TY - JOUR

T1 - Exposure and Transport of Alkaloids and Phytoestrogens from Soybeans to Agricultural Soils and Streams in the Midwestern United States

AU - Hama, Jawameer R.

AU - Kolpin, Dana W.

AU - LeFevre, Gregory H.

AU - Hubbard, Laura E.

AU - Powers, Megan M.

AU - Strobel, Bjarne W.

PY - 2021

Y1 - 2021

N2 - Phytotoxins are naturally produced toxins with potencies similar/higher than many anthropogenic micropollutants. Nevertheless, little is known regarding their environmental fate and off-field transport to streams. To fill this research gap, a network of six basins in the Midwestern United States with substantial soybean production was selected for the study. Stream water (n = 110), soybean plant tissues (n = 8), and soil samples (n = 16) were analyzed for 12 phytotoxins (5 alkaloids and 7 phytoestrogens) and 2 widely used herbicides (atrazine and metolachlor). Overall, at least 1 phytotoxin was detected in 82% of the samples, with as many as 11 phytotoxins detected in a single sample (median = 5), with a concentration range from below detection to 37 and 68 ng/L for alkaloids and phytoestrogens, respectively. In contrast, the herbicides were ubiquitously detected at substantially higher concentrations (atrazine: 99% and metolachlor: 83%; the concentrations range from below detection to 150 and 410 ng/L, respectively). There was an apparent seasonal pattern for phytotoxins, where occurrence prior to and during harvest season (September to November) and during the snow melt season (March) was higher than that in December-January. Runoff events increased phytotoxin and herbicide concentrations compared to those in base-flow conditions. Phytotoxin plant concentrations were orders of magnitude higher compared to those measured in soil and streams. These results demonstrate the potential exposure of aquatic and terrestrial organisms to soybean-derived phytotoxins.

AB - Phytotoxins are naturally produced toxins with potencies similar/higher than many anthropogenic micropollutants. Nevertheless, little is known regarding their environmental fate and off-field transport to streams. To fill this research gap, a network of six basins in the Midwestern United States with substantial soybean production was selected for the study. Stream water (n = 110), soybean plant tissues (n = 8), and soil samples (n = 16) were analyzed for 12 phytotoxins (5 alkaloids and 7 phytoestrogens) and 2 widely used herbicides (atrazine and metolachlor). Overall, at least 1 phytotoxin was detected in 82% of the samples, with as many as 11 phytotoxins detected in a single sample (median = 5), with a concentration range from below detection to 37 and 68 ng/L for alkaloids and phytoestrogens, respectively. In contrast, the herbicides were ubiquitously detected at substantially higher concentrations (atrazine: 99% and metolachlor: 83%; the concentrations range from below detection to 150 and 410 ng/L, respectively). There was an apparent seasonal pattern for phytotoxins, where occurrence prior to and during harvest season (September to November) and during the snow melt season (March) was higher than that in December-January. Runoff events increased phytotoxin and herbicide concentrations compared to those in base-flow conditions. Phytotoxin plant concentrations were orders of magnitude higher compared to those measured in soil and streams. These results demonstrate the potential exposure of aquatic and terrestrial organisms to soybean-derived phytotoxins.

KW - phytotoxins

KW - herbicides

KW - soybean

KW - surface water

KW - leaching

KW - aquatic pollution

KW - ISOFLAVONE CONCENTRATION

KW - PYRROLIZIDINE ALKALOIDS

KW - REPRODUCTIVE TOXICITY

KW - SOY ISOFLAVONES

KW - SURFACE WATERS

KW - PHYTOTOXINS

KW - PHARMACEUTICALS

KW - METABOLITES

KW - HERBICIDES

KW - ATRAZINE

U2 - 10.1021/acs.est.1c01477

DO - 10.1021/acs.est.1c01477

M3 - Journal article

C2 - 34342221

VL - 55

SP - 11029

EP - 11039

JO - Environmental Science & Technology

JF - Environmental Science & Technology

SN - 0013-936X

IS - 16

ER -