What Are Mycotoxins?

Mycotoxins are substances produced naturally by a type of fungi called molds. Molds are filamentous and grow from fungal spores that settle on any warm, moist surface. If the surface is rich in the organic products of decaying matter, molds grow as saprophytes, but if on the surface of living organisms, as parasites.

Mycotoxins are not parasites but rather chemicals that molds produce after nutrient uptake. Molds produce mycotoxins in quantities unsafe for livestock or human exposure. Contact with mycotoxins may carry the risk of harm (myotoxicity) depending on whether the mycotoxin's toxicity threshold is reached.

Each mycotoxin has its harm threshold defined by pharmacokinetic conditions and factored into public health regulations. The threshold of harm specified for food security differs between humans and livestock.

Mycotoxins enter the body through food or drinks, where they cause acute poisoning, immune suppression, cancer, or damage to organs such as the gut, lungs, kidneys, and liver. Among several diseases, liver cancer has been closely associated with the ingestion of aflatoxin, one of more than five hundred known mycotoxins.

Types of Mycotoxins:

Ochratoxin A

Aspergillus and Penicillium species of mold produce ochratoxin A. Ochratoxin A is toxic and likely carcinogenic, especially in the kidneys and liver.

Ochratoxin A is found in cereals, coffee, wine, dried fruits, beer, and grape juice. It also occurs in grain-fed animal organs (kidneys, liver). Ochratoxin A can have a severe immunosuppressant effect at low and high exposure doses in humans. Ochratoxin A also changes the absorption of nutrients in the intestines.


Fusarium species produce zearalenone. It can bind to estrogen receptors (mimic estrogen) and is a reproductive toxin in animal studies. Additionally, zearalenone is toxic to the liver and leads to cell death.

One study describes zearalenone as: “It is a non-steroidal compound that exhibits estrogen-like activity in certain farm animals such as cattle, sheep, and pigs.”


A couple of different Aspergillus species produces aflatoxins. There are multiple types of aflatoxins, with aflatoxin B1 being one of the most toxic and carcinogenic.

Aflatoxins are often found in peanut products and milk from cows fed with contaminated grain. Aflatoxin B1 is also found in cottonseed oil.

“Aflatoxicosis is toxic hepatitis leading to jaundice and, in severe cases, death.”

Chronic dietary exposure to aflatoxins is linked to liver cancer.


Fumonisins are metabolites produced by Fusarium species. Specific fumonisin subtypes are linked to an increased risk of esophageal cancer, and in general, fumonisins are considered a WHO class 2B carcinogen.

An interesting observation by researchers is that fumonisins interact with folate uptake in cells: “Because fumonisin B1 reduces uptake of folate in different cell lines, fumonisin consumption has been implicated in neural tube defects in human babies”.


Trichothecene mycotoxins encompass about 100 subtypes of metabolites from Fusarium species. Trichothecenes can contaminate corn, wheat, barley, oats, rice, rye, vegetables, and other crops. They are a common cause of poisoning in animals eating contaminated feed. Trichothecenes are easily absorbed and then distributed throughout the animal’s tissues. Human exposure comes from consuming meat, milk, and eggs from animals fed contaminated grains.

Consumption of trichothecene-contaminated foods can cause gastrointestinal issues. This mycotoxin affects actively dividing cells, such as intestinal or oral mucosa, and causes cell death.

Ergot Alkaloids

Unlike mycotoxins such as penicillin and ergot alkaloids which are medicinal and have been therapeutically formulated, most mycotoxins confer no clinical benefit. Worse still, molds producing mycotoxins are also infectious, spreading through food or air.

Ergot alkaloids are compounds created by Claviceps species, which are fungal pathogens that attack grasses such as rye. Ergot poisoning has been known for centuries. It was described as a “slow nervous fever” in the summer after a wet winter in the Middle Ages.

Modern grain processing methods eliminate ergot as a problem in human food sources, but it can still affect animals grazing on grasses or contaminated grains.

St. Anthony’s fire refers to an illness caused by consuming ergot-contaminated grain (usually rye). The symptoms recorded throughout history include convulsions, sores, hallucinations or mania, headaches, nausea, gangrene, and burning extremities.[ref]

The gangrene occurs because ergot is a vasoconstrictor, and too much constriction cuts off blood circulation to the extremities. The neuroactive components in the ergot alkaloids are similar to precursor molecules for LSD. Interestingly, a couple of Parkinson’s drugs are derived from ergot.


Deoxynivalenol is a mycotoxin produced by Fusarium species. It is found in wheat, beans, and some spices. Deoxynivalenol causes severe gastrointestinal issues when consumed via contaminated foods.

Types of Mycotoxins

Mycotoxins are produced by just over 360 species of mold, mostly belonging to the type of Aspergillus, Fusarium, and Penicillium. Mycotoxin product happens fast, and it does not take long to spread. They have a low molecular weight and are most often thermo-stable in non-aqueous medium, and therefore difficult to degrade. In most cases, they can survive in food even after mold elimination.

There are several hundred types of mycotoxins, but the most harmful ones with toxic effects on our health are Aflatoxins, Ochratoxin A, Patulin, Fumonisins, Zearalenone, and Nivalenol. They appear in the food chain because of the contamination of crops by molds, these toxins can also contaminate human beings by air. Even if they are mostly known for long-term harmful effects, such as immune deficiency or cancer, mycotoxins can also expose to immediate complications such as acute intoxication.

Where are Mycotoxins Found?

According to the World Health Organization, mycotoxins are toxic compounds naturally produced by certain types of molds (fungi). They grow on either on the floor or walls in a humid and confined environment or on some foods. Mold growth can occur before or after harvest, during storage, on or in the food itself, often in a hot, humid and moist environment.

Mycotoxin Testing and Detection

Exposure to mycotoxins is a serious issue that many people do not realize is impact their health until it is too late!

If you find mold growth or suspect you may have mycotoxins in your body it is important to get tested and begin treatment as soon as possible.

Mycotoxin poisoning and illness looks different in everyone and looks similar to other conditions like chronic fatigue syndrome.

Types of Mycotoxins


A family of fungi strains that affect plant products, aflatoxins have been linked to liver cancer, hepatitis, cirrhosis, and other health issues. Exposure occurs when consuming contaminated plant products, eating meat or dairy from animals that have eaten contaminated feed, or inhaling dust while working with contaminated products.

  • Aflatoxin B1 – Of the four aflatoxins that cause cancer in humans and animals, aflatoxin B1 is the most toxic, and is classified by the World Health Organization as a class 1 carcinogen. Though it primarily attacks the liver, this mycotoxin can also affect the kidneys, lungs and other organs.
  • Aflatoxin B2 – Like aflatoxin B1, aflatoxin B2 is produced by the fungi Aspergillus flavus and A. parasiticus. It’s also a toxin and carcinogen that contaminates food products, primarily affects the liver and kidneys and enters the body through the lungs, mucous membranes (nose and mouth), or even the skin, but is less potent than aflatoxin B1.
  • Aflatoxin G1 – Born from a soil-borne fungus like the other aflatoxins, G1 also contaminates a wide range of food products including peanuts, cottonseed meal, oilseeds, vegetable oils, corn, and other grains in human food and animal feed. Aflatoxin contamination is most common in humid environments, especially tropical and subtropical regions.
  • Aflatoxin G2 – The least toxic aflatoxin, G2 is still dangerous to humans and animals. Though less lethal than some of the other aflatoxins, G2 can also cause liver problems (including cancer, chronic hepatitis, and jaundice) and appears to play a role in Reye’s syndrome. Like all aflatoxins, it can also adversely affect the immune system.


Produced by at least five types of fungi, this group of mycotoxins includes around 170 types of toxins. Some types contaminate plants, including grains, fruits, and vegetables. Others thrive in soil and decaying organic material. Several types of trichothecenes are infamously produced by Stachybotrys chartarum, also called black mold.

  • Satratoxin G – Though all of the trichothecenes are highly toxic, tests have determined that Satratoxin G is the most dangerous to people and animals. The black mold Stachybotrys chartarum produces several types of trichothecenes, but produces Satratoxin G and H in greater amounts than other toxins.
  • Satratoxin H – Not all strains of black mold (Stachybotrys chartarum) produce mycotoxins, but the ones that do typically produce more than one kind, including Satratoxin H. The mold is found on some agricultural materials, and in damp or water-damaged environments. Evidence suggests the mold is a serious problem in North America.
  • Isosatratoxin F– Another trichothecene mycotoxin produced by Stachybotrys chartarum, Isosatratoxin F is one of the contributors to “sick building syndrome,” where health issues of building occupants are directly tied to time spent in mold-infected buildings. A 1984 World Health Organization Committee report suggested that up to 30 percent of new and remodeled buildings are possible causes of health problems due to poor air quality.
  • Roridin A – Like other macrocyclic trichothecenes, Roridin A is produced by mold, and is associated with a number of acute and chronic respiratory tract health problems. Experiments have shown that exposure to Roridin A can cause nasal inflammation, excess mucus secretion, and damage to the olfactory system.
  • Roridin E – Like many of the mycotoxins, Roridin E can cause the above respiratory and olfactory issues, and may also disrupt the synthesis of DNA, RNA, and protein, which can impact every cell in the body. Roridin E grows in moist indoor environments, but can also be produced by a soil fungus that contaminates foodstuffs, and is passed down the food chain to animals and then to humans.
  • Roridin H – Affecting human and animal health in much the same ways as other trichothecene mycotoxins, Roridin H is produced by mold, especially Stachybotrys chartarum, which grows well on many building materials subject to damp conditions, including wood-fiber, bards, ceiling tiles, water-damaged gypsum board, and air conditioning ducts.
  • Roridin L-2 – This mycotoxin is also produced by molds, including black mold. Interestingly, environmental tests cannot always detect Stachybotrys, since its spores are large and heavy and not easily dispersed into the air. Unfortunately, mycotoxin molecules, including the very toxic Rorodin l2, are light and easily airborne and inhaled by occupants of an infected building.
  • Verrucarin J – Yet another mycotoxin produced by Stachybotrys chartarum,Verrucarin molecules are small enough to be airborne and easily inhaled. Experiments have determined that inhalation is the most dangerous form of exposure, but trichothecene mycotoxins can easily cross cell membranes, which means they can also be absorbed through the mouth and even the skin.
  • Verrucarin A – One of the most toxic trichothecenes, Verrucarin A is also produced by fungi and mold. Like Roridin E, Verrucarin A is found not only in molds in damp environments but also in molds that occur naturally on a variety of crops intended for human and animal consumption.


  • Gliotoxin – The most common cause of mold diseases in humans is Aspergillus fumigatus, which produces gliotoxin, a mycotoxin that suppresses the immune system. Found in many homes and buildings, A. fumigatus typically only infects individuals with compromised immune systems but can be deadly: Invasive Aspergillosis (IA) is the leading cause of death in immunocompromised people.
  • Ochratoxin A (OTA) – A toxin produced by different Aspergillus and Penicillium species — is one of the most-abundant food-contaminating mycotoxins. It is also a frequent contaminant of water-damaged houses and of heating ducts. Exposure can also come from inhalation in water-damaged buildings.

Mycotoxins As Airborne Aerosols In Your Home

In the past, scientists and pundits have said that mold toxins [1] are not easily transported from the infestation surface into the air in a house, and that mold [2] does not always, or more rarely, produce toxins. At the same time, some of these people have tried to show that the amounts of mycotoxins that we in sick houses [3] inhale are so low that they cannot cause health effects. In 2007, this attitude changed to some extent through Swedish care via Lund University and the discovery that mold poisoning in damp-damaged houses was far more common than previously thought. [1,4] The debate flared up when a person, seen by public society as an expert, formally kicked the rear and said that despite the new findings from the university, there was nothing to worry about. This nay-saying party had indeed invested a lot of money in finding out that there were no risks. However, no actual study was shown. The critic was also careful to point out that the researchers at the university were not doctors and therefore could not comment on health risks. [5]

Now a further study has been carried out which proves that the researchers in Lund were right. The poisons from the mold are easily spread from the point of attack itself into the air. It is not only via the mold spores that the mycotoxins are spread, but also via dust and very small fragments, so small that they pass far down into the airways and lungs. The study from France is based on a controlled experiment in which an indoor environment with growth of mold on wallpaper is simulated. Three mold species, Aspergillus versicolor, Stachybotrys chartarum and Penicillium brevicompactum were included in the test. The experiments showed that the poisons changed into aerosol form at certain air flow speeds, i.e. that ventilation and air circulation in houses can control how much is released from the site of attack. The gist of the observations is that the exposure must be weighed into further studies where the intention is to find out what it is that makes people sick in houses with current problems. [6,7]

We already know that there is more than ventilation speed and air movement that affects how much metabolites are released from a place with mold. The amount of moisture in both air and material, air pressure and temperature, where the mold growth is in the house's climate shell, etc., are other factors. The French study does not address factors such as these. Here we see a research gap that will hopefully be filled.

Another research gap is how mold toxins affect our health when inhaled. The French point out that their findings are important for further risk assessment and evidence for the possible emergence of later toxic effects after inhalation. No clear relationship between dose and response has yet been established. However, it has been shown that intranasal exposure to the mycotoxins Satratoxin and Tricothecenes from the black mold Stachybotrys chartarum can be highly toxic, with several potentially serious health effects, e.g. neurological. [8-11,29]

Visible mycotoxin-emitting mold in housesAlthough it is important to study, it is not possible to lock yourself away from mold spores and mold toxins. Damp-damaged houses mean that the air is variably contaminated with different chemical substances and more bioaerosols than mycotoxins. For example. emitted from microbial attack MVOC - Microbial Volatile Organic Substances. Recently, suggestions have come from Professor Joan W. Bennett that these, often odorous [12] substances, can be called Volatoxin, as they exhibit harmful effects in experimental trials. [13] More and more are suggesting that myotoxins as well as other substances released by molds and bacteria need to be given more attention. The science bank is growing [14] despite naysayers trying to cast the subject in controversial guises. Not least, the evidence is strengthened that children and adults who stay in a house damaged by damp and mould, actually gets worse through various symptoms and developing a wide range of health effects as well as lifelong illness. [15-17]

Mycotoxin aerosol from crawl space

From the crawl space [18], mycotoxins, volatoxins etc. can enter through passages for pipes, via the gap between floor and wall, etc. places, be aerosolized into the house. We have encountered this phenomenon thousands of times during inspections and moisture measurements and mapped it through analyzes and odor samples. A crawl space without a dehumidifier can be seen as a risky construction, where in case of leaks due to pressure differences between the crawl space and the living space, bioaerosols like mold poison can easily be transported. Up in the house there can be continuous or seasonally varying negative pressure. Negative pressure means that not as much air is added as is drawn out through the ventilation. [19,20] Then "leak air" is taken from the crawl space. Bacteria and mold aerosols accompany the air. For us, this phenomenon is self-evident. Among other thingsCrawl space contaminates the indoor environment – ​​mold and bacteria . [21]

There are more risk constructs [22] that follow this crawl space example. Basements [23] and older types of slabs on the ground [24] are often affected by moisture and microbes. The same applies to the house's attic, although it is relatively less often that mycotoxin aerosols etc. find their way directly into the home from the attic. [25] In connection with our receiving information about the French studies on mycotoxins, further new knowledge was found where Uppsala University publishes a summary of the so-called " SBS - Sick Building Syndrome ", symptoms and health effects related to the overall poor condition of Sweden's property stock/single-family homes are in. This reinforces the information that substances that negatively affect the indoor environment are added from moisture-damaged places in houses, such as crawl spaces, basements and slabs on the ground. [26]

Returning to the research that exists around mold toxins, it is seen as relatively strong and elaborated regarding exposure intake via food and drink. Here it is established that mold toxins such as Aflatoxin are carcinogenic. More mold toxins are classified lower as suspected of causing cancer. A wide range of other health effects have also been researched. [15,27] As we interpret it, luck has now come to find out more about the exposure effects after inhalation. The not entirely public MYCOMIX project shows that different mycotoxins together can have an additive effect, even in low doses. Through the information available in MYCOMIX, it was suggested that moisture-damaged houses should also be considered as an additive source of mycotoxins. [28] We can only agree. This should be common sense. The concept of common sense should also include that lower exposure amounts of mycotoxins over time have the potential to cause a chronic toxicological effect. [30]


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