Currently, key sources include emissions from iron and steel production, smelting operations, and lead-acid battery manufacturers. Cigarette smoke is also a source of lead. Most of the lead in water is from lead plumbing and solder in houses and other buildings, lead-contaminated dust and soil carried into water by rain and wind, and wastewater from industries that use lead. Lead in soil often comes from lead-contaminated wastes in landfills and from fertilizers. Because plants can absorb lead from contaminated soil, food may contain lead as a result.
Lead exposure stems primarily from contact with contaminated dust or water.
Lead has been found at over 800 Superfund sites. Lead can enter the body if you breathe air contaminated with lead particles. Nearly all lead entering the lungs moves to the blood and then to other parts of the body. In adults, very little of the lead they ingest enters the blood. In children who swallow food or soil containing lead, however, much more of the lead enters their blood and moves to other parts of their bodies.