Lead poisoning ( (Plumbism/ Saturnism) is a chronic multisystem toxicological disorder caused by accumulation of lead in body tissues. Lead is a non-essential heavy metal widely distributed in the environment and has no physiological role in human metabolism.

Toxicity is particularly dangerous because:

• It accumulates slowly

• Symptoms appear late

• Damage is often irreversible — especially neurological injury in children

Lead primarily affects:

• Nervous system (most sensitive)

• Bone marrow

• Kidneys

• Gastrointestinal tract

• Cardiovascular system

• Reproductive system

Children are far more vulnerable because of:

• Increased gastrointestinal absorption (up to 50%)

• Immature blood-brain barrier

• Rapid brain development

2. Sources of Exposure

Environmental

• Lead-based paint (most common worldwide cause)

• Contaminated soil and dust

• Lead plumbing pipes

• Industrial emissions

• Batteries and recycling sites

Household

• Cosmetics (traditional eye cosmetics)

• Ceramic cookware glazing

• Contaminated drinking water

• Toys and jewelry

Occupational

• Battery manufacturing

• Mining and smelting

• Welding

• Painting

• Printing

• Construction work

Food-related

• Contaminated spices

• Stored food in lead containers

3. Toxicokinetics

Absorption

Distribution

Lead binds to:

• Red blood cells (95%)

• Bone (long-term storage: half-life decades)

• Brain

• Kidney

• Liver

Bone acts as a reservoir, releasing lead during:

• Pregnancy

• Lactation

• Osteoporosis

• Severe illness

Mechanism of Toxicity

Lead interferes with:

1. Heme synthesis → anemia

2. Neurotransmitter release → cognitive impairment

3. Calcium signaling → neuronal death

4. Renal tubular transport → Fanconi syndrome

4. Risk Factors

Children

• Pica behavior

• Old painted houses

• Malnutrition

• Iron deficiency

Adults

• Occupational exposure

• Battery recycling

• Alcohol use

• Poor ventilation

Pregnancy

• Mobilization of maternal bone lead

• Fetal neurotoxicity

5. Clinical Manifestations

Symptoms depend on:

• Age

• Dose

• Duration

A. Newborns (Prenatal Exposure)

• Prematurity

• Low birth weight

• Slowed growth

• Developmental delay

B. Children (Most Severe Effects)

Neurological

• Developmental delay

• Learning difficulties

• Lower IQ

• ADHD-like behavior

• Irritability

• Anxiety

• Depression

• Hearing loss

• Seizures

• Encephalopathy (late)

Gastrointestinal

• Abdominal pain (lead colic)

• Constipation

• Vomiting

• Anorexia

• Weight loss

Behavioral

• Sluggishness

• Fatigue

• Poor school performance

• Pica (eating paint chips, soil)

C. Adults

Neurological

• Memory impairment

• Headache

• Peripheral neuropathy

• Wrist drop (radial nerve palsy)

Hematological

• Microcytic anemia

Renal

• Fanconi syndrome

• Chronic kidney disease

Reproductive

• Reduced sperm count

• Miscarriage

• Stillbirth

• Premature birth

Cardiovascular

• Hypertension

6. Diagnostic Criteria

Clinical suspicion based on:

• Neurobehavioral problems in child

• Abdominal colic + anemia

• Occupational exposure history

• Peripheral neuropathy (wrist drop)

7. Investigations

Laboratory Tests

Blood Lead Level (BLL)

Primary diagnostic test

Additional Tests

• Free erythrocyte protoporphyrin (FEP) ↑

• FBC → microcytic anemia

• Basophilic stippling (blood smear)

• Renal function tests

• Liver function tests

Imaging

• Long bone X-ray → metaphyseal lead lines (children)

• Abdominal X-ray → ingested lead fragments

• Brain CT (encephalopathy)

8. Management

Treatment depends on blood lead level AND symptoms

8.1 Non-Pharmacological Treatment

1. Remove exposure source immediately

2. Environmental decontamination

3. Adequate hydration

4. Monitor neurological status

5. Monitor renal and liver function

6. Nutritional correction

   • Iron

   • Calcium

   • Zinc

8.2 Chelation Therapy

Chelation binds lead → urinary excretion

Blood Lead 25–40 µg/dL

D-Penicillamine

• 30–40 mg/kg/day PO

• 1–6 months

• Give away from meals

Blood Lead 45–70 µg/dL

Succimer (DMSA)

• 10 mg/kg every 8 hrs × 5 days

• Then every 12 hrs × 14 days

Blood Lead ≥70 µg/dL OR

Encephalopathy (Emergency)

Dimercaprol + EDTA

Dimercaprol:

• 3 mg/kg IM every 4 hrs × 48 hrs

• Then every 12 hrs × 10 days

PLUS

Calcium disodium EDTA:

• 10 mg/kg IV every 8 hrs × 5 days

9. Complications

• Permanent intellectual disability

• Epilepsy

• Chronic kidney disease

• Infertility

• Hypertension

• Behavioral disorders

• Death (encephalopathy)

10. Special Populations

Children

Most vulnerable — even low levels reduce IQ permanently

Pregnancy

Maternal bone lead → fetal brain injury

Chronic exposure

Produces subtle neuropsychiatric disease

11. Prognosis

12. Prevention

Do’s

• Store chemicals safely

• Child-resistant containers

• Maintain original packaging

• Read labels carefully

Don’ts

• Transfer chemicals

• Leave containers open

• Remove labels

• Store medicine loosely

• Call medicine sweets

• Take medicine in front of children

Public Health Prevention

• Remove lead paint

• Safe water supply

• Occupational protection

• Screening of high-risk children