TOXIC LEAD IS STILL ROBBING OUR CHILDREN OF BRAIN POWER
By Peter Montague

In a front-page story June 22, the New York Times reported that a first-born child typically has a 3-point IQ advantage over any brothers or sisters born later.[1] The editors of the Times considered this information so important that they featured it in a second news story, an op-ed commentary, and four letters to the editor.

Here is how the Times initially described the importance of a 3-point IQ advantage:

"Three points on an I.Q. test may not sound like much. But experts say it can be a tipping point for some people -- the difference between a high B average  and a low A, for instance. That, in turn, can have a cumulative effect that could mean the difference between admission to an elite private liberal-arts college and a less exclusive public one."

The Times did not mention it, but for some children the loss of 3 IQ points could mean the difference between a high D average and a low C, with a cumulative effect that could mean the difference between staying in school and dropping out.

In other words, a 3-point loss of IQ may be crucially important in every child's life, not just those headed for the Ivy League.

The U.S. Department of Labor says 19 million jobs will be created in the next decade and 12 million of them (63%) will require education beyond high-school.[5] As the globalized economy puts U.S. workers under greater competitive pressure, workers are expected to survive by retraining themselves 2 or 3 times during their working years. In this new world, every IQ point takes on new importance.

Unfortunately, the loss of 4 to 7 IQ points is far more widespread among U.S. children than anyone has so far reported, except in obscure medical journals.

One of the main causes of widespread loss of IQ is the toxic metal, lead, which is a potent neurotoxin. This soft gray metal was widely used in paint, in leaded gasoline, in sealing "tin" cans, and in water pipes throughout most of the 20th century, and the residuals are still taking a toll today in the form of peeling paint, toxic house-dust in older homes, contaminated soil, and a measurable body burden in almost all our children.

The most common units of measurement for lead in blood are micrograms per deciLiter of blood (ug/dL). A microgram is a millionth of a gram and there are 28 grams in an ounce. A deciLiter is a tenth of a liter and a liter is roughly a quart.

As lead in your blood goes up, your IQ goes down. And paradoxically the first few micrograms of lead are the most damaging.

As a child's lead rises from less than 1 ug/dL up to 10, he or she loses an average of 7 IQ points. If lead continues rising from 10 to 20, another 2 IQ points get shaved off. The first 5 ug/dL reduce a child's IQ by about 4 points.

According to the latest available data, 26 percent of all children in the U.S. between the ages of 1 and 5 have 5 to 10 micrograms of toxic lead in each  deciLiter of blood[11] -- which corresponds to a loss of 4 to 7 IQ points.[7,8,9,10] The estimate of lead in blood was published in December 2003, covering  the period 1988-1994. Average levels today are probably somewhat lower because the trend for lead in children's blood is downward.

Unfortunately this 26% average for all U.S. children masks a disproportionate effect among non-whites, who tend to live in families with low income and in older homes that may have peeling paint containing toxic lead.

In the 2003 report, nearly half (47%) of non-Hispanic Black children ages 1 to 5 had blood lead levels in the range of 5 to 10 ug/dL, which corresponds to a loss of 4 to 7 IQ points. Nineteen percent of white children and 28% of Hispanic children fell in the same range.

This means that exposure to toxic lead is still a huge problem in the U.S., robbing more than a million children each year of the intellectual potential they were born with.

Unfortunately, there is widespread misunderstanding (and muddled reporting in the media) about this problem, due in no small part to confusing and contradictory policies set by the federal Centers for Disease Control and Prevention (CDC) and U.S. Environmental Protection Agency (EPA). State governments by and large just go along.

Prior to 1971, doctors only treated children for lead poisoning if they had more than 60 ug/dL. At this level many children died, and those who survived had major permanent brain damage. Permanent damage from lead poisoning was well documented at least as early as 1943, but it wasn't until 1971 that the definition of "elevated" lead in children's blood was reduced to 40 ug/dL. By 1978, it was apparent that children were still being brain-damaged at 40 ug/dL, so the definition of "elevated" was reduced to 30. In 1985, the definition of "elevated" was reduced again, to 25, and in 1991 it was reduced again, to 10 ug/dL.

In 2005, the Centers for Disease Control and Prevention (CDC) reaffirmed its 10 ug/dL "level of concern," using tortured logic. CDC first acknowledged that "there is no 'safe' threshold for blood lead levels." [15, pg. ix] In other words, CDC acknowledges that any amount of lead greater than zero causes some harm. CDC then says, "Although there is evidence of adverse health effects in children with blood lead levels below 10 ug/dL, CDC has not changed its level of concern, which remains at levels equal to or greater than 10 ug/dL.... If no threshold level exists for adverse health effects, setting a new BLL [blood lead level] of concern somewhere below 10 ug/dL would be based on an arbitrary decision," CDC says.

In other words, since any amount of lead in blood greater than zero is harmful to children, then 10 is as good a number as any for defining where the problem begins. It's like saying automobiles are dangerous at any speed above zero, so setting the legal speed limit at 100 mph is as good as any other number.

So this is where it stands today: CDC says children are being harmed at levels below 10, yet CDC retains its official "level of concern" of 10 because picking any number below 10 (except zero) would be arbitrary.

It gets worse: CDC says 10 ug/dL is the "level of concern" but finding 10 ug/dL in a child's blood still does not trigger official attention to that individual child. When a community finds 10 ug/dL in some of its children, it is supposed to take community-wide action to prevent lead exposures -- urging homeowners to wet-mop to reduce household dust, for example. Yes, this will help, but it is an adequate response?

By current CDC guidelines, a child must have 15 ug/dL before the local health department is supposed to initiate "case management," visiting the home, for example, to discuss ways to reduce exposure. If a child has 20 ug/dL or more, then serious intervention may be initiated -- forcing homeowners or landlords to remove sources of lead (such as old paint) from the home, for example.

But here's the worst news: CDC's "level of concern" is widely interpreted as a "safe" level by other government agencies. It was never intended as such. As one lead researcher has written, "Although the CDC's intervention level is not a statement concerning the level of childhood blood lead considered 'safe' or 'acceptable,' it has been interpreted as such by the general public and by federal regulatory agencies." And, we should add, by state agencies as well.

For example, U.S. Environmental Protection Agency (EPA) has never set a "reference dose" for inorganic lead, as it has for several other neurotoxins about which far less information is available. EPA uses CDC's logic: it cannot find a level of exposure to lead that is "likely to be without deleterious effects during  a lifetime" of exposure. So it ignores the problem by refusing to set a reference dose.

As you can probably gather from this description, CDC guidelines do not flag 10 ug/dL as a serious threat to children. And that is the way it is understood across America, as a recent scan of newspapers revealed [with my comments inside square brackets]:

** The Wasau (Wisc.) Daily Herald reported May 27, 2007, that in Marathon County, Wisconsin, 1617 children were tested "with 43 registering levels higher than 10 micrograms per deciliter of blood." [With only 43 out of 1617 affected, the problem doesn't sound very serious, does it?]

** The Arizona Daily Star reported Feb. 4, 2007 that only 1 percent of children in Pima County have "elevated blood-lead levels." [Only 1 percent? Sounds like the problem has been solved, doesn't it?]

** The Westerly, Rhode Island, Sun reported Feb. 3, 2007 that "In 2005, about two percent of 31,669 children screened in Rhode Island, or 621 children, showed an elevated lead count in their blood..." [Only two percent -- sounds like the problem is small.]

** In Fitchburg, Massachusetts the Sentinel & Enterprise reported Nov. 6, 2006, that childhood lead poisoning has dropped from 8.2 per 1000 children in 1998 to 2.7 per 1000 in 2005 (with "lead poisoning" defined as 20 ug/dL). [Sounds like the problem is small and under control.]

** The Erie (Pa.) Times-News reported Dec. 3, 2006, "... the U.S. Centers for Disease Control and Prevention estimates that 310,000 children nationwide between the ages of 1 and 5 have blood lead levels of 10 micrograms per deciliter or greater. Ten micrograms per deciliter is the federal threshold for lead  poisoning in children that can result in development, learning and behavior problems." [A wonderfully clear statement of the point I'm making -- 10 ug/dL is  almost universally reported as a level below which there are no real problems.]

** The Denver Post reported April 29, 2007, "About 38 out of every 100,000 children under the age of 6 tested in Colorado in 2003-04 showed elevated levels of lead." [Only 38 out of 100,000? Sounds like the problem has been solved.]