Free and conjugated estrogens detections in drainage tiles and wells beneath fields receiving swine manure slurry

Authors: CASEY, FRANCIS - North Dakota State University; Hakk, Heldur; DESUTTER, THOMAS - North Dakota State University

Submitted to: Environmental Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2019
Publication Date: 10/25/2019
Citation: Casey, F.X., Hakk, H., Desutter, T.M. 2020. Free and conjugated estrogens detections in drainage tiles and wells beneath fields receiving swine manure slurry. Environmental Pollution. 256. https://doi.org/10.1016/j.envpol.2019.113384.
DOI: https://doi.org/10.1016/j.envpol.2019.113384

Interpretive Summary: Estrogens are steroid hormones eliminated by animals in urine and feces and are considered endocrine disrupting compounds. As good stewards of surface waters livestock producers are interested in ensuring that very low levels of estrogens are transported into surface and groundwater after treating fields with animal waste as fertilizer. In a field study designed to measure the impact of injected swine manure slurry into an agricultural field it was discovered that the frequency of detection and concentration of estrogens were very low in both tile drain and wells installed in the field. The tile drain, whose flow goes directly to surface water, only consisted of estrogen metabolites known to be biologically inactive, while shallow wells contained both inactive estrogen metabolites and active parent estrogens. Our findings demonstrated that high concentrations of estrogens present in animal wastes can be greatly attenuated following passage through the organic layers of soil, but the elimination of all endocrine disrupting estrogens are very difficult due to unknown sources.

Technical Abstract: Swine (Sus scrofa domestica) manure has a high capacity to introduce endocrine-disrupting estrogens into the environment. Estrogen conjugates present in swine manure have a greater mobility in the environment compared to free estrogens. The objective of this study was to quantify the estrogens from applied swine manure that enter subsurface tile drains and wells installed beneath fields, and to observe the contributions of conjugates to the mobility of estrogenic compounds in soil. Three field treatments were established, two receiving manure and one with no manure. Manure slurry from a swine lagoon was injected into soils at a shallow depth (~8 cm) and water samples from tile drains and shallow wells were sampled for about three years. Glucuronide and sulfate conjugates of 17ß-estradiol (E2) and estrone (E1) were the only estrogen compounds detected in the tile drains (total detects = 31; 5% detection frequency; conc. range = 3.9 – 23.1 ng L¬-1), indicating the major role conjugates played in the mobility of estrogens. Free estrogens and conjugates were more frequently detected in the wells compared to the tile drains (total detects = 70; 11% detection frequency; conc. range = 4.0 – 1564.2 ng L-1). No correlations were found between estrogen compound detections and organic carbon (OC) fractions. Although estrogenic compounds were more frequently detected beneath the manure application treatments compared to the non-manure treatment, the total potential estrogenic equivalents (i.e. estrogenicity of hydrolyzed conjugates + free estrogens) were similar between manure and non-manure plots. Sources other than the swine manure, perhaps wildlife and/or legacy manure applications, were putative contributors to estrogenic activity in the environment.