Occupational and Environmental Medicine

Piper, Robert

doi: 10.1136/oem.22.4.247pmid: 5836564

A review of paint hazards is made, giving brief descriptions of methods of application in use in 1965, of paint usage according to resin base, and of paint ingredients. The most interesting and complex of these are the resin bases, which have much in common with plastics. Reference is made to some of the many minor ingredients. The problem of keeping abreast of the possible toxic effects, so that paint manufacturers and their customers may be warned and protected, will be clear.

Newhouse, Muriel L.; Thompson, Hilda

doi: 10.1136/oem.22.4.261pmid: 5836565

A series of 83 patients from the London Hospital with a diagnosis of mesothelioma confirmed by necropsy or biopsy has been studied for possible exposure to asbestos. The series consisted of 41 men and 42 women; 27 of the patients had peritoneal and 56 pleural tumours. The earliest death recorded was in 1917, but only 10 of the series died before 1950 and 40 (48%) between 1960 and 1964. In 76 of the series full occupational and residential histories were obtained. Forty (52·6%) gave a history of occupational or domestic (living in the same house as an asbestos worker) exposure to asbestos compared with nine (11·8%) out of 76 patients from the same hospital suffering from other diseases (p < 0·001). None of the 17 suspected cases of mesothelioma, rejected on pathological grounds, was found to have had any exposure to asbestos. There was also evidence that neighbourhood exposures may be important. Among those with no evidence of occupational or domestic exposures, 30·6% of the mesothelioma patients and 7·6% of the in-patients with other diseases lived within half a mile of an asbestos factory (p < 0·01). Out of the 31 patients with occupational exposures only 10 were in jobs scheduled under the Asbestos Regulations of 1931. The interval between first exposure and the development of the terminal illness of mesothelioma ranged between 16 and 55 years. In 47 patients in the mesothelioma series, lung tissue or sputum was available for examination. In 30 (62·5%), either asbestosis or asbestos bodies were present.

Davies, G. M.; Jones, J. Graham; Warner, C. G.

doi: 10.1136/oem.22.4.270pmid: 5836566

A continuously recording carbon monoxide monitoring system with fully automatic alarms is described for use in blast furnace areas. The equipment comprised the Mines Safety Appliances Model 200 infra-red analyser, pumping system, recorder, extension meter, and alarm unit. Use of the apparatus showed that concentrations of carbon monoxide in the blast furnace area studied were mostly in the range of 0 to 49 p.p.m. Readings of 200 p.p.m. and over generally indicated that some abnormal and potentially dangerous incident had occurred. Examples of such incidents are given. A visual alarm was set at 200 p.p.m., a level at which work could safely continue for a limited period, and an auditory alarm at 500 p.p.m., at which level immediate action was necessary. The theoretical reasons for selecting these levels are discussed, and practical results are quoted to confirm their suitability.

Warraki, S. E.; Gammal, M. Y.; Awny, A. Y.

doi: 10.1136/oem.22.4.279pmid: 5836567

Bone marrow specimens were obtained from seven workers who had been exposed to the dust of a calcareous sandstone consisting of 56·3% free silica. The pattern of changes was in the form of generalized hyperplasia, and in particular there were very high figures for the myeloid series, reticulum cells, and plasma cells. The eosinophils showed a slight but definite increase but the erythrocytes, megakaryocytes, lymphocytes, and monocytes were within the normal range. These changes were considered to be related to silicosis since other diseases causing stimulation of the bone marrow had been adequately excluded. The findings correlate with the histopathological changes which are reported to occur in the lungs of silicotic patients; they indicate a high degree of stimulation of the reticulo-endothelial system. If these changes are considered together with the industrial history and clinical and laboratory data, they may provide a clue to the diagnosis of silicosis and help in the differential diagnosis from other diffuse pulmonary lesions.

Ahlmark, A.; Bruce, T.; Nyström, Å

doi: 10.1136/oem.22.4.285pmid: 5836568

Previous knowledge of silicosis in the Swedish granite industry suggested that the disease was neither common nor severe. In recent years, however, changes in working methods have involved a considerably increased formation of dust, and it was considered likely that the risk of contracting silicosis was increased. Reports from other countries supported this conjecture. The 34 known cases of silicosis caused by quarrying and working of granite in Sweden were therefore reviewed. The mean duration of exposure to siliceous dust when stage I silicosis was diagnosed was 32 years, and the mean age at diagnosis was 55 years. Despite the relatively long `prediagnosis' exposure to dust, the disease showed a pronounced tendency to progression, and six cases were complicated by pulmonary tuberculosis. Eighty per cent of the men were awarded disablement benefit because of their pulmonary lesions, and four men died from silicosis alone or in combination with tuberculosis. In Swedish granite works there is room for considerable improvement in dust suppression. Careful checks of such preventive measures and periodic medical examination of exposed persons are strongly advocated.

Kondakis, X. G.; Pournaras, N.

doi: 10.1136/oem.22.4.291pmid: 5836569

The prevalence of byssinosis in a sample of cotton ginnery workers in Greece was investigated. The respiratory symptoms, F.E.V.1·0, and V.C. of 70 male ginnery workers were recorded. No case of clinical byssinosis was found, but a statistically significant relationship exists between years of exposure to cotton dust and impairment of lung function. On the contrary no significant relationship exists between smoking and lung function, or between sputum production and lung function. The findings suggest the hypothesis that the cotton dust may exert, in the case of a prolonged exposure, a chronic deleterious action without producing the typical symptoms of clinical byssinosis.

Gandevia, Bryan; Milne, James

doi: 10.1136/oem.22.4.295pmid: 5836570

The same plan of investigation as was used in a previous study of jute workers (Gandevia and Milne, 1965) has been applied to a survey of 50 workers in the blowroom and carding and spinning area of a Sydney cotton mill. Significant decreases in ventilatory capacity were recorded on Friday, Monday, and the following Thursday, with, on the average, complete `overnight' recovery, as indicated by similar morning values. Slightly, but not significantly, greater differences were observed in seven subjects with mild byssinotic symptoms and in five subjects with an observed productive cough on request. No effect of sex, shift, or history of cough and sputum was demonstrable. By contrast with the jute workers, no influence of smoking habit was apparent. The larger decreases in ventilatory capacity were observed in those with the higher F.E.V.1·0:F.V.C. ratios, whereas the reverse trend was noted in the jute workers. The occurrence of significant large decreases in those employed in the industry for less than a month, in conjunction with other evidence, suggests that a factor of `self-selection' may be operative among cotton employees in this country and may be related to the apparently low prevalence of clinically important byssinosis. Attention is drawn to two different patterns of change of ventilatory capacity over a week in subjects exposed to dusts sometimes associated with symptoms of byssinosis; the relationship of these changes and of chronic bronchitis to the development of clinical byssinosis is discussed.

McAulay, I. R.; Carey, G. C. R.; Merrett, J. D.; McClarin, R. H.; Elwood, P. C.; Pemberton, J.

doi: 10.1136/oem.22.4.305pmid: 5836571

The concentrations in the air of total and of respirable (less than 7 microns equivalent diameter) dust were measured in 142 workrooms of 17 Northern Ireland flax spinning mills using a hexhlet air sampler. Neither the distribution of total nor of respirable dust concentrations (mg./100 m.3 air) measured in each of four large workrooms conformed to the normal (or Gaussian) distribution, but it is shown that the logarithms (to the base 10) of these concentrations are normally distributed. In order to make valid statistical comparisons between the dustiness of the different types of room, mean log. concentrations are therefore used. The mean log. concentrations of total and of respirable dust, and the 95% confidence limits derived from these, were calculated for each room surveyed. For total and respirable dust the ranges of mean log. concentrations followed in brackets by the respective antilogs. (mg./100 m.3 air) were as follows: [Table: see text] Thus, dust concentrations varied widely within each category of room, although in general the pre-preparing rooms had the highest levels followed by other preparing rooms, other finishing rooms, and wet finishing rooms, in that order.

Cramér, Kim; Selander, Stig

doi: 10.1136/oem.22.4.311pmid: 5836572

The urinary output of δ-aminolaevulic acid (ALA), coproporphyrins, and lead in 15 leadintoxicated workers was determined and correlated with the degree of intoxication. Raised levels of ALA in the urine show the best agreement with clinical evidence of intoxication. In addition these values were correlated with the amount of lead excreted after treatment with a total dosage of 9 g. penicillamine. Weak correlations were found between therapeutically excreted lead and initial values for lead and coproporphyrin in urine. In contrast the initial values for ALA correlate very closely (P < 0·001). It is concluded that determinations of the output of ALA are to be preferred in the evalution of lead intoxication and that they point directly to the amount of metabolically active lead in the organism.

Kretser, A. J. de; Waldron, H. A.

doi: 10.1136/oem.22.4.315pmid: 5836573

Further experiments on the effects of lead on the mechanical fragility of the red cell confirm previous findings, that lead does not increase the mechanical fragility index of the red cell at the blood lead levels found in clinical plumbism. Above these levels lead does increase the mechanical fragility index, reaching its maximum effect at about 50 μg. of lead/ml. blood.