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RP5 Endocrine Disruption and Pharmaceutical Issues
(YON-1117-824977) Transport dynamics of 17 -estradiol via runoff from poultry litter-amended agricultural fields to surrounding surface waters.
Yonkos, Lance1, Fisher, Daniel1, Staver, Kenneth1, 1 University of Maryland Wye Research and Education Center, Queenstown, Maryland, USA
ABSTRACT- Nearly 1.6 billion lbs of poultry manure or litter are generated annually as a by-product of the Delmarva poultry industry. Disposal of this material is accomplished by application to regional agricultural fields as organic fertilizer, usually in excess of crop requirements, and often results in runoff of litter-associated contaminants into receiving waters following rain events. Of particular concern are sex steroids, 17 -estradiol (E2), estrone (E1), and testosterone (T), excreted naturally by birds during development and persistent in dry manure until the time of field application. Poultry litter samples collected from Delmarva broiler operations (n=8) prior to field application had mean (±SD) E2 and T levels (measured via radioimmunoassay) of 126 ± 23.7 g/kg and 42 ± 16.5 g/kg, respectively. Application of this material to fields at 3 tons/ac (typical for cropping corn) introduces approximately 350 mg E2/ac. Transport dynamics of poultry litter-associated E2 under two cropping strategies (conventional-till vs no-till) were monitored by employing two 35 acre instrumented (weather station, metered discharge flumes) research fields during 2000 and 2002 growing seasons. Intense rain following litter-application produced abundant runoff (29% lateral transport of precipitation) from the no-till field (soil surface left intact) while greater infiltration of rain on the conventional-till field (surface disked to 20 cm) produced significantly less runoff (8.4%). E2 in no-till runoff, where litter was applied directly to the soil surface, averaged 125 ng/L and resulted in transport of ∼ 2.7% of initially applied E2 from the field to surrounding waters. Integration of litter into the top 20 cm of soil on the conventional-till field limited contact of precipitation such that runoff contained only 42 ng E2/L and resulted in lateral transport of only 0.26% of applied E2. Concentration in a retention pond peaked at 82 ng E2/L and persisted above the 18 ng/L detection limit for < 21 days.
Key words: CAFO, poultry litter, 17 -estradiol, runoff
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