Press Release: Swackhamer and Estrogen Mimics

As part of the course requirements for FOR 797 Women in Scientific and Environmental Professions, students share the responsibility for reporting on our speakers for distribution to co-sponsors and the Knothole.  The following press release was prepared by Karen Howard.

Dr. Deborah L. Swackhamer, Professor of Environmental Chemistry in the School of Public Health at the University of Minnesota, presented her research on Estrogen Mimics and Sex Education for Fishes on Tuesday, January 27, 2004 as part of SUNY ESF’s Women in Scientific and Environmental Professions Spring Seminar Series.  The Faculties of Chemistry and Environmental and Forest Biology, the Graduate Student Association, and the ESF Women’s Caucus jointly sponsored the seminar. 

            Dr. Swackhamer discussed a variety of endocrine disrupting compounds in the environment (also called EDCs) that mimic endogenous hormones.  Examples include synthetic hormones, organohalogens, pesticides, detergent components, and plasticizers.  These compounds bind to estrogen receptors in organisms.  The effects of these compounds on organisms and the levels of exposure required to cause effects are still widely unknown. 

Attention was first focused on EDCs through observations of their effects in the field.  Colonial nesting birds around the Great Lakes have been greatly affected by DDT (through eggshell thinning) as well as PCBs and dioxins, which cause developmental deformities resulting in early death.  Nearly 50% of the beluga whales in the St. Lawrence River exhibit hermaphroditic characteristics thought to be caused by organochlorine exposure.  These and similar cases led Congress in 1998 to enact regulations requiring the screening of all commercially available chemicals for endocrine disrupting ability.  This screening has been delayed to date by the lack of validated assays.

            Within Dr. Swackhamer’s research group, studies have been conducted to determine the effects of EDCs on walleye and carp.  They have found that wild fish captured during the spawning season in the discharge channel from a sewage treatment plant exhibit high levels of estradiol, low testosterone levels, smaller gonads than reference fish, and a lack of milt.  However, a controlled laboratory study exposing fish directly to the effluent from the treatment plant produced no reduction in sperm quantity or quality but did indicate a behavioral failure to compete for females during spawning.  Current and future research is focused on the identification of an appropriate indicator compound that could be used in the field to identify populations affected by EDCs.

Dr. Swackhamer received her B.A. in Chemistry from Grinnell College, and her M.S. in Water Chemistry and Ph.D. in Oceanography and Limnology from the University of Wisconsin at Madison.  She serves as co-director of the Water Resources Center at the University of Minnesota.  She sits on the Science Advisory Board of the International Joint Commission of the U.S. and Canada, and serves on the Advisory Board for the National Undersea Research Program of NOAA for the North Atlantic-Great Lakes Region.

For more information about this or upcoming speakers in the Women in Scientific and Environmental Professions Seminar Series, please visit http://www.esf.edu/womenscaucus.