Information Still Needs to Be Shared 

My grandmother used to call it “Beating A Dead Horse”¹; to keep talking about a subject that has already been fully discussed. It sure seems like there has been plenty of information and shared opinions about mycotoxins – the chemical poisons produced naturally by certain molds and mushroom. The restoration and remediation industry has seen a plethora of studies and data on the subject over the past 3 years. Yet, even when I think the topic has been talked to oblivion, I keep getting questions about them. Just recently a friend who is a long-time professional in the restoration industry emailed asking about them and wondering if mycotoxins were really something to be concerned about. His plea led to this latest effort to explain mycotoxins.

Always Build on a Solid Foundation

Understanding a few background facts are necessary to put their risks/danger of mycotoxin exposure in a proper perspective. As their name implies, ("myco" comes from the Greek word for mushrooms/fungus while "toxin" is the Latin word for poison) mycotoxins are actual poisonous chemicals secreted from the body and spores of various fungal types. The poisons are most typically associated with slow growing, water loving, mold types. Those factors mean that the fungal organism cannot out compete competitors by growing quickly or colonizing other materials.

There are a multitude of fascinating studies that have shown that mycotoxins are not universally produced, in the mold species that have the ability to make the chemicals. Research has repeatedly shown that a colony growing in a petri dish or on a surface without nearby competitors typically does not waste the energy on producing mycotoxins. However, when a competitor is introduced into the petri dish, even inches away, the colony (in this case Stachybotrys) began producing the mycotoxins within a few hours. Even more fascinating was the fact that the mycotoxins were only identified on the third of the colony that was facing the competitor.

For hundreds of years medical professionals knew that ingesting feedstocks impacted by mycotoxin producing mold was harmful to animals and people. Lots of stories/scientific evidence in this area about the devastating effect of ingesting mycotoxins was gleaned from the starvation of the Ukrainian people in the 1930s. Because of an early heavy snow, rye and corn crops were knocked down and covered for weeks. The appropriation of the previous year’s harvest by Soviet authorities resulted in people digging through the melting snow to reach the unharvested grain, much of which was covered by black mold. Regardless of what preparation and cooking methods were used, the devastating effect of ingesting mycotoxin-laden crops sickened and killed untold numbers of animals and people.

Inhalation of Mycotoxins Versus Ingestion

Despite the realization of serious health damage from ingestion, the belief up until the early 2000s was that inhalation of mycotoxins were generally so miniscule that they could not cause identifiable health effects. Twenty years ago, it was a combination of studies that showed that mycotoxins can cross the barrier at the back of the sinus and get directly to the brain without having go through the digestion/blood systems that got doctors looking closely at the inhalation issues.

An additional feature of many of the mycotoxins is the sticky nature of the chemical compounds. The poisons from mold make an effective inhalation hazard despite the initial tendency to cling to the mold structure and spores. Once the mycotoxin microdroplets get liberated from the structure it is oozing from, the hazardous chemicals adhere to whatever it encounters. It will stick to walls, ceilings, furniture, clothes, dishes, silverware and plants. When the mycotoxin droplets attach to a dust particle, it is now free to be transported throughout a building on air currents produced by HVAC systems, door opening for entry/exit and even the movement of the occupants.

The tacky texture of many of the mycotoxin chemicals that make it effective as an inhalation contaminant also make it a serious health hazard. Initially it sticks to dust particles that get carried on air currents. After the particles are inhaled, the gummy mycotoxins attach to the nose/throat where the poisons can access the neurological system. Most knowledgeable doctors consider the majority of neurological symptoms in mold-exposed individuals to be the result of mycotoxin exposure.

Significant Variability in Symptoms from Mycotoxin Exposure

It is difficult to separate mycotoxins as the source of mold problems from other biological contaminants that crop up in water-damaged buildings. Although mycotoxins are dangerous by themselves, they seem to pose a greater problem when occupants are exposed to mold spores, colony fragments, mycotoxins, endotoxin bacteria, exotoxins from other bacteria and a variety of microbial contaminants that grow on wet materials. But, whether it is the mycotoxins alone, or the mold poisons in conjunction with other biological contaminants from water-damaged buildings, the effects are often dramatic. The following graphic lists some of the more frequently reported health symptoms from mold/mycotoxin exposure.

Nor is the list complete as new research on mycotoxin exposure is ongoing.  A recent study now pinpoints mycotoxins as a contributing factor to many addictive behaviors. Serious research shows that mold exposure with mycotoxins can make it harder for drug- and alcohol-addicted individuals to rehab.

The Science Behind the Symptoms

The medical connection to these problems is getting clearer as doctors and researchers build on some of the basics of the mycotoxin chemical structure. The ability of mycotoxins to bioaccumulate, build up in body tissue, is a result of the poisonous chemicals generally being fat-soluble. Once ingested or inhaled mycotoxins readily migrate to, and into, fat accumulations in the body. This bioaccumulation damages all aspects of a body with some of the most pronounced problems in the nervous, digestive, adrenal and skin systems. Like a poison “bonus”, as the mycotoxins move through the various parts of a person, they trigger an immune response which both leads directly to inflammation and many other symptoms. As this inflammation process continues, it also indirectly fatigues the immune system, making a person more susceptible to infections and cancer development.

The impact on brain function and fine motor skills explains why the visual contrast sensitivity test has become a well-accepted, non-invasive, quick, inexpensive, method of checking someone for potential mold exposure/problems. In 10 to 15 minutes an occupant of a water damaged building with access to the internet can take the test which evaluates a person’s ability to distinguish images that vary in contrast from light to dark.

Another factor which impacts the danger mycotoxins pose to a particular individual is whether the person is genetically susceptible to mold sensitivity. There are two specific genes, of the approximately 20,000 in a typical human, that have been identified as inhibiting the body’s ability to flush out mycotoxins, causing a number of mold sensitivity issues.

Do Mycotoxins Change the Approach to Remediation?

There has been a lot of interest lately in mycotoxins during mold remediation primarily because the industry now has mycotoxins specific testing. Both surface and air samples can be analyzed for mycotoxins. Even so, the real question becomes Do we need to do anything different in our remediation efforts to address mycotoxins? 

As always, the answer is a bit complicated. For the majority of building occupants, "standard" remediation projects completed according to the IICRC standard of care will generally be adequate. A few simple changes can be made to improve the process and specifically improve mycotoxin removal. The early evidence shows a benefit from switching from a HEPA sandwich (HEPA vac, damp wipe, HEPA vac) to a HEPA pizza (HEPA vac, damp wipe, microfiber wipe) cleaning process. The use of disposal microfiber wipes on a mop head, (think Premira by Contec), has been proven to do a better job of removing the sticky mycotoxin material from the surfaces.

The situation changes when we are talking about remediation for an individual who is mold sensitized. In those cases, following the standard of care is not good enough. That is because most standard remediation projects focus on the condition 3 (i.e., removal of visible mold). Even if they do a great job with containments, negative pressure, cleaning and avoiding cross contamination, it will leave many sensitized occupants still hurting. 

For sensitized individuals it is nearly impossible to complete the work properly without doing the contained remediation of the source material as a first step. Following the source removal, a whole structure and HVAC cleaning to take care of the inevitable mold residue and mycotoxins that were present from long-term exposure to the growing colonies needs to be undertaken.

Always More Questions Than Answers

Studying mold/mycotoxin-related health effects is equal parts fascinating and frustrating. Frustrating because there is so much about how mold exposure effects people that we do not know. Fascinating because we have learned so much over the past decade that has made life better for those suffering from exposure to mold and water damaged buildings. Despite answering so many questions about how mycotoxins impact human health, it is likely that there will always be three or four new questions for each current inquiry that is solved.

1. An idiom first popularized in England in 1859 meaning that a particular effort is futile. According to Wikipedia, in 2018, the organization People for the Ethical Treatment of Animals (PETA) campaigned for the general public to cease usage of the idiom, along with other idioms which mentioned animals, to "remove speciesism in daily conversation". As an alternative, PETA proposed that the general public replace "beating a dead horse" with "feeding a fed horse". Having been raised on a farm and loving animals, if my grandmother was still alive, she would probably swear in Bohemian and say that PETA needed the stick instead of the dead horse.