METABOLIC VARIABLES AFFECTING THE EFFICACY, SAFETY, AND FATE OF AGRICULTURAL CHEMICALS
Location: Animal Metabolism-Agricultural Chemicals Research
Title: Transport of 17ß-Estradiol and Testosterone in a Field Lysimeter
| Casey, Francis - NORTH DAKOTA STATE UNIV. |
| Oduor, Peter - NORTH DAKOTA STATE UNIV |
| Larsen, Gerald |
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 24, 2007
Publication Date: November 8, 2007
Citation: Casey, F.X., Oduor, P.G., Larsen, G.L., Hakk, H. 2007. Transport of 17ß-Estradiol and Testosterone in a Field Lysimeter. Meeting Abstract. Annual Meeting of ASA, CSSA, and SSSA, November 4-8, 2007, Madison, WI.
Interpretive Summary: meeting abstract - no interpretive summary
17ß-estradiol (E2) and testosterone (T) are naturally present in manures and have the potential to disrupt aquatic organisms at low concentrations. Laboratory studies have indicated that E2 and T would have limited mobility and would attenuate rapidly in soils; however, these hormones are consistently detected in the environment. A steady-state, near-saturated, field lysimeter (2.4m length x 2.4 m width x 2.3m deep) study was done to identify the fate and transport of E2 and T, to try to understand why E2 and T are consistently detected in the environment. The transport of E2 (0.2 g applied) and T (1.2 g applied) were compared to the transport of a conservative, non-sorbing tracer, pentafluorobenzoic acid (PFBA). Concentration redistributions of E2, T, and PFBA through depth were determined. Also, lysimeter effluent drainage concentrations of E2, T, and PFBA were determined. Effluent concentrations of PFBA were modeled with the convective-dispersive equation assuming no sorption, and indicated that there was no preferential transport. The mass recovery of PFBA in the effluent was 100%. The mass recovery of the E2 and T in the lysimeter profile was calculated to be 0.46% and 0.02%, respectively. Air-filled porosity (theta-a) and percent saturation (%sat) significantly effected the concentrations in the profile, where lower theta-a and higher %sat corresponded to higher E2 and T concentrations. This result likely indicated greater persistence of E2 and T (i.e., less degradation) where soil oxygen levels were low). In the lysimeter effluent, the mass recovery of E2 and T were 1.3% and 0.2%, respectively. 17ß-estradiol and T were detected before the PFBA in the effluent. Also, E2 and T concentrations were correlated to lysimeter drainage. These results suggested that colloidal facilitated transport was a significant factor in the transport of E2 and T. This study helps to bridge the understanding between laboratory fate and transport studies on E2 and T in soil and reported environmental observations.