Acknowledging mounting evidence that children can suffer lasting harm from ingesting even minute amounts of lead, the Centers for Disease Control and Prevention said it would reduce the level at which it recommends that doctors, families and health authorities act to lower a child's exposure to the toxic metal.
But the federal agency's move comes even as its own funding for fighting lead poisoning has been slashed, leaving state and local governments with fewer resources to tackle what has now been recognized as a much bigger problem.
Baltimore's Health Department, for instance, received $300,000 from the CDC this year to track poisoning cases and help families reduce their children's exposure. Since last summer, according to spokesman Brian Schleter, the department has contacted about 270 families of children whose blood showed levels of lead below the old CDC threshold, offering to visit their homes and share tips on how to reduce exposure.
But those federal funds are due to run out by September, as Congress this year slashed the CDC's budget to fight lead poisoning from $29 million to $2 million. Schleter said the loss presents "significant budgetary challenges" that could force cuts in staff assigned to deal with a drastically increased caseload.
Since 1991, the CDC's "level of concern" had been a level of lead in a child's blood as low as 10 micrograms per deciliter – as little as 100 parts per billion. But Christopher J. Portier, director of the agency's Center for Environmental Health, said in an interview that studies have shown for years that children with even lower levels can suffer adverse effects, such as learning and behavior problems.
By dropping its threshold, Portier said, the agency is emphasizing what it has been saying for some time: There is no safe level of exposure.
Though poisoning cases occur statewide, the bulk of the lead problem in Maryland has long been in Baltimore, which, according to the Health Department has eight times the nationwide incidence of poisoning cases.
The vast majority of Maryland cases have been linked to ingestion of dust and flakes from lead-based paint, which at one time was widely used in housing. Baltimore banned its use in homes in 1950, and the federal government outlawed its residential use in 1978, but the paint remains in many older houses. Other possible sources include older water pipes, lead dust in soil and imported toys or jewelry made of lead or coated with lead-based paint.
Under the old threshold, the number of lead-poisoning cases in Maryland has declined 98 percent since the mid-1990s, when state law began requiring that owners of pre-1950 rental housing take steps to repair and clean their units to reduce the risks to young tenants of ingesting lead paint dust or flakes.
State officials say they are already talking about how to respond to the CDC's action. Maryland's lead poisoning laws are based on the old poisoning threshold, officials note, so the law might have to be changed before the state can take regulatory action to further reduce exposure levels.
"There are practical barriers to doing that, but lower lead levels are better for kids, and the best level for kids is zero," said Dr. Clifford S. Mitchell, head of environmental health in the Maryland Department of Health and Mental Hygiene.
One concern is that the state's current blood testing procedure might not be good enough to reliably measure lead at levels below the old CDC threshold, said Horacio A. Tablada, land management director of the Maryland Department of the Environment, who oversees state efforts to reduce lead exposure.
Without more funds, Tablada said, his office might be unable to follow up on a vastly expanded number of new poisoning reports without diluting the attention they give the most serious cases. Ten inspectors now check on pre-1950 rental housing across much of the state, he said, though Baltimore's Health Department handles its own cases.
State health officials, meanwhile, say they are trying to figure out what to advise pediatricians and health-care providers to do with children who show lead below the 10 microgram level in their blood. The new reference level would effectively lower the standard for poisoning to about 5 micrograms per deciliter.
The CDC's Portier said his agency wants doctors to recheck the files of children not previously considered at risk of poisoning.
"It's going to have to be handled on a case-by-case basis by physicians, but our recommendation would be to revisit those cases," Portier said. Doctors should routinely ask families of children 6 years old and younger for an environmental history, he said, including asking whether they live in a house built before lead paint was banned.
Though acutely dangerous levels of lead in the blood can be reduced through chelation therapy, health experts point out there is no effective treatment for reducing already-low lead levels, other than removing the source of the poisoning — or the victim. The best treatment, they say, is preventing exposure in the first place.
Ruth Ann Norton, executive director of the Coalition to End Childhood Lead Poisoning, said the CDC declaration ought to prompt renewed government efforts to further reduce lead poisoning hazards in housing and elsewhere in the environment, including soil and water.
"This is a nasty, tragic and irreversible poisoning," said Norton, adding that the CDC's declaration also should alert parents to be more vigilant about their children's exposure.
But with CDC funding slashed, state and local agencies across the country are handicapped in their ability to respond to the expanded number of children now considered at risk, she said.
State lawmakers did authorize the Maryland Department of the Environment to raise the fees next year that it charges rental property owners to regulate lead paint risk-reduction efforts, but it is not clear whether that will be enough to cover the increased workload, especially with the loss of federal funding. The state also is expanding its oversight of rental housing to include homes built before 1978.
The increase in the number of children officially deemed at risk of lead poisoning also appears likely to increase the number of lawsuits filed by former tenants against rental property owners, mainly in Baltimore.
Landlords who have long complained of "frivolous" lead-poisoning litigation appealed for help from the General Assembly this year in the wake of a Maryland Court of Appeals ruling striking down a cap on damages if the property owners had complied with state requirements to reduce lead paint hazards. Lawmakers balked at a proposal to set up a state-sponsored compensation fund, instead ordering a study of why landlords seem unable to get insurance coverage for such litigation.
Scott Nevin, an attorney with the law office of Peter T. Nicholl, which specializes in lead-poisoning suits, said the new CDC threshold likely will lead to more lawsuits against landlords as families of children whose tests indicated lead exposure below the old threshold now know they had something to worry about.
"The children were always injured," he said, but now they may be able to show in court that their learning or other problems were related to lead exposure.
Baltimore Sun reporter Meredith Cohn contributed to this article.
New standard on lead
The U.S. Centers for Disease Control and Prevention effectively halved its threshold for diagnosing childhood lead poisoning, from a blood level of 10 micrograms per deciliter to about 5 micrograms per deciliter. The number of cases in Maryland is likely to multiply as a result.
Why: Research has shown lower levels can have harmful effects, including difficulty learning and controlling behavior.
What doctors should do: The CDC recommends that they contact parents of patients who tested below the old threshold and counsel them on how to identify and reduce exposure.
What families should do: Contact doctors or local health departments for possible retesting of children with levels in the 5 to 9 microgram level before, and for advice on how to reduce exposure.
How to reduce exposure: In pre-1978 homes, test for lead paint. If positive, consider replacing windows, hire an EPA-certified contractor to deal safely with any chipping or peeling paint and use a HEPA-vacuum to clean up dust.
For more, go to cdc.gov/nceh/lead/tips.htm or mde.state.md.us/lead or baltimorehealth.org/lead.html or leadsafe.org