Rachel’s News #689, March 2, 2000

We have previously published considerable information about toxic lead and its permanent detrimental effects on young children.[1] At low levels, lead impairs hearing, diminishes growth, and reduces IQ. Children with low levels of lead in their blood may have a hard time paying attention, controlling their impulses, and learning. In some children, lead contributes to delinquency and violence.

In recent weeks we started asking, Why are governments refusing to comply with a 1989 federal law that requires all infants and toddlers in the Medicaid program to be tested for lead poisoning? Medicaid is a federally-funded medical insurance program for poor people. It is well-established that lead poisoning now occurs mainly in poor neighborhoods.[2] In 1998, 13.5 million children (18.9% of all children in the U.S.) lived in poverty.[3] The General Accounting Office (an investigative branch of Congress) reported during 1999 that “hundreds of thousands of children exposed to dangerously high levels of lead are neither tested nor treated,” because state governments are refusing to comply with the law, the NEW YORK TIMES said.[4]

The current federal “acceptable” level of lead in children’s blood is 10 micrograms (mcg) of lead in each deciliter (tenth of a liter) of blood, expressed as 10 mcg/dL. One way to get this lead toxicity standard into perspective is to compare it to naturally-occurring levels. Even before Europeans arrived in North America, humans had some lead in their blood (and bones, where it is still measurable today) because lead is a naturally-occurring element and some of it is always blowing around on the wind. We could argue about whether it is proper to call this a “natural background level” because humans have been mining lead out of the ground for perhaps 6000 years, so some human-mobilized lead has been blowing on the wind for aeons, adding to the levels that nature produces by itself.[5]

In any case, according to the National Research Council, people in the U.S. have average body burdens of lead approximately 300 to 500 times those found in our prehistoric ancestors.[6]

So how does the “acceptable” limit of 10 mcg/dL compare to pre-historic lead levels? The relationship between lead in people’s bones and lead in their blood is well-known. Careful measurements of the bones of pre-Columbian inhabitants of North America reveal that average blood lead levels were 0.016 mcg/dL — about 625 times lower than the 10 mcg/dL now established as “acceptable” for our children.[7] On the face of it, the current 10 mcg/dL standard seems imprudent because it assumes that a potent nerve poison at levels 625 times as high as natural background is “acceptable” for children.

Indeed, some of the nation’s most prestigious medical organizations acknowledge that children are being harmed at the current federally-established “acceptable” level. The American Academy of Pediatrics in 1993 reviewed 18 medical studies showing that lead diminishes a child’s mental abilities. “The relationship between lead levels and IQ deficits was found to be remarkably consistent,” the Academy said. “A number of studies have found that for every 10 mcg/dL increase in blood lead levels, there was a lowering of mean [average] IQ in children by 4 to 7 points.” Four to 7 IQ points may not sound like a major loss, but an average loss of 5 IQ points puts 50% more children into the IQ 80 category, which is borderline for normal intelligence. It also reduces the number of high IQs; for example, one group that should have had 5% children with IQs of 125 (or above) contained none.[8] So 10 mcg/dL of lead — the federal government’s current “acceptable” standard for lead poisoning