It's a metallic element that is widely dispersed in the environment. It was used in house paint until 1978, when it was banned. It was also widely used in gasoline, but has since been removed. Near major traffic corridors, soils may be contaminated from the long-term use of leaded gas.
Water is a potential source of lead.
This is usually from lead in solder, fixtures and piping in the home. Small amounts of lead dust, consumed regularly, can cause delayed development, reading and learning problems, lowered IQ, hyperactivity and discipline problems. Larger does can cause high blood pressure, anemia, and kidney and reproductive disorders in both kids and adults. Lead accumulates in the body and its effects are irreversible. If you live in an older home, your children may be at risk.