RENEE MONTAGNE, host:
Thanksgiving weekend is an opportunity for some in New Orleans to forget about their problems. Soon enough, though, the aftermath of Katrina will have to be dealt with again. Since the hurricane in August, New Orleans has become a haven for fungi. Mold has appeared on ceilings, behind walls, in bathrooms and basements and crawl spaces. That's got a lot of residents worried about their health. As to how worried they should be, NPR's Jon Hamilton tracked down some of the world's experts on mold to find out.
JON HAMILTON reporting:
If anyone should know about mold, it's the mycologists at the National Fungus Collections in Beltsville, Maryland. They keep a million different fungi behind locked doors.
Ms. AMY ROSSMAN (Systematic Botany and Mycology Lab): And here, you have the ascomycetes, the hyphomycetes and ceolomycetes, which include the molds. Mold is a common term, and polypores are down there and jelly fungi and...
HAMILTON: Amy Rossman heads up the Systematic Botany and Mycology Lab here. She doesn't usually worry about fungi in homes. Her primary job is studying the ones that destroy farmers' crops. And she's reminded every day how little scientists know about fungi.
Ms. ROSSMAN: People send us fungi that are important for some reason or another, and we are not surprised when they turn out to be new species, because there are--I would say most of the fungi have yet to be described and named and characterized.
HAMILTON: Let alone assessed as potential health threats. Rossman says microscopic fungi are all around us: buried in the ground, floating through the air. They spend their lives looking for a home that's warm and damp, like the flooded buildings of New Orleans or like a forgotten room in Rossman's own building.
Ms. ROSSMAN: Somehow, a pipe broke, so steam was in that room for quite a while, and when they opened it up, the ceiling was just beautiful. It was full of concentric rings of different colors of yellow and black and gray.
HAMILTON: They weren't escaped fungi from the collection, just random fungi that found a great place to grow. In New Orleans, the big question is whether mold is making people sick. Nick Money seems like a guy who should know. He's a botany professor at Miami University in Ohio, and he wrote a book about fungi called "Carpet Monsters and Killer Spores."
Professor NICK MONEY (Miami University): I wish I could say run for your lives or this really doesn't represent a threat to anybody's health. We really don't know at this point. I think we're at least a decade or more away from really understanding the health threat of some of these mold species.
HAMILTON: One fungus that's got people in New Orleans especially alarmed is called stachybotrys or black mold. It can cause allergy symptoms and asthma attacks. But Dr. Peyton Eggleston, a pediatric allergist at Johns Hopkins University, doubts that black mold is New Orleans' biggest fungal threat.
Dr. PEYTON EGGLESTON (Johns Hopkins University): Stachybotrys requires pretty specific conditions to grow, and we're not so sure that exposures and illness from that are anywhere near as important as from penicillium, for instance.
HAMILTON: Penicillium is the type of mold used to make penicillin. It can produce toxins and often shows up in samples of indoor air. So who better to ask than an expert on indoor air quality. Jan Sundell from the Technical University of Denmark has studied molds in both his country and Sweden. He's not sure that mold is the real problem in New Orleans.
Mr. JAN SUNDELL (Technical University of Denmark): People are getting sick in buildings, home, school, day cares, offices, with dampness problems. It's not really shown that mold is the important factor in it.
HAMILTON: If mold were the primary problem, not dampness, he says you would expect to see a lot of respiratory illness in places like the Philippines. Sundell says houses in that country often have more than a square meter of mold growing on a wall or ceiling.
Mr. SUNDELL: A square meter of mold growth, that is almost as much as there is in all of Sweden, and still, we have the same association between dampness/mold in both countries.
HAMILTON: Eggleston, the allergist, agrees that mold may not be the biggest problem in damp houses.
Dr. EGGLESTON: If you think of the damp dishcloth or even the damp washcloth in your bathroom, the smell from those, by and large, is bacterial, and so damp environments support all sorts of things.
HAMILTON: And there are probably a lot of bacteria growing in the soggy houses of New Orleans. Scientists say there's a lot of work to do in that city before they know what the real health hazards are.
Jon Hamilton, NPR News.
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