textile workers than silk workers. After adjustment for age, gender, and smoking in logistic regression models, the odds ratios for the effect of working in cotton textile mills on chronic bronchitis, chronic cough, and frequent chest illness were 3.3, 2.9 and 4.7, respectively. Although none of the symptoms were related to current dust levels, the range of exposures was narrow, and information was only available on current levels of cotton dust. This study represents the first respiratory survey of the textile industry in China using diagnostic criteria similar to that used in the United States and England; it defines a cohort for prospective investigation.     

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.     

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 Hong Kong

After a report in 1980 of the first three diagnosed locally cases and a preliminary epidemiological investigation that found little evidence of the disease, a survey was aimed at determining the prevalence of byssinosis in Hong Kong. Some 1776 workers in six cotton mills were studied using the standard MRC questionnaire and portable spirometers. Only 48 (2.7%) of the mill workers had symptoms acceptable for a diagnosis of byssinosis. The pattern of relation to dust exposure levels was similar to findings in other countries: blowing and carding process operatives had twice the prevalence rate of the spinners. Another 178 workers (10%) had symptoms of chest tightness or breathlessness or both that were not related to the first exposure after a break and therefore did not fit the standard diagnosis. Some 257 workers (14.5%) had chronic obstructive airflow disease but only 12 (4.7%) had chronic bronchitis. Job mobility had self selection of sensitive cases out of cotton dust exposure seem the most likely explanations for the low prevalence. The significance of non-specific lung ailments needs further assessment to elucidate the possible connection with cotton dust exposure.     

Byssinosis in Hong Kong.

After a report in 1980 of the first three diagnosed locally cases and a preliminary epidemiological investigation that found little evidence of the disease, a survey was aimed at determining the prevalence of byssinosis in Hong Kong. Some 1776 workers in six cotton mills were studied using the standard MRC questionnaire and portable spirometers. Only 48 (2.7%) of the mill workers had symptoms acceptable for a diagnosis of byssinosis. The pattern of relation to dust exposure levels was similar to findings in other countries: blowing and carding process operatives had twice the prevalence rate of the spinners. Another 178 workers (10%) had symptoms of chest tightness or breathlessness or both that were not related to the first exposure after a break and therefore did not fit the standard diagnosis. Some 257 workers (14.5%) had chronic obstructive airflow disease but only 12 (4.7%) had chronic bronchitis. Job mobility had self selection of sensitive cases out of cotton dust exposure seem the most likely explanations for the low prevalence. The significance of non-specific lung ailments needs further assessment to elucidate the possible connection with cotton dust exposure.     

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.

     

BYSSINOSIS IN CARDROOM WORKERS IN SWEDISH COTTON MILLS

The prevalence of byssinosis and chronic respiratory symptoms was studied in 117 workers in four Swedish cotton mills. Changes of forced expiratory volume in 0·75 sec. (F.E.V._0·75) during a Monday and a Wednesday were assessed in 64 male workers in four cardrooms in these mills. Dust sampling was performed with weighed millipore filters.

Prevalences of byssinosis as judged from the workers' histories were 68%, 55%, 44%, and 25% in the four mills; the lowest prevalence of 25% was found in a mill spinning both high grade cotton yarn and rayon. Among 67 workers in the mills having a byssinosis prevalence of 68% and 55%, 60% were non-smokers, 70% had chronic cough, and 27% had chronic dyspnoea. The F.E.V._0·75 decreased on Monday in workers who gave a history of Monday dyspnoea, and to a lesser degree, but still significantly, in those who did not.

In spite of marked differences in fine dust (i.e., dust smaller than 2 mm. diameter) concentrations in the four cardrooms, no significant relations between dust content, byssinosis prevalence, and F.E.V._0·75 changes on Monday could be demonstrated.

The prevention and treatment of byssinosis is discussed. Workers at risk should receive a periodical medical examination including at least a spirographical pulmonary function test at intervals of one year or less.

     

A Clinical and Environmental Study of Byssinosis in the Lancashire Cotton Industry

The prevalence of byssinosis was measured in a population of 189 male and 780 female workers employed in three coarse and two fine cotton mills. Ninety-eight per cent. of the male and 96% of the female population were seen.

The workers were graded by their histories as follows:

Grade 0—No symptoms of chest tightness or breathlessness on Mondays

Grade ½—Occasional chest tightness on Mondays, or mild symptoms such as irritation of the respiratory tract on Mondays

Grade 1—Chest tightness and/or breathlessness on Mondays only

Grade 2—Chest tightness and/or breathlessness on Mondays and other days

The dust concentrations to which the workers were exposed were measured with a dust-sampling instrument based on the hexhlet. Altogether 505 working places were sampled. In the card-rooms of the coarse mills 63% of the men and 48% of the women had symptoms of byssinosis. In the card-rooms of the fine mills the corresponding prevalences were 7% for the men, and 6% for the women. Prevalences were low in the spinning-rooms in the coarse mills. The mean dust concentrations in the different rooms ranged from 90 mg./100 m.³ in one section of the card-room in a fine mill, to 440 mg./100 m.³ in one of the card-rooms of the coarse spinning mills. The prevalence of byssinosis in the different rooms was closely related to the overall dustiness (r = 0·93). For the three main constituents of the dust, namely, cellulose, protein, and ash, the prevalence of byssinosis correlated most highly with protein, particularly with the protein in the medium-sized dust particles, i.e., approximately 7 microns to 2 mm.

The symptoms of byssinosis may be caused by something in the plant débris which affects the respiratory tract above the level of the terminal bronchioles. This is the site where the medium-sized dust deposits. The possible importance of the fine dust is discussed.

For routine measurements in industry, it is necessary to have a method of assessing dustiness in which the sampling equipment is simple and assessment rapid. As total dust concentration is relatively easy to measure, and correlates closely with the prevalence of byssinosis, permissible levels of dustiness have been expressed in terms of total dust. On comparing the prevalence of byssinosis among workers with short and long exposures and low and high concentrations (Table 11), it appears that a mill with a concentration of 100 mg./100 m.³ or less would be reasonably safe, but in dusty card-rooms it seems that such levels are not possible to achieve at present. As it is necessary to adopt a realistic target that can be achieved, it is suggested that dust concentrations in cotton mills should be less than 250 mg./100 m.³ and that periodic medical examinations should be adopted to protect susceptible workers who can be advised to leave their dusty environment before they are permanently disabled.

     

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 and respiratory symptoms among spinners in Sudanese cotton mills

Byssinosis, other respiratory symptoms, and ventilatory capacity were investigated in 186 male spinners in two Sudanese textile mills located in Khartoum and Hassaheisa. The prevalence of byssinosis was 37% among Khartoum spinners where coarse cotton was processed, significantly higher (p less than 0.01) than the 1% found among Hassaheisa spinners, where fine cotton was used. The prevalence of chronic bronchitis was 29% in Khartoum and 2% in Hassaheisa spinners. A significant reduction in forced expiratory volumes (FEV1 after a shift) was observed in spinners of both factories. Our findings provide evidence that very low rates or absence of byssinosis, related respiratory symptoms, and significant functional abnormalities (FEV1) in the late stages of cotton yarn processing all depend on the quality of cotton used and low levels of cotton dust concentration.     

Additive effect of smoking and cotton dust exposure on respiratory symptoms and pulmonary function of cotton textile workers

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.     

A Study of Byssinosis, Chronic Respiratory Symptoms, and Ventilatory Capacity in English and Dutch Cotton Workers, with Special Reference to Atmospheric Pollution

An epidemiological survey of 414 English and 980 Dutch male cotton workers was undertaken to determine the prevalence of byssinosis and respiratory symptoms, and to compare the ventilatory capacities in the two populations, with particular reference to the influence of air pollution. The English workers were employed in six mills in Lancashire and the Dutch workers in three mills in Almelo spinning similar grades of cotton.

The methods used included a questionnaire on respiratory symptoms and illnesses, the collection and examination of sputum, and the measurement of the forced expiratory volume over 0·75 sec. Concentrations of smoke and sulphur dioxide were measured in the English and Dutch towns.

The crude rates for byssinosis were similar, 13·5% and 17% respectively in the English and Dutch card and blow rooms, and 1·5% and 1·6% respectively in the spinning rooms. The English workers had significantly higher prevalences of persistent cough and persistent phlegm and significantly lower indirect maximum breathing capacities. These findings were supported by the results of a sputum survey. Nearly twice as many English produced specimens, and the mean volume of sputum was greater for the English workers.

The prevalence of bronchitis, defined as persistent phlegm and at least one chest illness during the past three years, causing absence from work, was higher in the English than in the Dutch workers in both types of work room, but not significantly so after standardizing for differences in age. Since there are important differences in the social security systems of the two countries, which may encourage more absence from illness among the Dutch, a comparison of bronchitis thus defined is likely to be invalid.

The higher prevalences of respiratory symptoms and lower ventilatory capacities in the English are unlikely to be due to observer error. They are discussed in relation to smoking habits, exposure to cotton dust, and air pollution. The most likely explanation of the unfavourable picture presented by the English workers is the much higher level of air pollution in Lancashire.

     

Respiratory symptoms and cotton dust exposure; results of a 15 year follow up observation

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.

     

Byssinosis among jute mill workers

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.     

Dust in Card Rooms: A Continuing Problem in the Cotton-Spinning Industry

The results are given of environmental and clinical investigations in four card rooms where one of the latest systems of exhaust ventilation to control dust has been installed. The concentration of air-borne coarse dust particles, larger than 2 mm., was reduced by between 80% and 90% around the carding engines. The card rooms consequently looked less dusty. However, the concentrations of medium and fine sized dust particles were not always reduced and were actually increased in some places. In one mill, when the new control system had been running for three years, there was found to be no reduction in the prevalence of non-specific chest symptoms, and there was an increase in the number of those with chest tightness on Mondays, a symptom characteristic of byssinosis. Evidence is given of a similar failure to reduce the dust sufficiently in three other mills where the same exhaust system is installed.

There is an urgent need to extend the limited investigations reported here to a larger number of mills. Meanwhile there is a continuing morbidity and mortality from byssinosis. Until work in card rooms has been made safe and proved to be so, it is necessary to have regular measurement of dust conditions and for the workers to have periodical medical examinations to enable managements to be advised about the hazards in their mills and advice to be given to the individuals affected by the dust.

     

棉纺车间空气中可吸尘,内毒素浓度与工人呼吸道反应

本文对338名棉工进行了呼吸道反应调查.并测定了车间空气中粉尘浓度及内毒素浓度.发现前纺车间可吸尘浓度在O.18～1.62m g/m~3,内毒素浓度在94.91～2682.18ng/m~3,棉尘有关症状(包括棉尘病症状和不典型症状)和慢性支气管炎患病率均比对照组高,且与车间粉尘和内毒素浓度呈正相关.与5年前比较,可吸尘或内毒素累积接触量高的男、女工人FEV_1下降均较累积接触量低者明显。