The recent water tragedy in Flint, Michigan has put lead back into the national spotlight. The situation in Flint is horrific for the town's residents and unforgivable on the part of the folks that made it happen. In my twenty plus years of treating patients with toxic poisoning and testifying in countless workers’ comp cases resulting from toxic exposures, lead has been one of the most pervasive and damaging toxins I have had the unfortunate task of dealing with. We have a tremendous problem in this nation with lead and, as John Oliver pointed out recently, we need to be doing more to deal with this situation.
Lead is a soft, naturally occurring element found in small amounts in the earth’s crust. Though lead has some benefits to humans—it's used in car batteries, munitions, and as a coloring pigment in paints and ceramic glazes, among other things—we’ve known for centuries that it’s poisonous, and removing it from gasoline and paint has dramatically reduced exposure for millions of Americans, especially kids.
However, new research is making it clear that lead’s toxic reach is much greater than previously thought. Indeed, lead poisoning is gaining a whole new level of appreciation from people you might least expect, including economists, criminologists and education experts, as the body of evidence grows as to how early life lead exposure damages children in ways that don't become apparent until years later, and in the process, ends up costing taxpayers in millions in increased spending on health care, special education and law enforcement.
Somewhat predictably, those hardest hit live in blighted urban areas with already high rates of violence, academic failure, and poverty. Twenty years ago, a study of children in Chicago’s Englewood neighborhood found that more than 80 percent had dangerous lead levels. More recently, a team of researchers from Indiana and Purdue Universities looked at the blood lead levels of 367,000 Detroit-area children, concluding that in poor urban areas throughout the United States children are inadvertently ingesting or breathing dust contaminated with fine lead particles when they play outside, particularly in the warm summer months of July, August and September. Evidence from the studied also confirmed that the primary source wasn’t lead-based paint, but airborne dust. In particular, late summer wind, a lack of rainfall and other meteorological factors increased ambient lead levels by more than 50 percent. Soil containing lead remnants from burned gasoline as well as lead from industrial sources such as smelting and manufacturing are the two leading sources of this lead dust.
None of this comes as a surprise to Flint Michigan’s poorest residents. They’ve been living under the specter of lead contamination for decades. When disgraced Michigan governor Rick Snyder’s chief of staff inquired about the state’s impending water crisis last July, the state health department responded that everything was OK But this “OK” turned out to be based on only one of two analyses of children’s blood lead levels. A third analysis, performed by State Health Department epidemiologists, showed the converse to be true. Compared with previous years, this third analysis showed that there were a higher proportion of children under 16 with “first time” elevated blood lead levels. This was particularly true in the summer months of July, August, and September of 2014.
What surprises me about so much of this is the Pollyannaish attitude of so many people regarding the safety of Flint’s water supply. As multiple news outlets have reported, two years ago, Michigan initiated what it termed as “cost cutting measures” by switching Flint's water supply from Lake Huron to the Flint River, a tributary that runs through town and is infamous for its pollution.
The switch was made during Michigan’s financial state of emergency, and was supposed to be temporary until a new supply line to Lake Huron was available.
Immediately, the residents began tasting iron, which isn’t shocking since The Flint River is 19 times more corrosive than Lake Huron, say researchers. Apparently, the water was eroding 100-plus year old iron water mains, which turned the water brown.
But what Flint’s residents couldn't see was far worse.. According to CNN, almost 50% of Flint’s home service lines are made of lead, and because the water wasn't properly treated, lead seeped into the water supply.
Though the city is now issuing bottled water to residents, the die is cast. The health problems affecting hundreds of residents don’t surprise me a bit. And I suspect that Flint’s water supply isn’t the city’s only source of lead contamination. Like so many blighted urban areas in the US, Flint’s lead problem started years before most people ever caught wind of it. Need evidence? Then look no further than the city’s steady rise in violent crime. Flint, in fact, is ranked among the most dangerous cities in America.
And here’s the worst part: Lead poisoning is irreversible. While there are environmental actions that can help mitigate exposure, these actions require resources, to which the poor have little to no access. And make no mistake about it: Lead kills! Indeed, persistent exposure to lead contamination leads to chronic lead poisoning,which carries a number of adverse consequences, including lowering children’s IQs and increasing the rate of attention deficit disorders. Children with long-term chronic lead exposure are several times more likely to eventually be jailed for violent crimes as adults. A ground-breaking University of Cincinnati study looking at cross sectioned images of the brains of elementary age African American kids found that those who’d been exposed to lead as toddlers, even in small amounts, had permanent and ultimately devastating changes. The study, headed by leading UC environmental health researcher Kim Dietrich, PhD, found that lead had robbed them of gray matter in the brain’s frontal lobe, which enables us to pay attention, regulate emotions, and control impulses. Basically, lead affects the frontal lobe by blocking the cells' signals. Without sufficient gray matter to connect to, these kids don’t have the ability to make appropriate choices and control behavior.
Lead also had scrambled the production of white matter that transmits signals between different parts of the brain, largely by mimicking calcium, an element that plays a critical role in brain development. Scars left by lead have had significant consequences for the study participants and their respective communities. Predictably, the exposed kids struggled in school more than those who had not been exposed. As teens, they committed crimes more often, the researchers found. The evidence is clear: Lead poisoning is now an inextricable part of the cycle of depravity facing millions of urban children.
While it would seem that high lead levels are associated with violence, one cannot discount the fact that many studies have been conducted with inner city residents, a demographic that usually sees its fair share of violence. Detractors claim that it’s the environment that contributes to the violence, and not the lead. However, the Cincinnati Lead Research Study—the first study to directly link lead exposure to criminal behavior—proves that lead must be considered as an independent variable, since the environment was the same for all participants.
The lead –violence connection is further supported by bone lead level studies, which are considered more significant than blood lead because they are a measure of lead accumulation over a long period of time. A child could have high bone lead while his blood levels are not high at the time they are measured, as an example.
In a now highly regarded study of 800 white, black and Hispanic boys who attended public schools in Pittsburgh, those with relatively high levels of lead in their bones were more likely to engage in aggressive acts and delinquent behavior than boys with less lead in their bones. Though none of the children studied were suffering from lead poisoning, a direct relationship was found between the amount of lead in their leg bones and reports by parents, teachers and even the children themselves of aggressive and delinquent behaviors.
The effects of lead on the brain are a no-brainer for those of us in the health community, but I accept that there will always be detractors, no matter how much evidence we present to the contrary. There are many, particularly the activist and law enforcement communities, who remain skeptical about the connection between lead exposure and violent crime. And it’s true that a drop in crime rates also has its antecedents in lower unemployment rates, increased police presence, higher rates of incarceration, and a shift away from the use of hard core drugs like crack cocaine. Still, it's sad that so many people dismiss lead as anything of consequence. While it may not be possible to tease out the underlying reasons for the spike in inner city violence, lead contamination is one of things contributing to urban decay, especially in the poorest communities.
What about “safe” lead levels?
Turns out, there really isn’t such a thing. A 2003 study published in the New England Journal of Medicine found that what was once considered a “safe” lead level of 10 micrograms of lead per deciliter was not safe, and in fact, caused significant damage to children. Blood lead levels of 10 micrograms of lead per deciliter were associated with lower IQ scores, behavioral dysfunction in memory, planning and problem solving, and poor attention. These findings underscore what I’ve been saying for years: there is no safe lead level exposure. These findings are the strongest argument for nationwide lead prevention policy.
While the elimination of lead from sources such as factories, gasoline, paint, water pipes and solder used to seal canned goods has stopped new sources of lead from entering the soil, lead that was deposited years ago remains in the surface soil—in some areas at 20 times the normal level—and continues to be swept into the air as fine particles. These lead particles will likely plague urban areas for decades to come.