Frequently Asked Questions - Health Questions

There are over 100,000 known species of mold, and the effects they have on humans is poorly understood. We do know that there are certain species that have been linked to adverse health effects in healthy humans. Molds can be allergenic, toxigenic, and carcinogenic in certain individuals. Most people tolerate exposure to normal mold levels without any adverse health effects, while others may have severe allergic reactions to the slightest amounts. While the research is limited, it has become apparent that individuals with suppressed or compromised immune systems may be at the greatest risk of developing a mold related illness.

Some people are genetically predisposed to developing a mold reaction, while others may develop a reaction after being “sensitized to a particular mold species over a period of time. Most people have no reaction to even elevated mold spore levels. The most susceptible people are are infants with under developed immune systems, elderly with weakened immune systems, AIDS and cancer patients, and anyone whose immune system has been compromised by respiratory infections such as pneumonia, bronchitis, and asthma. Immonusuppression can also result from medications, chemotherapy, alcoholism, and short duration illnesses such as influenza.

The answer to this question will be different for every person, and science cannot yet predict who will be affected and who will not.

There are no documented deaths related to mold growth in a home. While there have been multiple infant deaths related to Stachybotrys, in all cases there were other environmental conditions that may or may not have contributed to the deaths. For most healthy individuals, mold related symptoms disappear when the mold is removed.Cryptococcus (yeast) and Histoplasma (yeast) are avian pathogens associated with bird and bat droppings that can cause severe illness or death. Both are fungi which can be found in your home or office, but neither are molds.

While many molds are black, and many molds are toxigenic, the term “black toxic mold” usually means Stachybotrys. Toxigenic molds are those species that are capable of producing mycotoxins. Not all molds can produce mycotoxins, and those that can only do so when environmental conditions are right. Mycotoxins can be divided into five major groups:

• Aflatoxins – Aflatoxins are a type of mycotoxin produced by Aspergillus species of fungi, such as A. flavus and A. parasiticus. The umbrella term aflatoxin refers to four different types of mycotoxins produced, which are B1, B2, G1, and G2. Aflatoxin B1, the most toxic, is a potent carcinogen and has been directly correlated to adverse health effects, such as liver cancer, in many animal species.
• Ochratoxin – Ochratoxin is a mycotoxin that comes in three secondary metabolite forms, A, B, and C. All are produced by Penicillium and Aspergillus species. The three forms differ in that Ochratoxin B (OTB) is a nonchlorinated form of Ochratoxin A (OTA) and that Ochratoxin C (OTC) is an ethyl ester form Ochatoxin A.  OTA has been labeled as a carcinogen and a nephrotoxin, and has been linked to tumors in the human urinary track, although research in humans is limited.
• Citrinin – Citrinin is a toxin that was first isolated from Penicillium citrinum, but has been identified in over a dozen species of Penicillium and several species of Aspergillus. Some of these species are used to produce human foodstuffs such as cheese (Penicillium camemberti), sake, miso, and soy sauce (Aspergillus oryzae). Citrinin is associated with yellow rice disease in Japan and acts as a nephrotoxin in all animal species tested. Although it is associated with many human foods (wheat, rice, corn, barley, oats, rye, and food colored with Monascus pigment) its full significance for human health is unknown. Citrinin can also act synergistically with Ochratoxin A to depress RNA synthesis in murine kidneys.
• Ergot Alkaliods – Ergot Alkaloids are compounds produced as a toxic mixture of alkaloids in the sclerotia of species of Claviceps, which are common pathogens of various grass species. The ingestion of ergot sclerotia from infected cereals, commonly in the form of bread produced from contaminated flour, cause ergotism the human disease historically known as St. Anthony’s Fire. There are two forms of ergotism gangrenous affecting blood supply to extremities and convulsive which affects the central nervous system. Modern methods of grain cleaning have significantly reduced ergotism as a human disease, however it is still an important veterinarian problem. Ergot alkaloids have been used pharmaceutically.  Patulin is a toxin produced by the P. expansum, Aspergillus, Penicillium, and Paecilomyces fungal species. P. expansum is especially associated with a range of moldy fruits and vegetables, in particular rotting apples and figs. It is destroyed by the fermentation process and so is not found in apple beverages, such as cider. Although patulin has not been shown to be carcinogenic, it has been reported to damage the immune system in animals.
• Fusarium Toxins – Fusarium toxins are produced by over 50 species of Fusarium and have a history of infecting the grain of developing cereals such as wheat and maize. They include a range of mycotoxins, such as: the fumonisins, which affect the nervous systems of horses and may cause cancer in rodents; the trichothecenes, which are most strongly associated with chronic and fatal toxic effects in animals and humans; and zearalenone, which is not correlated to any fatal toxic effects in animals or humans. Some of the other major types of Fusarium toxins include: beauvercin and enniatins, butenolide, equisetin, and fusarins.

There are no definitive guidelines for mold spore levels in the air, so it is impossible to determine what level is safe and what level is unsafe. It is safe to say that the level that will affect one person will be different for another. In general, mold professionals rely on the outdoor mold spore concentrations to define what is “normal”, and those levels can change very rapidly. In the indoor environment, we expect the air to be reflective of normal outside fungal ecology. 

You should leave your home when you feel that the indoor air quality is affecting, or may affect your health.  Any consultant that advises you to leave your home is over stepping his role, unless he is also a physician. Pacific IAQ always advises its clients to seek professional medical advice before evacuating their home. 

The typical reaction to elevated levels of mold spores is an allergic reaction similar to pollen allergies. These reactions include sneezing, nasal and sinus congestion, irritation in the eyes, nose, and throat, and coughing. In sensitive individuals, more serious problems may develop such as:

• Shortness of breath
• Headaches
• Trouble concentrating
• Fatigue
• nausea and dizziness    

In most cases, mold related illnesses go away after the mold is removed or after the occupants leave the impacted building. It is believed, though, that the affected individuals may have a greater sensitivity to molds in the future so that later it will take exposure to lower levels of mold spores for a shorter duration of time to develop the same problems.