NEW ORLEANS — When Sarah Hess looks at her daughter Josie, she sees a healthy, happy child.
"She's a really, really smart little girl and everybody tells me not to worry," Hess said.
Yet, she does. She worries about an element that is all around them.
A test from her doctor found that Josie had acute lead poisoning, a potentially damaging diagnosis for a child which can affect how pathways in the brain develop. The Hess family immediately began lead remediation on their home.
"During that time, we started spending a lot more time at playgrounds and out of doors, trying to stay out of houses not realizing that the playgrounds that we were going to had higher lead levels than our house," Hess said.
The lead levels in Josie's blood shot up from the initial diagnosis of 8.8 micrograms to 18 micrograms, which led Hess to seek out as much information as she could about lead in the soil.
"It felt like a tragedy because here we had this beautiful daughter, who seemed perfect in every way, and people were telling us that her reading comprehension would never be as good," she said.
Dr. Howard Mielke is a Tulane University researcher who has spent his career studying lead contamination in soil across the city. While much his attention has focused on lead-based paint from years past, Mielke places a lot of the blame squarely on something else – decades of using lead-based gasoline in cars, which began in the 1950s and was used until leaded gas was permanently banned in the United States in 1996.
"It's hard for people to appreciate how much lead entered the city through just use of leaded gasoline," Mielke said.
Consider this example – one packet of artificial sweetener contains about one gram of material in it. A gallon of leaded gas would release about one gram of lead into the air. In older cars, a tank of gas could usually hold around 20 gallons. That equals 20 grams of lead per car being released every time it went through a tank of gas.
"That's one car," Mielke said. "You think of the hundreds or thousands of cars that are moving around, you can start understanding the quantities that we are talking about."
Using Census tracts as a foundation, Mielke and his team have collected more than 10,000 samples of soil from neighborhoods across New Orleans. The most recent tests included 5,500 samples and Mielke published a paper about those results late last year. When they mapped out their lead findings, they discovered a startling correlation.
"The high lead levels of the city are the areas that you tend to have the highest crime and that of course is the current situation," Mielke said.
Lead in the bloodstream can lead to behavioral problems in children. It affects the way synapses develop in a child's brain, especially the part of the brain which oversees impulse control. However, not everyone is convinced about a direct connection between lead and violent crime.
"Everyone wants a murder get-well pill," said Tulane criminologist Peter Scharf.
Scharf said the roots of violent crime run deep.
"My own view is that this is a very complex process and lead may be a part,” Scharf said. “But really you have to look at it in comparison with other hypotheses - economic changes, cultural changes, gun laws in some cases.”
Mielke agreed that lead is not the only factor in crime, but he believes it is a major one.
"Lead is just a contributor and it seems to be a significant contributor to the tendency for crime," he said, "but it's not the only contributor."
Researchers said the effects of lead poisoning have a 20-year lag time. That means leaded gas used in the 50s could be part of the reason behind the rise in violent crime in the 70s. It works the other way around, too. Leaded gasoline phased out in the early 90s could explain the drop in violent crime happening in a number of major cities now.
But that's not the case in New Orleans.
"It's a more soiled city," Mielke said of New Orleans. "It has more open areas that are yards. (It’s) a yard-oriented type of city."
Meaning, the lead stubbornly stays put. It does not break down.
The most-touted solution is containment and replacing soil, much like what the city did two years ago when it found high levels of lead at city playgrounds. Yet, Mielke thinks lead contamination should be considered a national issue, such as the way Norway handled lead contamination in its public spaces across the country.
"One of our problems at the federal level is that we have a Clean Air Act. We have a Clean Water Act," he said. "We don't have a Clean Soil Act."
Meanwhile, Sarah Hess is working hard at trying to keep her children's lead exposure to a minimum. That includes making everyone take off their shoes before entering their home and making sure the kids wash their hands properly.
In the meantime, she keeps a close eye on Josie.
"Josie seems fine, but we talk about empathy every day," she said. "We do that because of her exposure, because we have to counteract it."
For more information on Dr. Mielke's research on crime and lead click here. For more information on Dr. Mielke's Lead Lab click here. For more information Sarah Hess' efforts click here and for the group NOLA Unleaded click here.