Big mold in the Big Easy


Author: Nina Welding

Keeping mold at bay requires moisture control. EPA guidelines tell you to dry water damaged areas within 48 hours to prevent mold growth. But what do you do when hurricane-force winds and a 20-foot storm surge break the levees protecting your neighborhood and leave your living room underwater for days?

Katrina, one of the 26 tropical storms in the record-breaking 2005 hurricane season, is still affecting the residents of New Orleans. Once flooded with water, the city is now overrun with mold.

Notre Dame researchers have been studying the mold growing in Katrina’s wake to help determine safe reconstruction guidelines and assess indoor air quality as evacuees return. The team, led by Jennifer R. Woertz, assistant professor of civil engineering and geological sciences, studied eight homes over a three-month period to identify what types of mold were present, how rapidly the mold was growing, how it was affecting indoor air quality and if it could be safely removed while maintaining the structural integrity of the buildings.

“Mold is everywhere,” says Woertz. “Before heading to New Orleans, we tested the lab where we work with mold on a daily basis and recorded 60 spores per cubic meter of air. When we surveyed the ambient air in the target homes, we found up to 20,000 spores per cubic meter, whether we could see the mold or not. After we broke into some of the walls, the concentration of mold spores rose to 400,000 spores per cubic meter.”

According to Woertz, the spores in the ambient air could pose a threat to people returning to the buildings—particularly elderly residents and young children with weaker immune systems. And the hidden mold would certainly cause problems for anyone attempting reconstruction if they are not wearing the proper respirators.

Currently, the EPA has no regulations for airborne mold contamination. “It is our hope,” says Woertz, “that this study will help the residents of New Orleans as they piece their lives and homes back together and that the knowledge we gain will help us better assess flood damage and mitigation efforts worldwide.”

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