Scientists disagree over spores
Since the mid-1990s, when preliminary research linked the mold Stachybotrys to a cluster of cases of infants with hemorrhaging lungs, an entire industry has grown up warning about — and offering to relieve — mold in the home.
But medical authorities are profoundly divided over the health threat posed by inhaling spores or mycotoxins, gases given off by the molds.
Physicians and researchers with similar credentials often come to opposite conclusions about mold, which is always present.
“Put a petri dish out for mold, and you’re always going to find stuff. It’s everywhere,” said Dr. Tim Feger, an allergist in the notoriously wet, humid Ohio Valley city of Louisville, Ky.
That said, mold growing in a home due to water leaks is not a good thing, though most doctors interviewed emphasized there is no scientific link between mold and serious disease.
That’s the majority view. A vocal minority believes that molds are one of the most serious public health threats.
One high-profile proponent of that position is David Straus, a microbiologist and professor at Texas Tech University Health Sciences Center.
If there are large numbers of soldiers living in mold-infested barracks and quarters in Germany, “then you’ve got a lot of sick people,” Straus said bluntly in a phone interview from his office in Lubbock, Texas. Stachybotrys produce mycotoxins, which he said inhibit humans’ ability to absorb proteins.
However, not all strains of Stachybotrys produce mycotoxins, he said. And of course, there are hundreds of other molds in addition to various strains of Stachybotrys including Aspergillus, Cladosporium and Penicillium — all suspected of causing toxic reactions in humans.
Other researchers and doctors are far more skeptical of such links, arguing that there is no proof molds cause anything other than allergies or flulike symptoms in the small percentage of people with acute sensitivity, including those with weakened immune systems.
In a 2001 report to the U.S. Council on Scientific Affairs, Dr. O. Edwin McClusky, senior vice president of Trinity Mother Frances Hospital in Tyler, Texas, stated that theoretically, molds can cause symptoms including toxic reactions and immune system reaction in which lung tissue becomes inflamed.
But, McClusky’s report adds, “a summary of available literature on Stachybotrys reveals that it is commonly found in water-damaged … dwellings, as are many other molds. However, there is no convincing evidence that Stachybotrys is a significant or even proven pathogenic antigen in either traditional allergic reactions, or the rare forms of hypersensitive pneumonitis.”
In other words, there is no proof that exposure to Stachybotrys or any other mold is a major health threat, Feger said.
“All this talk about people spitting up blood is blown out of proportion,” he said.
Asked if he’s ever seen a toxic reaction in his practice, Feger said, “No. And you talk to most allergist, they will tell you no, as well.”
On the other hand, it’s not unusual to have 20 or 30 people a day with mold-related allergies at his four-physician practice, he said.
No matter which side you come down on, mold in the home at the very least smells bad.
Molds thrive in moist conditions. The first step to eliminating mold is stop all water intrusion, Straus said. If that is not done he warned, nothing else will be of any consequence. “Painting does nothing,” he said.
Then, all affected materials including wallboard and any contaminated fabrics should be removed and replaced, Straus said. “It’s just that simple.”
The U.S. Army Center for Health Promotion and Preventive Maintenance in Maryland offers these tips for preventing mold in homes:
• Keep household humidity below 60 percent — ideally it should be between 30 percent and 50 percent. Use ventilation fans while cooking or showering.
• Make sure ventilation fans vent to the outside, not into crawl spaces or attics where moisture can support mold.
• Keep heating, cooling or dehumidifying equipment clean.
• Clean, dry or remove anything from your home that is water damaged, particularly carpets and padding. When installing wall-to-wall carpet over a concrete floor, be sure to install a moisture barrier.
• Vent and dehumidify attics, crawl spaces and basements.
The following Web sites offer in-depth information about molds:
• The Environmental Protection Agency: www.epa.gov/iaq/pubs/airduct.html
— Terry Boyd