Lead poisoning and lead absorption

by Sir Thomas Morison Legge; Kenneth Weldon Goadby

In times of stress where some particularly dangerous process is in operation, as, for instance, where portions of a building which has become thoroughly impregnated with lead dust is being pulled down, or where machines are being altered, removed, or rebuilt, especial care should be exercised with the workmen so employed, and it is advisable in such cases to adopt preventive measures on the supposition—generally correct—that such persons are absorbing a larger quantity of lead owing to their peculiarly dusty employment than they were under normal circumstances. At such times, also, it may be advisable to administer some form of mild iron cathartic to all persons employed in the factory for, say, a week at a time. It must not be supposed, however, that these methods of treatment in any way supersede the precautions for the prevention of lead poisoning by mechanical and hygienic means; they are merely additional precautions which may be put in force under special circumstances.

The Treatment of Lead Poisoning.

—The treatment of definite lead poisoning, as the treatment of lead absorption, is directed towards the elimination of the poison, the promotion of repair to the damaged tissues, and special treatment directed towards those special organs which suffer mostly in lead poisoning. At the same time, special treatment of urgent symptoms may be called for; but in the treatment of the urgent symptoms the fact of the general elimination of the poison must not be lost sight of.

We have already seen that the channel through which the poison leaves the body is mainly the fæces. Treatment must therefore be directed, as in the former instance (lead absorption), towards eliminating the poison by this means as much as possible, both by the use of enemata, and later the use of sulphate of magnesia, which may be added to the ordinary fluid enema; and it is far better in obstinate cases of constipation and colic to give enemata than to continue with the huge doses of salines or other aperients, such as croton-oil, elaterinum, or castor-oil.

Colic.

—Lead colic may be simple, acute, recurrent, or chronic and continued. In whatever form colic appears pain is invariably referred to the lower part of the abdomen, frequently into the groins, and occasionally to the umbilicus. The pain has to be distinguished particularly from acute gastritis, and occasionally from appendicitis, and sometimes from that of typhoid fever. Acute colitis—not common in this country—and dysentery, may, to some extent, simulate the pain of lead colic, but John Hunter’s[2] original definition of “dry bellyache” conveys very vividly the type of pain. Occasionally diarrhœa may be met with, but as a rule obstinate constipation is present. In continued colic, or chronic colic, sometimes lasting for several months, obstinate constipation is the rule. In the simple acute colic the pain passes off in the course of five or six days, generally disappearing about four days after the lower intestine has been thoroughly cleared.

The pain of lead colic is relieved by pressure upon the abdomen, whereas that of gastritis and most other forms of abdominal pain may be generally elicited along the descending colon and splenic flexure; mucus is commonly found in the stools, especially the first evacuation, after obstinate constipation occasionally of several days’ duration associated with an ordinary attack of lead colic. Blood may be passed, but this symptom is not common. The pain in the acute form is paroxysmal; it is rarely persistent, being typically intermittent. During the paroxysm distinct slowing of the pulse-rate with an increased blood-pressure takes place, and the administration of vaso-dilators—such, for instance, as amyl nitrite—during a paroxysm rapidly relieves the pain and lowers the blood-pressure, and in this way distinguishes acute colic of lead poisoning from, say, subacute appendicitis.

Vomiting may or may not be present, though the patient usually complains of feeling sick, but there may be at times vomiting of a frothy mucus.

It is unusual for a patient to die from acute colic, but acute paroxysms have been recorded in which yielding of the blood-vessels of the brain has occurred.

Recurrent colic is as a rule less severe than the simple acute form, but may last for several weeks, clearing up for three or four days at a time and then recurring with little diminution in violence from the first attack. Such cases are probably due to the gradual excretion of lead by the intestine, and should be treated on this supposition.