Postgrad Med J: first published as 10.1136/pgmj.35.406.470 on 1 August 1959. Downloaded from 470 LUNG DISEASE DUE TO INHALED DUST By K. M. A. PERRY, M.D., F.R.C.P. Physician to the London and Royal Masonic Hospitals There is gradual realization that there is a severe carcinoma of the lung. In I900 there were 273 air pollution in the industrial areas of the world deaths in England and Wales from this condition; and that this is a danger to the communities that in 1920, 500; and in 1955, 17,272. It is possible live in them. In the week following the dense fog that the part played by air pollution is greater on December 8, 1952, there were 4,ooo deaths in than is at present realized. excess of those usual for the time of year, and these were attributed to acute bronchitis and its com- Inert Dusts plications, resulting from the inhalation of the The most important dust to cause X-ray dioxide and trioxide ofsulphur extruded by factory shadowing is iron oxide. It occurs commonly in and domestic chimneys (Beaver Report, I954). industry: welders, oxy-acetylene cutters, polishers,Protected by copyright. The air pollution of cities is constantly present tool makers, cutlery makers, foundry workers and and the noxious substances are by no means con- haematite miners have considerable exposure. The fined to the oxides of sulphur. The concentrations last two occupations involve exposure to a mixed may sometimes be higher in the factory than in dust, including silica, and in consequence silicosis the city atmosphere. These lesser concentrations is a recognized risk in these occupations. The certainly play an important part in the causation radiological shadowing in siderosis is discrete and of chronic bronchitis and its resultant emphysema nodular. The condition produces no symptoms, and cor pulmonale, the death rate for these diseases and it has been shown that if no more iron dust being i,6oo per million in Merseyside, compared is inhaled the iron oxide is gradually eliminated with 6oo per million in East Anglia and Hamp- from the lung parenchyma and the shadowing will shire. It is, therefore, evident that strenuous be reduced. Histologically, in the lungs there is efforts should be made to control fume and thus much amorphous pigment in the periarterial and reduce air pollution, which produces disease in the peribronchial lymphatic channels and the alveolar whole community. This is essentially industrial sacs, but no fibrosis has been found either in http://pmj.bmj.com/ in origin, though it is not always classified as lymph glands or in lung tissue. industrial disease. The Registrar-General's Supplementary Report on Occupation Mortality in 1931 shows that there Dust Diseases were 123 deaths among II,452 welders, compared It has been known since prehistoric times th at with an expected i6i on the basis of age rates for dust will produce diseases of the lung. It must be all males. This evidence alone shows conclusively of a particle size of less than to pass the that iron oxide is an inert dust in the lungs. Other 5s, through on September 29, 2021 by guest. smallest bronchioles and reach the alveoli. Some dusts which produce radiological shadowing in dusts are inert and, therefore, produce no tissue industry are tin oxide, the atomic weight of tin reaction in the lungs. They are important, how- being II7.8, and barium, which has an atomic ever, since they may be radio-opaque and, accord- weight of 137.4. Because of the higher atomic ing to their atomic weight, produce shadows in weight of these two metals, the shadowing is more radiographs-these often cause alarm to patients dense than in the case of siderosis and the con- and even doctors. Other dust will cause fibrosis ditions have been called, respectively, stannosis and this disease has been called pneumonocoriosis and baritosis. (Greek: pneumon, lung; konis, dust), a word Silver polishers use rouge, which is iron oxide, sometimes incorrectly abbreviated to pneumo- and are, therefore, exposed to a dust which con- coniosis. Yet other dusts will produce either a tains a mixture of silver and iron. X-rays of silver sensitivity or inflammatory reaction. A few more polishers' lungs show the typical picture ofreticula- have been proved to be carcinogens and to con- tion. This is partly caused by iron oxide, and also tribute to the great increase in the incidence of in part caused by thei intra-vitam staining of the Postgrad Med J: first published as 10.1136/pgmj.35.406.470 on 1 August 1959. Downloaded from August 1959 PERRY: Lung Disease Due to Inhaled Dusts 471 elastic tissue of the arterial, alveolar and bronchial course of the disease is suggestive of an acquired walls with silver oxide. hypersensitivity, but the primarily toxic qualities of the protein prevent the condition from being Sensitivity Reactions regarded as purely allergic. There is little doubt that certain dusts of organic Cotton arrives in England in tightly com- origin will produce a sensitivity reaction in the pressed bales and it is the workers who are engaged lung, which results in attacks of shortness of breath on the earlier processes who are involved; those with a wheeze. This is probably the result of who open the bales and those who work on the oedema of the bronchial wall and over-activity of carding engines, particularly the strippers and the bronchial mucosal glands, producing narrowing grinders. After working for several years in of the smaller bronchioles. Pollens and the dust the dusty atmosphere the patient begins to of wheat and grain are notorious for giving rise sneeze and develop a dry and irritating cough, to this condition, and it therefore occurs mostly with a tight feeling in the chest and restricted in millers and bakers. Hair dandruff will also intake of breath. To start with the symptoms are produce such a reaction, and this will be found temporary and pass off in a few days, but they in hairdressers and those concerned with the return after a short absence from work, such as a care of horses or other fur-bearing animals, in- weekend, and it is for this reason that the con- cluding furriers. The complex salts of platinum dition is sometimes called 'Monday morning also cause an irritation to the nasal passage, throat fever,' ' mill fever' and 'factory fever.' Disable- and trachea. The symptoms are repeated sneezing, ment and incapacity for work does not occur until followed by tightness of the chest, shortness of the man has been exposed to the dust for io years breath and a wheeze. The symptoms persist as or more, when the symptoms may become more long as the worker remains in the but severe and persistent, and the factory, patient develop Protected by copyright. about half an hour after he has left they subside. attacks of shortness of breath associated with a Radiograms reveal no abnormality. wheeze, shallow breathing, cough and a small Organic vegetable dusts have been reported amount of sticky, mucoid sputum. The disease from all over the world as producing pulmonary progresses and finally arrives at an incurable stage reactions. Farmer's lung, which was first de- so that many of these workers die before the age scribed in England in I932, occurs particularly in of fifty from right-sided heart failure. haymakers, but it has been described in all harvest The physical signs and X-ray findings are in no workers and was in Scandinavia called Thresher's way different from those associated with chronic lung. A similar reaction has been described in tea bronchitis and emphysema. Necropsies also reveal tasters, and the disease ' broken wind ' in horses is no specific changes in the lung. Death frequently probably a similar disease. results from cor pulmonale. In the earlier stages of the war a disease was found in those who worked with bagasse, which is Silicosis sugar cane after the sugar has been extracted. Silicosis is a fibrosis of the lung caused by the http://pmj.bmj.com/ Respiratory disease is common in cotton workers inhalation of free crystalline silica or quartz and has been called byssinosis. In all these diseases particles. It is the most disabling of all the dust the vegetable material seems to be contaminated diseases, yet the precise method by which the by fungi, and many writers have ascribed the silica causes the disease is not yet established. It disease to these organisms. They are consistently was thought to be mechanical in origin, being present in all the dusts, but they are probably not caused by the movement of the lung on the sharp the immediate cause, though it is possible that by crystals, until in I932 Gardner, in Saranac Lake producing toxic substances they indirectly con- laboratories, showed that carborndum (silicon on September 29, 2021 by guest. tribute to the aetiology of the condition. carbide) crystals, which are just as sharp and hard Of these diseases, that caused by cotton is by as those of silica itself, do not produce the disease far the most important in this country. As early in animals. It was then suggested that silica went as i8i8 Jackson drew attention to the fact that into solution in the phagocytes forming silicic acid those who worked in the cotton industry, particu- and when this was released, as a result of destruc- larly card-room workers, suffered from a charac- tion of the phagocyte by infection, either tubercu- teristic respiratory disease. Foreign literature on lous or non-tuberculous fibrosis resulted. This is the condition is scanty, but it has been reported known as the Solubility Theory.