People may be exposed to lead by eating shellfish, such as mussels, that accumulate it in their flesh. Because it does not break down in the environment, lead released by past use of leaded gasoline or leaded paints and glazes remains in the soil today. Children are easily exposed to lead from these sources because they commonly put things that have contacted lead-contaminated soil into their mouths. They may also eat flaking paint chips that contain lead. Those who smoke may inhale lead found in tobacco, and industrial workers may breathe lead dust.
Lead affects people's health in the same way, whether they drink, eat, or breathe it.
Short-term exposure to large amounts of lead can cause brain or kidney damage. Long-term exposure to small amounts of lead can increase blood pressure, alter the function of red blood cells to cause anemia, damage the brain and kidneys, and harm reproduction. Children are especially sensitive to lead exposure, which can retard their growth and intelligence. Babies whose mothers are exposed to lead during pregnancy have lower birth weights and slower development than other babies. Although laboratory animals that ate lead had more kidney cancers than other animals, human studies have not confirmed that exposure to lead can cause cancer in people.