Take a flooded building in steamy New Orleans, and within days dark mold blooms on every surface, bringing the stench of decay to much of the hurricane-hit city.
Authorities encourage residents to wear masks and protective clothing when clearing their homes, especially during dusty work like removing drywall. They say the risk depends on a person’s overall health and exposure to mold.
But an environmental group, alarmed by readings that show mold spores at extraordinarily high levels, said Wednesday that approach is not enough.
It wants the government to set up spore testing sites as New Orleans starts to gut moldy buildings and the spores are released into homes and into the air.
“The outdoor mold spore concentrations could easily trigger serious allergic or asthmatic reactions in sensitive people,” said Dr. Gina Solomon of the Natural Resources Defense Council.
“The indoor air quality was even worse, rendering the homes we tested dangerously uninhabitable by any definition.”
The group tested 14 sites in the New Orleans area for mold spores over a three-day period in mid-October, some six weeks after Hurricane Katrina flooded large parts of the city.
They reported spore counts as high as 645,000 spores per 1 cubic metre (35 cu ft) inside a building in the badly flooded Uptown area, and levels up to 102,000 spores per cubic metre in the air.
Solomon said a normal level would be about 25,000 spores per cubic metre, and the National Allergy Bureau views outdoor mold counts above 50,000 as “very high.”
Solomon said her group was testing again this week, and those results, due in a couple of weeks, would show if mold levels were subsiding, or if repair work was releasing more spores into the air.
“I do not anticipate that New Orleans will be a moldy city forever, but as long as there is this much mold growing, and all this work going on, the mold is going to be stirred up, and people with allergies need to be concerned,” she said.
So far, the government’s focus has been on education through flyers, radio spots and other advertisements, rather than on expensive testing. It sees health risks for people with allergies, lung problems or weak immune systems.
“Because of the large number of flooded and mold-contaminated buildings in New Orleans and the repopulation of those once-flooded areas, a large number of people are likely to be exposed to mold and other microbial agents,” the U.S. Centers for Disease Control said in a report that urges health authorities to monitor health trends.
Adding a note of caution about interpreting mold levels, it adds: “There are no criteria for using either the concentration or type of mold in buildings to make informed decisions.”
CDC spokeswoman Jill Smith said the CDC had already tested for mold in New Orleans, focusing on the type of mold rather than on the spore count. Results were not yet available.
“All people are not the same,” she said. “Our current recommendations are precautionary, to try to avoid exposure.”