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1.  Role of family susceptibility, occupational and family histories and individuals' blood groups in the development of silicosis. 
A previous investigation has shown that family susceptibility and occupational and family histories have a decisive role in the development of byssinosis among workers exposed to flax dust. Results of investigation of silicosis in 814 male workers exposed to silica-bearing dust showed that family susceptibility has an important role in the development of silicosis among examined workers, and workers whose fathers had an occupational history of exposure to silica-bearing dust were more resistant to the development of the disease than those with non-exposed fathers. The degree of consanguinity of parents and individuals' blood groups, also, have a role. Workers with cousin parents were relatively highly susceptible to the development of silicosis as well as workers with blood groups "O" or "AB". It has been concluded that the investigated factors might have a role in the development of other occupational diseases and further investigations are indicated.
PMCID: PMC1008760  PMID: 6255981
2.  Endemic Byssinosis in an Egyptian Village 
Previous epidemiological surveys of flax byssinosis may have underestimated the incidence of permanent pulmonary disability by failing to reach those who have had to leave work. In the present study a representative sample of the inhabitants of a village where flax is processed both in the homes and in small plants was examined for byssinosis. The one in five random sample included a total of 190 male family heads living in the village. Dust exposure was evaluated. The study showed that 48·4% of the sample had byssinosis, and this included 92·5% of those working with flax in their homes and 75% of those working in plants. Permanent disability from byssinosis was present in 2·6% of the total sample and 12·1% of those exposed to dust for more than 20 years, whereas 75·8% of the latter group had symptoms of the earlier grades of byssinosis. It is concluded that prolonged exposure to flax dust did not result in a high incidence of permanent disability, and that is disability is not necessarily an eventual outcome in flax byssinosis. The absence of air pollution in the village may play a role in lowering the probability of workers becoming disabled by byssinosis in spite of the high prevalence of symptoms.
PMCID: PMC1038360  PMID: 14180483
3.  Dust exposure in manual flax processing in Egypt. 
Manual flax processing originated in Egypt in 2 000 BC. In the present study a representative sample of the workers involved in this trade, where flax is processed in small workshops or homes, was examined, and their dust exposure was evaluated. The study showed that workers handling and processing flax are exposed to high concentrations of dust; the levels of dust at hackling and combing are considerably higher than at batting and spinning. Byssinosis prevailed in 22-9% of the examined workers, and 18-4% of them had their forced expiratory volume in one second reduced by more than 10% at the end of the first morning work period (4 hours) of the week. Both the rates and the grades of these syndromes increased with duration of exposure. Smoking appeared to be one of the important contributory factors in the production of byssinosis. The relationship between dust concentration and prevalence of byssinosis seems to be curvilinear.
PMCID: PMC1008040  PMID: 1131341
4.  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 FEV1·0 and ˙Vmax 50% VC on Monday were recorded in subjects with and without byssinosis with a significantly larger mean reduction in byssinotics (FEV1·0, P < 0·01; ˙Vmax 50% VC, P < 0·05). ˙Vmax 50% VC proved to be a more sensitive test for detecting acute effects of vegetable dust than FEV1·0. 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.
PMCID: PMC1069478  PMID: 4753721
5.  HLA antigen frequencies in flax byssinosis patients. 
Not all workers exposed to flax dust contract byssinosis. It is not known what determines susceptibility or insusceptibility. This study is an attempt to establish whether the incidence of histocompatibility antigens is involved in susceptibility to the disease. Forty patients suffering from flax byssinosis were tissue-typed for HLA-A and -B antigens. HLA-B27 was significantly more common in the patients (22.5%) than in the controls (5.5%); P = 0.029 after correction for the number of antigens compared. HLA-A11 was present in twelve patients (30%) compared with 14% in the controls; after correction for the number of comparisons, this is not a statistically significant increase. Because HLA-B27, though significantly more common in flax byssinosis, is not necessary for its occurrence (77.5% of our patients did not have it), it is possible that the increase in the frequency of HLA-B27 is attributable to an association with other genes, perhaps those regulating the immune response or coding for antigens at other HLA loci.
PMCID: PMC1008527  PMID: 465375
6.  Byssinosis Prevalence and Flax Processing* 
Previous evidence suggested that byssinosis in flax workers is caused by the inhalation of dust of biologically retted flax. In the present study no cases of byssinosis were found among workers in a flax plant which produces yarn by chemical degumming instead of biological retting. The absence of byssinosis in this plant could not be attributed to differences in the quantities of dust developed as compared with the conventional retting procedure.
These findings support the view that the agent in flax dust which causes symptoms of byssinosis originates during biological retting of flax and is absent from unretted flax. Chemical degumming of flax appears to be superior to biological retting procedures with respect to the health of the workers.
PMCID: PMC1038385  PMID: 14072625
7.  Role of histamine in the aetiology of byssinosis. I Blood histamine concentrations in workers exposed to cotton and flax dusts. 
The formation or the accumulation, or both, of histamine in the lungs may be potentiated by agent(s) present in cotton dust at higher level(s) than in flax dust and negligible in cottonseed dust. It has been suggested that such potentiation may be due to the activation of the ability of the lung to produce histamine and/or produce or recruit mast cells; this may present an acceptable explanation of the mechanism by which the propagation of the chronic effect of the dust proceeds in cotton and flax workers. Histamine accumulated in the lung over the weekend is released on exposure to dust causing the symptoms of byssinosis. The difference in the rate of histamine metabolism relative to the rate of histamine formation in byssinotic subjects leads to a more prolonged histamine accumulation than in symptom free subjects, with the consequent appearance of the symptoms of byssinosis. Continuous exposure to dust, without weekend interruption, leads to equivalent rates of histamine formation and metabolism with non-considerable histamine accumulation in the lungs and consequent absence of the symptoms of byssinosis.
PMCID: PMC1009284  PMID: 6202313
8.  Dust Diseases in Dundee Textile Workers 
A survey of respiratory symptoms and function was carried out in Dundee among 123 men and women in the jute industry and 242 in the flax industry. The selection of workers was biassed in favour of those working in the dustier departments as judged by eye and those in the older age groups. A group of 72 men in a heavy engineering firm were also selected as controls for comparison.
Chronic bronchitis, as defined by Ogilvie and Newell (1957) was recorded in 27% of those interviewed, whose average age was 49. Byssinosis of various grades was recorded in 30% of all working in flax; of these 35 had cough alone worse on Monday, 34 had other respiratory symptoms worse on Monday and in only four persons did the exacerbation persist longer in the week.
In spite of the occurrence of byssinosis, chronic bronchitis was no more prevalent among flax workers than among the others, the average ventilatory function was no worse, and radiographs of the chest revealed no differences. The characteristic fall in expiratory flow rate during the course of exposure to flax dust on Mondays is similar to that found in cotton workers, and is absent in jute workers and in flax workers not admitting to symptoms of byssinosis.
PMCID: PMC1038081  PMID: 13765497
9.  A study of rope workers exposed to hemp and flax 
Smith, G. F., Coles, G. V., Schilling, R. S. F., and Walford, Joan (1969).Brit. J. industr. Med.,26, 109-114. A study of rope workers exposed to hemp and flax. Respiratory symptoms and ventilatory capacities were studied in 54 men and 22 women exposed to the mixed dusts of hemp and flax in an English rope factory. The preparers and most of the spinners were exposed on average to concentrations of 1·7 mg./m.3 total dust and 0·5 mg./m.3 fine dust. Those employed on subsequent processes had lower exposures at concentrations of 0·5 mg./m.3 total dust and 0·1 mg./m.3 fine dust.
Six men, all in the high exposure group, had symptoms of byssinosis. After adjustment for age and standing height there was no statistically significant difference in the forced expiratory volume (F.E.V.1·0) between those in high dust concentrations and those in low concentrations; neither was there a significant difference between the ventilatory capacities of men with and without byssinosis.
This study shows that byssinosis is an occupational hazard confined to male workers in this factory. It does not appear to be a very serious problem and will diminish with the increasing use of synthetic materials instead of natural fibres.
PMCID: PMC1008903  PMID: 5780101
10.  The larger bronchi in byssinosis: a morphometric study. 
Journal of Clinical Pathology  1984;37(1):20-22.
The proportions of gland, muscle and cartilage were measured in the named bronchi of 43 byssinotics, and compared with the proportions in normal subjects and chronic bronchitics. The smoking habits and symptomatology of the byssinotics were also investigated. In the byssinotics the proportions of gland, muscle and cartilage were higher than in the normal, non-smoking subject at all levels in the bronchial tree, and were similar to those in chronic bronchitics. The increase was not confined to the lobar bronchi as the results of a previous investigation had suggested. It is concluded that although exposure to cotton dust is a factor in the pathogenesis of chronic byssinosis, anatomical changes in the bronchi of Lancashire cotton workers are non-specific, and are confounded by other environmental factors. Smoking has a deleterious effect on the natural history of the disease, but no morphological difference between smokers and non-smokers was found.
PMCID: PMC498611  PMID: 6707218
11.  Prevalence of byssinosis in Swedish cotton mills. 
The prevalence of byssinosis and of chronic bronchitis was studied in a questionnaire investigation among workers in bale opening areas, carding rooms, and spinning rooms in five Swedish cotton mills. Airborne dust and Gram-negative bacteria was measured. Nineteen per cent of the interviewed workers reported symptoms of light byssinosis (grade 1/2). The prevalence of symptoms was not related to the duration of employment, and cases of byssinosis were found among people who had worked in cotton mills for only a few years. A significantly higher proportion of male than female workers reported symptoms. No difference in the extent of byssinosis was found between smokers and non-smokers, but the prevalence was significantly higher among those workers who had ceased smoking. The prevalence of byssinosis was related to the number of airborne viable Gram-negative bacteria as well as to the dust level in the different mills.
PMCID: PMC1008836  PMID: 7236538
12.  Prevalence of Byssinosis and Dust Levels in Flax Preparers in Northern Ireland 
The association between the prevalence of both byssinosis and chronic bronchitis and the level of airborne dust was examined in workers in preparing departments in flax mills in Northern Ireland. A weak association between the dust level and byssinosis was found but not between the dust level and chronic bronchitis. It is suggested that the disparity of these associations may have arisen because the diagnosis of byssinosis, as in most recent published studies, was based on relatively acute and reversible symptoms which are more likely to be closely related to the current dust levels than the slowly developing symptoms on which the diagnosis of chronic bronchitis was based. Furthermore an association between chronic bronchitis and the dust levels is likely to be obscured to some extent by the effects of other non-industrial respiratory irritants such as tobacco smoke. Some hypotheses of the basic aetiology of byssinosis are discussed.
PMCID: PMC1008428  PMID: 5946128
13.  Respiratory disability in ex-flax workers. 
Acute respiratory effects occur in a high proportion of subjects exposed to textile dusts. The extent to which these lead to permanent respiratory symptoms and loss of lung function is unknown. A survey of random population samples was therefore conducted in ten towns in Northern Ireland in which flax processing had been a major source of employment. The MRC questionnaire on respiratory symptoms was administered and Vitalograph tracings recorded on subjects aged 40 to 74 inclusive. An occupational history was taken at the end of each interview. Lung function in ex-flax workers was slightly lower than in control subjects never exposed to flax dust, but the presence of a positive interaction with age meant that differences were apparent only in the younger subjects. Over about the age of 65 the lung function in the ex-flax workers was comparable with that of the controls and overall the loss was at most about half that due to light smoking (1-14 cigarettes a day). The association between a "dust exposure score" and lung function was inconsistent in the two sexes. In men there was a small decrement with increasing dust exposure. In women there was also a small decrement, but a positive interaction with age meant that the women with the highest dust exposure scores had a lower loss with increasing age than the women with the least dust exposure. There was an excess in symptoms in the ex-flax workers but the size of the excess was greater than would be expected from the lung function results. It is possible that, although the survey was conducted without explicit reference to the flax industry, knowledge throughout Northern Ireland that many flax workers have been awarded compensation on the grounds of respiratory disablement may have led to an increased reporting of symptoms in the ex-flax workers.
PMCID: PMC1007653  PMID: 3707867
14.  Respiratory symptoms and ventilatory function changes in relation to length of exposure to cotton dust 
Thorax  1972;27(4):454-458.
The prevalence of byssinosis, respiratory symptoms, acute changes of ventilatory capacity over the shift, and chronic changes of ventilatory capacity were studied in two groups of non-smoking female workers exposed to practically identical concentrations of the same type of cotton dust but for very different periods of time (16 and 4 years respectively). The prevalence of non-specific respiratory symptoms increased with the duration of exposure to cotton dust only in the subjects with byssinosis. Exposure to cotton dust caused significant reductions over the shift of the mean FEV1.0, FVC and PEF in all the groups of cotton workers examined. In byssinotics the reduction in ventilatory capacity was considerably greater in subjects with longer than in those with shorter exposure to cotton dust, while in non-byssinotics the response was approximately equal in the two groups. Inhalation of a bronchodilator at the end of the shift restored ventilatory function to its pre-shift values except in byssinotics with a longer duration of exposure to cotton dust. Chronic changes of ventilatory capacity developed only in subjects with a longer exposure to cotton dust and were common in the byssinotics.
PMCID: PMC469950  PMID: 5075615
15.  Effects of different vegetable dust exposures1 
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 FEV1·0 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 FEV1·0 falls over the work shift in all the groups studied.
PMCID: PMC1009427  PMID: 5044600
16.  Mortality of flax workers. 
A total of 2528 workers in flax mills in Northern Ireland were followed up for 16 years. Follow-up was 97% complete. Deaths were identified and date and cause ascertained. Expected deaths were calculated on the basis of age and sex specific rates for Northern Ireland. Both male and female workers had fewer deaths than expected, and mortality showed no clear relationship with type of work. There was a small excess in the mortality of the workers who had had byssinosis at the time of the original survey, but there was no evidence that the more severe grades of byssinosis were associated with higher mortality than the less severe grades. Workers who smoke are known to have an increased risk of developing byssinosis, and cigarette smoking may be responsible for most of the excess deaths in the workers with byssinosis.
PMCID: PMC1008922  PMID: 7066216
An attempt was made to assess the importance of selective discharge by death or retirement of workers with respiratory symptoms in a flax mill in Northern Ireland.
One hundred and two men who had worked in a flax mill during 1952-62 and who were aged 35 years or more at the time of leaving were followed up. Fourteen of the men had died and 75 were interviewed. The proportion who had dyspnoea on exertion at the time of interview was significantly higher (at P<0·05) in those who had had byssinosis than in those who had not had byssinosis while in the mill, although the proportions with dyspnoea in preparers and nonpreparers did not differ significantly. The proportion who stated that they had left the mill because of exertional dyspnoea of increasing severity was also significantly higher among those who had had byssinosis than among those who had not. Most of the men who had had byssinosis stated that their symptoms had improved after they left the mill, though some thought that work in the mill had permanently affected their chests, and two said that their symptoms had become gradually more severe since discharge. Of the 14 who had died, certificates of the cause of death were traced for 12, in none of which had respiratory disease been entered as a cause of death. In one man who had been a flax preparer, chronic bronchitis had been considered a `significant condition, contributing to the death'.
The study indicates that any estimate of the prevalence of byssinosis based solely on the examination of workers in the mills underestimates the true magnitude of the problem.
PMCID: PMC1008213  PMID: 14261705
18.  Byssinosis, respiratory symptoms and spirometric lung function tests in Tanzanian sisal workers 
ABSTRACT Byssinosis and other respiratory symptoms and acute and chronic changes in FVC and FEV1·0 were investigated in 77 workers in sisal spinning and 83 workers in sisal brushing departments in six Tanzanian sisal factories. Although the prevalence of byssinosis in spinning departments was found to be low (5·2%), it was very high in brushing departments (48·2%). Workers in brushing were exposed to sisal dust for a significantly longer period (11·77 ± 7·3 years) compared to workers exposed to sisal in spinning (2·85 ± 2·56 years). Although the number of smokers in brushing (42%) was similar to that in spinning (37%), smokers were more prone to byssinosis than were non- or ex-smokers after standardisation for duration of exposure. We were unable to measure dust levels in this study, but dust levels in spinning and brushing are cited from previous studies. These confirm our impression that the dust level in spinning is higher than that in an average cotton carding department and far higher in brushing than in spinning. Acute falls in FVC and FEV1·0 were found during the work shift. The extent of the fall in FEV1·0 correlated well with the severity of byssinosis; 75% of the workers with grade II byssinosis and 33% of those with grade ½ + I were found to have acute falls in FEV1·0 greater than 0·2 litres. However some workers, 10% in spinning and 33% in brushing, who denied symptoms of byssinosis, were also found to have acute falls in FEV1·0. Some workers had slight or severe chronic ventilatory impairment from dust (FEV1·0 less than 80%, or less than 60% of the respective predicted values), and these workers were mostly from the brushing department. The prevalence of chronic cough and chronic bronchitis was found to be negligible in workers in the spinning and in the brushing departments: 9·6% had a chronic cough and 12% had chronic bronchitis. It is concluded that a high prevalence of byssinosis associated with chronic and acute changes in FVC and FEV1·0 occurs in the brushing departments of sisal factories, and that this is related to lengthy exposure, high dust level and smoking.
PMCID: PMC1008365  PMID: 656336
19.  An investigation of allergy in byssinosis: sensitization to cotton, hemp, flax and jute antigens 
Popa, V., Gavrilescu, N., Preda, N., Teculescu, D., Plecias, M., and Cîrstea, M. (1969).Brit. J. industr. Med.,26, 101-108. An investigation of allergy in byssinosis: sensitization to cotton, hemp, flax, and jute antigens. The authors investigated allergy to cotton, hemp, flax, and jute in 41 subjects with byssinosis. In contrast with immediate skin reactions, which were seldom observed, delayed reactions were nearly always present. The incidence of positive skin tests in byssinosis was similar to that observed in all textile workers. Inhalation tests with textile allergens were negative in all but four subjects who also had a concomitant bronchial asthma. Fifteen out of 31 subjects with byssinosis had positive inhalation tests to acetylcholine but only one of the 13 tested had a positive response to the inhalation of textile macerate. Haemagglutinating antibodies to low titres could be observed in byssinosis as well as in chronic bronchitis, in bronchial asthma, and in the general population. The significance of various types of antibodies existing in byssinosis is further discussed. The authors stress the need to standardize textile allergens.
PMCID: PMC1008902  PMID: 5780100
20.  Byssinosis in the Cotton Industry of Egypt 
An epidemiological investigation in 11 ginneries representing the ginning industry in Egypt demonstrated the existence of byssinosis among 38·4% of the workers. Studies of two pressing plants and two card-rooms in Alexandria showed a prevalence of byssinosis of 52·6% and 26·6% respectively. The ages of those exposed and the duration of exposure were considered in relation to the prevalence of byssinosis, and it appears that a short duration of exposure in ginning may result in early manifestations of byssinosis at a relatively young age. The interruption of exposure due to seasonal activity in ginning and partially in pressing resulted in a higher proportion of workers with the early stages of the disease. This contrasted with results in carding where exposure is continuous, and a higher proportion of workers have later stages of the disease. This suggests a delay in the progress of the disease due to periodic interruption of exposure.
The comparison between the prevalence of byssinosis and that of chronic bronchitis has shown that these diseases are not necessarily associated, although additional stress due to dust exposure in chronic bronchitis is not denied.
PMCID: PMC1038170  PMID: 13875361
21.  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.
PMCID: PMC1035330  PMID: 1998605
22.  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 FEV1·0, 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.
PMCID: PMC1009330  PMID: 5124836
23.  First report of byssinosis in Hong Kong. 
There has been no report of byssinosis in Hong Kong although the textile industry has been one of the leading industries for many years. Three workers with a long history of exposure to cotton dust had chronic obstructive airways disease precipitated by their work environment. One had irreversible airways obstruction but none had chronic bronchitis, emphysema, or asthma. Only one gave a history of "Monday morning tightness," and this was attributed to the fact that most of the textile workers in Hong Kong work seven days a week. It was suggested that a survey be carried out to ascertain the importance of byssinosis in the textile workers of Hong Kong and tha byssinosis should there be added to the list of notifiable occupational diseases.
PMCID: PMC1008888  PMID: 7272243
24.  Byssinosis in the Egyptian Cotton Industry: Changes in Ventilatory Capacity during the Day 
A study in Egypt of 99 male cotton workers in a cotton ginnery and spinning mill, and of a control group of 12 power station workers, showed that the groups exposed to cotton dust had significantly greater falls in indirect maximum breathing capacity (I.M.B.C.) during the shift than groups not exposed to dust. Long-term effects of exposure to cotton dust were studied by examining the I.M.B.C.s measured at the beginning of the shift after adjustment to allow for differences in age and sitting height. The adjusted mean value for those with byssinosis was 10·1 litres/min. lower than for normal cotton workers and 19·6 litres/min. lower than for the power station workers. Four men were judged by their breathlessness on slight exertion and low ventilatory capacities to be seriously disabled with byssinosis.
In four other mills, all spinning similar types of cotton, changes in I.M.B.C. during the shift correlated highly with dust concentrations and indicated a safe level of dustiness of 1 mg./m.3 (total dust) at which the effects on ventilatory capacity were minimal.
PMCID: PMC1039190  PMID: 14106129
25.  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.
PMCID: PMC1128206  PMID: 7795743

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