Many people are concerned about the effects of toxic molds on humans. According to the exhaustive 2004 Institute of Medicine study on damp indoor environments, toxic mold exposure in the home and office as well as allergenic mold exposure in the home and office and even exposure to mold odors in such environments often cause many of the same upper respiratory tract problems such as allergy and asthma like reactions.

According to current scientific and medical consensus toxic molds do not appear to be poisoning people in their homes because inhalation of spores does not appear likely to expose a person to high enough doses of toxins to cause a toxic reaction. Of course their may be exceptions and this is the current scientific opinion, this information may change in the future.

In animals and in persons living in third world countries toxic mold exposure often has much worse effects than the allergy and asthma type reactions so common in our world. The reasons is that farm animals, like poor starving people in third world countries often have little choice but to eat foods contaminated with toxic mold.

Some important lesson that can be learned from the information contained in the blog is:

1) Be careful to store pet food, farm livestock feed, and other animal foods in appropriate clean places away from mold, moisture, and excessive humidity. I am not a vet or a farmer so I will not telly you how to store animal feed, but keeping foods below 60% RH would likely be a good idea.

2) Take the same precausions you own families food, and never eat foods contaminated with mold or bacteria, unless of course they are suppose to be contaminated with good bacteria or good molds such products are often quite healthy, (Meso soup, soy sauce, blue cheese, cottage cheese, Sauerkraut, Prosciutto ham, beer etc.) This is making me hungry so I will stop with the list of fermented foods.

3) If you are living in a moldy home, you should not panic over toxic mold, it can likely be remediated and you will likely not have to burn you house down. Contact a properly trained and certified mold testing specialist. Certified indoor environmentalist, and certified industrial hygienist often make the best mold inspectors.

Below is information taken from two trusted web resources, both discuss the effects of the consumption of a specific type of mold toxin (aflotoxin) from a specific toxic mold species (Aspergillius flavus).

In the 1960’s 100,000 turkeys died on farms in England.  The condition was called Turkey X disease .

Later it was found that Turkey X disease was caused by turkey feed made from Brazilian peanuts.

Evidence of acute aflatoxicosis in humans has been reported from many parts of the world , namely the Third World Countries, like Taiwan, Ouganda, India, and many others . The syndrome is characterized by vomiting, abdominal pain, pulmonary edema, convulsions, coma, and death with cerebral edema and fatty involvement of the liver , kidneys , and heart.
Conditions increasing the likelihood of acute aflatoxicosis in humans include limited availability of food, environmental conditions that favor fungal development in crops and commodities, and lack of regulatory systems for aflatoxin monitoring and control.
Because aflatoxins, especially aflatoxin B1, are potent carcinogens in some animals, there is interest in the effects of long-term exposure to low levels of these important mycotoxins on humans .In 1988, the IARC placed aflatoxin B1 on the list of human carcinogens. This is supported by a number of epidemiological studies done in Asia and Africa that have demonstrated a positive association between dietary aflatoxins and Liver Cell Cancer (LCC) .Additionally , the expression of aflatoxin-related diseases in humans may be influenced by factors such as age, sex, nutritional status, and/or concurrent exposure to other causative agents such as viral hepatitis (HBV) or parasite infestation.

Aflatoxicosis and Aflatoxins

Aflatoxicosis is a disease that can affect many species of fish, and results when feed contaminated with aflatoxins is eaten by the fish (Ashley, 1970). Aflatoxins are chemicals produced by some species of naturally occurring fungi (Aspergillus flavus and Aspergillus parasiticus) commonly known as molds. Aflatoxins are common contaminants of oilseed crops such as cottonseed, peanut meal, and corn. Wheat, sunflower, soybean, fish meal, and nutritionally complete feeds can also be contaminated with aflatoxins.

Four major aflatoxins (AFB1, AFB2, AFG1 and AFG2) are direct contaminants of grains and finished feeds. Factors that increase the production of aflatoxins in feeds include environmental temperatures above 27°C (80°F), humidity levels greater than 62%, and moisture levels in the feed above 14%. The extent of contamination will vary with geographic location, feed storage practices and processing methods. Improper storage is one of the most important factors favoring the growth of aflatoxin-producing molds, and it is a major element that can be controlled by the fish producer.

Implications of Aflatoxins in Fish Feeds

Aflatoxin B1 (AFB1) is one of the most potent, naturally occurring, cancer-causing agents in animals. The first documented incidences of aflatoxicosis affecting fish health occurred in the 1960s in trout hatcheries. Domesticated rainbow trout (Oncorhynchus mykiss) that were fed a pelleted feed prepared with cottonseed meal contaminated with aflatoxins, developed liver tumors (Ashley, 1970). As many as 85% of the fish died in these hatcheries. Although cottonseed meal is no longer used as a major ingredient in feed formulations, poor storage of other feed ingredients and nutritionally complete feeds can lead to contamination with aflatoxins.

Aflatoxicosis is now rare in the rainbow trout industry due to strict regulations enforced by the U.S. Food and Drug Administration (FDA) for aflatoxin screening in oilseeds, corn and other feed ingredients. However, interest in the toxic effects on cultured warm-water fishes, such as tilapia (Oreochromissp.) and channel catfish (Ictalurus punctatus), has increased as diets for these species are now being formulated to contain more plant and less animal ingredients. This increases the potential for development of aflatoxicosis in these species because, as noted earlier, plant ingredients have a higher potential than animal ingredients for contamination with aflatoxins.

In tropical and subtropical conditions, this potential is further increased due to storage under humid and hot conditions. International trade in affected commodities and exposure to aflatoxins are worldwide concerns and the economic impact due to animal losses can be enormous.

Daryl Watters is a certified mold inspector, certified home inspector, and certified indoor environmentalist


Gary Burtle

Good comments on molds and toxins.  Our animals are a barrier between us and these plant-associated toxins.  The subject of fish and aflatoxin is interesting since there is a wide range across fish species for aflatoxin tolerance.  Catfish seem to be 1,000 times more tolerant to aflatoxin B1 than are trout.  Tilapia are also relatively tolerant to aflatoxin.  One study has shown that aflatoxin is eliminated from catfish tissue a day after the catfish quits consuming it.  I would like to see more reserch on peanut, cottoseed, and corn sources of mold toxins related to fish.  The future of aquaculture seems to depend on the development of safe fish feeds.


Thanks for the interesting info on fish feed and micotoxins on the following blog:
It is a helpful scientific addition to the pool of knowledge reguarding mold issues.
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