Lead Poisoning Concerns Continue
Just this past week, in a move that was not unexpected expected and long-overdue, the Centers for Disease Control lowered the “level of concern” for the amount of lead in a child’s bloodstream. This new CDC policy expands significantly the number of children that should be considered for lead poisoning interventions. The level of concern had been previously established at 10 µg/dl (micrograms for a deciliter of blood), and last week the CDC lowered the level to 5 µg/dl based on extensive scientific evidence.
Lead, a metal, is a potent neurotoxin, which can be particularly damaging in the developing brains of small children. Even at very low levels, lead exposure can cause IQ loss, behavioral problems, and mental retardation in children. And these effects are essentially irreversible.
The typical pathway for exposure is the normal hand-to-mouth behavior of very small children, but in an environment where lead is present. In most of the U.S., the exposure is through deteriorating lead-based paint, which is still present in older housing stock. (Unless they’ve been completely renovated, houses built prior to 1950 are likely to have lead paint somewhere. Houses built before 1978 when lead-based paint was banned, may still be risky.)
These very low levels of concern are such that a child doesn’t need to eat paint chips to be of concern, but ingestion of lead dust alone can cause permanent damage. A microgram, for reference, is about three small grains of sand.
Although older housing is still a concern in parts of our region, a significant additional concern in our area is residual contamination from mine waste that can be found throughout the Coeur d’Alene basin. Indeed, the ongoing EPA cleanup of the basin has been focused, primarily, on removing the potential pathways for human exposure. The EPA has replaced hundreds of residential yards throughout the silver valley to remove lead and other metals from where children might play. But there is a lot of cleanup left to do.
Unfortunately, just as CDC is ratcheting down on their level of concern, the levels of concern in our region are probably at an all-time low. Very few children in North Idaho are being testing for lead, and anti-EPA rhetoric in the Silver Valley downplays the potential for human health effects from continuing contamination. With this new emphasis from CDC, we hope that family physicians, government and community health professionals — and parents — renew their vigilance. Childhood lead poisoning is entirely preventable. But it requires an awareness and concern that the CDC has recently re-emphasized, but seems to be diminishing here.