Lead poisoning: an "out-of-school" factor in student achievement

“[A 2010] report found that of 39,199 DPS students tested as young children, only 23 had no lead in their bodies.”

As parents, we work hard to protect our children from everyday dangers – obvious, and not so obvious. For those of us who were doing home repair or renovation while our children were young, a big concern was making sure that our little ones did not ingest lead that was a standard element of paint sold before 1978. Those who are able can spend considerable amounts testing for lead and then having it carefully removed or encapsulated.

Not all children are so fortunate. In particular, children growing up in highly urbanized areas are especially at risk for lead exposure. Older housing with exposed lead paint or deteriorating coatings that free chips of lead paint is a particular problem. Large cities also tended to have higher concentrations of auto exhaust over decades – until unleaded gasoline was required, these pollutants contaminated the soil of large cities with lead. Think yards and playgrounds, and how young children play.

We have known for some time that even low levels of lead, previously considered harmless, do in fact have a serious effect on the brain development and intellectual ability of children. Other findings indicate that very low lead levels can have health effects on adults as well.

But a just-released study, evaluating the effect of blood lead levels on children attending Detroit Public Schools, has brought these issues home. (See the study abstract here. Read the coverage in the Detroit Free Press here.) Students with blood levels of lead historically considered low, but above the new threshold of 5 micrograms per deciliter of blood, were 50% more likely to score poorly on the state MEAP tests. Even children with lead levels below the new limit (between 2 and 5 micrograms per deciliter) were one third more likely to score poorly on their MEAP exams.

The study controlled for numerous other factors, providing strong evidence that it was the lead in their bloodstream as young children which affected later academic performance.

Should we take this seriously? Here is the recommendation of an advisory panel to the US Centers for Disease Control issued one year ago:

Based on a growing body of studies concluding that blood lead levels less than 10 micrograms/dL harm children, the CDC Advisory Committee on Childhood Lead Poisoning Prevention recommends elimination of the use of the term “blood lead level of concern”. This recommendation is based on the weight of evidence that includes studies with a large number and diverse group of children with low blood lead levels and associated IQ deficits. Effects at blood lead levels of less than 10 micrograms/dL are also reported for other behavioral domains, particularly attention-related behaviors and academic achievement. New findings suggest that the adverse health effects of levels less than 10 micrograms/dL in children extend beyond cognitive function to include cardiovascular, immunological, and endocrine effects…. Therefore, the absence of an identified blood lead level without deleterious effects combined with the evidence that these effects, in the absence of other interventions, appear to be irreversible, underscores the critical importance of primary prevention.

In other words, any lead in the bloodstream is dangerous, and the effects are difficult if not impossible to reverse.

In the education policy arena, we have spent months and years debating the relative importance of teacher effectiveness and how to measure it. Just last week, former state Representative Timothy Melton, now a lobbyist for the “reform” group StudentsFirst, hammered away at the need for rigorous and “objective” teacher evaluation tools because teacher quality was the “most important in-school factor” in student achievement. He neglected to mention that out-of-school factors swamp all in-school factors put together – by about three times, in most research.

So here is an out-of-school factor that we can easily identify and measure. We even know how to stop it. The question is: will we address the problem of lead poisoning in our urban cores with the same energy that we have been trying to regulate and evaluate our public schools? Maybe school reform is not the “civil rights issue of our time.” Perhaps child health – including the right for children to have their brains develop without the effects of poisons – is the civil rights struggle we should be waging today.