Earth crust | Naturally enriched areas (e.g., black shale areas) | Ingestion and dermal contact |
Dietary sources | Contaminated food, lead accumulated in plants (e.g., urban agriculture), game hunting meat | Ingestion |
Medicinal sources | Some traditional medicines | Ingestion |
Cosmetics | Lipstick, Nail polish | Intradermal (organic forms only) |
Industrial sources | Lead-based paints, mining and smelting, lead acid battery production, solder and glassware production, recycling activities | Ingestion/Inhalation |
Recreational activities | Use of indoor firearms, recreational shooting activities and/or fishing activities | Inhalation, dermal contact, ingestion |
Air | Combustion of lead-based gasoline, tobacco smoke, leaded aviation fuel | Inhalation |
Drinking water | Lead pipes | Ingestion |
Soil | Contaminated soil | Ingestion (mainly in children) |
Metallic taste | Myalgia | Arthralgia (especially nocturnal) | Lead palsy (wrist or foot drop) |
Abdominal pain | Paraesthesia | Muscular exhaustibility | A bluish black lead line on gums (Barton's line) |
Constipation or diarrhoea | Fatigue | Tremor | Lead colic (intermittent severe abdominal cramps) |
Vomiting | Irritability | Headache | Lead encephalopathy |
Hyperactivity or lethargy | Abdominal discomfort | Diffuse abdominal pain | |
Ataxia | Anorexia, metallic taste, vomiting | ||
Behavioural changes | Constipation | ||
Convulsions and coma | Weight loss | ||
Hypertension |
Earth crust | Rocks (e.g., volcanic eruptions), naturally enriched areas (e.g., serpentine areas) | Ingestion/ Inhalation |
Dietary sources | Seafood, contaminated water, accumulation in food crops, fruits and grains | Ingestion |
Medicinal sources | Arsenic trioxide treatment for acute promyelocytic leukemia Arsenic-based drugs in veterinary medicine | Ingestion |
Cosmetics | Skin lightening products and fairness creams | Intradermal |
Industrial sources | Pesticide production, wood preservatives, microelectronics production, microwave devices, and lasers | Ingestion/inhalation |
Air | Use of pesticides and agrochemicals, industrial sources | Inhalation |