Because the liver and kidneys are especially affected, common physical problems include mild anemia, loss of appetite, constipation, and diarrhea. Visual and motor disturbances affect children's fine and gross motor skills.

According to experts, intellectual problems from lead poisoning range from learning difficulties and reduced scores on IQ tests to serious developmental delays and severe mental retardation. In mild cases, the results are clumsiness, poor handwriting, and various learning difficulties; tremor, paralysis, and seizures result from more serious poisoning.

Effects of Prenatal Exposure

Damage from prenatal exposure to lead does not seem to be reversible. The severity of the symptoms from postnatal exposure and the extent to which they can be reversed depends on how much lead was absorbed and the duration of the exposure. Ingesting large quantities can cause permanent brain damage and can be fatal.

Some experts believe that even a slightly elevated level of lead in the body may produce ADHD-like symptoms ranging from mild to severe. Because brain development is so rapid before birth and during the baby years, the effects of lead on unborn children, infants, toddlers, and preschoolers may be especially great as their livers are less efficient at ridding the body of toxins, causing stronger reactions to very low levels of lead.

Behavior Problems that May Result from Lead Poisoning

Some experts also believe that lead poisoning can cause attention deficits, distractibility, hyperactivity, restlessness, aggression, hostility, violence, anti-social behavior, anxiety, irritability, and lethargy.

Acute cases of lead poisoning do occur, but chronic, low-level exposure to lead is by far the most common. Symptoms usually disappear once lead has been cleared from a child's system. Some experts claim that IQ test scores then increase an average of nine points, although this has not been proven by controlled studies.

The Need for Testing

Every child with ADHD symptoms should be tested for lead poisoning. Some of the inexpensive do-it-yourself lead poisoning test kits may not register the low levels of lead that the government has now determined are harmful.

Your child may be eligible for free testing through your local Child Health and Disability Program (CHDP). To find out, contact your local public health department. Phone the National Lead Information Center at (800) 424-LEAD for information about how to have your home tested.