Lead exposure is a global issue since lead mining and smelting, and battery manufacturing/disposal/recycling, are common in many countries.
Lead enters the body via inhalation, ingestion, or skin absorption.
Almost all inhaled lead is absorbed into the body; for ingestion, the rate is 20–70%, with children absorbing a higher percentage than adults.

Poisoning typically results from ingestion of food or water contaminated with lead, and less commonly after accidental ingestion of contaminated soil, dust, or lead-based paint.
Seawater products can contain lead if affected by nearby industrial waters.
Fruit and vegetables can be contaminated by high levels of lead in the soils they were grown in.
Soil can be contaminated through particulate accumulation from lead in pipes, lead paint, and residual emissions from leaded gasoline.

The use of lead for water pipes is a problem in areas with soft or acidic water.
Hard water forms insoluble layers in the pipes whereas soft and acidic water dissolves the lead pipes.
Dissolved carbon dioxide in the carried water may result in the formation of soluble lead bicarbonate; oxygenated water may similarly dissolve lead as lead(II) hydroxide.
Drinking such water, over time, can cause health problems due to the toxicity of the dissolved lead.
The harder the water the more calcium bicarbonate and sulfate it will contain, and the more the inside of the pipes will be coated with a protective layer of lead carbonate or lead sulfate.

Ingestion of applied lead-based paint is the major source of exposure for children:
a direct source is chewing on old painted window sills.
Alternatively, as the applied dry paint deteriorates, it peels, is pulverized into dust and then enters the body through hand-to-mouth contact or contaminated food, water, or alcohol.
Ingesting certain home remedies may result in exposure to lead or its compounds.

Inhalation is the second major exposure pathway, affecting smokers and especially workers in lead-related occupations.
Cigarette smoke contains, among other toxic substances, radioactive lead-210.

Skin exposure may be significant for people working with organic lead compounds.
The rate of skin absorption is lower for inorganic lead.
Lead exposure is a global issue since lead mining and smelting, and battery manufacturing/disposal/recycling, are common in many countries. Lead enters the body via inhalation, ingestion, or skin absorption. Almost all inhaled lead is absorbed into the body; for ingestion, the rate is 20–70%, with children absorbing a higher percentage than adults.
Poisoning typically results from ingestion of food or water contaminated with lead, and less commonly after accidental ingestion of contaminated soil, dust, or lead-based paint. Seawater products can contain lead if affected by nearby industrial waters. Fruit and vegetables can be contaminated by high levels of lead in the soils they were grown in. Soil can be contaminated through particulate accumulation from lead in pipes, lead paint, and residual emissions from leaded gasoline.
The use of lead for water pipes is a problem in areas with soft or acidic water. Hard water forms insoluble layers in the pipes whereas soft and acidic water dissolves the lead pipes. Dissolved carbon dioxide in the carried water may result in the formation of soluble lead bicarbonate; oxygenated water may similarly dissolve lead as lead(II) hydroxide. Drinking such water, over time, can cause health problems due to the toxicity of the dissolved lead. The harder the water the more calcium bicarbonate and sulfate it will contain, and the more the inside of the pipes will be coated with a protective layer of lead carbonate or lead sulfate.
Ingestion of applied lead-based paint is the major source of exposure for children:
a direct source is chewing on old painted window sills. Alternatively, as the applied dry paint deteriorates, it peels, is pulverized into dust and then enters the body through hand-to-mouth contact or contaminated food, water, or alcohol. Ingesting certain home remedies may result in exposure to lead or its compounds.
Inhalation is the second major exposure pathway, affecting smokers and especially workers in lead-related occupations. Cigarette smoke contains, among other toxic substances, radioactive lead-210.
Skin exposure may be significant for people working with organic lead compounds. The rate of skin absorption is lower for inorganic lead.
Lead