The Centers for Disease Control and Prevention's decision to redefine the "action level" for lead exposure in kids has renewed some parents' concerns about the best ways to protect their children.
Children will now be considered at risk � and qualify for careful medical monitoring � if they have more than 5 micrograms per deciliter of lead in their blood. That's half the previous threshold.
Public health leaders have applauded the move, noting that the change will allow governments to take broader action to protect children.
Yet parents may feel more confused about when and how to test their children and homes for lead. Even some experts disagree about the best approach.
In its statement on lead poisoning, the American Academy of Pediatrics says, "Most U.S. children are at sufficient risk that they should have their blood lead concentration measured at least once."
Some health departments issue recommendations about how often to test children for lead, based on test results in the area or particular risks, the group says.
Without that kind of specific guidance, however, kids should generally be tested at age 1 and again at 2, when blood lead concentrations peak, it says.
Philip Landrigan, a leading authority on lead poisoning, agrees that all children should be tested.
While most American children are still well below the new action level, with average blood lead levels of 1.8 micrograms, Landrigan notes there is no safe amount of lead, which can cause brain damage and lower IQ.
"I recommend all children be tested, because you never know," says Landrigan, director of the children's Environmental Health Center at the Mount Sinai School of Medicine in New York.
Many insurance plans don't pay for blood lead testing, Landrigan says. And not all pediatricians offer it. Some refer patients to private labs or the health department.
Blood testing is especially important for poor children, although few of the highest-risk kids are ever tested, according to the pediatrics group.
Most lead poisoning cases occur in substandard housing, where window frames are still coated with lead-based paint, which was banned in 1978. About 25% of U.S. kids fall into this category, the group says.
Yet middle-class neighborhoods aren't immune. Tap water in many neighborhoods in the Washington, D.C., area exceeded safety standards for lead in 2003 and 2004, after lead leached from water pipes.
Test the house, not the child
Jerome Paulson, chairman of the pediatrics group's council on environmental health, agrees that families in homes built before 1950 should be "vigilant" about monitoring for lead. And parents should remember that children can also be exposed outside the home, such as at the homes of relatives or a regular babysitter.
But he says some kids can probably skip the needle stick.
"Kids living in homes built after 1978 don't need to be screened," says Paulson, a pediatrician at children's National Medical Center in Washington. "If the health department is saying, 'We don't see kids in this five-block area or this ZIP code with elevated lead levels,' then we don't need to screen kids in that ZIP code.�
"We really need to focus on preventing the kids from coming into contact with lead," Paulson says. "By testing kids, you're sort of identifying the kids after the fact. It really does make more sense to check the home than to check the child. What counts is the home."
Yet testing the home isn't always simple.
While home lead test kits are popular � sold online and at many hardware stores � they're often not reliable, says Scott Wolfson, spokesman for the Consumer Product Safety Commission. It tested home lead test kits in 2007 and found many produced false results, falsely finding lead in some homes and failing to find lead in others where it was present. The agency hasn't tested newer kits.
Professional contractors can get more accurate lead-testing results, but at a higher price.
The most vulnerable
Landrigan notes that testing allows people to identify sources of lead exposure and remove them.
Most often, testing doesn't lead to treatment, Landrigan says. Because treating children for lead poisoning carries its own serious risks, it is performed only when blood lead levels are extremely high. Most children with blood lead levels above the new threshold will be monitored, rather than treated with medication. Once the lead source is removed, children's blood lead levels typically return to a more normal range within weeks, Landrigan says.
About 90% of lead poisoning comes from lead-based paint in windows, Landrigan says. About 10% comes from home renovations, which can pose a particular risk to untrained do-it-yourselfers trying to fix up older houses, he says.
Sometimes, youngsters chew on peeling paint chips.
More often, children take in lead through paint dust, sometimes in microscopic particles, created when windows are closed or doors are slammed, Paulson says.
Children also can be exposed to lead by playing in the dirt, which may contain lead from car exhaust, factory smoke or even paint dust, if the soil is within a few feet of the house, Paulson says.
Most children exposed to lead are poor.
About 80% of kids with high lead exposures are eligible for Medicaid, according to the pediatrics group, which recommends lead tests for all children eligible for Medicaid. Few get them.
Babies and toddlers are exposed to more lead than adults because they spend more time crawling and playing on the floor, transferring dust to their mouths from everything they touch, Paulson says.
Babies' developing brains are especially vulnerable to lead's toxic effects, which can damage the brain and kidneys and, at higher doses, cause behavioral problems and rob kids of IQ points, Paulson says.
Blood lead levels tend to peak at around age 2, according to the pediatrics group's policy statement on lead exposure. Lead levels tend to decline after this age, as children's growing body size dilutes the concentration of lead in their blood.
School-age children, teenagers and adults, however, face little risk, Paulson says.
And doctors note that children today have dramatically lower blood lead levels than a generation ago.
Before 1970, health officials took action only if children had blood lead levels above 60, Landrigan says.
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