Mold - The Next Menace

What Katrina's wind and waters haven't claimed, fungi are now starting to devour

By Beth Daley, Globe Staff  |  September 12, 2005

When Hurricane Katrina's floodwaters poured into the Gulf Coast -- saturating walls, shoes, sofas, floors, and roofs -- billions of dormant mold spores woke up.

Now, fueled by moisture and temperature, those spores are growing furiously.

For the buildings left standing by the winds and waters; for the houses that escaped serious damage from the toxic soup of bacteria and chemicals still sloshing in Katrina's wake, the next plague coming, experts say, is mold.

''These are the most successful organisms on the Earth. . . . They have this amazing ability to [survive]," said Michael Rinaldi, director of the Fungus Testing Laboratory and professor of pathology and medicine at the University of Texas Health Science Center at San Antonio. ''Many of those houses are useless, they are going to have to be rebuilt.

"Mold is a type of fungus that can weaken buildings, make people sick, and streak walls and baseboards with black and green discolorations that can be nearly impossible to scrub clean. While debate continues over how dangerous household molds may be, people with allergies, asthma, or weakened immune systems can suffer severe respiratory problems when they breathe in spores. Some fungal
organisms feed on wood for their growth, leaving a gooey, structurally unsound beam behind.
 
Residents in hot and humid New Orleans have long lived with the creep of mold and fungus everywhere from bathrooms to barroom walls, keeping it at bay with dehumidifiers, air conditioners and bleach.

But day-to-day humidity levels -- as sweaty as they make people feel -- are not nearly as hospitable to mold growth, as the last two weeks have been. Moisture has crept into crevices of homes, schools, and businesses since Katrina struck the Gulf Coast on Aug. 29. Most air conditioners and dehumidifiers haven't been turned on since because of the lack of electricity. No one can reach the walls to coat them with bleach. And the mold has kept on multiplying.

Mold had already begun to spawn in Sandy Guild's spacious Gulfport, Miss., home when she returned to it just days after the storm. In each spot, the mold started out gray then turned black and spread like a weed, she said. Guild's husband is an architect and she knows about the dangers of mold, so she and her family worked furiously to rip out all the sheetrock and insulation on the flooded first floor of the house, leaving only the studs. She bleached her kitchen cabinets.

''I had to get it out," said Guild, who owns a gift shop. ''It was going up the walls and up the doors. I feel sorry for a lot of people who don't even have sheetrock out [by now]; they are going to be in trouble.

"After floods, federal agencies often urge homeowners to strip homes of wet carpets and furniture and dry the building out within 48 hours to stop mold infestation -- but there are no guidelines for what to do with a house that has been partly submerged for weeks.

''The problem we are wrestling with is even if we eliminate the water . . .there will still be moisture present because we don't have air conditioning or a way to dry it out," said Michael McGinnis, the director of the Medical Mycology Research Center at the University of Texas Medical Branch in Galveston. ''The mold will get into the cracks in the ceiling, behind the paint. It really creates difficulty because there is going to be lots and lots of mold growing.

"Mold acts as nature's recycler, digesting dead or decaying material in dark, damp places to allow new growth to take hold. In existence for hundreds of millions of years, mold spores are among the most resilient and common organisms on Earth.
 
When a mold's environment goes dry, its spores enter a kind of hibernation, able to sometimes exist for decades in an inactive state. These microscopic dry spores are lightweight, and wind blows them virtually everywhere -- into homes, businesses, and schools; onto furniture, countertops, and rugs. In dry conditions, they're mostly invisible but can still make some people with allergies
sneeze, cough, and rub their itchy eyes.

With enough moisture, mold spores can germinate in just hours and begin eating wood, sheetrock, wallpaper glues, and other organic material that are in the home. Within days, a few spores can produce millions more, which are then carried to other locations by air currents. By the time mold is visible -- which can take from a day to several weeks after germination -- it often has taken root in walls and may be impossible to get out.

Companies that offer dry-out services say Gulf Coast residents and business owners are already contacting them, but it's unclear if any regime of drying, bleaching, and disinfecting will make the structures salvageable.

Mark Decherd of Dryout Inc., a national company that rehabilitates water-damaged homes, said his company has already received more than 300 calls from Gulf Coast homeowners. He said he's unsure what, if anything, he can do for them.

Scientists worry many poor homeowners will spend tens of thousands of dollars attempting to get rid of mold, only to find out their efforts failed.

In Metairie, La., which was hit hard by floodwaters, mold is beginning to spider walls -- not only where water once was, but throughout homes.

''The mold keeps going up and up," said Bharti Patel, who returned to her house a week ago. ''We're just surrounded by mold."

Marcella Bombardieri of the Globe staff contributed to this report from Gulfport, Miss., and Stephen Smith of the Globe staff contributed from Metairie, La. Beth Daley can be reached by email at bdaley@globe.com.

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