Most children with lead poisoning get sick from ingesting paint dust that lingers in homes built before 1978 -- the year that lead was banned from household paint. The American Academy of Pediatrics (AAP) estimates that one out of four homes with young children still has lead. Blaine Baker, of St. Louis, was diagnosed by a routine blood test at his 1-year checkup. His parents had recently renovated their 100-year-old home and, in the course of sanding and scraping away old paint from the original windows and doors, had unwittingly released minuscule lead-paint particles into the air. Every time they opened a window, the friction caused more lead dust to fall, and whenever Blaine crawled or played nearby, his hands and toys became coated with the nearly invisible poison.
Lead can invade a young child's body surprisingly quickly. Once ingested, it seeps into the bloodstream, damages the central nervous system, and disrupts brain circuits that are critical for learning. "Kids exposed to lead tend to have lower intelligence, learning disabilities, hearing problems, and behavioral issues like aggression," says Marcel Casavant, MD, chief of pharmacology and toxicology at Columbus Children's Hospital, in Ohio. Lead can also harm the heart, liver, and kidneys. "A child with lead poisoning might have headaches or stomach pains, or become easily tired," says Dr. Casavant. Since the symptoms of exposure aren't obvious, parents and doctors often assume they're caused by something else. Even more commonly, though, a child won't have any symptoms at all.
Babies and toddlers are the most vulnerable because their brains are still developing and they absorb up to 50 percent of ingested lead (adults absorb only about 10 percent). Of course, they also spend lots of time crawling on the floor and putting their hands in their mouth, and because lead tastes sweet, leaded items can be irresistible.
Even unborn babies are at risk. A pregnant woman who has lead in her system is at increased risk of miscarriage, stillbirth, and preterm labor. But unless the exposure was recent, blood tests won't detect the toxin because lead eventually leaves the bloodstream and settles in bones. "If a woman with prior lead exposure doesn't get enough calcium in her diet, her body will pull the mineral from her bones to help her baby grow -- but lead comes with the calcium," says Michael Shannon, MD, chair of the AAP Committee on Environmental Health. Ask your obstetrician to give you the Centers for Disease Control and Prevention (CDC) lead risk-assessment questionnaire; if you're found to be at high risk, eating a diet high in calcium can help protect you and your baby.