Toxigenic Fungi and Mycotoxins

Fungi are found in every environment and have been estimated to constitute about 25% of the earth’s biomass [1]. Many fungi reproduce and disperse by forming billions of spores, and these fungal spores are present in the indoor and outdoor air. Thus, not surprisingly, our respiratory tract is constantly exposed to the aerosolized fungal spores. In addition, fungal spores may contain potent allergens to which certain people respond with strong hypersensitive (allergic) reactions. These allergenic fungal spores are particularly problematic for farmers. In fact, farmers can contract a lung disease called farmer’s lung from breathing the billions of tiny fungal spores shaken out of bales of moldy hay. Over time, some people develop an allergic reaction to them. The symptoms are serious, and once the allergic reaction begins, the person will always have the potential for symptoms upon exposure to hay mold. Even worse, many fungi are toxigenic and produce toxic compounds called mycotoxins. These toxins can be present in fungal spores and elicit a response in the lungs. The presence of mycotoxins in the lungs can interfere with the cellmediated immune responses. Fungal spores and associated mycotoxins are troublesome agents that raise a number of health and safety issues.