Mold toxins in buildings damaged by moisture are much more prevalent and more potent than previously thought, according to new international research from Lund University in Sweden. Scientific research concerning toxic mold has broad implications for not only patients with respiratory illnesses but also U.S. home sellers, building contractors, trial lawyers and insurance companies.
Researchers in the university’s medical microbiology lab analyzed dust and material samples from buildings damaged by mold using mass spectometry. The 167 samples studied came from numerous sources, including some buildings flooded in New Orleans during Hurricane Katrina. They found that 67% of all of the samples contained at least one mold toxin.
“Previously it was claimed that the occurrence of mould does not necessarily mean that there are toxins present. But they are! On the contrary, we can assume that wherever there is visible mould, there are also mould toxins,” says Erica Bloom a doctoral candidate at Sweden’s Lund University. Bloom’s study also asserts toxins produced by mold are more potent than previously thought. “It has now been shown, for instance, that mould toxins (mycotoxins) not only directly kill cells but can also affect immune cells in a way that increases the risk of allergies,” wrote Bloom. “Even incredibly tiny amounts of these toxins can do this, as little as a few picograms (a picogram is one millionth of a millionth of a gram).”
These extremely small particles can enter the lungs more easily than the spores that have been the focus of much more study, said Bloom. “We looked at 6-7 different mycotoxins and found them in a majority of the samples. And since there are at least 400 sorts of mycotoxins, what we have seen is probably just the tip of the iceberg,” she says.
The Lund team will continue to study the health effects of mold, and will take part in a large EU study on the possible connection between asthma and allergies and indoor environments in schools.
Keeping mold (and other) research news in perspective
In 2007 I reported on a Thorax-published study of 95 asthma patients and 87 controls in South Wales that found the patients’ respiratory illnesses improved after the visible mold was removed from their homes.
“Asthma and rhinitis symptoms and the use of medications to treat them were reduced in patients who took part in a randomized controlled trial to see if removing visible household mould would relieve symptoms.”
After a year the intervention group (those whose mold was removed) reduced their use of medications by 22% while the controls reduced their medications by 16%. The intervention group also reported about 24% net improvement in rhinitis and rhino conjunctivitis symptoms than the control group, and the intervention group also showed an improvement in wheeze that affected their activities like sleeping and speaking (31% vs 7% improvement reported by the control group).”
In the story about the South Wales study, I included comments from Ashley Woodcock, MD, University of Manchester, UK, who outlined some of the challenges researchers face when attempting to isolate causes of respiratory diseases thought to be the result of indoor mold. Among them are the lack of sophisticated and standardized skin prick tests for mold susceptibility and the million-wide range of fungal species.
Woodcock said the results of the South Wales mold and asthma study were important but not wholly conclusive because improvement in symptoms could have been due to factors other than removing mold, such as a reduction in passive smoking or exposure to mite allergens.
Often, news announcements from research institutions are reported as is by reporters challenged by deadlines, word length and background. To serve readers and do the research justice, journalists should read and cite the published study and, when possible, contact experts not involved with the study to discover possible opposing views and drawbacks.
A few years ago, Chris Rangle, MD, author of RangleMD.com, wrote a column, Toxic Mold Hysteria, in which he responded to a news report about a mass outbreak of illnesses related to mold found in a Connecticut school. Rangle asserted that it was only after mold was discovered that “occupants begin reporting symptoms.”
After clarifying that common molds, and particularly aspergillus, can aggravate existing diseases, he added that “in none of these patient populations is the mold blamed for causing the disease, only for aggravating it.”
Mass spectrometry and data sharing is growing among researchers, and the public’s growing awareness about mold, expect to hear much more about its health and legal impacts.
Citations
Bloom, Erica, Mycotoxins in Indoor Environments: Determination using Mass Spectrometry. Doctoral Thesis 2008
Burr ML, Matthews IP, Arthur RA, Effects on patients with asthma of eradicating visible indoor mould: a randomized controlled trial. Thorax. 2007 Sep;62(9):766-71. Epub 2007 Mar 27.
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