Trichothecenes in the environment: relevance to human health.

Trichothecenes are agriculturally important mycotoxins of relevance to human health. Fungi capable of producing trichothecenes can be found throughout the world, and include certain species of Fusarium, Myrothecium, and Stachybotrys. The production of mycotoxins by these toxigenic species is determined by genetic factors and the environmental conditions of their growth. The environmental fate of trichothecenes may be affected by other microorganisms that can detoxify them. Deoxynivalenol and T-2 toxin are examples of trichothecenes that are detectable as natural and unavoidable contaminants of certain agricultural commodities as well as commercial foods. Current estimates of dietary exposure to deoxynivalenol and T-2 toxin are below thresholds for adverse effects that have been reported in experimental animal studies, although historical epidemics of human illness have rarely been described in association with consumption of food derived from heavily contaminated grains. The toxicodynamic properties of trichothecenes include inhibition of protein synthesis and immunomodulatory effects. Very little information is available relating to their toxicokinetics and toxicodynamics in humans. While there is general agreement that the diet represents an important source of human exposure to trichothecenes, risk assessment from non-dietary routes of exposure is complicated by the limited epidemiological data that are currently available.