Yesterday on The PediaBlog, we discussed where lead comes from and how it gets into the air, water, and soil, and thus, into us. All of us alive today should be grateful that powerful people in high places understood the risks of lead exposure to public health (especially the health of children) and worked to remove it from many common products including gasoline, paint, and cosmetics.

Lead can be acutely toxic to the body if ingested in large amounts, but that doesn’t happen very often. Instead, it is better to think of lead as a cumulative toxic: small amounts are ingested and accumulate in the body over time. We should pause here and state one vital fact: There is no safe level of exposure to lead.

Lead acts very much like calcium in the bloodstream, so it tends to build up in bone. Children’s growing bones are metabolically active to the extreme, so lead doesn’t stay there for long. Instead, it travels to other metabolically active and growing organs, particularly the brain. It is here that lead, a natural heavy metal, can do the most unnatural damage.

The injuries caused by lead in a developing child’s brain may be profound, or they may be subtle, but they are always permanent. We know that brain damage from lead causes lower IQ’s and other cognitive delays, learning disabilities, hearing impairments, difficulties with attention and concentration (ADHD), decreased academic achievement, and anti-social and other behavioral problems. All these effects have life-long consequences for children when they become adults, and for the rest of society.

Children experience other health effects when they are poisoned with lead. Kidney damage and anemia, short stature and pubertal delays, peripheral nerve damage and muscle weakness all can result in chronic and often painful, lifelong sickness and disability, and early death.

Adults can also get lead poisoning, often through occupational exposure. Muscle and joint pain, abdominal pain and digestion problems, memory and concentration problems, high blood pressure, headaches, dizziness, dementia, kidney disease and decreased fertility are just a few of the symptoms adults experience. Complications of pregnancy due to lead exposure include miscarriage, premature birth, and low birth weight. Lead crosses the placenta from the mother’s bloodstream, resulting in babies being born “pre-polluted.”

If lead is so ubiquitous in nature and presents as a potential and dangerous toxic exposure most everywhere we live, work, and play, how much lead is permissible in one’s body? We already answered that: ZERO. Even very small amounts of lead detected in a child’s bloodstream can cause permanent intellectual damage. Until recently, children with a blood lead level of 10 or more micrograms per deciliter had “a level of concern,” according to the CDC:

Experts now use a reference level of 5 micrograms per deciliter to identify children with blood lead levels that are much higher than most children’s levels.


Far too many children are still exposed to far too much lead in their environment. In one unfortunate American city, bureaucrats — adult decision-makers who should have known better — made a horrible policy decision that poisoned tens of thousands of people with lead, including thousands of children who will be permanently injured. This story involves politicians and scientists, villains and heroes (one of whom happens to be a pediatrician), and everyday people like you and me. We’ll take a look at what is going on in Flint, Michigan, tomorrow on The PediaBlog.