Aflatoxins are a family of toxins produced by fungi in the Aspergillus genus. These toxins are among the most famous and most widely studied of the mycotoxins, toxins produced by mushrooms, and they can be found all over the world. Trace amounts of aflatoxins are present in many foods, as it is essentially impossible to completely eliminate them without very costly processing procedures. Regulatory agencies in fact specifically admit set levels of aflatoxins in food, recognizing that it would be impossible to adhere to a safety standard which banned all of these mycotoxins.
Aspergillus fungi like to live on grains, nuts, and some legumes such as peanuts. The fungi may settle on crops in the field, producing aflatoxins which contaminate the crop before it even reaches the market, and they flock to cereals, nuts, and legumes stored in warm, moist conditions. Poor food handling can result in fungal colonization of foods stored in home pantries, food processing facilities, and so forth, resulting in an increase in aflatoxin levels.
These toxins primarily act upon the liver, and they are injurious to most organisms on Earth, although humans appear to be more resistant than some other animals. When an animal, whether a human being or a trout, ingests aflatoxins, the liver can become severely inflamed, impairing liver function and potentially shutting down the liver altogether. Lower doses may result in chronic immune problems. Aflatoxin exposure also radically increases the risk of developing liver cancer, with some aflatoxins actually having the ability to mutate the DNA in the liver to trigger the production of tumors.
High doses can result in immediate aflatoxicity, causing severe illness. Chronic exposure to moderate doses can also lead to the development of liver cancers. In people with hepatitis B, aflatoxins can interact with the hepatitis to make the patient's condition much worse. If exposure is suspected, testing is available for aflatoxin poisoning to determine whether or not the toxins are present in the body, and in what concentrations.
People can avoid aflatoxins by handling cereals, nuts, and legumes with care, storing them in a cool dry place which is not hospitable to Aspergillus fungi. Foods with signs of mold and mildew should be discarded, rather than consumed. In the case of processed foods which contain ingredients which could be contaminated with aflatoxins, people should take care to purchase products from reputable producers which have high quality facilities where contamination is limited. Being vaccinated for hepatitis B is also advised, both to reduce sensitivity to aflatoxins and to avoid infection with this vaccine-preventable disease.