When the story broke a couple years back about the high lead levels in the public water supply in Flint, Michigan, I had intended to investigate the matter more closely, suspecting that from the little actual data reported in the media that the story was being hyped in the usual way to whip up hysteria and be used for partisan gain. (Flint is a city run by Democrats, but somehow the whole thing was blamed on Republicans.) The claim spread that children were being poisoned! Poisoned deliberately!
My suspicion was that the blood lead levels in children being found in screenings would turn out to be much lower than the typical blood lead levels found in about 90 percent of American children as recently as the mid-1970s, before we phased lead out of gasoline. (I used to follow the CDC long-term trend data on toxic chemical exposure back in my masochist days.) Also, lead breathed in from the air gets into the bloodstream a lot more readily than lead ingested in water. But I never found the time to chase down the data and had to let the idea drop (which is typical—I usually have about five more story ideas than I have time for nearly every day).
So it is with no little surprise that the New York Times ran a terrific article yesterday by two experts in toxicology that vindicates all of my suspicions. The article, “The Children of Flint Were Not ‘Poisoned’,” is based on a much longer and data-intensive study the authors published in the Journal of Pediatrics, and is worth taking in if you have time. Here are some highlights from the Times article:
In the mid-1970s, the average American child under the age of 5 had a blood lead level of 14 micrograms per deciliter. The good news is that by 2014 it had fallen dramatically, to 0.84 micrograms per deciliter, largely because of the banning of lead in paint and the phaseout of lead in gasoline, among other measures.
The Centers for Disease Control and Prevention now considers a blood lead level in children of 5 micrograms per deciliter and higher to be a “reference level.” This measure is intended to identify children at higher risk and set off communitywide prevention activities.
It does not suggest that a child needs medical treatment. In fact, the C.D.C. recommends medical treatment only for blood lead levels at or above 45 micrograms per deciliter. Not a single child in Flint tested this high. This was a surprise for several visiting celebrities, who requested a visit to the “lead ward” of Hurley Children’s Hospital.
Nonetheless, the reference level has been misinterpreted by laypeople — and even public health officials — as a poisoning threshold.
After Flint’s water was switched from Detroit’s municipal system to the Flint River, the annual percentage of Flint children whose blood lead levels surpassed the reference level did increase — but only from 2.2 percent to 3.7 percent. . .
Moving from evaluating percentages to examining actual blood lead levels in children, we found that levels did increase after the water switched over in 2014, but only by a modest 0.11 micrograms per deciliter. A similar increase of 0.12 micrograms per deciliter occurred randomly in 2010-11. It is not possible, statistically speaking, to distinguish the increase that occurred at the height of the contamination crisis from other random variations over the previous decade.
For comparison, consider the fact that just 20 years ago, nearly 45 percent of young children in Michigan had blood lead levels above the current reference level. If we are to be consistent in the labeling of Flint children as “poisoned,” what are we to make of the average American who was a child in the 1970s or earlier? Answer: He has been poisoned and is brain-damaged. And poisoned with lead levels far above, and for a greater period, than those observed in Flint. . . A comprehensive analysis of blood lead levels across the United States reveals at least eight states with blood lead levels higher than Flint’s were during the water switch.
Kudos to the Times for publishing a story that totally debunks one of the favorite talking points of its readers.