View Full Table | Close Full ViewTable 1.

Network of stream sampling sites in Iowa and streamflow encountered during each sampling period.†

 
Map no.‡ Station ID Stream name Drainage area Streamflow
Mar. June July/Aug. Sept. Oct.
km2 m3 s−1
1 05412500 Turkey River at Garber 4,002 36.5 884 25.0 16.8 11.7
2 05418600 Maquoketa River at Spragueville 4,227 37.1 796 45.6 28.0 21.6
3 05420500 Mississippi River at Clinton 221,704 1210 2040 858 685 830
4 05420680 Wapsipinicon River near Tripoli 896 10.8 442 2.46 1.02 1.02
5 05422000 Wapsipinicon River near De Witt 6,035 60.3 303 34.6 15.6 14.1
6 05451070 South Fork Iowa River Headwaters near Blairsburg 7 0.2 1.39 0.01 0.01 0.02
7 05451210 South Fork Iowa River northeast of New Providence 580 36.2 163 2.8 0.42 0.48
8 05465500 Iowa River at Wapello 32,375 558 935 476 198 123
9 05474000 Skunk River at Augusta 11,145 175 640 66.3 34.0 48.4
10 05490500 Des Moines River at Keosauqua 36,358 513 3000 561 70.5 274
11 06485500 Big Sioux River at Akron 21,818 30.9 337 40.2 14.7 76.5
12 06607500 Little Sioux River near Turin 9,132 68.0 351 60.9 20.3 38.8
13 06609500 Boyer River at Logan 2,256 45.0 391 22.0 9.91 17.2
14 06610000 Missouri River at Omaha 836,052 632 1140 818 821 705
15 06810000 Nishnabotna River at Hamburg 7,268 57.8 651 110 26.4 41.4
median flow 57.8 640 45.6 20.3 38.8
Data from USGS National Water Information System (2009)
See Fig. 1



View Full Table | Close Full ViewTable 2.

Targeted phytoestrogens, mycotoxins, and herbicide compounds investigated for this study.

 
 



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Summary results for the 75 stream samples collected in Iowa during 2008.† A total of 15 samples were collected during each sampling period, except where noted.

 
Compound Mar. June July/Aug. Sept. Oct. All samples
Max. Freq. Max. Freq. Max. Freq. Max. Freq. Max. Freq. Max. Freq.
ng L−1 % ng L−1 % ng L−1 % ng L−1 % ng L−1 % ng L−1 %
Biochanin A det 27 1.7 13 5.6 27 1.7 20 det 27 5.6 23
Coumestrol ND 0 ND 0 ND 0 ND 0 ND 0 ND 0
Daidzein 41 73 det 7 10.5 27 23.6 7 22.69 47 41 32
Equol 40.4 93 3.2 20 9.5 40 12.9 20 5.07 53 40.4 45
Genistein 8 47 det 7 ND 0 ND 0 ND 0 8 11
Formononetin 12.3 93 5.3 93 13.5 87 12.1 40 13.15 87 13.5 80
Deoxynivalenol 583 53 –‡ ND 26 60 11 47 583 43
Zearalenone 8 47 ND ND 0 ND 0 8 13
Atrazine 258 100 7300 100 347 100 240 100 305 100 7300 100
Deethylatrazine 212 100 1174 100 261 100 238 100 299 100 1174 100
det, detected but not quantified; Freq., frequency of detection; Max., maximum concentration; ND, not detected.
Not analyzed due to improper extraction.
§ Eleven samples were analyzed because four were improperly extracted.