ALEX COHEN, host:
Two years after Hurricane Katrina there are concerns about children and the safety of the places where they play. The threat comes from arsenic. There are dangerous amounts of it in the soil in schoolyards. That's according to a report released earlier this week by the Natural Resources Defense Council, or NRDC.
Gina Solomon is a senior scientist for the NRDC and a lead researcher for this study. She says arsenic is known to cause cancer in humans.
Dr. GINA SOLOMON (Natural Resources Defense Council): There's no debate about that. So long-term exposure to kids who are putting their hands in their mouths is not good news. Arsenic also is damaging to the liver, to the kidneys, and to the skin.
COHEN: Solomon says the NRDC tested the soil at schools throughout New Orleans and they compared their new soil samples to ones taken before Hurricane Katrina. Gina Solomon says the amount of arsenic has increased dramatically. For example, in the Ninth Ward they found 15 times as much as there was before the storm.
Dr. SOLOMON: We're not sure, frankly, where the arsenic came from, but we've got several theories. One is from various hazardous waste sites that are located around the city that were flooded. Another is from the sediment that was on the bottom of the canals, and also on the floor of Lake Pontchartrain. Another possibility is from all of the arsenic-treated wood that was soaked in the flooding and that may have leeched its arsenic out.
COHEN: Wood that was used in homes?
Dr. SOLOMON: Arsenic-treated wood used to be used for decks and other outdoor wood purposes, fencing, et cetera, and that kind of wood is now banned but was widely used in the South in the past.
Mr. TOM HARRIS (Louisiana Department of Environmental Quality): I've read the NRDC press release seven or eight times, and basically half of the statements they make are completely and factually inaccurate. And at best, the other half are misleading.
COHEN: Tom Harris is a toxicologist with the Louisiana Department of Environmental Quality. He disputes most of the NRDC's claims. We'll get back to him in a bit. But first, let's take a look at some of those claims.
Dr. SOLOMON: Out of 20 schools that we tested, we found that about one-third of those schools had levels of arsenic that would normally trigger a clean-up or at least further assessment by state standards.
COHEN: Okay. This is where we get into a bit of a debate over numbers - and what exactly is a safe amount of arsenic? Arsenic in the soil is measured in milligrams per kilogram.
Dr. SOLOMON: The U.S. EPA says that at about .4 milligrams per kilogram, arsenic begins to become a health threat to people that are exposed to it over a long period of time.
COHEN: If .4 is a health threat, then how unsafe would a level like 12 be? That's the amount of arsenic the NRDC found at the McMain Magnet Secondary School in uptown New Orleans.
Mr. HARRIS: Half of the statements they make are completely and factually inaccurate. And at best, the other half are misleading.
COHEN: Remember, that's Tom Harris of the Louisiana Department of Environmental Quality. He says the claim that the levels of arsenic are unsafe falls under the misleading category. Harris says the state has also tested the soil, 2,000 samples of it. Most of their samples show about 12 milligrams per kilogram of arsenic, and Harris says that's not a number he considers unsafe.
Mr. HARRIS: All of the health agencies have concluded that arsenic is not a problem in New Orleans. What we're seeing in New Orleans is consistent with levels throughout Louisiana and throughout the United States.
COHEN: What would be a number that you would see that would make you say, okay, this is a problem, we need to address this? If it's not 12, what is that number?
Mr. HARRIS: If we saw an average concentration above 22 milligrams per kilogram, an average, mind you, not a single sample point but an average concentration in a given area that exceeded that, I'd be interested in seeing that. I have not seen that to date.
COHEN: There are two samples here from the NRDC's research. They're both from the mid-city district. One comes in at 22.8, the other at 34.4.
Mr. HARRIS: Those are single sample points points. The data that they gave us was one sample taken at a school. They go to the next school, take one sample. When you see a result like that, the prudent thing to do is to go back and collect more information.
COHEN: Tom Harris says the Department of Environmental Quality went to the schools where the NRDC found these high levels, and they took their own samples of soil. They got their results in two nights ago, and the numbers they found were much lower than those of the NRDC.
I called Gina Solomon of the NRDC back this morning to get her response.
Dr. SOLOMON: We sampled very carefully in the top half-inch of soil on the surface. That's what kids would get on their hands. The state of Louisiana, according to their protocol, dug down four inches for their soil samples. That means that they were sampling old dirt and dirt that kids aren't really going to be getting on their hands even, if they are playing. So I don't actually trust their samples as much as I trust ours.
COHEN: This is where the debate starts looking a bit like kids throwing dirt at each other in a playground. The Department of Environmental Quality says taking soil samples four inches deep is a standard they've developed in conjunction with the EPA and soil science experts. They say the NRDC's single samples are inferior to their multiple samples. The NRDC argues it's just a nonprofit without the funding for such extensive research. But why fight over such things, says the NRDC's Gina Solomon, when cleaning up the soil is relatively easy to do.
Dr. SOLOMON: It's not that expensive to clean up the top couple of inches of soil and replace it with clean soil. It's probably better to just do the clean-up rather than argue about it.
COHEN: Again, I picked up the phone and called the Department of Environmental Quality's Tom Harris in New Orleans.
Why not just clean it up anyway?
Mr. HARRIS: That's a real good question, Alex. And let me ask you, what city do you live in?
COHEN: I live in Los Angeles.
Mr. HARRIS: In Los Angeles, if you go to your backyard or to the park where you bring your children to play, there is the same level of arsenic there as anywhere in the New Orleans.
COHEN: I wouldn't want it here either. I'm asking you about your city. Why not clean it up? The NRDC says it's not that expensive. It just requires replacing about the top six inches of topsoil. Why not do that?
Mr. HARRIS: Well, where are you going to get that topsoil? Anywhere on planet Earth the soil has arsenic. I don't know how - any other way to say it. The soil on Earth and the Earth's crust contains arsenic. As much as we might not like it, that was here before we got here and there's not a whole lot you, me or really anyone can do about that.
COHEN: There is no easy way to resolve this debate.
Here is what toxicology professor Sharon Meyer of the University of Louisiana at Monroe has to say about what's a safe level of arsenic.
Dr. SHARON MEYER (University of Louisiana at Monroe): Anywhere between one and a million and one in ten thousand is an acceptable risk level of additional cancer cases.
COHEN: She says with arsenic, as with any contaminant, the range of risk is incredibly vast and open to interpretation.
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