The reason that fungi are such potent and highly specific inhibitors of key enzymes and cellular receptors is not known. It is suspected that these biologically active molecules offer adaptive benefit to the fungi in their intense competition with other fungi for limited resources. Fortunately, the ongoing warfare between fungi appears to be less a war of attrition and more of a struggle for occupation. This may explain why so few fungal metabolites are acutely toxic. However, the fact that a metabolite is not acutely toxic should not be taken to mean that exposure is without potentially adverse consequenses.
Many fungal metabolites are chronic toxicants for humans and other organisms.
It is quite likely that changing agricultural, environmental, and societal practices play an important role in the selection of fungi and toxins that are considered to be possible health risks. Since the social and environmental ecology will continue to change, new fungal problems, including toxins, will appear. A proactive approach to better understand the potential of low levels of fungal metabolites as contributors to human and animal disease is to understand their mechanism of action and possible interaction with other factors, such as microbial toxins, nutrition, drugs, and disease. He is also an Associate Professor within the College of Pharmacy at the University of Georgia and serves on the World Health Organization's Scientific Expert Committee for Selected Mycotoxins. These studies have been hindered by the lact of adequate dosimetry data on aflatoxin intake, excretion, and metabolism in people, as well as by the general poor quality of world-wide cancer morbidity and mortality statistics.