No one knows what can be saved from toxic stew
By MATTHEW WAITE
Published September 5, 2005
Hidden in the waters drowning New Orleans are things experts never thought would float inside a house for a month.
There isn't a lot of research on what happens when carpet, drywall and kitchen cabinets sit under clean water for weeks. Add sewage, gasoline, pesticides and toxic chemicals, and "it's a slowly developing enormous problem," said Thomas W. La Point, a professor of biological sciences and water quality expert at the University of North Texas.
Before rescue officials can even get everyone out of the flooded areas of New Orleans, the unimagined difficulty of fixing the city is starting to set in. Some, including House Speaker Dennis Hastert of Illinois, are wondering if it can even happen. If it does, the reconstruction will be massive and cost billions.
"There may be decisions to be made as to whether large areas of the city can or should be rebuilt," said Ed Pasterick, a Federal Emergency Management Agency specialist.
The problems with rebuilding cascade, starting with the water.
The Army Corps of Engineers estimates it will take 36 to 80 days to drain the city.
The longer the water sits, the worse the chemical contamination becomes, La Point said. Some substances - such as pesticide powder stored in cardboard boxes - already are in the water. More serious toxins, such as those used in industrial processes, will stay sealed for a while. But eventually water will rot and rust those containers, too.
The chemicals will bond to sediments in the water and turn into muck in the streets, creating hazardous mud needing specialized environmental cleanup and disposal sites, La Point said.
"The streets are going to be pretty grossly polluted until this muck is cleaned out," La Point said.
Then there is the mold and wood rot growing in flooded buildings.
"It's going to be incredible," said Doug Rice, a mold expert and director of Colorado State University's Environmental Quality Laboratory. "We're going to have quite the lab experiment going on there."
Given the conditions in New Orleans now, mold likely has started to grow already.
A lack of humidity control is critical, Rice said. Without air conditioning, the steamy conditions are right for mold growth, from the houses in the neighborhoods to the upper floors of hotels.
"If they don't have electricity for two months or three months, that's going to be a problem," he said.
Rice has studied areas damaged by hurricanes for more than a decade. The closest comparison Rice can think of is Hurricane Floyd in 1999, which left parts of North Carolina under water for weeks. The mold growth after that storm, Rice said, was "incredible."
New Orleans will be worse.
Healthy people without allergies won't notice some mold in their house. Allergic people will react badly to small amounts. Everyone can be affected by high levels of mold.
Given the right conditions, mold turns toxic, Rice said. Health effects then turn serious: respiratory distress, memory loss, lost use of senses.
And, Rice said, most insurers no longer cover mold under homeowners policies.
Mold can be cleaned up, he said, even in large amounts. But it will take time - optimistically, Rice estimated, eight months to a year.
Wood rot is harder to predict.
Denis Hector, an associate professor of architecture at the University of Miami, and Mike O'Reilly, a professor of structural engineering at Colorado State University, both have studied houses after hurricanes. They said just because a house is under water doesn't necessarily mean it will have to be razed.
Wood rot occurs when the material is subjected to repeated wet-dry cycles. Completely submerged wood won't rot because the organisms involved need air. Dry wood won't rot because there is no water.
"What I would be worried about is the 2 to 3 inches around the surface, above and below," O'Reilly said. "That's where the rot is going to occur."
If the house has been opened up to the elements - windows blown out or broken, doors open - the wood will dry out naturally when the water is drained out of the city, O'Reilly said. If the house stayed closed up, the wood won't dry and will rot.
"It's sounds kind of simplistic, but if the building hasn't had major structural damage ... it's just a matter of letting it dry out," he said.
Homes flooded by rising water - as opposed to rushing water, which does serious structural damage - could be saved.
"It's the interiors that will be damaged the most," Hector said. "I wouldn't assume you'd have to knock it all down. I would like to see the water recede before we decide that."
[Last modified September 5, 2005, 01:16:12]
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