Lead poisoning and lead absorption

by Sir Thomas Morison Legge; Kenneth Weldon Goadby

The fact that an examination is made on factory premises, is directed to detection and prevention, treatment taking a subordinate place, and is often made on persons who, unlike hospital patients, seek to conceal their symptoms, causes it to be an examination sui generis. Hence the surgeon must trust his sight more than his hearing. A surgeon with experience of such work has said: “The worker in lead must be surveyed as an individual, and idiosyncrasies must be carefully studied and allowed for; the ‘personal equation’ is of vital importance”[1].

For the examination a well-lighted room affording privacy is essential. While it is desirable for the surgeon periodically to see the processes and conditions under which work is carried on, systematic examinations of workers should not be made elsewhere than in a private room. The custom of marshalling workers in a queue, although perhaps unavoidable in many cases, is liable to detract from the seriousness of the proceedings, a sense of which it should be one of the aims of the examination to arouse. In discussing the method of interrogation and usual examination, Dr. King Alcock[2], Certifying Factory Surgeon of Burslem, says: “Note the general manner assumed in answering questions and any indications of carelessness in dress and toilet. Inquire into the state of digestion, existence of colicky pains, regularity of bowels, menses, history of pregnancies and miscarriages, whether before, in the intervals of, or during lead employment; existence of headache, diplopia, or amaurosis. Note the type, facies, state of teeth and nails, complexion, speech, tongue, strength of grasp (if possible, with dynamometer), any tremor in outstretched hand, resistance to forcible flexion of wrist.... If strabismus is present, note whether of old standing or recent; and if ocular troubles seem imminent, examine for optic neuritis, either at once or at home (this is very important, as cases of acute and serious optic neuritis still baffle examination by their intermensual development).” He recommends the surgeon, apart from entry in the health register, which must necessarily be very brief, to keep a private notebook, and to enter in it as a matter of routine such details as name, process, age, duration of employment, condition (married or single), pregnancies, state of bowels and menses, dental toilet, and any special point worthy of note in individual workers. A card index, if in use, might conveniently serve for such entries.

In the actual routine examination it may be useful to describe the procedure where a large number of workers pass before the surgeon in a white-lead works every week. The points noted are:

1. The general appearance of the man as he walks forward, especially the face with regard to anæmia, which in the majority of cases of early lead absorption is not a true anæmia, but is due to vaso-motor spasm of the arterioles of the face and eyes. Frequently, on speaking to a lead-worker, the face, apparently anæmic, flushes directly.

2. The brightness of the eyes, state of the pupils, and condition of the conjunctiva and of the ocular muscles.

3. The mouth should next be examined, and search made for any evidence of blue line around the gum.

4. The gait should be watched both on advancing to, and retiring from, the surgeon. If necessary, the man should be made to walk a few steps. Although the peroneal type of palsy is extremely rare, the possibility of its occurrence should never be absent from the mind of the surgeon.

5. The man should then be directed to stretch his hands out in front of him, with wrists extended and fingers widely spread. Presence or absence of tremor should be looked for, and the condition of the finger-nails, as to the practice of biting, etc. The extensor power should then be tested, firstly of the fingers. While the hands of the workman remain outstretched, the surgeon places the forefinger of his hand in the outstretched palm of the workman, and the ball of the thumb upon the extreme tip of each finger, and by gently pulling it down, noting the spring present in the muscles. This test is probably the most delicate there is for detection of early extensor paralysis. The condition of the lumbricals and interossei are noted on movement of the fingers. The extensors of the wrist are then further examined, the workman being directed to flex his arm at the elbow and strongly pronate the wrist, so that the palm of the hand is directed forwards. He is then told to close the fist when the surgeon endeavours to flex the wrist, the workman at the same time resisting by forcible extension of his wrist. Ordinarily the extensor communis digitorum and minimi digiti are sufficiently powerful to resist a very powerful pull upon the wrist; and if the wrist is found to yield, it is a sign that the muscles are affected. Sometimes the strength of the wrists and fingers is judged by the surgeon placing his palms on the dorsum of the patient’s outstretched hands, and seeing whether the patient can be prevented from lifting them without flexing the wrists or finger-joints.

The test detects (1) paralysis which has been recovered from to a large extent; (2) commencing partial paralysis; and (3) weakness of muscular power, especially in those who have worked in lead for a number of years. This weakness appears to be an effect of lead upon the muscular tissue or dependent on debility, the result of lead absorption, and independent of nerve implication. We have known the condition to remain unaltered for years, and also to undergo alteration, being at times absent for months together. Occasionally reports of definite paralysis refer to pre-existing weakness.

6. The pulse is next noted. The pulse-rate need not ordinarily be counted, but if it is either very slow or fast careful examination at the conclusion of the general inspection should be made.