Lead Poisoning 

It is a heavy steel-grey metal. Metallic lead and all its salts are poisonous.

 

FATAL DOSE:

20 gm - lead acetate

40 gm - lead carbonate

FATAL PERIOD: 1-2 days

 

The principal salts which produce toxic effects are:

1. Lead acetate (Sugar of lead): white crystals

2. Lead carbonate: a white crystalline powder

3. Lead chromate: a bright yellow powder.

4. Lead monoxide (litharge); pale brick-red or orange masses.

5. Lead tetra-oxide (Red lead, vermilion - sindur)

6. Lead sulphide

 

Lead is used in storage batteries, solders, paints, hair dyes, electric cable insulations, pottery and ceramics, and petrols.

 

Symptoms of Acute Lead Poisoning:

• An astringent and metallic taste,
• Dry throat, thirst,
• Burning abdominal pain, nausea, vomiting, sometimes diarrhea,
• Peripheral circulatory collapse,
• Headache, insomnia, paraesthesias, depression, coma, and death.

 

TREATMENT of Acute Lead Poisoning: (Ref Reddy)

1) Gastric lavage with 1% solution of sodium or magnesium sulphate.

2) Demulcents

3) The combination of B.A.L. and calcium disodium versenate or DMSA is effective.

4) Penicillamine.

5) Calcium chloride 5 mg. of a 10 percent solution i.v. causes deposition of lead in the skeleton from the blood.

6) Peritoneal or hemodialysis

7) Symptomatic treatment.

 

 

LABORATORY FINDINGS: (NTK)

Porphyrinuria, mainly due to coproporphyrin Ill, is a valuable screening test. In the blood, levels above 0.07 mg percent, and in the urine 0.15 to 0.3 mg. per liter is diagnostic.

 

POSTMORTEM APPEARANCES of Acute lead poisoning:

Signs of acute gastroenteritis are seen.

The mucosa of the stomach may be thickened and softened with eroded patches and may be covered with a grayish-white deposit.

 

 

Chronic Poisoning (Plumbism/Saturnism):

Causes:

1) Inhalation of lead dust and fumes by makers of white lead and makers and users of lead paints (the most common source of exposure for children), smelters, plumbers, glass-polishers, printers, enamel workers, glass blowers, etc.

2) Continuous absorption of minute amounts from drinking water stored in lead cisterns, from tinned food contaminated with lead from the solder, and from constant use of hair dyes and cosmetics containing lead.

3) Absorption through raw or intact skin.

4) Use of ghee stored in brass or copper .vessels lined inside with tin in which oleate of lead is formed and also by taking food cooked in the tinned vessel.

5) Absorption of vermilion applied to the scalp.

6) Children can be chronically poisoned through chewing or licking toys, walls, furniture, etc. painted with lead-based compounds.

 

Chronic poisoning results from a daily intake of 1-2 mg of lead. Lead vapor is more dangerous than dust.

 

 

Signs and Symptoms of Chronic Lead Poisoning: (Ref Reddy)

1) Facial Pallor: One of the earliest and most consistent sign. It seems to be due to vasospasm.

2) Anaemia:

NiceToKnow - The anemia is probably due to decreased survival time of red blood cells and inhibition of heme synthesis by interference with the incorporation of iron into protoporphyrin.

Anemia which is associated with punctate basophilia, nucleated red cells (sideroblasts), and a decrease in platelets.

Punctate basophilia or basophilic stippling means the presence of many dark blue-colored pinhead-sized spots in the cytoplasm of red blood cells, due to the toxic action of lead on porphyrin metabolism.

3) Lead Line/Burtonian line: (Blue line appeared at the junction between gum & teeth)

A stippled blue line, called the Burtonian line, is seen on the gums in 50 to 70% of cases. It appears due to sub-epithelial deposit of granules at the junction with teeth, only near dirty or carious teeth, within a week of exposure, especially on the upper jaw.
It is due to the formation of lead sulphide by the action of hydrogen sulphide formed by decomposed food in the mouth.

A similar blue line may be seen in cases of poisoning by mercury, copper, bismuth, iron, and silver.

 

4) Colicky pain and Constipation:

Colic pain of the intestines, ureters, uterus, and blood vessels occurs in 85% of cases.

 

5) Lead Palsy:

There may be tremors, numbness, hyperesthesia, and cramps before the actual muscle weakness.

Usually, the extensor muscles of the wrist (wrist drop; radial nerve is affected) are affected, but the deltoid, biceps, anterior tibial (foot drop), and rarely muscles of the eye or intrinsic muscles of hand or foot are affected.

6) Encephalopathy: Lead encephalopathy is said to be present in almost every case of plumbism.

The symptoms are vomiting, headache, insomnia, visual disturbances, irritability, restlessness, delirium, hallucinations, convulsions, coma, and death. Lead encephalopathy is usually irreversible and about 85% have permanent brain damage. Death occurs in about 25% of cases.

7) Cardiovascular System and Kidneys:
Lead causes vascular constriction, leading to hypertension and permanent arteriolar degeneration. Chronic arteriosclerotic nephritis and interstitial nephritis occur.

8) Reproductive System:
Menstrual derangements, such as amenorrhoea, dysmenorrhoea, menorrhagia, sterility of both sexes, and abortion are frequent. Abortion occurs in pregnant women between 3 to 6 months.

9) Other Systems:
They are dyspepsia, anorexia, emaciation, general weakness, exhaustion, irritability, foul breath, headache, vertigo, loss of hair, and drowsiness.

 

Retinal stippling is noticed by ophthalmoscopic examination showing the presence of greyish glistening lead particles in the early phase of poisoning.

 

Diagnosis: (NTK)

1) History

2) Clinical features

3) X-ray evidence of increased radio-opaque bonds or lines at the metaphyses of long bones and along margins of the iliac crest is seen in children.

4) Erythrocyte protoporphyrin (EP) commonly assayed as zinc protoporphyrin (ZPP) is usually below 35 micro/I, is not sufficiently sensitive at lower blood lead levels.

5) Basophilic stippling.

6) X-ray may show radio-opaque material in the G.l. tract if a lead is ingested during the preceding 36 to 48 hours.

 

 

Treatment of Chronic Lead Poisoning (Ref Nandy)

1. Curative

1. Removal of the patient from the source of poison

2. Chelating agent: Disodium calcium edetate is the best chelating agent for Lead

3. Potassium or sodium iodine 1-2gm, thrice daily to eliminate circulatory lead through urine.

4. To prevent constipation, magnesium sulphate purgative is used.

5. For severe colic, atropine sulphate and or hot compression on the abdomen is useful.

6. Symptomatic Treatment

 

2. Prophylaxis

To prevent chronic lead poisoning in factory workers, the following measures should be taken.

1) Maintenance of proper ventilation in factories.

2) Maintenance of personal hygiene of the workers and periodical medical examination.

3) A diet rich in calcium.

4) Small amounts of sulphuric acid in water.

5) Weekly saline purgative.

 

 

Postmortem Appearances just of Chronic lead poisoning:

1. A blue line may be seen on the gums.
2. Paralysed muscles show fatty degeneration.
3. The stomach and intestines may show ulcerative or hemorrhagic changes and are contracted and thickened.
4. The liver and kidneys are contracted.
5. The brain is very pale and greatly swollen.
6. Bone marrow shows hyperplasia of leucoblasts and erythroblasts with a decrease in fat cells.

 

Cause of Death in Lead Poisoning:

In acute poisoning, death is due to gastroenteritis and subsequent shock.

In chronic cases, all below be the direct causes.

• Malnutrition,
• Intercurrent infection,
• Failure of liver function,
• Respiratory failure,
• Renal failure and
• Encephalopathy

 

Complication of lead poisoning (SUST-18N) (Ref Endeavour)

• Gastroenteritis
• Malnutrition
• Intercurrent infection
• Hepatic failure
• Respiratory failure
• Renal failure
• Encephalopathy
• Lead palsy (Wrist drop)

 

Medicolegal importance of lead Poisoning

• Acute poisoning is very rare. Chronic poisoning is more common and is regarded as an industrial disease.
• Homicidal poisoning is rare.
• Accidental chronic poisoning occurs in workers with the metal.
• It is not used for suicide.
• DiachyIon paste (lead oleate), or red lead is used locally for abortion.
• Red lead is sometimes used alone or mixed with arsenic as a cattle poison.
• Lead missiles remaining embedded in the tissues due to gunshot injuries may produce poisonous symptoms in 12 to 48 days

 

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Copper Poisoning

Copper as a metal is not poisonous. Copper compounds are powerful inhibitors of enzymes.

 

Poisonous Compounds:

(1) Copper sulphate (blue vitriol) occurs in large, blue crystals.

(2) Copper subacetate occurs in bluish-green masses or powder.

 

Fatal Dose: Copper sulphate - 30 gm Copper subacetate - 15 gm

Fatal Period: 1-3 days

 

Use of copper

• Anti-fungal
• Fruits ripping (Banana)
• Emetics
• Book binding
• Industrial use

 

Signs and Symptoms of Copper Poisoning: (Ref Reddy)

There is a metallic taste, increased salivation, burning pain in the stomach with colicky abdominal pain, thirst, nausea, eructations, and repeated vomiting.

The vomited matter is blue or green.

There is diarrhea with much straining; motions are liquid and brown but not bloody.

Oliguria, haematuria, albuminuria, acidosis, and uremia may occur.

 

In severe cases, hemolysis, hemoglobinuria, methemoglobinemia, jaundice, pancreatitis, and cramps of the legs or spasms and convulsions occur.

The breathing is difficult, and cold perspiration and severe headache occur.

In some cases, paralysis of limbs is followed by drowsiness, insensibility, coma, and death due to shock.

Later deaths occur due to hepatic or renal failure or both.

 

Treatment of Copper Poisoning: (Ref Reddy)

(1) Stomach wash with 1% solution of potassium ferrocyanide, which acts as an antidote by forming an insoluble cupric ferrocyanide.

(2) Emetics are contraindicated.

(3) Demulcent drinks form insoluble albuminate of copper.

(4) Hemodialysis is useful in the early stage of poisoning.

(5) Castor oil is given to remove poison from the intestines.

(6) Chelation with penicillamine or EDTA or BAL.

 

 

Postmortem Appearances of copper poisoning: (Ref Reddy)

The skin may be yellow.

Greenish-blue froth may be present at the mouth and nostrils.

The gastric mucosa and stomach contents are greenish or bluish.

The gastric mucosa may be congested, swollen, inflamed, and occasionally eroded.

The liver may be soft and fatty.

Spontaneous hemolysis of blood and degenerative changes in proximal tubules of the kidney may occur.

 

 

CHRONIC POISONING of Copper:

It may occur in workers with the metal due to inhalation of dust or from food being contaminated with verdigris.

Chronic inhalation of copper sulphate spray can cause vineyard sprayer's lung disease characterized by a histiocytic granulomatous lung.

Chronic poisoning causes Wilson's disease.

 

The symptoms consist of gradual anemia, green line on gums, nausea, vomiting, colic, diarrhea, malaise, peripheral neuritis, degeneration, and atrophy of muscle may occur.

The presence of copper deposits in the tissues is called CHALCOSIS.

 

Medicolegal Importance of Copper Poisoning: 

1) It is rarely used for homicide because of the color and taste.

(2) Suicide cases are rare.

(3) Accidental poisoning results from eating food contaminated with verdigris which is formed from the action of vegetable acids on copper cooking vessels that are not properly tinned on the inside. Ingestion of food to which copper has been added to keep the green color of the vegetable may cause poisoning. Children sometimes swallow copper sulphate attracted by its color.

(4) Sometimes, the salts are taken internally for abortion.

(5) Rarely it is used as a cattle poison.