CaEDTA Suppositories to Treat Elevated Blood Lead Levels in Children

By Ted Rozema, MD

Childhood lead poisoning is one of the most common pediatric health problems in the world today, and it is entirely preventable and reversible. Enough is now known about the sources and pathways of lead exposure, about ways of preventing this exposure, and about ways of reducing the lead content of the body to begin the efforts to eradicate this disease permanently. The persistence of lead poisoning, in light of all that is known, presents a singular and direct challenge to public health authorities, clinicians, regulatory agencies, and society.

Lead is ubiquitous in the human environment as a result of industrialization. It has no known physiologic value. Children are particularly susceptible to lead's toxic effects. Lead poisoning, for the most part, is silent: most poisoned children have no symptoms. The vast majority of cases, therefore, go undiagnosed and untreated. Lead poisoning is widespread. It is not solely a problem of inner city or minority children. No socioeconomic group, geographic area, or racial or ethnic population is spared.

Previous lead statements issued by the Center for Disease Control (CDC) have acknowledged the adverse effects of lead at lower and lower levels. In the most recent previous CDC lead statement, published in 1985, the threshold for action was set at a blood lead level of 25 mcg/dL, although it was acknowledged that adverse effects occur below that level. In the past several years, however, the scientific evidence showing that some adverse effects occur below levels at least as low as 10 mcg/dL in children has become so overwhelming and compelling that it must be a major force in determining how we approach childhood lead exposure.

It is not possible to select a single number to define lead poisoning. Epidemiological studies have identified harmful effects of lead in children at blood lead levels at least as low as 10 mcg/dL. Some studies have suggested harmful effects at even lower levels, but the body of information accumulated so far is not adequate for effects below about 10 mcg/dL to be evaluated definitively. As yet, no threshold has been identified for the harmful effects of lead.

Because 10 mcg/dL is the lower level of range at which effects are now identified, primary prevention activities are typically directed at reducing children's blood lead levels below 10 mcg/dL or 14 mcg/dL. While the overall goal should be to reduce children's blood lead levels below 10 mcg/dL, there are entrenched reasons for not attempting to do interventions directed at individual children to lower blood lead levels of 10-14 mcg/dL. First, practical medical interventions for children with blood lead levels in this range have previously been unavailable.

established intravenous therapy. Clearly, a simply and effective therapy such as suppository is needed.

Second, the sheer numbers of children in this range would preclude effective case management in