Any lead that is not excreted is absorbed into the bones, where it accumulates over a lifetime. According to the EPA, blood testing has shown correlations between low levels of lead and the following symptoms in children: learning disabilities, reduced IQ and attention span, hyperactivity, behavioral problems, poor academic performance, impaired growth and hearing loss.

High levels of lead in the blood can cause severe neurological problems, including coma, convulsions, or even death. The only way to check for lead exposure in children is through a blood test. According to the Centers for Disease Control and Prevention (CDC), children should see a doctor if their blood lead content exceeds 50 parts per billion (or less than a millionth of an ounce in a pint).

Pregnant women may be at even higher risk than children for lead-related complications. Lead exposure can cause serious health and development problems in children, but fetuses are even more sensitive to exposure. Women exposed to lead during pregnancy have an increased risk for miscarriage, and their babies are at risk for severe organ damage and developmental problems.

In adults, lead exposure can cause damage to nearly every organ and system in the body. The central nervous system, kidneys, and reproductive system are particularly affected. In men, lead exposure has also been associated with increased blood pressure.