Mycotoxins are toxic compounds formed by certain types of fungi (mold).  Mycotoxins are derived from chemicals such as polypeptides, amino acids, phenols, or terpenoids, which these fungi use in normal metabolism and physiology.   There are hundreds of known mycotoxins produced by molds and macrofungi and additional toxins are discovered each year.  Mycotoxins are capable of causing short-term and long-term health effects, ranging from headaches, fatigue, and skin irritations to organ damage and cancer. 

What are the symptoms of mycotoxin poisoning?

The symptoms of mycotoxin poisoning are largely dependent on the type of mycotoxin, the dose, route of exposure, and the sensitivity of the person exposed.  Here are just a few of the many short-term symptoms that have been documented in the scientific and medical literature:

Mycotoxin Testing

Because mycotoxins are known to contaminant human food products, animal feeds, and even indoor air, specific tests have been developed to assess the presence of mycotoxin-producing species and/or the type and relative effects of the mycotoxins present.   The testing procedure of choice is determined by the type of information required and the level of detail necessary to address your concerns.  For example, the presence of mycotoxin species, as determined by laboratory identifications, is typically sufficient as presumptive evidence for mycotoxin exposure.  When more definitive evidence is required, the most preferred choice are analytical techniques that determine the level of toxin present and its identity.  Analyses such as HPLC (High Pressure Liquid Chromatography) or GC-MS (Gas Chromatography-Mass Spectrometry) are the most widely employed methods for mycotoxin analysis.   All tests are performed on representative samples obtained from the suspected material, body fluids, or cultured cells.  There are no analytical approaches that can detect mycotoxins in real-time.  All materials must be carefully sampled and chemically  processed prior to analysis.    

Mycotoxin testing is not part of routine sampling for most indoor air investigations, although special air samples can be obtained for mycotoxin analyses.  The most significant problem associated with aerosolized mycotoxin tests (i.e. toxins on airborne spores) is obtaining a suitable amount of spores from which the toxin can be extracted for chemical analyses.  For this reason, many air samples result in an "inconclusive" assessment.  If you are seeking a conclusive determination of mycotoxin exposure, be sure to discuss these issues with your consultant.  Failure to identify the potential pitfalls of sampling and analysis will only result in wasteful spending.  Mycotoxin sampling and testing can be very expensive, ranging from $150 to over $500 per sample. 

Here is a summary of some of the most common types of testing protocols:  

Can mycotoxins contaminate building materials?

There has been much attention placed on mycotoxin contamination of building materials.  Although contamination of building materials by the presence of toxic spores is well recognized, the transfer of toxins from spores to actual building materials is an entirely different matter.  In support of this theory are those who cite an article documenting the presence of mycotoxins in over 40% of the indoor substrates tested (Tuomi et. al. 2000. Appl. Env. Microbiol. pages 1899-1904).  This study correlates mycotoxin presence with the occurrence of culturable (viable) molds, including mycotoxin-producing species.  On some occasions, mycotoxins were detected in areas where viable toxin-producing molds were not present; however, the presence of non-viable spores was not appropriately assessed.  The incorrect assumption drawn by some experts and lay-persons alike is that mycotoxins may be transferred from the spore to certain types of building materials.  In our opinion, such conclusions should not be made without a thorough analysis of viable and non-viable spores as well as spore fragments.  Remember, mycotoxins are an integral part of the spore surface.  If spores and spore fragments are removed, so are the mycotoxins.    At present, evidence does not exist to demonstrate that mycotoxins are transferred to building materials.  Clearly, further research is needed to determine the fate and transport of mycotoxins and their persistence in indoor environments.   If further research does indicate that mycotoxins are chemically extracted and transferred from spores to building materials, current abatement strategies will need to be drastically revised.  

Airborne Mycotoxins & Mycotoxicosis

Despite the growing evidence supporting a causal relationship between airborne mycotoxins and health effects, mycotoxicosis due to inhalation of indoor spores remains highly controversial.  The amount of toxins contained in aerosolized spores, even at high levels, may be insufficient to cause classical mycotoxin poisoning such as that caused by mycotoxin-contaminated food.  Nonetheless, many mycotoxin-related effects may actually involve mechanisms not explained by conventional dose-response models.  In other words, the mycotoxins could act as irritants or allergens.  The synergistic effects of mycotoxins, VOCs, and fungal glucans also remain unknown and it is conceivable that such complex mixtures could account for effects that are otherwise unsubstantiated by quantified mycotoxin concentrations in sampled spores.