PARENT SESSION
PHA03 - Endocrine Disruption
8:00 AM to 6:30 PM - Thursday, November 15, 2001
Exhibit Hall A

(PH064) Temporal and Spatial Variability in the Estrogenicity of a Municipal Wastewater Effluent.

Hemming, Jon¹, Allen, H², Waller, William², Lazorchak, James³, Lattier, David³, Chow, Marjorie⁴, Denslow, Nancy⁴, ^{1 2 3 4}

ABSTRACT- Over several years the estrogenicity of a local municipal effluent has been monitored. Final treated wastewater effluent from the City of Denton's Water Reclaimation Facility is released into a receiving creek which flows downstream to a reservoir. A small fraction of that effluent is continuously diverted to an experimental constructed wetland prior to release. Estrogenicity has been monitored using the vitellogenin biomarker in adult male fathead minnows (Pimephales promelas). Variability in the expression of the vitellogenin biomarker has been evident among monitoring periods. Significant (=0.05) increases in plasma vitellogenin concentrations have been detected in the months of March, August and December, but not in June. Additionally, the magnitude of expression has been variable. March fish exposures showed vitellogenin concentrations 3 orders of magnitude greater than fish exposed in August. December exposed fish showed vitellogenin concentrations more than 1 order of magnitude higher than August exposed fish. June exposed fish showed no increases in plasma vitellogenin with exposure to this effluent. Variability in the spatial scale was also evident during the March and June exposure months. Concurrent exposures in both the receiving creek and experimental wetland showed estrogenicity to be different with distance from the respective effluent inflow sites. March exposures showed estrogenicity to be somewhat persistent in the receiving creek (>600m), but to decrease rapidly within the experimental wetland (<40m). Conversely, June exposures showed no estrogenicity in either the receiving creek or experimental wetland environment. Results will be discussed relative to monitoring season, spatial distribution of response in both environments, and relative to possible causative factors contributing to the effluent estrogenicity.

Key words: xenoestrogen, wastewater effluent, vitellogenin, Pimephales promelas