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6.  Hazards of deep-sea fishing1 
Schilling, R. S. F. (1971). Brit. J. industr. Med., 28, 27-35. Hazards of deep-sea fishing. During the nineteenth century sailing smacks suffered heavy losses at sea. Their replacement by steam trawlers and motor vessels reduced casualties to both ships and men. The accident mortality of fishermen in England and Wales has been grossly underestimated by the Registrar General of Births and Deaths because all but a few deaths at sea are reported separately to the Registrar General of Shipping and Seamen and are not taken into account in calculating mortality rates. By including deaths at sea in the period 1959-63, fishermen's standardized mortality ratio for accidents is increased from 466 to 1 726. Between 1958 and 1967, 92 fishermen on British trawlers lost their lives as a result of casualties to vessels; and 116 from individual accidents, mostly by drowning. The importance of individual accidents is emphasized by the fact that in years when ther was no heavy loss of life from vessel casualties, fishermen's fatal accident rates were at least twice those of coal miners and more than 20 times the rate of men in manufacturing industries. Crews of distant-water vessels have higher fatal accident rates than crews of near- and middle-water vessels (2·3 against 1·8 per 1 000 man-years); for skippers and mates on distant-water vessels the rate is 3·2 per 1 000 man-years which is higher than the corresponding rate of 2·6 for deck-hands and almost double that for other crew members.
In 47 out of 90 trawlers lost or serioulsy damaged, the cause of the casualty was attributable to negligent navigation. Fatigue due to excessively long hours of work may contribute to casualties to both vessels and individuals. The Committee of Inquiry into Trawler Safety set up by the British Government after the loss of three trawlers in 1968 made many recommendations for higher standards of design, construction, and stability of vessels for the deep-sea fleet and for a reduction in the hours of work for deck-hands. The Committee also recommended the supply of a support ship at sea offering special services such as weather forecasting, medical and technical aid, and the provision of occupational health services for fishermen in port.
PMCID: PMC1009188  PMID: 5101166
7.  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
8.  Byssinosis among Winders in the Cotton Industry 
In a mill spinning coarse cotton the prevalence of byssinosis and other respiratory symptoms, and the F.E.V.1·0, were measured in a group of 29 men and 117 women employed in the winding room. All the men and 95% of the women at risk were included.
Dust concentrations, measured with a modified Hexhlet at various work points in the winding room, ranged from 1·65 to 6·05 mg./m.3 total dust. These concentrations are higher than 1·0 mg./m.3, which is the threshold limit value for cotton dust recommended by the American Conference of Governmental Industrial Hygienists. The mean dust concentration was 3·48 mg./m.3 compared with 2·85 mg./m.3 in the card room of the same mill.
The prevalence of byssinosis was 18·8% among the women and 13·8% among the men. A comparison among the women showed that those with symptoms of byssinosis had, on the average, significantly lower F.E.V.s than women of similar age without such symptoms. Four women and one man with moderately severe symptoms of byssinosis showed evidence of permanent respiratory disability with effort intolerance and a substantial diminution in F.E.V.1·0. Further studies should be carried out in other winding rooms because, if these findings are repeated elsewhere, they would indicate the necessity for medical surveillance, dust control, and extending the compensation scheme to include winding room workers.
PMCID: PMC1008542  PMID: 6023077
9.  Diurnal Variation in Ventilatory Capacity: An Epidemiological Study of Cotton and other Factory Workers employed on Shift Work 
The change in F.E.V.0·75 during a working shift was studied in a random sample of 473 men employed in three cotton mills in The Netherlands working a three-shift system. Results were also obtained for 198 men, not exposed to industrial dust, who were working in a biscuit factory and two textile factories in the same area. The men were seen only during the shift on which they were working at the time of the study.
Men with byssinosis gave a typical picture of the effects of cotton dust on susceptible workers: a generally low F.E.V. with a marked reduction during the shift; –0·16 l. on the early morning shift, and –0·25 l. and –0·33 l. respectively on the afternoon and night shifts.
Men without byssinosis in the card and blow rooms showed mean changes in F.E.V. during the shift similar to those of men working in the spinning room: a slight rise in the early morning shift of +0·02 l. followed by a fall in both afternoon and night shifts in the region of –0·10 litres. This pattern of change was also found among the workers in the non-dusty factories. The rise in the early shift cannot be explained by the clearing of mucus from the air passages; cotton workers without respiratory symptoms and men in the non-dusty factories who did not produce sputum still showed an increase in F.E.V. during the early shift, though less marked than that of men with respiratory symptoms or who produced phlegm.
The evidence suggests that a diurnal variation in lung function exists and should be taken into consideration both in epidemiological studies and when ventilatory capacity tests are used in periodic medical examinations.
PMCID: PMC1008387  PMID: 5932069
This paper gives the results of a small environmental, symptomatic, and respiratory function study of byssinosis in a rope factory. An attempt was made to relate the changes in ventilatory function during the working day to the differing dust concentrations within the factory. The tests used included the forced expiratory volume, the forced vital capacity, and, in half the subjects, other derivatives of the forced expiratory spirogram. The inspiratory airways resistance was measured by the interrupter technique.
Measurements were made at the beginning and end of a working shift on either a Monday or a Tuesday in 44 subjects, of whom 22 were in a relatively dusty part of the factory and 14, involved in making wire rope, were exposed to very little dust.
None of the subjects had symptoms of byssinosis, but significant falls were found in the F.E.V.1·0, F.V.C., and other derivatives of the forced expiratory spirogram in those in the dusty parts of the factory. There was some evidence that the peak flow rate, the maximal mid-expiratory flow, and similar indices might be a little more sensitive as measures of the acute changes in ventilatory capacity during the day than the F.E.V.1·0 and F.V.C. There were no significant changes in the airways resistance by the interrupter technique but the results were rather variable.
The fall in ventilatory capacity during the day was not greater in those with symptoms of chronic cough and sputum than in those without, nor did it seem to be related to smoking, but the number of subjects studied was small.
PMCID: PMC1008298
In a rope works handling manila, sisal, and St. Helena hemps, the prevalence of respiratory symptoms and the change in forced expiratory volume (F.E.V.1·0) during the work shift were studied in a group of 41 women and 41 men who represented 93% of the population at risk.
Dust concentrations, measured with a modified Hexhlet, ranged from 0·11 to 4·51 mg./m.3 for total dust and 0·02 to 1·46 mg./m.3 for fine dust. The highest concentrations were found in the preparing rooms, in which the workers, all of whom were women, showed on the average a fall in ventilatory capacity during the shift. The workers in the rope walk, all of whom were men, showed a rise in ventilatory capacity during the shift. The difference between the men and women was statistically significant (p < 0·05). No worker gave a characteristic history of byssinosis, although nine women complained of chest tightness associated with their work.
Undue breathlessness on exertion and persistent cough and phlegm were also more common among the women, but they were on the average 18 years older than the men. When the ventilatory capacities and the prevalence of respiratory symptoms of women rope workers were compared with those of a group of women employed elsewhere in the dockyard, the only significant difference was that the rope workers had more chest tightness associated with their work (p < 0·02).
Exposure of volunteers to St. Helena hemp, which is apparently the most likely of the hard hemps to give rise to respiratory symptoms, caused only a slight fall in ventilatory capacity and a small rise in airways resistance.
A sample of St. Helena hemp assayed on guinea-pig ileum had only a relatively small degree of contractor activity. The evidence suggests that the dusts of hard hemps do not cause byssinosis under the conditions in this factory. However, the irritant nature of the dust indicates the need to prevent total dust levels exceeding about 2 mg./m.3.
PMCID: PMC1008297
The prevalence of respiratory symptoms and the smoking habits of 224 industrial `executives' aged 30 to 69 years in Social Classes I and II were ascertained by means of the Medical Research Council's questionnaire on respiratory symptoms; 31% had persistent cough, 25% had persistent phlegm, and 21% were short of breath on hurrying or going up a hill; 9% had had one or more chest illnesses in the past three years lasting for about a week, and 4% had `chronic bronchitis'—defined as persistent phlegm and one or more chest illnesses in the past three years; 67% were smokers, 21% smoking more than 25 cigarettes (or equivalent tobacco) per day; another 20% had stopped smoking. The prevalence of cough, phlegm, and breathlessness was closely related to smoking habit.
Data for those aged 40 to 59 years are compared with that obtained from London Transport Board workers and a sample of the population studied by the College of General Practitioners. The latter was further analysed and suggests that the prevalence of cough and phlegm is more closely related to the amount smoked than to social class. The prevalence of chest illness is probably more closely related to social class and less to the amount smoked. It is suggested that, although smoking may initiate irritative respiratory symptoms, the precursors of bronchitis, additional factors are important in causing progression to disabling or fatal chronic bronchitis.
PMCID: PMC1008262  PMID: 14278803
13.  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.
PMCID: PMC1038333  PMID: 14145373
14.  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
15.  The Size of Cotton Dust Particles Causing Byssinosis: An Environmental and Physiological Study 
Fourteen subjects of whom 12 were cotton mill blow- or card-room workers were exposed in a plastic tent for periods of three or four hours to airborne mill dust either of unrestricted size distribution (total dust) or containing only particles of less than 7μ(fine dust).
A significant fall in indirect maximum breathing capacity followed exposure to either total or fine dust in most experiments. The response to total dust usually appeared a little larger than to fine but the concentration of fine particles in the unfiltered air was rather higher. The changes in the single-breath nitrogen clearance index and the inspiratory airways resistance were less constant, but the general pattern followed that of the ventilatory capacity.
It is concluded that the fine fraction (under 7μ) of cotton mill dust produces changes in respiratory function and may be alone responsible. The findings suggest a direct action by the dust on the smaller air passages and imply that to be completely effective dust suppression measures in cotton mills should remove fine dust.
PMCID: PMC1038125
16.  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.
PMCID: PMC1038126  PMID: 13898707
17.  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.
PMCID: PMC1039177  PMID: 14437722

Results 1-24 (24)