Phytoestrogens and mycotoxins in Iowa streams: An examination of underinvestigated compounds in agricultural basins

Journal of Environmental Quality
By: , and 



This study provides the first broad-scale investigation on the spatial and temporal occurrence of phytoestrogens and mycotoxins in streams in the United States. Fifteen stream sites across Iowa were sampled five times throughout the 2008 growing season to capture a range of climatic and crop-growth conditions. Basin size upstream from sampling sites ranged from 7 km2 to >836,000 km2 Atrazine (herbicide) also was measured in all samples as a frame-of-reference agriculturally derived contaminant. Target compounds were frequently detected in stream samples: atrazine (100%), formononetin (80%), equol (45%), deoxynivalenol (43%), daidzein (32%), biochanin A (23%), zearalenone (13%), and genistein (11%). The nearly ubiquitous detection of formononetin (isoflavone) suggests a widespread agricultural source, as one would expect with the intense row crop and livestock production present across Iowa. Conversely, the less spatially widespread detections of deoxynivalenol (mycotoxin) suggest a more variable source due to the required combination of proper host and proper temperature and moisture conditions necessary to promote Fusarium spp. infections. Although atrazine concentrations commonly exceeded 100 ng L-1 (42/75 measurements), only deoxynivalenol (6/56 measurements) had concentrations that occasionally exceeded this level. Temporal patterns in concentrations varied substantially between atrazine, formononetin, and deoxynivalenol, as one would expect for contaminants with different source inputs and processes of formation and degradation. The greatest phytoestrogen and mycotoxin concentrations were observed during spring snowmelt conditions. Phytoestrogens and mycotoxins were detected at all sampling sites regardless of basin size. The ecotoxicological effects from long-term, low-level exposures to phytoestrogens and mycotoxins or complex chemicals mixtures including these compounds that commonly take place in surface water are poorly understood and have yet to be systematically investigated in environmental studies.
Publication type Article
Publication Subtype Journal Article
Title Phytoestrogens and mycotoxins in Iowa streams: An examination of underinvestigated compounds in agricultural basins
Series title Journal of Environmental Quality
DOI 10.2134/jeq2010.0121
Volume 39
Issue 6
Year Published 2010
Language English
Publisher American Society of Agronomy
Publisher location Madison, WI
Contributing office(s) Iowa Water Science Center, Toxic Substances Hydrology Program
Description 11 p.
First page 2089
Last page 2099
Time Range Start 2008-01-01
Time Range End 2008-12-31
Country United States
State Iowa
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