LEFT BEHIND

The stench of death hung over New Orleans in a hot, humid cloud last September. Three Texas Tech scientists forged their way through post-hurricane debris, towing a trailer full of supplies and camping gear.

The trio’s task: Take samples of animals, soil, sediment and standing water left in Hurricane Katrina’s wake. What they collected would in some cases prove to be unhealthy for living things.

The team, led by Steve Presley of The Institute of Environmental and Human Health at Texas Tech, came to see how contaminated New Orleans had become and what dangers to human health would challenge the rebuilding process. Scientists also wanted baseline data to help them find how the ecology would be affected by pollution and contaminants pumped out of the city and into Lake Pontchartrain.

Thirteen Texas Tech scientists compiled the results and published them in the American Chemical Society’s peer-reviewed journal Environmental Science & Technology. They found areas containing high levels of arsenic, lead, pesticides and Aeromonas bacteria.

“There were definitely some areas where the exposure hazard to certain chemicals and other toxicants was high,” Presley says. “Others were fairly clean or fairly typical. Our purpose has not been to advise on whether New Orleans is safe for habitation; that is for the elected decision-makers to do. Our job is to analyze and present the scientific results of our study to them and explain the implications.”

War Zone

The scientists were unsure of what they’d encounter as they drove toward the Crescent City on their first trip, says Thomas Rainwater, who coordinated wildlife toxicology and field sample collection.

“We didn’t know if we would even be allowed to enter the city,” Rainwater says. “We were unsure about our safety if we did gain access. We had contacted the U.S. Environmental Protection Agency, The Centers for Disease Control and Prevention and the United States Geological Survey to see if they had sampling teams in New Orleans at that time, and whether we could collaborate with them and gain entry into the city. All were appreciative of our offer but said they couldn’t accept any non-governmental assistance at that time.”

So the Texas Tech scientists went on their own.

Team members (L-R) George Cobb, Les McDaniel, Steve Presley and Galen Austin

“We approached the normally vibrant city on I-10 and weren’t able to see any sign of human activity,” Rainwater says. “Then we began to encounter abandoned vehicles. Many had windows broken and doors left open. The whole scene reminded me of something out of a post-apocalyptic movie.”

In town, a thick mold crawled up the walls in some of the grandest old homes. A fish stuck in the window sash of one residence told how high the water had risen.

Team members began taking samples of soil, sediment and standing water for contaminants.

“We developed our sampling strategy to get a good cross section of the flooded areas, both in and outside the city,” Presley says. “During the first trip, we established a transect that ran from the French Quarter northward all the way to Lake Pontchartrain. We took samples every half-mile along that transect. We didn’t really get into the extremely poor or extremely affluent areas.

Sediment Sampling

Everything seemed to be covered in a layer of sediment deposited by the flooding—even the tops of some telephone poles. As rescue and rebuilding workers began restoring the city, clouds of this sediment rose into the air. Some workers wore face masks for protection. Others didn’t and risked inhaling the dust that may have been laden with toxins.

“The sediment didn’t just all drain into the street, get pumped out and dry,” Presley says. “It’s in houses. It’s on tops of houses and in cars. It’s everywhere you can imagine. So cleaning up the contamination is a much larger issue than just taking a grader and front-end loader and cleaning up the streets. Residents have to tear out the drywall and insulation in the homes and buildings.”

Once results from the first sampling were obtained, the researchers found high levels of 11 toxicants in the sediment that included arsenic, iron, lead and pesticides. Lab analyses found two samples containing lead that exceeded the U.S. Environmental Protection Agency’s Human Health Soil Screening Levels, which are typically used to determine human health hazards.

Presley says he wanted people to be aware of what was in the sediment and may be stirred up from the rebuilding process.

“We found elevated levels—elevated but not the-sky-is-falling levels —of arsenic, lead and the usual suspects you would expect in an urban flooding situation,” he says. “We also found pesticides.”

“a Bomb in the Swamps”

The swamps and wetlands surrounding the city were no better, Presley says.

The storm surge and winds had shorn off treetops at 10 feet in some areas. Leaves and branches that had once been underwater were brown and dead.

In Bayou St. John, carcasses of deer, feral hogs and alligators floated along shorelines. An unnatural silence filled the air.

“It literally looked like someone had set off a bomb in the swamps,” Presley says. “Much of New Orleans is under sea level, and the city relies on pumping floodwater into Lake Pontchartrain to keep it dry. That water has to go somewhere. Lake Pontchartrain’s swampy marshlands are a very sensitive ecosystem where toxicants can really damage wildlife, plant life and the whole natural balance in the lake.”

The Answers

Texas Tech’s was the first team of environmental scientists to sample, analyze and publish the findings of contaminants found in soils of New Orleans after Hurricane Katrina. They began assessing potential detrimental impact of toxicants being pumped into Lake Pontchartrain’s wetlands ecosystem.

The team’s initial results suggest homeowners and workers run the risk of inhaling toxicants and microbial agents that remain in the dried sediment. And children could ingest lead contained in the sediment as they play in the dirt and put their hands in their mouths. This can cause developmental problems and impaired nervous system development.

“We found toxic hazards in New Orleans,” Presley says. “By publishing the findings on this first trip, we’re hoping to provide planners with information to better protect the people. That’s the ultimate goal.”

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