Toxic Mold Illness 101

Ask a doctor: What are the health effects of living or working in water-damaged buildings?

Toxic Mold Illness 101
Molds and bacteria that grow in water-damaged buildings produce toxins that affect our health. Once discovered a thorough cleaning needs to be done before it can be considered safe. (riopatuca/Shutterstock)

Buildings used to breathe. It was inevitable and somewhat helpful, but it can make it more expensive to heat and cool those spaces with common central heating and cooling systems. When the oil embargo of the 1970s came along, building practices shifted to focus on more hermetically sealed buildings as a means to save energy.

And just as our wooden furniture and cotton clothes gave way to cheaper particle board, plastics, and polymers, building materials also shifted from stone, brick, and post-and-beam framing to stick framing, and OSB board (pressed plywood), and drywall. We sealed these spaces with sheets of plastic inside the walls or thicker membranes under the exterior finish.

Many multi-use buildings, such as office buildings, are built with fixed windows that can't be opened. Central HVAC systems that move air through an entire house or building are situated in basements, attics, or roofs where changes in temperature in ductwork can cause condensation. Such changes in building practices and heating/cooling methods have resulted in significant health problems because they create environments conducive to toxic indoor mold. Beyond condensation that forms inside, any kind of water intrusion from a roof leak, basement leak, or burst pipe will contribute to a moist environment where toxic mold species and bacteria can flourish.

Molds and bacteria that grow in water-damaged buildings produce toxins that affect human health. Bacteria make endotoxins that are found in bacterial outer cell membranes or cell walls. Typical toxic bacteria include actinomycetes, mycobacteria, and gram-negative species. Mold species release toxin-containing spores into the environment to kill other organisms nearby to secure their own territory. Typical toxic molds include species of Penicillium, Aspergillus, Stachybotrys, Fusarium, and many others. The antibiotic penicillium is an example of a toxic released by mold that is useful to humans.
Unfortunately, many mold and bacterial toxins are very damaging to human health regardless of whether the mold or bacteria are alive or dead. This means actively growing and dried-out dead mold and bacteria can all present health challenges.
Bacteria growing in water-damaged buildings may release endotoxins that have been associated with asthma and sarcoidosis, a progressively damaging disease in which granulomas or clumps of inflammatory cells form, most frequently in the lungs. Other health effects or diseases associated with inhaling bacterial endotoxins include fever, diffuse aches, headache, cough, shortness of breath, chest tightness, airway inflammation, nose and throat irritation, and nausea.


Much of the scientific literature describing the health effects of mold toxins (mycotoxins) has focused on the ingestion of foodstuffs contaminated with mold toxins, yet also note that exposure to mycotoxins also occurs by inhalation or through intact skin. Effects can be either acute or chronic. Chronic toxicity results from low-dose exposure over prolonged periods of time that may lead to health effects such as cancer, liver failure, kidney failure, chronic fatigue, and neuropsychiatric symptoms attributed to other causes.

Mycotoxins are known to cause: cancer; inhibition of protein synthesis, which interferes with growth and bodily repair; immunosuppression, which makes fighting infections more difficult; rashes and skin irritation; asthma; chronic respiratory infections; and damage to metabolic processes.

Not all molds produce mycotoxins but those that do are of public health and agricultural concerns. Some of the worst mycotoxins that are found in contaminated food as well as in water-damaged buildings include aflatoxins, ochratoxins, zearalenones, and trichothecenes.
Aflatoxins, made by some Aspergillus species, mainly damage the liver but also suppress the immune system and cause cancer and birth defects. Exposure to aflatoxins in synergy with concomitant hepatitis B infection are extensively linked to liver cancer. Aflatoxin-induced impairment of human cellular immunity may decrease resistance to infections in general. They have also been linked to inflammation of the brain and fatty degeneration of liver and kidneys.
Ochratoxins are produced by some strains of Aspergillus and Penicillium molds. Ochratoxin A, the most toxic, has been shown to damage the kidneys, suppress the immune system, and cause cancers and birth defects.
Zearalenone, a mycotoxin produced mainly by fusarium molds, is known for its estrogenic effects which include precocious or early puberty and atrophy of the testes. Fumonisin, another fusarium toxin, has been linked to hypertensive emergencies in pregnancy and with neural tube defects.
Trichothecenes are mycotoxins produced mostly by fusarium molds, which include Trichoderma and Stachybotrys (the deadly black mold). In high doses, trichothecenes are so deadly that they are considered biowarfare agents. The main effect is to stop the body from making new proteins, which affects rapidly dividing cells in the gastrointestinal tract, the skin, the lymph nodes, and the bone marrow.
Stachybotrys molds growing in water-damaged buildings were found to cause a syndrome known as “sick-building syndrome” where people complained of cold and flu-like symptoms, sore throats, diarrhea, headache, nose bleeds, blurred vision, rashes, itchiness, intermittent focal hair loss, lung damage with bleeding and shortness of breath, burning pain in the hands or feet, nausea, stomach aches, generalized aches and pains, chronic fatigue, anxiety, depression, and even personality changes. Medical case reports have described the death of infants from bleeding into the lungs or pulmonary hemorrhage from living in homes contaminated with trichothecene-producing molds.
In one rat study, the trichothecene T-2 toxin caused gastric ulcers, decreased food intake, and elevations of blood cholesterol and triglycerides. Another studied the toxic effects of trichothecenes on the liver and brain.

What Is Sick-Building Syndrome?

Sick building syndrome (SBS), also known as biotoxin illness or chronic inflammatory response syndrome (CIRS), is the constellation of symptoms that occur in those exposed to either growing or dead mold found in water-damaged buildings or vehicles. Building practices and materials in use over the past several decades have unfortunately made buildings more susceptible to mold growth.

A full 25 percent of the world’s population has the genetic predisposition to develop chronic illness when exposed to indoor toxic molds that grow in water-damaged buildings. This means that fully one-quarter of the employees, students, and families who spend time in these buildings may develop chronic illnesses of varying degrees that affect their respiratory systems, immune systems, and central nervous systems.

Biotoxin illness or CIRS can manifest as any combination of flu-like syndromes, chronic headaches, nasal congestion, sinusitis, pharyngitis, bronchitis, pneumonitis, pneumonia, asthma, fatigue, brain fog, profound fatigue, cognitive dysfunction, focus and concentration problems, memory abnormalities, emotional lability, irritability, anxiety, paranoia, anger and rage, hormonal dysfunction, gastrointestinal distress, leaky gut, inadequate digestive function, peripheral vascular disease, autoimmune disease, muscle pain and weakness, aerobic exercise intolerance, and more.

Short-term exposure is associated with many of the symptoms listed above, whereas long-term exposure causes ongoing up-regulation of systemic inflammation with resultant damage to the body that may or may not be reversible. Patients can develop chronic restrictive lung disease or asthma from long-term inflammation of the airways. The central nervous system’s control of the neuro-immune and neuro-endocrine systems is damaged with resultant deficiencies in crucial central regulatory hormones such as melanocyte-stimulating hormone, vasoactive intestinal peptide, and antidiuretic hormone.

The entire hypothalamic-pituitary-adrenal axis and thyroid gland can be affected. Alterations in leptin metabolism affect the body’s entire energy metabolism of fats, carbohydrates, and proteins. Salt and water balance, blood osmolality, and blood pressure control are disrupted. Immune system confusion and dysfunction result in chronic polymicrobial infections. Needless to say, the clinical ramifications are diverse and highly significant.

Many aspects of indoor toxic molds cause adverse reactions in genetically susceptible individuals. The toxins on the mold spores, any portion of cell wall fragments or any microparticles of the mold cells or cell contents, as well as mold gases released from actively growing molds, can all stimulate an inflammatory innate immune response.

Variability in response from individual to individual has to do with prior lifetime exposure as well as other comorbidities. Patients who have had prior mold exposure will react more strongly to new exposures. This inflammatory innate immune response can occur even at mold levels that might be considered “within normal limits” on air quality testing or at levels that might not affect other people.

Often people are confused and think that the sick-building syndrome is just a mold allergy. It's not. This is a different branch of the immune system that's not involved with true IgE medicated allergic reactivity. Yet the adverse inflammatory response does occur as quickly as an anaphylaxis type reaction when sensitized individuals are exposed to mold.

Biotoxin patients’ immune systems don't recognize the mycotoxins given off by molds in water-damaged buildings as foreign things to be eliminated from the body. Innate immune system activation occurs but the cellular branch of the immune system doesn’t get adequate messaging to start making antibodies to bind and eliminate the mold toxins or mycotoxins. These small mycotoxins, which include ochratoxins, aflatoxins, trichothecenes, and zearalenones, are both fat and water-soluble and thus can enter every cell in the body. They migrate to the nuclei and turn on the cell’s production of inflammatory cytokines, acting as epigenetic modifiers that alter how the cell’s genetic material is transcribed.

Treating Biotoxin Illness

The first and most crucial thing to do in treating biotoxin patients is to remove them from any ongoing mold exposure. Unless ongoing exposure to the mold that is causing the illness is stopped, there is little hope for improvement.

Due to chronic inflammation and dysregulated immune systems in these patients, a complete medical workup is required. Many will be suffering from significant systemic inflammation, leaky guts with markedly abnormal gastrointestinal microbiomes and poor digestive function, nutritional deficiencies, inadequate liver detoxification pathways, damaged mitochondrial energy production, abnormalities of coagulation, and chronic vector-borne and community-acquired infections. Laboratory testing to elucidate comorbidities helps to guide treatment. Both inflammatory markers in the blood and mycotoxins measurable in the urine provide useful means for following treatment progress.

Treatment begins with reducing inflammation, healing the gastrointestinal tract, normalizing liver detoxification, optimizing organ drainage and regulation, and binding toxins for elimination via the stool. If the patient has enough vitality to exercise or sauna, sweating is another good way to eliminate toxins. Active infections also need to be addressed. As treatment progresses, patients recover gastrointestinal integrity, physical and psychic energy, aerobic exercise tolerance, and cognitive function.

Unfortunately, most doctors have little understanding and no training in the recognition, evaluation, and management of patients suffering from mold illness. Thankfully, over the past 15 years, there has been a growing acknowledgment of the profound health effects of mold exposure and refinement of treatment practices among the environmental and integrative medical communities. 

Addressing Mold in Buildings

Patients need to be guided on how to safely eradicate mold from water-damaged buildings. If the patient owns the home or building, this will be easier to accomplish. It's more challenging to deal with situations when the patient is a tenant in an apartment or house, or employee in a business or work vehicle, or a student in a moldy school. In these cases, the owners may not adequately address the water damage and mold growth. The best action for health is to leave the home, apartment, business, or school immediately and not return.

The source of water intrusion into a building must be found. Heating and air-conditioning systems and all ducting must be closely evaluated. Plumbing conduits, basement, crawl spaces, roof and soffits, flashing and stucco need thorough examination for signs of moisture or microbial growth.

The contents of a water-damaged building may also be contaminated with mold particulates and toxins and need special attention. Anything that is nonporous, such as most dishes, utensils, pots and pans, metal, glass, porcelain, or stone objects, can be cleaned with a nontoxic moldicide. Simple household cleaners such as borax, bleach, and vinegar may be useful. Porous materials such as rugs, drapes, bedding, furniture, and clothing may or may not be salvageable. Wool and leather clothing, drapes, and area rugs can be dry cleaned. Other bedding, clothes, and towels can be washed in a hot wash load with moldicide soaps. Be sure to check washing machines for mold. Many front load washers become moldy if the unit is not allowed to dry completely between loads. In severely contaminated homes, mattresses, washing machines, and vacuum cleaners may need replacing.

When the water intrusion is fixed and all the mold remediated by a reputable company, the building will need deep, deep cleaning. All the interior surfaces, including ceilings, walls, and floors should be both dry and wet mopped. Remove all dust with a HEPA-rated vacuum cleaner. It's also advised to do a whole house fogging to remove all microparticulates of mold and then vacuum again. Some remediation companies routinely do this for clients.

Now the home is ready for all the cleaned belongings to be replaced and true healing can begin in a clean and healthy environment.

For more information on doctors who treat mold illness, please visit The American Academy of Environmental Medicine (AAEM), The International Society for Environmentally Acquired Illness (ISEAI), and