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2.  Chest symptoms in farming communities with special reference to farmer's lung. 
Surveys were carried out on random samples of the farming population in Devon and Wales in order to estimate the prevalence of respiratory symptoms and of positive precipitin reactions to thermophilic fungi. Bronchitis, as defined, was common among the Welsh hill farmers, and the proportion of positive serological tests was higher in both the areas surveyed in Wales as compared with Devon. All three surveys confirmed a previous finding that the proportion of positive precipitin tests was higher among non-smokers than smokers. Although the numbers were small there was some indication that measurement of peak expiratory flow showed different relationships with age in non-smokers according to the presence or absence of positive precipitin tests. The difficulty of determining prevalence rates for farmer's lung is discussed, but the results suggest a rate not dissimilar to those found in two areas of Scotland which were more than 20 times higher than any figure previously reported in Britain.
PMCID: PMC1008064  PMID: 1156571
3.  Coalworkers' pneumoconiosis. 
British Medical Journal  1970;4(5730):305.
PMCID: PMC1819814  PMID: 5475857
4.  Pneumoconiosis 
British Medical Journal  1956;1(4980):1428-1429.
PMCID: PMC1979457  PMID: 13316177
6.  International classification trial of AIA set of 100 radiographs of asbestos workers. 
A series of 100 full size radiographs illustrating the range of asbestos related radiographic changes was collected by the Asbestos International Association to provide a demonstration and teaching supplement to the ILO 1980 International Classification of the Radiographic Appearances of Pneumoconioses. Each film was read by 12 experienced readers from ten countries; the readings have been summarised by a median reading, with the range covered by two thirds of the readers. The occupational histories and some relevant clinical information are also available. It is proposed that, in the use of this set, readers should classify each film using the ILO classification rules, particularly without reference to the summary reading or the additional information. Comparing the individual readings by the 12 readers, most of the variation in reading the profusion of small opacities was ascribable only to random variation, with little consistent bias between readers. By contrast, two readers recorded pleural changes much more frequently than their colleagues. This illustrated a major problem with the ILO 1980 Classification. Several others which occurred in this reading trial are also discussed.
PMCID: PMC1009647  PMID: 3415919
7.  UK Naval Dockyards Asbestosis Study: radiological methods in the surveillance of workers exposed to asbestos 
ABSTRACT In a survey of the effects of exposure to asbestos in the UK Naval Dockyards, small- and large-film chest radiographs of 674 men have been examined. These films have been read under survey conditions by two readers using a simple screening classification, and also in a controlled trial by five readers using the full ILO U/C classification. Comparison between the reading methods showed a deficiency, independent of the size of film, of at least 30% in the detection of asbestos-related radiographic abnormalities when the screening classification was used. For adequate diagnostic sensitivity the ILO U/C classification appears to be essential. There was a deficiency of 43% in significant abnormalities observed by a majority of readers in the small films when directly compared with large film readings. This deficiency could be reduced to 7% by using readings of the small films at any level of abnormality by any of the five readers. When the ILO U/C readings were related to the clinical diagnoses, the only abnormality missed was a small pleural plaque. Films with previously agreed coding were inserted at intervals during the reading trial and helped to maintain the consistency of reading. Right oblique views were taken for 1884 men, in addition to the full-sized postero-anterior view, but the contribution provided by this view proved insufficient to justify its use in large surveys. The cost of a survey when small films are used as a screening method is reduced to between one-third and one-half of the cost when large films are used, assuming that the abnormality rate is not more than 5%. However, this cost advantage for small films is likely to be overtaken by the development of automatic large-film units. The radiation dose when small films are used is increased by a factor of about 20, but is within the prescribed safety level. It is concluded that at least three readers should be involved, using the full ILO U/C classification. Small films may be of particular use in a large-scale survey, in which the abnormality rate is expected to be low, and which might otherwise be too expensive. A sensitive reading method and a high standard of film quality are essential factors in the use of this technique.
PMCID: PMC1008405  PMID: 698132
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
11.  National Epidemiology 
British Medical Journal  1961;1(5236):1389-1390.
PMCID: PMC1954512
14.  Pneumoconiosis 
British Medical Journal  1955;1(4928):1473.
PMCID: PMC2062259
16.  Significance of finger clubbing in asbestosis. 
Thorax  1987;42(2):117-119.
The prognostic significance of finger clubbing in asbestosis has been assessed in 167 cases certified by the London Pneumoconiosis Medical Panel from 1968 to 1974. Finger clubbing developed early in the clinical course of the disease and was associated with a lower gas transfer, a higher mortality and a greater likelihood of progression in intrapulmonary fibrosis than was found among cases without finger clubbing. Finger clubbing was not associated with heavier asbestos exposure. Its presence appears to be associated with a more severe form of disease.
PMCID: PMC460637  PMID: 3433234
17.  Mortality in cases of asbestosis diagnosed by a pneumoconiosis medical panel. 
Thorax  1987;42(2):111-116.
One hundred and fifty five male cases of asbestosis certified by the London Pneumoconiosis Medical Panel during 1968-74 were followed up during 1978-9, 4-11 (mean 7.5) years after certification. Fifty nine patients had died, 23 (39%) from lung cancer, 6 (10%) from mesothelioma, and 11 (19%) from other respiratory causes. The number of observed deaths was 2.25 times greater than expected and 7.4 times greater than expected for lung cancer. Adenocarcinoma was the commonest histological type but other cell types were also increased. Finger clubbing (p less than 0.01) and percentage of predicted FEV1 (p less than 0.01) were of value in predicting death, but increasing profusion of small opacities greater than 1/0 (ILO/U-C international classification of radiographs of pneumoconiosis, 1971), duration of exposure to asbestos, time from first exposure to asbestos, and percentage of predicted vital capacity and transfer factor did not predict death.
PMCID: PMC460635  PMID: 3433233
18.  A long-term follow-up of workers exposed to beryllium 
ABSTRACT The relationship of features of beryllium disease to the estimated exposure to beryllium has been investigated over a 30-year period at a factory manufacturing beryllium products. The factory opened in 1952. Of the 146 men who had worked there for more than six months up to 1963, 89% were seen at that time and were followed up in 1973. The nine who continued to work in the factory and those who were engaged subsequently were examined in 1977. On each occasion a clinical interview, occupational history, chest radiograph, and assessment of lung function were carried out. The findings of the main survey were related to the beryllium content of the dust measured by mass spectrometry for 1952-60 when over 3000 determinations were made. In no part of the plant did the estimated average daily exposure exceed 2 μg m-3, and only 9% of individual determinations exceeded this level. Twenty determinations exceeded 25 μg m-3. During the period under review, four men developed the clinical, radiographic, and physiological features of beryllium disease. Two men acquired abnormal chest radiographs consistent with beryllium disease but without other features, and one developed probable beryllium disease despite the diagnosis not being confirmed at necropsy. The affected men were all exposed to beryllium oxide or hydroxide but in a wide range of estimated doses. In six the changes developed after exposure had ceased; trigger factors including patch testing may have contributed to their illness. Seventeen men recalled episodes of brief exposure to high concentrations of dust, two developed pneumonitis from which they recovered completely, and one developed chronic beryllium disease after a further 23 years' exposure. In subjects without clinical or radiographic evidence of disease no convincing evidence was obtained for any association between the lung function and the estimated exposure to beryllium.
PMCID: PMC1009111  PMID: 6824594
19.  Asbestosis: a study of dose-response relationships in an asbestos textile factory 
ABSTRACT A group of 379 men who had worked at an asbestos textile factory for at least 10 years has been followed up. The prevalence of crepitations, 'possible asbestosis', certified asbestosis, small opacities in the chest radiograph and values of lung function have been related to dust levels. The type of asbestos processed was predominantly chrysotile although a substantial amount of crocidolite had also been used in the past. There was a higher prevalence of crepitations than had been observed previously at the same factory. The presence of crepitations is not a specific effect of asbestos exposure and 'possible asbestosis', a combined judgement of two physicians on whether a man had developed signs which might be attributable to early asbestosis, was preferred. Fifty per cent of men with a diagnosis of possible asbestosis were certified as suffering from asbestosis by the pneumoconiosis Medical Panel within 3-5 yr. The most reliable data relate to men first employed after 1950; 6·6% of men in this group had possible asbestosis after an average length of follow-up of 16 yr and an average exposure to 5 fibre/cm3 where the dust levels were determined by static area samplers. The forced expiratory volume and forced vital capacity declined significantly with exposure, after allowing for age and height, but there was no decline in the total lung capacity. The transfer factor also declined with exposure, but not to a statistically significant extent. The non-smokers and light smokers as a group had less crepitations, asbestosis and small opacities on the chest radiograph than heavier smokers with similar exposure. Combining dust concentrations to form the cumulative dose may not be completely satisfactory, and a family of measures was investigated which allows for elimination of dust from the lungs and includes the cumulative dose as a special case. Because the rate of elimination of dust from the lungs is unknown and cannot be estimated from the data, this approach leads to a wide range of possible interpretations of the data; for example the concentration such that possible asbestosis occurs in no more than 1% of men after 40 years' exposure could be as high as 1·1 fibres/cm3 or may have to be as low as 0·3 fibres/cm3. This range is wide because the data relate to higher dust levels, and a shorter period of follow-up. Until data are available on groups exposed to lower levels it will not be possible to assess the effects of the current standard with any certainty. However, the results of this study show that it is important to continue to reduce dust levels to values as low as possible.
PMCID: PMC1008524  PMID: 465379
20.  Occupational bronchitis? 
PMCID: PMC1812192  PMID: 5477056
21.  A controlled trial of anti-tuberculosis chemotherapy in the early complicated pneumoconiosis of coalworkers 
Thorax  1969;24(4):399-406.
A controlled trial in coalminers under the age of 50 in South Wales with sputum-negative, early complicated pneumoconiosis was used to compare three regimes: (1) chemotherapy (rest in hospital and 1 g. streptomycin, 200 mg. INH, 10 g. PAS, for 3 months; then 200 mg. INH, 10 g. PAS for 9 months); (2) rest (in hospital for 3 months); and (3) a working group. The initial and three-year radiographs were assessed by two methods in 173 (96%) of the 180 men entering the trial. No beneficial effect of chemotherapy was demonstrated and this factor was not related to the completeness of the chemotherapy. The variation between individuals in the rate of progression and in the development of new shadows was unrelated to chest symptoms, smoking habits, initial erythrocyte sedimentation rate, or special features in the initial radiographs, so these did not provide any useful predictive characteristics. Those with an initial negative Mantoux (1 T.U.) showed significantly less progression than those with a positive Mantoux. The lack of benefit and the short- and long-term complications of chemotherapy (weight gain, reduction in ventilatory capacity, dyspepsia, and streptomycin toxicity) show that this treatment is contra-indicated in miners with early complicated pneumoconiosis without a positive sputum. That new shadows develop during chemotherapy adds to the evidence from other sources that tuberculosis is unlikely to be a major factor in the pathogenesis of complicated pneumoconiosis in this area. Mycobacterium peregrinum (Runyon group IV) was isolated in three cases.
PMCID: PMC472002  PMID: 5795642
23.  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
24.  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
25.  Population Studies of Chronic Respiratory Disease: A Comparison of Miners, Foundryworkers, and Others in Staveley, Derbyshire 
Mortality and morbidity statistics suggest that miners and foundryworkers are more prone to bronchitis than other industrial workers but it is not yet certain that this excess is due to occupational factors. The present investigation was designed to compare the prevalence of bronchitis and respiratory disability in a representative sample of miners, foundryworkers, and other industrial groups living in Staveley, Derbyshire, a town of some 18,000 inhabitants, and to study some of the possible aetiological factors. A random sample of 776 men, stratified by age into two groups, 25 to 34 and 55 to 64 years, and by occupation into four groups, non-dusty, miners and ex-miners, foundry and ex-foundryworkers, and other dusty jobs, was used. Respiratory symptoms were recorded on a standardized questionnaire and the ventilatory capacity was assessed by means of the forced expiratory volume (F.E.V.0·75) and recorded as the indirect maximum breathing capacity (M.B.C.).
Miners and ex-miners recorded a higher prevalence of respiratory symptoms and a lower mean M.B.C. than men who had worked only in dust-free occupations. In the older age group the differences were not large and were not statistically significant but in the younger men the difference in the mean M.B.C. was significant. Foundry and ex-foundryworkers with a pure industrial history recorded a similar prevalence of symptoms to the men who had never worked in dusty occupations and their mean M.B.C. was only slightly and insignificantly lower. A higher prevalence of symptoms and a lower mean M.B.C. was, however, recorded by the foundrymen who had also been exposed to other dusts or fumes and the occupational histories suggested that such exposure was more likely than foundry work to account for the findings.
The number of years spent on the coal-getting shift was used to assess the importance of exposure to coal dust. In the elderly miners without pneumoconiosis there was a significant increase in the prevalence of breathlessness, accompanied by a reciprocal fall in the mean M.B.C. with increasing years spent on the coal-getting shift; but in no other group was a consistent trend found.
In both age groups the prevalence of respiratory symptoms was lower and the mean M.B.C. higher in non-smokers than in smokers and ex-smokers. Heavy smokers (those smoking 15g. and over/day) recorded a higher prevalence of symptoms and a lower mean M.B.C. than light smokers, and the values for ex-smokers approximated to those of the non-smokers.
The wives of the elderly men in the sample were studied to try to determine how far the apparently high rates of bronchitis shown by national mortality statistics are attributable to social factors. The findings suggested that the wives of the men who worked in dusty jobs had a somewhat higher prevalence of cough and/or sputum and of chest illness during the past three years than the wives of those who had worked only in dust-free occupations.
PMCID: PMC1037963  PMID: 14401755

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