Lead poisoning and lead absorption

by Sir Thomas Morison Legge; Kenneth Weldon Goadby

In laying down the general lines of treatment for both lead poisoning and lead absorption, it is essential in the first place to distinguish carefully between the two states; for although lead absorption may gradually drift into definite lead intoxication and lead poisoning, with all the classical symptoms associated with the saturnine cachexia, a large number of cases, particularly those in industrial processes, do not and should not progress beyond the early symptoms of lead absorption. The treatment, therefore, will depend in the first place on whether the case be one so constantly met with in industrial processes, where generalized symptoms of lead absorption are manifest without any definite and disabling symptoms traceable and sufficiently pronounced to enable a diagnosis of lead poisoning to be made.

The facts given in the chapter on [Pathology], on the methods of entrance of lead, on the toxic manifestations, and the blood-changes, and, above all, the facts relating to microscopical hæmorrhages and other profound changes in the bloodvessels, point clearly to the lines along which the general treatment for amelioration, prevention, or cure of poisoning should be undertaken.

The treatment of the so-called “presaturnine state,” or what is preferably termed the “state of lead absorption,” is one that the appointed surgeon or certifying surgeon in lead factories or other processes in which lead is manufactured or used, is constantly called upon to treat. Lead poisoning is a definite entity as a disabling disease, whereas lead absorption, although the prodromal stage of such disease, cannot be defined as actual lead poisoning, as in many instances persons may show signs of continued lead absorption, but their powers of elimination can be maintained at such a level that the ratio of absorption to elimination remains in equilibrium.

With the preventive treatment of lead poisoning we have dealt in another place (see [p. 199]). What is particularly required here is the medicinal treatment, which may be helpful in preventing lead absorption passing on to definite lead poisoning.

For many years it has been customary in the treatment of men employed in lead works to give occasional purgatives, and it is, moreover, a common and proper precaution to keep a stock of some simple aperient medicine, preferably saline composed of sodium sulphate and magnesium sulphate, at the works in charge of the foreman, so that any man who so desires may obtain a dose of an ordinary aperient mixture. We have seen from the pathological evidence that the largest proportion of lead is excreted by the bowel, and that, therefore, the sweeping away of the bowel contents—particularly where constipation is set up—will naturally tend to remove from the body a good deal of the lead which has been already excreted into the intestine and which may presumably become reabsorbed unless it be swept away. In a large electric accumulator factory Epsom salts in the form of the granular effervescing preparation is much appreciated. In winter 50 per cent., and in summer 90 per cent. of the men are said to take a daily dose. In an important white-lead works chocolate tablets containing hypo-(thio-)sulphite of sodium are supplied to the workers.

Another medicine made use of in lead works is the sulphuric acid lemonade, this being acidulated with sulphuric acid and flavoured with lemon. It is very questionable whether this substance has any definite effect in the special direction in which it is supposed to work—namely, that of forming an insoluble sulphate of lead in the stomach and so preventing its absorption. The use of this drug was suggested on the presumption that lead poisoning as a rule took its origin from the dust swallowed and converted into a soluble form in the stomach. As we have seen, there is very little evidence that this entrance of lead is of much importance, although it does occasionally take place. Furthermore, from the experiments of one of us [K. W. G.[1]], it has been found that the sulphate of lead is at any rate as soluble as other lead salts, such as white lead or litharge, when acted upon by normal gastric juice.

With regard to the drinks supplied to workers in lead factories, it is highly important that some form of fluid should be supplied which the men may drink without harm, particularly in the more laborious forms of employment, and, above all, in the factories where smelting, desilverizing, etc., of lead is carried on. In these factories the use of some type of lemonade containing sodium citrate is to be recommended, as it has been shown that one of the pathological effects of lead absorption is to produce an increased viscosity of the blood, and the use of such drugs tends to some extent to diminish this. A drink containing a few grains of sodium citrate to the ounce and flavoured with lemon is freely drunk by workmen engaged in the laborious processes.

Finally, as a general routine treatment, it is advisable to keep at the factory some form of mixture containing iron, which may be given to those persons who are showing signs of slight anæmia, generally associated with some degree of constipation, and it is therefore better to use a form of iron cathartic. This medicine should also be kept in the care of the foreman, who will see that it is administered to the men properly. In this way any persons who at the weekly examination exhibit signs of anæmia may be promptly treated, and what is more, the surgeon is assured that the workmen in question actually obtain the medicine prescribed regularly.

During the routine weekly or monthly examination, or at whatever intervals the medical examination takes place, particular attention should be paid to the records kept of the state of health of the various persons, and whenever possible alteration of employment should always be enjoined when early signs of anæmia make their appearance.

The surgeon should spare no pains to determine if any of the workmen are confirmed alcoholics, and such persons should be removed from work in dangerous processes, while at the same time care should also be taken to eliminate any persons suffering from those diseases which are known to be predisposing causes of lead poisoning. The card system of registration of any symptoms noted or treatment given facilitates supervision of the health of the men.