PT04 Endocrine-Disrupting Chemicals in Wastewater Treatment Effluents
Exhibit Hall
8:00 AM - Tuesday

(PT049) Characterization of exposure to and effects of wastewater effluents in Las Vegas Bay, Lake Mead, Nevada.

Gross, T1, 2, Leiker, T3, Goodbred, S4, Orsak, E5, Weiser, C1, Ruessler, D1, 1 USGS-FISC-CARS, Gainesville, FL2 University of Florida, Gainesville, FL3 USGS, Denver, CO4 USGS, Sacramento, CA5 USFWS, Las Vegas, NV

ABSTRACT- An initial survey of fish health was conducted during 1995 and 1998 for multiple sites in Lake Mead. Results suggested potential effects on reproductive function for fish exposed to wastewater effluents in Las Vegas Bay and Wash, which recieves the wastewater discahrge for the Las Vegas greater metropolitan area. A yearlong survey of fish health and reproductive function was conducted during 2000-1 to assess exposure to and effects of wastewater contaminants in Las Vegas Bay. Las Vegas Bay and multiple sites within the Overton Arm of Lake Mead were utilized for these efforts. Common carp were collected bimonthly (n=12 per sex) and largemouth bass and razorback sucker collected duirng the spring reproductive season (n=15 per sex). Carp and bass were sacrificed for collection of plasma and tissues. The endangered razorback sucker was captured and released following the collection of plasma. Samples were analyzed for sex steroids (estradiol, testosterone and 11-ketotestosterone), vitellogenin, GSI, thyroid hormones (T3 and T4), and sperm quality (motility and morphology). Tissues were analyzed for chemcial contaminants. Results indicated significant exposures to a wide variety of chemcial contaminants in Las Vegas Bay, including exposure to potential endocrine disruptors: ethinyl estradiol, triclosan, perchlorate, brominated fire retardants etc. Reproductive health (biomarkers) were adversely effected for all three species, however, the magnitude of effcet of much greater for male fish. Male fish from Las Vegas Bay had decreased concentrations of plasma androgens and thyroid hormones, as well as decreased sperm quality, regardless of species. Concentrations of chemcial contaminants were analyzed for correlations to biomarker effects. Significnat correlations were indicated for multiple contaminnats, including correlations between decreased sperm quality and plasma hormones for both ethinyl estradiol and triclosan. These results indicate endocrine disrupting effects for fish exposed to wastewater effluents. Significant exposure to chemical components of wasterwater, such as those of pharmaceutical and heath care product orgin are among those potentially involved in these effects on fish. Future efforts should utilize paired field and laboratory approaches to assess cause-and-effect relationships to wastewater effluents and specific components.

Key words: fish, wastewater, Lake Mead, pharmaceuticals and health care products

Internet Services provided by
Allen Press, Inc. | 810 E. 10th St. | Lawrence, Kansas 66044 USA
e-mail assystant-helpdesk@allenpress.com | Web www.allenpress.com
All content is Copyright © 2004 SETAC