Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2008
Publication Date: 7/1/2008
Citation: Casey, F.X., Oduor, P., Hakk, H., Larsen, G.L., Desutter, T.M. 2008. Transport of 17beta-estradiol and testosterone in a field lysimeter. Soil Science 173:456-467. Interpretive Summary: 17ß-estradiol (E2) and testosterone (T) are present in sources such as waste treatment effluent and manures, and can potentially disrupt aquatic organisms at low concentrations. Laboratory studies consistently indicate that hormones are bound to the soil and degraded rapidly, however, E2 and T are regularly detected in the environment. A field experiment was done in which water was flowed through the soil at a steady rate and collected at a depth of 2.3 m. This experiment was done to identify the major factors controlling E2 and T movement and degradation though soil in the field setting. The transport of E2 and T were compared to the transport of a non-binding, non-degrading tracer. Statistical analyses indicated the amount of water in the soil pores and the amount of organic matter in the soil were significant evidence that E2 and T could be transport bound to small soil particulates, called colloids. This was one of the first field studies that gives evidence for likely processes that explain greater than expected mobility and concentrations of E2 and T in the environment.
Technical Abstract: 17ß-estradiol (E2) and testosterone (T) are present in sources such as waste treatment effluent and manures, and can potentially disrupt aquatic organisms at low concentrations. Laboratory studies consistently indicate limited mobility and rapid attenuation of E2 and T in soils; however, these hormones are regularly detected in the environment. A steady-state, field lysimeter (2.4 m length x 2.4 m width x 2.3 m deep) study was done to identify the significant fate and transport factors controlling E2 and T disposition in the field. The transport of E2 and T were compared to the transport of a conservative, non-sorbing tracer, pentafluorobenzoic acid (PFBA). Concentration redistributions of water extractable E2, T, and PFBA through depth were determined. Also, lysimeter effluent drainage concentrations of water-dissolved E2, T, and PFBA were determined. Effluent PFBA was successfully modeled with the convective-dispersive equation assuming no sorption or preferential transport. Effluent mass recovery of PFBA was 100%. Resident profile mass recoveries of E2 and T were 0.46 (±0.01)% and 0.02 (±0.01)%, respectively. Statistical analyses indicated soil water status and organic matter were the predominant factors effective in explaining variations of E2 and T in the lysimeter profile. Lysimeter effluent mass recoveries of E2 and T were 1.3(±0.15)% and 0.2(±0.02)%, respectively. 17ß-estradiol and T were detected before the PFBA peak in the effluent, which may have indicated the antecedent presence of E2 and T, analytical nonspecificity, and/or facilitated transport (likely colloidal). Also, E2 and T concentrations were correlated to lysimeter drainage, perhaps indicating significant colloidal facilitated transport. This is one of the first field studies that gives evidence for likely processes that explain greater than expected mobility and concentrations of E2 and T in the environment.