St. Louis University pioneers new approach to preventing lead poisoning
This article first appeared in the St. Louis Beacon, Nov. 15, 2010 - A St. Louis University scholar thinks it's time for cities to refine the way they address lead hazards.
The attack on lead poisoning often begins with the discovery that a child has an elevated level of lead, usually exceeding 10 micrograms for each deciliter of blood. The next step involves a little detective work to find the source of the lead. It usually turns out to be peeling lead-tainted paint and lead dust in an older home. This approach, some say, amounts to making kids the equivalent of canaries in coal mines.
Although many cases of lead in homes still come to the attention of St. Louis health workers after a child has been poisoned, the city's approach has become more refined and proactive over the years. Aside from public awareness campaigns, the city now gives special attention to homes where expectant mothers live and tries to treat those units for lead poisoning before children are born.
But thinking creatively might help cash-strapped cities find more cost-effective ways to find lead before the lead finds the child, says Roger Lewis, an associate professor at St. Louis University's School of Public Health.
Mapping is a Key to Prevention
Lewis praised St. Louis' program to screen more children and reduce the incidence of lead poisoning. Still, he believes public health workers here and elsewhere might eventually have access to a better system of finding and measuring lead levels in older homes and figuring out where best to spend limited dollars to address the problems.
"The city's efforts to remove lead in housing are guided by existing cases of elevated blood-lead in children," Lewis says. "The goal of our work is to predict where we would find lead and remove it before kids get sick."
Lewis was referring to a $530,000 federal grant that a SLU team got from the Department of Housing and Urban Development to devise better ways to help a city figure out which properties to target for lead removal.
The approach involves property mapping, based on information from multiple databases. These include census data, building division information, real estate records, and state and local health records. Lewis says the city already does some of this work by looking at housing and locations based on zip codes.
Referring to the layers of data his team is using, Lewis says, "What we're doing that's a little out of the box is going to census blocks." Much smaller than a zip code, a census block corresponds, in many cases, to an individual city block. He says the method is like looking at a smaller site through a microscope.
Maximizing Dollars; Reducing Lead Exposure
The team hopes to be able to help the city pinpoint where most of the lead exposure is occurring and use information from the statistical model "to establish how much it would cost (to address lead) in that block, which has x amount of lead exposure, as opposed to another block."
The goal, Lewis says is "to maximize our dollars and maximize our reduction of lead at the same time."
What the team has found so far hasn't surprised it.
"If you live in an older home in St. Louis, you're going to be exposed to lead," he says. "If you're unemployed and low income, there's a likelihood that you live in a house with lead. It's a picture that's not surprising for people living in older housing in the rust belt."
Like some other ideas thought to be breakthroughs in an earlier time, lead in paint used to be regarded as a welcome development.
"Lead is a great adhesive," Lewis says. "It makes colors stand out, and we thought it was a great thing. Opening and closing windows and doors (containing lead paint) cause friction, which releases dust, which is ingested by young children."
The drawback, he notes, is that children under age 6 are particularly vulnerable to lead exposure because their brains and central nervous systems are not fully developed. He adds that elevated levels of lead in the blood can result in a variety of health and developmental problems: reduced IQ, learning disabilities, attention deficit disorder, behavioral problems, impaired hearing, stunted growth and kidney damage.
This story was written with the assistance of the Dennis A. Hunt Fund for Health Journalism, which is administered by the California Endowment Health Journalism Fellowships, a program of USC's Annenberg School for Communication and Journalism. Funding for health reporting is provided in part by the Missouri Foundation for Health, a philanthropic organization whose vision is to improve the health of the people in the communities it serves.