Trichothecene mycotoxins are naturally occurring toxic compounds produced by various types of fungi. These substances frequently contaminate agricultural products and, at times, indoor environments.
Where Trichothecenes Are Found and How They Form
Trichothecenes are secondary metabolites primarily produced by Fusarium species, such as Fusarium graminearum and Fusarium culmorum, which are common plant pathogens. Another producer is Stachybotrys chartarum, often called black mold, found in water-damaged buildings. These fungi thrive under high moisture, moderate temperatures (20-30°C), and plant stress, such as drought, insect damage, or nutrient deficiencies.
Contamination often occurs in the field before harvest, especially in humid conditions favoring fungal growth on plants. Common agricultural products susceptible to trichothecene contamination include cereal grains like wheat, corn, barley, and oats. These toxins can persist in harvested grains if drying and storage conditions are not properly managed.
In indoor environments, Stachybotrys chartarum can grow on cellulose-rich building materials like drywall or wood if they remain damp for extended periods. This indoor growth can lead to the release of spores and mycotoxins into the air, potentially affecting air quality.
How Trichothecenes Affect Health
Trichothecenes exert their toxicity by interfering with fundamental cellular processes, primarily inhibiting protein synthesis in eukaryotic cells. They bind to the ribosomes, blocking the translation step and preventing cells from producing necessary proteins. This disruption can lead to cell cycle arrest and programmed cell death, known as apoptosis, in affected tissues.
These mycotoxins also compromise the integrity of cell membranes, leading to cellular damage and inflammation in various organs. Their impact extends to the immune system, where they can suppress both innate and adaptive immune responses, making individuals more susceptible to infections. The extent of health effects depends on the specific trichothecene, the dose, and the duration of exposure.
Acute exposure can cause rapid symptoms like nausea, vomiting, diarrhea, and abdominal pain, especially with deoxynivalenol (DON), also known as vomitoxin. Skin irritation and dermal lesions can occur upon direct contact, while inhalation may lead to respiratory issues, dizziness, and headache.
Chronic exposure, even at lower doses, can lead to health problems. Immunosuppression is a significant concern, increasing vulnerability to various pathogens. Neurological symptoms such as tremors, uncoordinated movements, and behavioral changes have been observed in animal studies.
Long-term exposure can cause growth retardation, particularly in younger individuals, and may impair reproductive function. T-2 toxin is another potent trichothecene, known for its severe effects on the immune system, bone marrow, and gastrointestinal tract. It can cause skin necrosis, hemorrhage, and even death at high doses.
Reducing Exposure to Trichothecenes
Minimizing trichothecene exposure begins with agricultural practices focused on preventing fungal growth in crops. Farmers can select resistant crop varieties and employ good agricultural practices, such as proper crop rotation and timely harvesting, to reduce field contamination. After harvest, rapid and thorough drying of grains to below 15% moisture significantly inhibits fungal proliferation and toxin production during storage.
Proper storage conditions, including cool temperatures and adequate ventilation, further prevent mold growth in silos and storage bins. Food processing techniques, such as cleaning, sorting, and milling, can reduce mycotoxin levels in final products, though complete removal is challenging. Regulatory limits for trichothecenes in food and feed are established in many regions to protect public health.
For the general public, careful food handling at home is important. Storing grains, nuts, and dried foods in cool, dry places in airtight containers helps prevent mold growth. Regularly inspecting food items for any signs of mold, discoloration, or unusual odors is advisable. If mold is visible on items like bread, soft fruits, or porous foods, the entire item should be discarded, as mycotoxins can spread beyond the visible mold.
Addressing indoor mold growth is important to prevent inhalation exposure. Promptly repairing water leaks and ensuring adequate ventilation can prevent the conditions necessary for mold development. For extensive mold contamination, especially if it covers more than a few square feet, professional assessment and remediation are recommended to ensure safe and thorough removal.