Determination of 17β-estradiol and Estrone Concentrations in Runoff and Topsoil from Plots Receiving Dairy Manure

Because of increasing concern about estrogenic compounds in animal wastes, the objective of this research was to measure 17β-estradiol and estrone concentrations in runoff and soil from plots fertilized with liquid dairy waste. Nine plots were established at The University of Tennessee Dairy Experiment Station located at Lewisburg, Tennessee, and dairy manure was applied to six of the nine plots in November, 2000. Three of the plots received manure at a rate sufficient to meet the nitrogen (N) requirement for winter wheat; three received manure at a rate sufficient to meet the phosphorus (P) requirement for winter wheat, and three received no manure. Runoff samples were collected after each of the first six runoff events producing natural rainfalls following manure application. A second manure application, based on the N and P requirements for sorghum/sudan grass, was made in March 2001. Soil samples were taken monthly after each manure application. Enzyme linked immunosorbant assays were used to determine the concentration of 17β-estradiol and estrone in the collected runoff samples, and soil samples. The results are reported herein, showing that 17β-estradiol concentrations in runoff from plots that historically received dairy manure, but which had not recently received manure, ranged from below detection threshold to 5.0 ng/L. In contrast, average 17β-estradiol concentrations in runoff from plots receiving manure at the N-rate were as high as 308 ng/L; plots receiving manure at the P-rate had average runoff 17β-estradiol concentrations as high as 29 ng/L. These values are above the 10 ng/L level that we have taken to be biologically significant. For estrone, runoff concentrations at the N-rate reached over 2000 ng/L; the runoff concentrations for the P-rate reached 55 ng/L and the control plots reached 68 ng/L at one point. Runoff concentrations of both hormones generally decreased with time following manure application.

17β-estradiol soil concentrations for the N-based plots ranged from 2-600 ng/kg; P-based plot soil concentrations ranged from 6-160 ng/kg; and control plot soil concentrations ranged from 5.5-220 ng/kg. Estrone soil concentrations for N-based plots ranged from 67-1260 ng/kg; P-based plot concentrations ranged from 72-2580 ng/kg; and control plots ranged from 43-200 ng/kg.β-estradiol soil concentrations for the N-based plots ranged from 2-600 ng/kg; P-based plot soil concentrations ranged from 6-160 ng/kg; and control plot soil concentrations ranged from 5.5-220 ng/kg. Estrone soil concentrations for N-based plots ranged from 67-1260 ng/kg; P-based plot concentrations ranged from 72-2580 ng/kg; and control plots ranged from 43-200 ng/kg. 17β-estradiol soil concentrations for the N-based plots ranged from 2-600 ng/kg; P-based plot soil concentrations ranged from 6-160 ng/kg; and control plot soil concentrations ranged from 5.5-220 ng/kg. Estrone soil concentrations for N-based plots ranged from 67-1260 ng/kg; P-based plot concentrations ranged from 72-2580 ng/kg; and control plots ranged from 43-200 ng/kg. β-estradiol soil concentrations for the N-based plots ranged from 2-600 ng/kg; P-based plot soil concentrations ranged from 6-160 ng/kg; and control plot soil concentrations ranged from 5.5-220 ng/kg. Estrone soil concentrations for N-based plots ranged from 67-1260 ng/kg; P-based plot concentrations ranged from 72-2580 ng/kg; and control plots ranged from 43-200 ng/kg.

In both winter and spring, biologically relevant concentrations of 17β-estradiol and estrone were observed in runoff from plots receiving dairy manure slurry at rates appropriate to crop N and P requirements. Masses of these compounds were positively correlated with estrogen mass application rates, and these compounds persisted in runoff water for several runoff events following manure application.

17β-estradiol masses in the soil positively correlated with estrogen mass application rates at statistically significant levels, but estrone masses did not. Both of these estrogens did persist in the soil for several months after manure applications in both winter and spring. Masses of 17β-estradiol in the soil did positively correlate with masses of this compound in the runoff, but concentrations of estrone in the soil did not correlate with runoff masses of estrone.