Environmental▼News actions to mold range from one extreme to the other, and levels of mold are constantly fluctuating. “You can’t turn them off and on like you can with a chemical substance,” Fellman notes, so “maintaining a consistent exposure rate of so many parts-permillion of some species of mold spore in the air would be hard to do.”
Instead of establishing safe exposure thresholds, panel members say the focus might be better placed on preventing or quickly remediating the moisture problems that lead to microbial growth in the first place. Key to this effort is public education on proper building maintenance, as well as national guidelines for the
construction industry, where energyefficient designs have been linked to a higher rate of indoor mold infestations (Environ. Sci. Technol. 2002, 36 (5), 95A–96A). For more information, the IOM report, Damp Indoor Spaces and Health, can be accessed at www. nap.edu. —KRIS CHRISTEN
significantly lower in environments that lacked mold growth. Even in buildings that did not For the first time, researchers have mold standards on previous page). have mold problems, the analysis measured airborne mycotoxins in In the new study, Brasel placed a detected the toxins, but at signifimoldy buildings, providing a possibioaerosol sampler in mold-contamcantly lower levels. “We got more ble link between “sick building syninated buildings to measure pollubackground noise than we would drome” and human health. tants. The sampler was originally have liked, but when you go into a “We believe that we are pioneers, designed to detect biowarfare agents, Stachybotrys environment, you can the first to find these toxins in naand similar models are now located definitely see a significant differtive, mold-contaminated buildings,” in U.S. post offices to protect workence,” adds Brasel. says Trevor Brasel, a graduate stuers against contamination during He attributes the background dent in the lab of David Straus, promail sorting. to false positives and nonspecific fessor of microbiology and binding. “The air sampler is immunology at Texas Tech collecting at a rate of 450 liters University’s Health Sciences per minute,” says Brasel. “So Center. “I think it opens up you’re collecting all types of the door to new research.” compounds, and you can imagThe study was presented this ine that some of them might May at the American Society have cross-reactivity to the of Microbiology meeting in antibody.” New Orleans. Mold toxins may be only “Previous studies looked part of the sick building synat agents that carried toxins drome, say experts. Besides [such as spores], but not the favoring mold growth, moistoxins themselves. So, this ture increases levels of bacteAmerican insurance companies have spent billions of might be a good step in the ria and dust mites, as well as dollars dealing with the thousands of cases filed every right direction,” says Harriet the release of chemicals such year in mold-related lawsuits. The majority of these Amman, a senior toxicologist as formaldehyde from plycases occur in states with high humidity such as Texas with the Washington state dewood. “The problem is that and Florida. partment of ecology. According there are so many things in to Amman, very little scientific eviThe collected samples were tested the air that interfere with any type dence exists to link mold with health against antibodies (using an ELISA) of analysis,” says Bruce Jarvis, proproblems often lumped together as for macrocyclic trichothecenes, which fessor of chemistry at the University sick building syndrome. Symptoms are the most toxic substances proof Maryland. “You would like to of sick building syndrome include duced by the common indoor mold have some idea of exposure to myheadache, dizziness, and fatigue. Stachybotrys chartarum. At low levcotoxins, which this work addressNevertheless, hundreds of lawsuits els, trichothecenes can cause skin ires. The second and more valuable have been filed and billions of dolritations, but the toxin can be lethal thing would be to have biomarkers lars have been paid by insurance if ingested in the range of milligrams in people that would be a measure companies to fix buildings with per kilograms of body weight. of their exposure to these toxins.” mold problems. In the six environments with S. Brasel says others in his lab are Last May, an Institute of Medichartarum, the toxin levels varied now looking for this additional evicine panel found evidence that from 12 to more than 1200 picodence. One group is testing houses mold and indoor dampness corregrams per cubic meter of sampled for airborne mycotoxins and then late with asthma and other respiraair. The effects of such airborne levsurveying the residents for health distory problems but was unable to els are not known because inhalaorders. Another project is examining show a correlation with sick buildtion studies with the toxin have not human serum to locate biomarkers ing syndrome (see story on elusive been conducted. Toxin levels were of exposure. —PAUL D. THACKER TREVOR BRASEL
Airborne mycotoxins discovered in moldy buildings
282A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / AUGUST 1, 2004
