Occupational and Environmental Medicine

Bloor, W. A.; Dinsdale, A.

doi: 10.1136/oem.19.4.229pmid: 13971816

Investigations into the factors affecting dust concentrations in the breathing zone of pottery operatives have shown that cotton overalls constitute a serious source of dust. Attempts to overcome this difficulty by treatment of the material were not successful, so other types of materials were investigated. Terylene was found to have outstandingly desirable properties; types of “terylene” material and designs of clothing were defined. Factory tests showed that with this new protective clothing reductions of up to 65% in breathing zone dust concentrations were achieved. This type of clothing is now being officially recommended by the Joint Standing Committee for the Pottery Industry.

Fisher, A. M.; Christie, Helen

doi: 10.1136/oem.19.4.236pmid: 13945262

A machine is described that permits the controllable production of dusty atmospheres in which experimental animals may be exposed for extended periods. This is accomplished by diluting the dust with dense inert material from which it is subsequently removed without involving changes in the particle size or physical nature of the dust which it is desired to suspend in the atmosphere.

Bech, A. O.; Kipling, M. D.; Heather, J. C.

doi: 10.1136/oem.19.4.239pmid: 13970036

In Great Britain there have been no published reports of respiratory disease occurring amongst workers in the hard metal (tungsten carbide) industry. In this paper the clinical and radiological findings in six cases and the pathological findings in one are described. In two cases physiological studies indicated mild alveolar diffusion defects. Histological examination in a fatal case revealed diffuse pulmonary interstitial fibrosis with marked peribronchial and perivascular fibrosis and bronchial epithelial hyperplasia and metaplasia. Radiological surveys revealed the sporadic occurrence and low incidence of the disease. The alterations in respiratory mechanics which occurred in two workers following a day's exposure to dust are described. Airborne dust concentrations are given. The industrial process is outlined and the literature is reviewed. The toxicity of the metals is discussed, and our findings are compared with those reported from Europe and the United States. We are of the opinion that the changes which we would describe as hard metal disease are caused by the inhalation of dust at work and that the component responsible may be cobalt.

McLaughlin, A. I. G.; Kazantzis, G.; King, E.; Teare, Donald; Porter, R. J.; Owen, R.

doi: 10.1136/oem.19.4.253pmid: 13932137

The clinical, radiographic, pathological, and environmental features of a case of extensive aluminium fibrosis of the lungs are reported in a man of 49 years of age who had worked for 13½ years in the ball-mill room of an aluminium powder factory. It is noteworthy that his symptoms were referable to the central nervous system, and that he died from terminal broncho-pneumonia following rapidly progressive encephalopathy, associated with epileptiform attacks. He had no presenting pulmonary symptoms, and ϰ-ray examination of the chest showed only slight abnormalities. Radiographic examination of the chests of 53 other workers in the same factory, and clinical examination with lung function tests of 23 of them revealed no other definite cases of aluminium fibrosis of the lung, nor any other cases with neurological signs and symptoms. Estimations of the aluminium contents of the body tissues such as the lungs, brain, liver, and bone are also recorded. When compared with normal values, it was found that the lungs and brain contained about 20 times and the liver 122 times more than normal. As a contribution to the study of the aluminium content of normal tissues, and as a control series for the results given by Tipton, Cook, Steiner, Foland, McDaniel, and Fentress (1957), and Tipton, Cook, Foland, Rittner, Hardwick, and McDaniel (1958, 1959), the aluminium content of eight “normal” brains was estimated and in all cases it was found to be less than 0·6 μg. Al/g. wet weight. The results of a survey of the dust concentrations in the factory are also given. The use of aluminium compounds in the experimental production of epilepsy in primates is reviewed, and it is suggested that the neurological signs and symptoms with epileptiform convulsions which occurred in this case might have been related to aluminium intoxication. We hold the view, however, that the interstitial and nodular fibrosis found in the lungs was undoubtedly associated with the inhalation and retention of aluminium dust.

Humphreys, P. W.; Lind, A. R.

doi: 10.1136/oem.19.4.264pmid: 13955707

This survey was intended to provide a basis of information on the energy expenditures for the main component tasks in coal-mining, carried out at different rates and in different postures. Such information is frequently required for studies of the physiological effects of coal-mining; these values reported here were required in particular for studies intended to define thermal limits of the environment suitable for miners at non-mechanized coal-faces, a situation where the metabolic heat produced makes up a large proportion of the total heat load of the individual. Regression lines have been drawn between energy expenditure and speed of shovelling for the miner working in different postures. When forced to work lying on the floor the man's energy expenditure dropped, but his coal output also dropped. Walking to and from the coal-face along roadways of good height yielded energy expenditures comparable to those of treadmill walking, although generally slightly higher in value. Stooped walking generally increased the energy expenditure of walking, but to smaller extent than was anticipated from previous laboratory work. Several time analyses of complete shifts from different collieries, in which the time spent at different tasks had been measured, yielded an average estimate of the energy expenditure for an eight-hour shift of 2,000 kcal.

Heath, D. F.; Magee, P. N.

doi: 10.1136/oem.19.4.276pmid: N/A

The title compounds, which have some commercial applications, are described, and their toxic action is reviewed. Most results refer to rats. Their main acute effect is hepatic centrilobular necrosis, though lung lesions may appear. The compounds also induce tumours in liver, lung, and kidney. One, dimethylnitrosamine, has been shown to cause kidney tumours after a single dose. The necrotic and carcinogenic doses of the compounds are closely related. The relation between structure and toxicity is discussed. Analogous formamides are much less toxic (the LD50's in rats by intraperitoneal injection of dimethyl- and diethyl-formamides are 3,800 mg./kg. and 1,740 mg./kg.) and they do not cause centrilobular necrosis or tumours. Nitrosamines are oxidized in vivo and by liver preparations in vitro. Their toxic action is due to the release of powerful alkylating agents in the liver. They also inhibit protein synthesis and alkylate liver protein and ribonucleic acid. In all cases the effective agent appears to be a metabolite. The possible hazard to man in the uses of these compounds is emphasized.

Magos, Ladislaus

doi: 10.1136/oem.19.4.283pmid: N/A

Observations are recorded on methaemoglobin-CN complex formation in rats poisoned with acrylonitrile, potassium cyanide, and acetone cyanohydrin. For information on methaemoglobin-CN formation, the methaemoglobin level was increased by sodium nitrite. The results show that the rate of methaemoglobin-CN formation in rats killed by acrylonitrile is lower than in animals surviving potassium cyanide or acetone cyanohydrin poisoning, and much lower than in animals killed by potassium cyanide. These findings indicate that the toxicity of acrylonitrile cannot be solely due to the liberation of cyanide.

Colquhoun, W. P.

doi: 10.1136/oem.19.4.287pmid: 14022450

An investigation was made of the effects of 1 mg. hyoscine hydrobromide and of 50 mg. meclozine hydrochloride on the performance of tasks of vigilance and short-term memory. In further trials the effects of these drugs were measured after ingestion of 32 g. ethyl alcohol. Efficiency was impaired by hyoscine taken alone, but meclozine alone had no significant effect. The effect of hyoscine was substantially increased by the presence of alcohol and under these conditions the effect of meclozine was equally great. The vigilance task appeared to be more sensitive to the effects of the drugs than the memory task, and possible reasons for this are considered in the discussion.

Buess, H.

doi: 10.1136/oem.19.4.297pmid: N/A

Industrial medicine saw its tentative beginnings among the inquiring minds of 16th century physicians such as Paracelsus. In the 17th century, reports of conditions in mines on the Continent prompted natural scientists at the Royal Society to initiate a research programme into what we now know as mercurial poisoning. The latter part of the eighteenth century witnessed the change from domestic to factory industry with its concomitant social, economic, and technological upheaval, resulting in great shifts of population away from the countryside to the towns. Men, women, and children were employed in the new factories in primitive, unhygienic conditions, and mill fever and illness generally were rife. It was against this background that Percival and Thackrah, prompted no doubt in large measure by the conditions of child labour, inquired into, and made recommendations for, the improvement of hygiene in the factories, thus laying the foundations of industrial medicine as we know it today.

Barnes, J. M.

doi: 10.1136/oem.19.4.303pmid: N/A