Looking for new ways to prevent lead poisoning of children, doctors at Kennedy Krieger Institute are beginning the first study in Baltimore of the potential benefits of a vitamin program containing zinc.
Doctors are seeking families to volunteer for the two-year project. Families will receive free vitamins, regular blood tests for their children, cleaning equipment and instructions on how to reduce the levels of toxic lead dust in their homes.
Researchers suspect that regular consumption of a basic vitamin supplement with zinc may prevent children from absorbing the toxin commonly found in paint in older Baltimore homes.
Baltimore ranks among the most hazardous cities in the nation for lead poisoning, with the majority of cases occurring in the rental slums of Park Heights, Sandtown and Middle East.
Lead can cause irreversible brain damage, resulting in profound learning disorders, hyperactivity and violent outbursts that last into adulthood.
More than 7,000 children a year are exposed to lead in the city, and 1,200 are poisoned, usually after coming into contact with dust particles from old lead-based paint in houses built before 1960.
Companies were banned from including the toxin in gasoline and new paint by federal law in the 1970s.
Lead levels in children's blood have declined sharply since then. But about 1 million children nationwide continue to be exposed every year, mostly from disintegrating paint in run-down houses in older U.S. cities - and especially in summer.
Fully half of Baltimore's most serious poisoning cases occur during the three warmest months of the year when families open windows for fresh air, according to the Maryland Department of the Environment.
Windows are notorious as the most hazardous component in older homes because they generate lead dust as they are opened and closed. Environmental testing firms routinely find lead dust in window wells hundreds of times higher than federal and state laws allow.
Preliminary research in Canada, India and Spain in recent years suggests that regular supplements of zinc may reduce the amount of lead children absorb in the digestive tract - the most common avenue of poisoning.
"Children have a really efficient gastrointestinal tract," says Dr. Cecilia T. Davoli, director of the Kennedy Krieger Lead Poisoning Prevention Clinic. "They absorb anything they put into their stomachs about five times as efficiently as adults.
"We know that's the most common route for lead into the bloodstream, and ultimately into the brain, so anything we can do to prevent the lead from being absorbed in the first place is a real benefit."
Children are at greatest risk when they begin to crawl.
Invisible lead dust, especially around windows and doors, clings to their clothes, toys and hands.
Poisoning occurs when they put tainted items or fingers into their mouths.
Farmers in British Columbia observed nearly 30 years ago that feeding zinc to their horses reduced the incidence of lead poisoning as the animals grazed in fields near toxic smelting plants. Subsequent laboratory studies on rats showed similar effects.
Researchers at Kennedy Krieger, one of the world's leading lead treatment hospitals, hope to replicate these findings in children as part of a series of studies into how best to prevent them from becoming permanently harmed.
Doctors and children's advocates say that only widespread repair or demolition of older homes in Baltimore's poorer neighborhoods will eradicate the problem - potentially saving millions of dollars a year in treatment, special education and criminal justice costs associated with lead poisoning.
Slow to act
But lawmakers have been slow to endorse plans that would force landlords to clean up their dilapidated properties.
"In the meantime," Davoli said, "vitamins and minerals may afford an opportunity to provide some protection for kids who are forced to live in these houses."
To participate in the Kennedy Krieger study, call 410-502-8386. For more information about protecting your child, call the Coalition to End Childhood Lead Poisoning at 1-800-370-5323.