OCCUPATIONAL INTOXICATIONS AND DISEASES Little definite data can be presented concerning the preva lence of occupational diseases, since little attention has been paid them until recent years, and but four states require their reporting. Their frequency as well will be proportional to the prevailing type of economic development. The experience in Ohio will give us perhaps our best guide to their prevalence. Thus recently during a period of seventeen months, there were reported a total of 1204 cases of occupational diseases. The following were the most numerous: Benzene and benzol poisoning 33 cases Brass poisoning 124 cases Lead poisoning 544 cases Pneumonokoniosis 15 cases I. Thus we see lead poisoning is by far the most important. Its importance is emphasized if we briefly survey the many occupations in which lead is handled and among whose workers lead poisoning may arise. This is presented in the following table, which represents the cases reported above.
From the foregoing it can be seen that the industries in which lead products are employed are varied, and that men engaged in considerably different occupations may suffer from lead poisoning. Painters and those who sandpaper (Figs. Io5, io6) painted work, workers in storage batteries, workers in rubber manufacture, printers (Fig. io4) and workers in lead products are the heaviest sufferers. The possibility of lead poisoning must always be borne in mind in the clinical examination of an industrial patient.
2. Channels by which Lead Gains Entrance into the Body.— In most manufacturing processes lead as a poison is encountered in the form of dust, as well as in lead smelting and the manufac tures of lead carbonate. Absorption by the lungs appears to be slight, the greater amount of dust gaining entrance by the alimentary canal. Most dust is caught in the nasopharynx and swallowed with the mucous secretions. The dust on enter ing the stomach reacts with the hydrochloric acid and soluble chlorids are formed which are absorbed. When it reaches the blood it is believed to form a rather insoluble albuminate. If
food is eaten at the same time less lead will be converted to the chlorid. Lead which is not changed to the chlorid passes out into the feces as the sulphid. Lead carbonate is more solu ble in the gastric juices than the sulphate.
In intoxication from lead fumes absorption is by the way of the lungs. It is a less common route than the alimentary, the principle occupations affected by this route being lead smelters and Linotype operators. (Fig. 104).
3. Symptomatology of Lead Poisoning.—Females and young persons are predisposed to lead poisoning. The onset is very variable, usually manifesting itself in two to four weeks, rarely longer. The onset is more certain and the symptoms more severe when small doses are absorbed over long periods. A gradually developing pallor (anemia) with basophilic stippling of the red cells, a blue line on the gums close to the dental margin, colic and constipation with headache are usually observed. The patient may have convulsions, disturbances of vision or paralysis. Pregnant women always miscarry.
4. Remedies.—Efficient exhaust ventilation is essential for the removal of both dust and fumes. The amount of dust produced can frequently be reduced by slight alterations in methods. Provision should be made so that a little food can be kept in the stomach during working hours. Workmen should be instructed to expectorate saliva instead of swallowing it. Adequate washing facilities will assist in removing dust, as will also the requirement that the clothing be changed upon leaving work. In the painting trades much will be accom plished by the substitution where possible of zinc paints for lead paints.
5. Arsenic.—Arsenic is chiefly encountered as a dust. Workers in the manufacture of Scheele's Green ( a pigment), wall paper, glazed colored paper, artificial flowers, the packing of white arsenic and at works where the ore is reduced, are affected. It acts as an irritant to the skin and mucous surfaces. (Fig. 107, 108).