By Hernán Gómez and Kim Dietrich
Dr. Gómez and Dr. Dietrich are experts in toxicology and environmental health.
FLINT, Mich. — Words are toxic, too. Labeling Flint’s children as “poisoned,” as many journalists and activists have done since the city’s water was found to be contaminated with lead in 2014, unjustly stigmatizes their generation.
Let’s be clear. It’s unacceptable that any child was exposed to drinking water with elevated lead concentrations. We know that lead is a powerful neurotoxicant, that there is no safe level, that the very young are particularly vulnerable and that long-term exposure to low to moderate levels of lead is associated with decreased I.Q.s and other cognitive and behavioral problems, including criminal behavior.
But there is no reason to expect that what happened for a year and a half in Flint will inevitably lead to such effects. The casual use of the word “poisoned,” which suggests that the affected children are irreparably brain-damaged, is grossly inaccurate. In a city that already battles high poverty and crime rates, this is particularly problematic.
[ANOTHER VIEW ON FLINT: How a Pediatrician Became a Detective]
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. One of us, Dr. Gómez, along with fellow researchers, reported these findings in a study in the June issue of The Journal of Pediatrics, which raised questions about how risks and statistics have been communicated regarding this issue.
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.
People were understandably dismayed by the government’s apparent failure to act quickly to switch back the water once concerns were raised in Flint. But based on this more comprehensive view of the data, we are forced to admit that the furor over this issue seems way out of proportion to the actual dangers to the children from lead exposure.
Furthermore, the focus on Flint seems to be distracting the public from a far more widespread problem. Although blood lead levels have long been declining nationwide, there remain many trouble spots. Right now in Michigan, 8.8 percent of children in Detroit, 8.1 percent of children in Grand Rapids and an astounding 14 percent of children in Highland Park surpass the C.D.C. reference level. Flint is at 2.4 percent. 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.
It is clear that lead exposure is not one city’s problem, but the entire nation’s.
In the case of Flint, even when taking into account the change in the water supply, the decrease in blood lead levels over the last 11 years has actually been a public health success. The Journal of Pediatrics study found that between 2006 and 2015, the percentage of Flint children testing above the reference level decreased substantially, to 3.7 percent from 11.8 percent.
It is therefore unfair and inaccurate to point a finger at Flint and repeatedly use the word “poisoned.” All it does is terrify the parents and community members here who truly believe there may be a “generation lost” in this city, when there is no scientific evidence to support this conclusion.