Occurrence of zearalenone on Fusarium graminearum infected wheat and maize fields in crop organs, soil, and drainage water.

The mycotoxin zearalenone (ZON) is a very potent natural endocrine disrupting chemical, produced by Fusarium graminearum fungi growing on crops such as wheat and maize. Although it is well-investigated in food and feed, very little is known about its environmental fate and behavior. Here, we report the occurrence of ZON on F. graminearum infected wheat and maize fields in crop organs and soil and its emission via drainage water. ZON amounts in the investigated crops and topsoil were between 6.1 and 25.0 and up to 5.6 g/ha, respectively. ZON concentrations in drainage water were in the low nanogram per liter range with a maximum of 35 ng/ L. Cumulated ZON amounts emitted via drainage water ranged from 0.1 to 4.3 mg/ha, depending on the crop cultivated in the respective period. This corresponds to fractions between 0.001 and 0.070% of the initially present ZON amount in the plants. Because of the low concentrations emitted via drainage water, it can be assumed that ZON contributes little if at all to the overall estrogenicity of major surface water bodies. However, in small creeks, mainly fed by agricultural runoff, ZON might be present in environmentally critical concentrations at times of F. graminearum infections.