foregoing pages concerning the prophylaxis against the opium habit
applies with equal force to chloral and other narcotics. The curative
treatment of habitual addiction to chloral is attended neither by the
{677} difficulties nor the dangers which are encountered in the
management of the opium habit. The symptoms attending the
discontinuance of chloral are less severe and less persistent; in
fact, individuals accustomed to the taking of large doses of chloral
not infrequently voluntarily discontinue its use for considerable
periods of time. As a rule, the treatment may be carried out at home,
the patient, however, being isolated and cared for by a watchful
attendant. The drug should be stopped at once. For the first few days
alcoholic stimulants should be freely given. Systematic feeding,
pepsin, full doses of quinine, followed after a time by strychnia,
and, as soon as the condition of the digestive system will permit of
it, by iron, fulfil the general indications. Cod-liver oil and malt
extracts may be given with advantage. Cardiac failure, collapse, and
delirium tremens are to be treated in the same manner as similar
complications occurring in the treatment of the opium habit. Vomiting
is much less likely to occur, and when present is less persistent and
less difficult of management. Diarrhœa does not usually prove
troublesome, the bowels, on the contrary, being constipated. The
latter condition yields to mild laxatives or to simple enemata.
Hemorrhages from the various mucous tracts may be controlled by fluid
extract of ergot, the hypodermic injection of solution of ergotin,
minute doses of wine of ipecac, or fluid extract of hamamelis. The
conjunctivitis which is occasionally present usually subsides
spontaneously upon the discontinuance of chloral. It may be treated by
instillations of a 2 per cent. solution of cocaine and mild borax
lotions (grs. v to fluidounce j). The after-treatment must be
carefully carried out. Relapses are less frequent than after the opium
habit.
The Treatment of Habitual Addiction to Paraldehyde, Cannabis indica,
Ether, Chloroform, etc. must be based upon the general principles
indicated in the foregoing pages. Cases of the habitual abuse of these
drugs are comparatively infrequent on the one hand, and on the other
do not often present the serious and progressive symptoms produced by
excesses in opium and chloral; hence they come but rarely under the
care of the physician, except in those unhappy individuals in whom the
propensity to vicious narcotism is such that any drug capable of
producing excitement and oblivion is made the means of gratification,
and all are used by turns as the opportunity occurs.
{678}
CHRONIC LEAD-POISONING.
BY JAMES C. WILSON, M.D.
DEFINITION.—The term chronic lead-poisoning is used to designate the
morbid phenomena induced by the gradual accumulation of lead in the
organism.
SYNONYMS.—Plumbism, Saturnism, Morbus plumbeus, Molybdosis,
Molybdonosus, Intoxication saturnine, Bleivergiftung.
CLASSIFICATION.—Chronic lead-poisoning manifests itself in serious
disorders of nutrition which are widespread and implicate all the
tissues of the body; but for the reason that its more striking and
characteristic symptoms relate to the nervous system, it has been
classed among disorders of that system as a toxic neurosis.
Acute poisoning by lead is an entirely different affection. It depends
upon the power of the salts of lead to coagulate albumen. Its symptoms
are those of acute corrosive gastritis; derangements of the nervous
system are secondary. It does not fall within the scope of the present
article.
HISTORY.—Chronic lead-poisoning must have existed from the infancy of
the arts in which the metal is employed. It does not, however, appear
to have been recognized until after the time of Hippocrates. Celsus
was aware of the danger attending the administration of lead.
Nicander, Dioscorides, Aretæus, and Paul of Ægina recognized lead
colic and the paralysis resulting from its long-continued introduction
into the stomach. Among Arabian physicians, Rhazes and Avicenna
accurately describe the effects of the preparations of lead. No
considerable addition to the knowledge of the subject was made until
the seventeenth century. In 1616 was printed at Poitou the famous work
of Citois, _De novo et populari apud Pictones dolore Colico bilioso
Diatriba_. The epidemic colic described by this author was caused,
although he little suspected it, by the common use of wine which had
been treated by lead to remove its acidity. This practice, which is of
very ancient date, and is described in the writings of Cato, Pliny,
and Columella, was at one period very general in Europe, and had been
forbidden by imperial ordinances as early as 1437.[1] It remained for
Stockhausen, in a treatise published at Goslar in 1656, and entitled
_De Lythargyrii Fumo, noxio, morbifico ejusque metallico frequentiori
morbo vulgo dicto Hutten-Katze_, to demonstrate that Poitou colic was
produced by lead in particles in {679} emanations, and for Wepfer in
1671 to first clearly point out the fact that the epidemic colic so
often described was usually caused by lead in wine. During the
eighteenth century the epidemic colic attracted much attention among
medical men, and its etiology was made clear. Henkel called the
affection founder's colic, and showed how it was produced in those
engaged in casting lead; Huxham, in his work on _Fevers_ (1745),
described the disease as it prevailed in Devonshire, and several
English observers conclusively proved that the epidemics of colic
frequently appearing in certain districts were caused by the presence
of lead in cider, and that it was due to the action of the apple-juice
upon lead used in the construction of the presses and implements
employed in the manufacture of that popular beverage.
[Footnote 1: Vide Tanquerel des Planches, _Lead Diseases_, translation
by S. L. Dana, M.D., LL.D., Lowell, 1848.]
During the current century the closer study of the etiological
relations of disease has revealed many unsuspected sources of
lead-poisoning in the arts, and of lead contamination, both accidental
and intentional, in articles of food, drink, and luxury. Hence the
literature of the subject has assumed very extensive proportions. The
French physicians have devoted much attention to this subject. The
great work of Tanquerel des Planches, to which reference has already
been made, remains to this day the most complete and comprehensive
authority. Quite recently valuable additions to existing knowledge
have appeared in some of the Paris theses.[2]
[Footnote 2: Vide Capelle, _De l'Intoxication saturnine_, Paris, 1883;
Séguin, Ch., _De l'Albuminurie transitoire des Saturnins_, Paris,
1883; Goudot, _Étude sur la Goutte saturnine_, Paris, 1883; Verdugo,
_Contribution à l'Étude de la Goutte saturnine_, Paris, 1883; and
Coutard, _La Colique du Poitou considérée comme Intoxication
saturnine_, Paris, 1884.]
ETIOLOGY.—_A_. Predisposing Influences.—Individuals exposed to lead
and its compounds are not all equally prone to its effects. The degree
of liability is to some extent dependent upon individual
susceptibility, and to a much greater extent upon circumstances which
are determined by the season, climate, age, sex, diet, and mode of
life of different persons. It will be convenient to consider the
predispositions which arise from occupation under the head of the
Exciting Cause.
Variations in the degree of susceptibility to chronic lead-poisoning
appear to be explicable in a majority of the cases solely upon the
theory of idiosyncrasy. While a large proportion of the cases are in
well-developed, strong, and previously healthy adults, individuals of
feeble constitutions do not escape. Those occupations which involve
the greatest exposure to the danger of contracting this affection at
the same time demand the powers of a robust frame. Habitual
recognition of these dangers, such as begets the habitual exercise of
reasonable precautions against them, diminishes to some degree the
liability of a few workmen.
Season.—Due allowance being made for the difference in the number of
workmen employed in manufactures which involve exposure to lead, and
especially in the making of white lead, at different seasons of the
year, it has been found that attacks of lead colic and of lead palsy
are more common in warm than in cold weather. Heat predisposes to the
attack, either by favoring the dissemination of the lead compounds or
by facilitating their absorption by various channels, especially by
the skin, which is more freely exposed in summer, and at the same time
more or less bathed in sweat in which the dust of lead salts may be
dissolved.
{680} Climate.—In the absence of definite statistics upon the subject,
it appears probable that the dangers of chronic lead-poisoning would
be greater in warm than in cold climates. The clinical features of the
affection are alike in all parts of the globe.
Age.—The majority of individuals attacked are adults. Nevertheless,
children employed in occupations involving exposure to lead are
attacked with great frequency—so much so that it may be concluded that
their liability is in fact greater than that of adults.
Sex exerts a decided influence, women being, under nearly similar
circumstances, less frequently attacked than the men employed in the
same factories—a fact to be explained only by their greater
willingness to exercise the recognized precautions.
Diet does not constitute a predisposing influence. It is nevertheless
probable that a deficient diet favors the development of the
affection. Excesses in food, and especially excesses in drink,
predispose to lead colic.
The mode of life is important. Those who lead sober, regular, and,
above all, cleanly lives are less liable to the affection than the
intemperate, irregular, and careless. Particularly are the dangers in
factories increased by neglect of ventilation. Persons suffering from
affections of the digestive tract are not, among lead-workers, more
prone to lead colic than their comrades who are free from such
diseases.
_B_. The Exciting Cause.—Metallic lead is probably inert, but, owing
to the ease and rapidity with which it oxidizes and forms salts, lead
in any form, if introduced into the body continuously for a length of
time, produces characteristic toxic effects. The oxides, acetates, and
carbonate of lead, being soluble in the gastric juice, act more
surely.[3] But the sulphate, the least soluble of the lead compounds,
may also have this effect (Gasserow).
[Footnote 3: Naunyn, _Ziemssen's Encyclopædia_, vol. xvii.]
The channels by which lead is introduced into the body are the
alimentary canal, the respiratory tract, and the cutaneous surface.
Hence the modes of introduction are of almost endless variety. The
conveyance of lead into the stomach constitutes the most common as
well as the most important means of access to the organism. This may
be in the form of medicine, as the acetate, the unduly prolonged use
of which, even in moderate doses, sometimes produces chronic
poisoning. Articles of diet are not infrequently contaminated by lead
derived from different sources, of which the most common is the lead
glaze of earthenware vessels, which is soluble in acid fluids.
According to Naunyn, beer drawn through lead pipes may cause chronic
lead-poisoning, which has also been frequently ascribed to the use of
shot in cleaning bottles used for wine and malt liquors.
Drinking-water is occasionally contaminated with lead derived from
pipes made of this metal and cisterns painted with lead colors. Pure
water, freed from gases, does not act upon lead when the air is
excluded. In the presence of air, however, an oxide of lead is formed
which is partially soluble in water. If nitrates, nitrites, and
chlorides, such as constitute ingredients of sewage, are also present,
they form soluble compounds with lead and increase the proportion of
lead salts soluble in the water. For this reason water contaminated by
sewage is rendered decidedly more dangerous if carried in leaden
pipes. On the {681} other hand, the purer the water the greater the
danger. Hence rain-water and pure spring-water cannot safely be stored
in cisterns painted with lead colors nor conveyed in leaden pipes, nor
can lead covers be used for cisterns, because of the condensation of
the vapor of water, which drops back, holding lead salts in solution.
The sulphates, phosphates, and carbonates usually found in
river-waters form insoluble lead compounds, which, being deposited
upon the interior of the pipes, act as protectives and prevent further
chemical changes.
Still more common is the accidental conveyance of lead dust and lead
compounds to the mouth in consequence of their adhering to the hands
or settling from the atmosphere upon articles of food and drink, in
the case of workmen engaged in the various arts in which lead is
freely used. As a rule, to which the exceptions are rare, the more
severe cases of chronic lead-poisoning occur only among workers in
lead, as miners, those employed in white-lead factories, painters,
typesetters, plumbers, and lapidaries.
Potters engaged in the glazing of common pottery and tiles, workmen in
file-factories, workers on colored papers and in enamels, especially
in glass enamels, brushmakers for the reason that the bristles are
sometimes colored by lead preparations, and those engaged in sewing
coarse goods because the thread is sometimes treated with a
preparation of lead in order to add to its weight, are likewise liable
to chronic lead-poisoning. The introduction of lead into the body
through the respiratory tract is a subject of the greatest importance
in the trades. Inadequate ventilation of working-rooms, living or
sleeping in apartments connected with or contiguous to factories in
which lead is largely used, and particularly in lead-factories, is
attended with serious dangers, as is also the habit of eating food in
such apartments or drinking water that has been standing in them. The
possibility of lead-poisoning by way of the respiratory tract has been
questioned. In view of existing knowledge as to the readiness with
which carbon in minute states of subdivision finds its way into the
connective lymph-channels of the lung, there can be no doubt that the
habitual respiration of an atmosphere loaded with the dust of lead or
its preparations in a minute state of subdivision may give rise to
chronic lead-poisoning. At the same time, the experiments of Hassel[4]
render it probable that less absorption takes place directly by means
of the pulmonary mucous membrane than by way of the mucous membrane of
the mouth and throat. It must be borne in mind that none of the
preparations of lead are volatile. This affection is also occasionally
observed in clowns and others upon the stage or elsewhere, who
habitually use cosmetics containing lead. The use of cheap tinfoil,
into the composition of which lead enters largely, as a wrapper for
tobacco and snuff is said to occasionally produce chronic
lead-poisoning. It is stated by Naunyn that mattresses filled with
horse-hair died black by lead compounds have occasioned this
affection. The same authority states that a proof-reader was poisoned
by reading printed proof for many years. Chronic lead-poisoning is
pre-eminently a disease of the industrial arts. The means of obviating
or diminishing the dangers of those exposed by their occupation to the
preparations of lead will be considered under the head of Prophylaxis.
{682} The quantity of lead absorbed is of less importance than is its
continuous introduction. As stated in the definition, the phenomena of
chronic lead-poisoning are those brought about by the gradual
accumulation of lead in the system, the amount absorbed into the blood
in any given cases being comparatively small, even where large
quantities are ingested. Hence prolonged exposure to small amounts of
lead is attended with greater danger than a comparatively brief
exposure to larger quantities. It is stated that the members of the
household of Louis Philippe at Claremont manifested the symptoms of
chronic lead-poisoning after the lapse of seven months in consequence
of drinking water which contained a mere trace of lead. On the other
hand, several grains of acetate of lead may often be administered
medicinally to patients for a week at a time without inducing the
phenomena of this affection, although, in view of the idiosyncrasy of
many individuals, the exhibition of lead preparations for prolonged
periods is not advisable.
[Footnote 4: _The Inhalation Treatment of the Diseases of the Organs
of Respiration, including Consumption_, London, 1885.]
According to Heubel,[5] the blood and internal organs contain but very
small amounts of lead—.02 per cent. in the maximum. It is probable,
therefore, that the more insoluble of the lead compounds may yield a
sufficient amount of absorbable lead to produce the characteristic
constitutional effects.
[Footnote 5: _Pathogenese und Symptome der Chronic Bleivergiftung_,
Berlin, 1871.]
So long as the urine remains free from albumen, it serves for the
elimination of a mere trace of lead. In albuminous urine the amount is
larger. Lead is found in the bile and feces in small quantities.
SYMPTOMATOLOGY.—The general description of chronic lead-poisoning must
include a great number of symptoms that do not always occur in regular
order or sequence. According to the prominence of certain of these
symptoms in particular cases the specific effects of lead may be
grouped under the following five heads: (1) disturbances of nutrition;
(2) the colic; (3) the arthralgia; (4) the paralysis; and (5) lead
encephalopathy.
1. Disturbances of Nutrition—After the long-continued introduction of
lead into the system the signs of impaired nutrition manifest
themselves in almost all cases. The appearance of the patient is
changed; he becomes thin, anæmic, and of a somewhat peculiar yellowish
complexion. This hue of the skin, to which the term icterus saturninus
has been applied, is not due to the deposition of bile-pigments. The
wasting of the tissues of the body seems to implicate the muscular to
a much greater extent than the adipose tissues. In the majority of
cases a dark or bluish-black line is observed at the border of the
gums. This line is more strongly marked in the upper than in the lower
jaw. It is, as a rule, more plainly developed in persons of careless
habits, whose teeth are the seat of deposits of tartar, but the teeth
in such individuals are often discolored and appear to be elongated in
consequence of the retraction of the edge of the gums. This bluish or
violet-black gingival line is due to the deposit of particles of
sulphide of lead in the substance of the gum, in consequence of the
reaction between the sulphuretted hydrogen formed by the decomposition
of particles of food and the lead particles present in the mouth.
According to Tanquerel, this color may extend over the greater part of
the gum or even to the mucous membrane of other portions of the mouth.
If due care be exercised, there is little danger {683} of confounding
the lead-line with the livid border of the gums frequently seen in
people whose teeth are in bad condition. The occasional absence of
this line in otherwise well-characterized cases of chronic
lead-poisoning is to be noted. It does not occur when the teeth have
been lost, and is slight if they are kept clean.
Patients complain of habitual dryness of the mouth and of an insipid,
mildly astringent, sweetish, or faintly metallic taste; the tongue is
coated, the breath fetid. There are nausea and occasional vomiting.
Constipation is common. The patient is now liable to attacks of lead
colic, joint trouble, and the specific palsy, or to cerebral
disturbances of grave character. Of these affections, colic is the
most frequent; the joint affection is next in order; the paralysis far
less common, and the cerebral disturbances comparatively rare.
Continued exposure results after a time in an intensification of the
malnutrition, either with repeated attacks of colic or the other
specific disturbances, or occasionally in their absence, although at
length the positive lead dyscrasia is established, characterized by
obstinate dyspepsia, constipation, and intensification of the curious
earthy or yellowish color of the skin, which is succeeded by the
pallor of profound anæmia. Loss of muscular power with transient œdema
now shows itself. The patient becomes apathetic, irritable, and
morose. As the condition of cachexia deepens muscular tremor
occasionally shows itself. After a prolonged period of profound
ill-health the patient succumbs to some complication, among the more
frequent of which are tuberculosis, pneumonia, and chronic
interstitial nephritis. Gout is a very common complication of chronic
lead-poisoning.