Chronic Lead Poisoning.—The sources of poisoning by lead are very numerous. Occupations in which lead is employed, however, predominate as causative fac tors, and painters, white-lead-paint mix ers or grinders, wall and other paper-mill operators, glaziers, etc., are the victims in the great majority of cases.
Adulterated foods and liquids repre sent the main sources of poisoning among those whose occupations do not involve exposure. Cooking utensils painted white inside, bread made of flour contaminated with a lead-filled grindstone, cake colored with lead bi chromate to avoid the use of eggs, im perfectly burnt pottery, fruit-jars glazed with lead, etc., are as many media through which lead can reach the sys tem. A fruitful cause of poisoning is pure water when conveyed through lead pipes, the lead being slowly dissolved. When, however, the water contains even a minute quantity of lime-salts, an in soluble coating is formed which arrests all further action as soon as the inside of the pipes is completely covered. Cos metics, hair-dyes, and face-powders occa sionally cause plumbism.
Constitutional Effects.— Slow absorp tion of lead, whether due to industrial, accidental, or criminal causes, mainly af fects the muscles, the peripheral nerves, the liver, and the kidneys. Pallor of muscles and mucous membranes is an early result, fibrosis occurring in ad vanced cases, accompanied by degenera tive changes in the nerve-endings. These changes become less marked as the spinal centres are approached, the spinal cord being usually normal. The brain, how ever, is not so exenipt from morbid changes. All the manifestations of urnine toxfumia are pathologically based upon the changes here outlined.
A blue line along the margin of the gums, at the base of the teeth, is an im portant sign. It is especially marked in persons who are not cleanly as regards their mouth.
Lead This symptom is most frequently met with in painters who mix and use white lead. The abdominal cramp is usually- very severe, the muscles being rigid and contracted. A peculiar ity of the pain is the fact that the tion of its greatest intensity is around the navel. It occurs by exacerbations, the accesses being often accompanied by nausea or vomiting. The tongue is white and contracted and there is thirst — sometimes intense. Constipation is the rule. The face is pale or jaundiced.
After continuing for a period varying from a few hours to several days, the symptoms gradually recede and the ac cess ceases. When no treatment is re
sorted to and the causative occupation is continued, the attacks return frequently, and death may finally occur through cacbexia or anvemia, paralysis of the spiratory muscles, cirrhosis of the liver.
or thromcrh some intercurrent disorder.
Five cases of lead colic treated by in jecting 1 pint of normal salt solution under the skin of the abdomen; in all the eases muscular pain soon disap peared, and, instead of the constipation, a beneficial diarrhoea set in the next day. which ceased of its own account a couple of days later. Del6arde (University Med. 'Mag., &in., '99).
Case in which erythrol-tetranitrate was used with benefit in lead colic. The arterial tension was high, the pulse hard, and the sphygmographic tracing characteristic. The remedy was admin istered in 1/2-grain dose. With the re duction of arterial tension there was a cessation of pain, and the patient slept. This was repeated twice with similar results. Mattirlo (Gaz. degli Osped. e delle (lin., No. 63, 1901).
Atropine used in several cases of colic due to lead intoxication with favorable results. The extract of belladonna in (loses of grain (0.015 g-ramme) was first frequently given, but preference was then given to the alkaloid in doses of V„ to 1/Bo grain (0.001 to 0.003 gramme) given hypodermically. Prompt relief generally follows except in eases in which opium has been previously ad ministered. In such eases even enor mous quantities of atropine remain in effectual, being neutralized by the opium. No untoward effects were ob served. Adolph Weber (Miinchener med. Woehen., xlix, No. 17, 1002).
Lead Encephalopathy.—In some eases marked cerebral symptoms occur. These may develop gradually or quite suddenly, violent headache, vertigo, tinnitus, stra bismus, and other cerebral tions presenting themselves. In the cases developing slowly the symptoms tend to demonstrate paresis of various systems, central and peripheral, the most characteristic of these being wrist-drop, due to paralysis of the extensor muscles of the forearm. Vertigo, loss of memory, disturbances of the special senses, cere bral palsies, hemiplegia, and monoplegia have also been noted. Alteration of the brain-structure, its arteries and menin ges, is usually found post-mortem.