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.

     

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.     

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 FEV_1·0 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 FEV_1·0 were found during the work shift. The extent of the fall in FEV_1·0 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 FEV_1·0 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 FEV_1·0. Some workers had slight or severe chronic ventilatory impairment from dust (FEV_1·0 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 FEV_1·0 occurs in the brushing departments of sisal factories, and that this is related to lengthy exposure, high dust level and smoking.     

Annual decline of ventilatory capacity and change in acute respiratory response in hemp exposure over a 10-year period

Summary A follow-up study of the effect of exposure to hemp dust on respiratory function over a 10-year period (1963–1973) was conducted in 24 female non-smoking hemp workers. The prevalence of byssinosis in 1973 (70.8%) was found to be significantly higher than 10 years earlier in 1963 (33%) (P<0.01). The prevalence of all other chronic respiratory symptoms was also considerably increased. In the control group the prevalence of all chronic respiratory symptoms was practically the same during both surveys.In hemp workers, there was a significant acute fall over the work shift in FEV_1.0 (1-second forced expiratory volume) and FVC (forced vital capacity), both in 1963 and 1973 (P<0.01), except in the group of workers who did not have byssinosis either in 1963 or in 1973. The lowest mean annual decline of FEV_1.0 within the 10-year period was found in the group without byssinosis in both 1963 and in 1973 (27 ml), followed by the group without byssinosis in 1963 but with byssinosis in 1973 (38 ml). The largest annual decline was observed in the subjects with byssinosis during both surveys (55 ml). The mean annual FEV_1.0 decline in the control group was 22 ml.     

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.     

Peak flow rate in relation to forced expiratory volume in hemp workers

Žuškin, E., and Valić, F. (1971).Brit. J. industr. Med.,28, 159-163. Peak flow rate in relation to forced expiratory volume in hemp workers. Measurements of the forced expiratory volume in one second (FEV_1·0) and the peak expiratory flow rate (PEF) were made in 99 non-smoking female hemp workers before and after the shift. A significant mean reduction of both FEV_1·0 and PEF (P<0·01) over the shift was found in workers both with and without byssinosis but the relative reductions of PEF were more pronounced (FEV_1·0 15·3%; PEF 20·8%). There was a significant positive correlation (P<0·01) both between absolute FEV_1·0 and PEF values measured before work (with byssinosis r = 0·605; without byssinosis r = 0·461), and between FEV_1·0 and PEF changes over the shift (with byssinosis r = 0·725; without byssinosis r = 0·631). There was also a significant correlation between FEV_1·0 and PEF changes following Alupent inhalation after the shift with more pronounced effects on PEF. The coefficients of variation in FEV_1·0 and PEF measurements (by the Bernstein type spirometer and the Wright peak flow meter) proved approximately equal.     

Respiratory symptoms and ventilatory function in sisal dust exposure

Summary A study of respiratory symptoms and ventilatory function was made in a group of 51 non-smoking female workers exposed to sisal dust and 51 control subjects matched in age and height. A higher prevalence of persistent cough (17.6%), persistent phlegm (13.7%), chronic bronchitis (9.8%) and nasal catarrh (19.6%) was found in sisal workers than in controls (5.9, 5.9, 5.9 and 0%, respectively). Not a single case of byssinosis was found in the workers surveyed.In sisal workers, FEV_1.0, FVC and PEF significantly decreased over the work shift (P<0.01). Control workers did not show significant acute changes in ventilatory function over the shift. Inhalation of Alupent (orciprenaline) before the shift significantly diminished acute reductions in ventilatory capacity during the shift. The results suggest that sisal dust does not cause byssinosis but affects ventilatory function of the exposed workers.     

Effects of Hemp Dust Exposure on Nonsmoking Female Textile Workers

Symptoms of byssinosis were found in 39% of 102 female hemp workers who were nonsmokers. A higher prevalence of chronic bronchitis (P < 0.01) was found in workers with symptoms of byssinosis than in those without such symptoms. In hemp workers, either with or without symptoms of byssinosis, FEV_1.0 and FVC significantly decreased during work on the study days, Mondays and Thursdays; significantly lower reductions were registered on Thursdays. Inhalation of metaproterenol sulfate (Alupent) before work significantly diminished FEV_1.0 reduction, although not completely preventing it. Metaproterenol inhalation after work significantly increased FEV_1.0, indicating the reversibility of acute lung function changes during work. Comparison of lung function values measured before work with values obtained in the control group indicates a chronic effect of hemp dust on ventilatory function.     

Respiratory-Function Changes in Textile Workers Exposed to Synthetic Fibers

The prevalence of respiratory symptoms and acute and chronic changes in ventilatory function were studied in three groups of textile workers: 68 workers with exposure to synthetic fibers only, 30 with previous exposure to cotton, and 77 with previous exposure to hemp. The prevalence of dyspnea, grade 3 or 4, was significantly lower (P < .0 1 ) in workers with a history of exposure to synthetic fibers only than in those previously exposed to hemp or cotton. No case of byssinosis was found in any of the workers studied. Values in ventilatoryfunction tests (FEV_1.0, FVC and MEF 50%) were significantly reduced during the work shift on Monday and Thursday. The Monday MEF 50% preshift values were significantly lower than expected in all three groups of workers. A comparison of the 1963–1973 data on the 77 workers previously exposed to hemp showed a lower prevalence of most chronic respiratory symptoms and smaller acute FEV_1.0and FVC reductions when they worked with synthetic fibers (1973) than when they were exposed to hemp (1963).     

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.

     

Preprocessing cotton to prevent byssinosis

Merchant, J. A., Lumsden, J. C., Kilburn, K. H., Germino, V. H., Hamilton, J. D., Lynn, W. S., Byrd, H., and Baucom, D. (1973).British Journal of Industrial Medicine,30, 237-247. Preprocessing cotton to prevent byssinosis. A fundamental approach of cleaning or deactivating cotton prior to manufacturing has long been advocated to prevent byssinosis, but no trial had been conducted to test the feasibility of such an approach. In the study described, it was possible to be directed by both biological observations and the results of manufacturing trials.

An exposure chamber was built in a cotton textile mill which had been previously studied as part of a large cross-sectional survey. The chamber was provided with an independent air conditioning system and a carding machine which served as a dust generator. Sixteen subjects, who had shown reductions in expiratory flow rate with exposure to cotton dust, were chosen to form a panel for exposure to raw cottons and cottons which had been preprocessed by heating, washing, and steaming. Indicators of effects were symptoms of chest tightness and/or dyspnoea, change in FEV_1·0, and fine dust levels over 6 hours of exposure.

Exposure of the panel to no cotton dust resulted in no change in FEV_1·0 and served as the control for subsequent trials. Exposure to strict middling cotton resulted in a byssinosis symptom prevalence of 22%, a significant decrement in FEV_1·0 of 2·9%, and a fine dust level of 0·26 mg/m³. Exposure to strict low middling cotton resulted in a byssinosis symptom prevalence of 79%, a decrement in FEV_1·0 of 8·5%, and a fine dust level of 0·89 mg/m³. Oven heating strict low middling cotton resulted in a byssinosis symptom prevalence of 56% and a relatively greater drop in FEV_1·0 of 8·3% for 0·48 mg/m³ of fine dust. Washing the strict low grade cotton eliminated detectable biological effects with a symptom prevalence of 8%, an increase of 1·4% in FEV_1·, and a dust level of 0·16 mg/m³, but the cotton proved to be difficult to process. As an alternative method, strict low middling cotton was steamed initially in large dyeing vats, on a conveyor, in an autoclave, and in a modified yarn dyeing apparatus or `pipe' steamer. Of these methods, autoclaving cotton was the most successful, reducing symptom prevalence to 8%, the drop in FEV<sub>1·0</sub> to 0·4%, and the dust level to 0·23 mg/m<sup>3</sup>. Development of a high capacity cotton steamer based on the small `pipe' steaming model resulted in a symptom prevalence of 8%, a decrement in FEV_1·0 of 0·8%, and a mean dust level of 0·27 mg/m³. Regressions calculated from raw and high capacity steaming trials indicate that at low dust levels steamed cotton dust was roughly one half as biologically active as raw cotton dust.

     

A population study in cotton ginnery workers in the Sudan

Khogali, M. (1969).Brit. J. industr. Med.,26, 308-313. A population study in cotton ginnery workers in the Sudan. An epidemiological study in cotton ginneries in the Sudan covered 323 permanently employed ginnery workers, a random sample of 35 seasonal farfara workers, and a control group of 24 members of a fire brigade. All the workers studied were men.

The study showed a prevalence of byssinosis (defined as chest tightness starting on return from the annual holiday and continuing for at least three consecutive days) in 20% of the ginnery workers and in 48·6% of the farfara workers. Workers exposed to dust showed a mean fall in F.E.V._1·0 of -0·10 litre during the shift, while workers not so exposed showed a mean rise of +0·23 litre; this difference was statistically significant. The F.E.V._1·0 was adjusted for age and standing height. The adjusted means of F.E.V._1·0 were significantly lower for workers exposed to dust compared with those in the control group.

The workers with byssinosis showed a statistically significant fall in F.E.V._1·0 when compared with all ginnery workers; and a highly significant fall when compared with cotton workers without chest symptoms. An attempt was made to grade the byssinotics according to the extent of fall in F.E.V._1·0 during the shift.

The concentration of fine dust (< 7 μ) was measured in each work place. There was a statistically significant association between the prevalence of byssinosis and the concentration of fine dust when comparing the ginnery and farfara workers. Also, there was a significant relationship between the mean adjusted F.E.V._1·0, the mean fall in F.E.V._1·0, and the fine dust concentration.

     

Dust Diseases in Dundee Textile Workers: An Investigation into Chronic Respiratory Disease in Jute and Flax Industries

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.

     

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.

     

A longitudinal observation of early pulmonary responses to cotton dust

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 FEV₁ at each follow up survey, and longitudinal declines in FVC and FEV₁ 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 FEV₁. In addition, one or more respiratory symptoms at three months was significantly, and pre-existing atopy marginally significantly, associated with cross shift drops in FEV₁ 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.

     

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.     

Byssinosis: The Acute Effect on Ventilatory Capacity of Dusts in Cotton Ginneries, Cotton, Sisal, and Jute Mills

Studies of ventilatory capacity change in small groups of employees during a shift in a cotton mill and in three cotton ginneries in Uganda, a sisal factory in Kenya, and a jute mill in England, have demonstrated that an effect is produced by the dust in the cotton mill and in a very dusty ginnery but not in two other less dusty ginneries. No significant effect was detected in the sisal factory or in the jute mill despite much higher dust concentrations than in the cotton mill.

The dust sampling instruments gave the weight in three sizes: Coarse (>2 mm.), medium (7μ to 2 mm.), and fine (<7μ). The samples were analysed for protein, mineral (ash), and cellulose (by difference). The fine and medium sisal and jute dusts contain less protein than cotton dusts. The physiological changes observed in the employees in the cotton mill indicate the need for general dust measurement and control, even when new carding machinery is installed in a new mill.

     

Steaming of cotton to prevent byssinosis—a plant study

Imbus, H. R. and Suh, M. W. (1974).British Journal of Industrial Medicine,31, 209-219. Steaming of cotton to prevent byssinosis—a plant study. Pulmonary function tests, respiratory questionnaires, and dust measurements were made in a cotton spinning plant during the processing of steamed cotton and after its discontinuance. During steaming the average drop in FEV₁ (Δ FEV₁) from the beginning to six hours into the work shift was 19 ml, and after steaming was discontinued 62 ml. In addition, the FEV₁ measurements, before work on the first day of the work week, were 60 to 100 ml higher during the time of steaming. The improvement in Δ FEV₁ with steaming was much greater for males than for females. Improvement was greatest in the higher dust areas, namely, opening, picking, blending, and carding, and less in spinning, winding, and twisting. Questionnaire results did not reveal any significant difference in the incidence of symptoms of byssinosis during the two periods, the reasons for which are not clear. There was an approximately 30% reduction in elutriated and total dust.     

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.

     

Histamine-releasing activity and bronchoconstricting effects of sisal

Nicholls, P. J., Evans, E., Valić, F., and Žuškin, E. (1973).British Journal of Industrial Medicine,30, 142-145. Histamine-releasing activity and bronchoconstricting effects of sisal. Extracts of dry and oiled sisal released histamine from pig and human but not from rat lung tissue. A suspension in Tyrode solution of the oil used for softening the sisal fibres had a pH of 8·1 and also released histamine from pig and human lung. The releasing activity was abolished when the pH of this suspension was adjusted to pH 7·4. As all the sisal extracts were adjusted to pH 7·4 for incubation with lung tissue, the histamine-releasing activity of sisal in vitro is unrelated to the presence of the oil.

Significant (P < 0·01) mean reductions over the work shift of ventilatory capacity (PEF and FEV_1·0) were recorded in all the workers exposed to airborne sisal dust. These reductions were greater in combers than in drawers and spinners. Sisal collected from combing machines possessed more histamine-releasing activity than material from drawing and spinning machines.

These results indicate that histamine release by sisal may be the cause of acute ventilatory capacity changes in sisal exposure.