Causes

Lead is a metal that occurs naturally in the earth's crust, but human activity — mining, burning fossil fuels and manufacturing — has caused it to become more widespread. Lead was also once used in paint and gasoline and is still used in batteries, solder, pipes, pottery, roofing materials and some cosmetics.

Lead in paint

Lead-based paints for homes, children's toys and household furniture have been banned in the United States since 1978. But lead-based paint is still on walls and woodwork in many older homes and apartments. Most lead poisoning in children results from eating chips of deteriorating lead-based paint.

Water pipes and imported canned goods

Lead pipes, brass plumbing fixtures and copper pipes soldered with lead can release lead particles into tap water. Lead solder in food cans, banned in the United States, is still used in some countries.

Other sources of lead exposure

Lead sometimes can also be found in:

• Soil. Lead particles from leaded gasoline or paint settle on soil and can last years. Lead-contaminated soil is still a major problem around highways and in some urban settings. Some soil close to walls of older houses contains lead.
• Household dust. Household dust can contain lead from lead paint chips or from contaminated soil brought in from outside.
• Pottery. Glazes found on some ceramics, china and porcelain can contain lead that can leach into food served or stored in the pottery.
• Toys. Lead is sometimes found in toys and other products produced abroad.
• Cosmetics. Tiro, an eye cosmetic from Nigeria, has been linked to lead poisoning.
• Herbal or folk remedies. Lead poisoning has been linked to greta and azarcon, traditional Hispanic medicines, as well as some from India, China and other countries.
• Mexican candy. Tamarind, an ingredient used in some candies made in Mexico, might contain lead.
• Lead bullets. Time spent at firing ranges can lead to exposure.
• Occupations. People are exposed to lead and can bring it home on their clothes when they work in auto repair, mining, pipe fitting, battery manufacturing, painting, construction and certain other fields.